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Proceedings, 2024, Eurosensors 2023

XXXV EUROSENSORS Conference

Lecce, Italy | 10–13 September 2023

Volume Editors:
Pietro Siciliano, Consiglio Nazionale delle Ricerche, Italy
Bruno Andò, University of Catania, Italy
Luca Francioso, CNR-IMM, Institute for Microelectronics and Microsystems, Italy

Number of Papers: 233
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Cover Story (view full-size image): The XXXV EUROSENSORS Conference will provide an opportunity for the presentation of updated results related to both theoretical and applied research of the sensor’s community. The conference [...] Read more.
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3 pages, 687 KiB  
Abstract
Contact Angle Measurement through Liquid Flow in Curved Open Microchannels
by Tina Mitteramskogler, Andreas Fuchsluger, Rafael Ecker, Thomas Wilfinger, Bernhard Jakoby and Robert Wille
Proceedings 2024, 97(1), 1; https://doi.org/10.3390/proceedings2024097001 - 12 Mar 2024
Viewed by 663
Abstract
Whether liquids in open microchannels show spontaneous capillary flow or not crucially depends on the involved surface energies and the shape of the microchannel. In this study, we present a two-dimensional model based on the Gibb’s free energy of a system that predicts [...] Read more.
Whether liquids in open microchannels show spontaneous capillary flow or not crucially depends on the involved surface energies and the shape of the microchannel. In this study, we present a two-dimensional model based on the Gibb’s free energy of a system that predicts the presence of spontaneous capillary flow in open microchannels. We expand our model to include curved microchannels and verify our findings using simulations of a liquid surface with Surface Evolver. Finally, we comment on how these results can be used to measure the liquid contact angle through open capillary flow. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Cross-section of a parabolic microgroove with the surface areas between the liquid and the gas (<span class="html-italic">A<sub>lg</sub></span>), the liquid and the substrate (<span class="html-italic">A<sub>sl</sub></span>) and the substrate and the gas (<span class="html-italic">A<sub>sg</sub></span>). The Gibbs free energy of the system is calculated by <span class="html-italic">G</span><sub>2</sub><span class="html-italic"><sub>D</sub></span> = <span class="html-italic">A<sub>lg</sub> γ<sub>lg</sub></span> + <span class="html-italic">A<sub>sl</sub> γ<sub>sl</sub></span> + <span class="html-italic">A<sub>sg</sub> γ<sub>sg</sub></span> with the corresponding surface energies; (<b>b</b>) Surface Evolver simulation of a liquid in a parabolic microgroove with bending radius <span class="html-italic">R</span> and liquid contact angle <span class="html-italic">θ</span> = 50°. The interface between the liquid and the microgroove is colored dark blue, whereas the free liquid surface is colored light blue. The black surface is connected to a pressure-free liquid reservoir; (<b>c</b>) Simulation of a liquid with a contact angle of <span class="html-italic">θ</span> = 80°.</p>
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<p>(<b>a</b>) Contact angle measurement through open capillary flow. In accordance with the theoretical model, only certain parabolic microchannels allow the spontaneous capillary flow of the test liquid. Evaluation of the filled microchannels allow us to estimate the liquid contact angle. (<b>b</b>) The scaling of the Gibbs energy <span class="html-italic">G</span><sub>3</sub><span class="html-italic"><sub>D</sub></span> for curved parabolic microchannels depending on their filling length. Note, that the liquids with a contact angle below the critical contact angle <span class="html-italic">θ</span> = 67.7° show capillary filling, indicated through a decrease in energy for increased filling length.</p>
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3 pages, 147 KiB  
Abstract
Concept Drift Mitigation in Low-Cost Air Quality Monitoring Networks
by Gerardo D’Elia, Matteo Ferro, Paolo Sommella, Sergio Ferlito, Saverio De Vito and Girolamo Di Francia
Proceedings 2024, 97(1), 2; https://doi.org/10.3390/proceedings2024097002 - 12 Mar 2024
Viewed by 583
Abstract
Future air quality monitoring networks will include fleets of low-cost gas and particulate matter sensors calibrated using machine learning techniques. Unfortunately, it is well known that concept drift is one of the primary causes of losses in data quality in operational scenarios. This [...] Read more.
Future air quality monitoring networks will include fleets of low-cost gas and particulate matter sensors calibrated using machine learning techniques. Unfortunately, it is well known that concept drift is one of the primary causes of losses in data quality in operational scenarios. This work focuses on addressing a low-cost NO2 sensor calibration model update triggered via a concept drift detector. This study defines which data are most appropriate for use in the model updating process in order to maintain compliance with the relative expanded uncertainty (REU) limits established by the European Directive, as well as evaluate the potential of general and importance-weighted calibration models in the mitigation of concept drift effects. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 414 KiB  
Abstract
The Application of Back-Compatible Color QR Codes to Colorimetric Sensors
by Ismael Benito-Altamirano, Ferran Crugeira, Míriam Marchena and J. Daniel Prades
Proceedings 2024, 97(1), 3; https://doi.org/10.3390/proceedings2024097003 - 13 Mar 2024
Viewed by 726
Abstract
We present the application of QR Codes as carriers for colorimetric dyes, whereby this refined version of machine-readable patterns applied to colorimetric sensing also allows us to maintain the data from the QR Code standard in a back-compatible way, which means that the [...] Read more.
We present the application of QR Codes as carriers for colorimetric dyes, whereby this refined version of machine-readable patterns applied to colorimetric sensing also allows us to maintain the data from the QR Code standard in a back-compatible way, which means that the QR Code is still able to encode digital data (readable with a standard QR Code decoder) alongside a hundred colorimetric references and the dyes. Also, we discuss in detail the effectiveness of different color correction methods in attaining color accuracy levels suited for sensing via colorimetry. Moreover, we illustrate how color correction techniques can be applied to take advantage of having hundreds of color references, with an exemplary case of a CO2 printed sensor used to monitor the integrity of modified atmosphere packaging (MAP). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Evolution over the years of machine-readable patterns which embed colorimetric dyes from 2018 to 2023. (<b>a</b>) Our first proposal for such patterns, presented at Eurosensors in 2018 [<a href="#B1-proceedings-97-00003" class="html-bibr">1</a>]; (<b>b</b>) our second attempt to fabricate the patterns [<a href="#B2-proceedings-97-00003" class="html-bibr">2</a>]; (<b>c</b>) Escobedo et al. proposal [<a href="#B3-proceedings-97-00003" class="html-bibr">3</a>] to embed sensors in pattern with digital data; and (<b>d</b>) our proposal to do a similar concept but maximazing back-compatibility [<a href="#B4-proceedings-97-00003" class="html-bibr">4</a>].</p>
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3 pages, 421 KiB  
Abstract
Data Processing Procedure for Real-Time Odour Concentration Estimation at Industrial Plant Fenceline by Sensor-Based Tools
by Christian Ratti, Beatrice Julia Lotesoriere, Carmen Bax and Laura Capelli
Proceedings 2024, 97(1), 4; https://doi.org/10.3390/proceedings2024097004 - 13 Mar 2024
Viewed by 579
Abstract
The realisation of an electronic nose network for the monitoring of the odour concentrations at the fenceline of a waste treatment plant has been investigated. One of the main challenges for instrumental environmental monitoring concerns the interference of the daily variability of humidity [...] Read more.
The realisation of an electronic nose network for the monitoring of the odour concentrations at the fenceline of a waste treatment plant has been investigated. One of the main challenges for instrumental environmental monitoring concerns the interference of the daily variability of humidity and temperature of the ambient air to which sensors are exposed. In this study, we propose a solution to overcome this problem, implementing a specific normalisation pretreatment into the data processing procedure. The preliminary results obtained show a better classification and quantification performance whenever humidity model compensation is applied. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Data processing procedure.</p>
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3 pages, 401 KiB  
Abstract
Amperometric Biosensing of L-Glutamate Using Reduced Graphene Oxide and Glutamate Oxidase
by Ieva Sakinyte-Urbikiene, Vidute Gureviciene and Julija Razumiene
Proceedings 2024, 97(1), 5; https://doi.org/10.3390/proceedings2024097005 - 13 Mar 2024
Viewed by 792
Abstract
The determination of L-glutamate in biological media is very important, as it is the most common excitatory neurotransmitter related to some neurological diseases, such as Parkinson’s, communication dysfunction, stroke, epilepsy and schizophrenia. When aiming to study the pathways of these diseases, as well [...] Read more.
The determination of L-glutamate in biological media is very important, as it is the most common excitatory neurotransmitter related to some neurological diseases, such as Parkinson’s, communication dysfunction, stroke, epilepsy and schizophrenia. When aiming to study the pathways of these diseases, as well as for the evaluation of medical treatments, it is very important to have rapid and reliable methods for the determination of L-glutamate. This study presents the new approach of an enzyme-based biosensor operating at −0.1 V, which ensures its good sensitivity and selectivity. The reduced graphene oxide used in the biosensor allowed for the monitoring of L-glutamate via the electro-oxidation of the NH3 released during the reaction catalyzed by Glutamate oxidase. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Principal scheme of two different pathways of amperometric biosensing of L-glutamate when Pt and RGO are utilized as electrode surfaces. Responses of biosensors to 0.5 mM of L-glutamate, obtained at potentials of +0.6 V (<b>left</b>) and −0.1 V (<b>right</b>).</p>
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3 pages, 153 KiB  
Abstract
Adoption of a Social Robot in a Sub Intensive Care Unit for the Autonomous Computation of Criticality Scores
by Giovanni Piccininno, Nicola Laurieri, Alessandro Anselmo, Sergio Russo, Alessandra Sorrentino, Daniele Sancarlo, Grazia D’Onofrio, Letizia Lorusso, Laura Fiorini, Filippo Cavallo, Antonio Greco and Francesco Giuliani
Proceedings 2024, 97(1), 6; https://doi.org/10.3390/proceedings2024097006 - 13 Mar 2024
Viewed by 620
Abstract
We describe an innovative case study focusing on a social robot able to help healthcare professionals compute criticality scores for patients hosted in a Geriatric Sub-Intensive Care Unit. The aim is to establish the feasibility of a scenario in which the robot modulates [...] Read more.
We describe an innovative case study focusing on a social robot able to help healthcare professionals compute criticality scores for patients hosted in a Geriatric Sub-Intensive Care Unit. The aim is to establish the feasibility of a scenario in which the robot modulates the frequency of its visits to the room of bedridden patients, based on the criticality scores it has computed. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 728 KiB  
Abstract
Development of Triboelectric Devices for Human–Machine Interface Applications
by Andreas Anastasopoulos, Vasiliki Zacharia, Achilleas Bardakas and Christos Tsamis
Proceedings 2024, 97(1), 7; https://doi.org/10.3390/proceedings2024097007 - 13 Mar 2024
Viewed by 998
Abstract
Haptic feedback, also known as tactile sensing, plays a vital role in human interactions with the external environment. The artificial replication of tactile sensations using triboelectric sensors has sparked the attention of the scientific community by developing advanced electronic skins with haptic perception. [...] Read more.
Haptic feedback, also known as tactile sensing, plays a vital role in human interactions with the external environment. The artificial replication of tactile sensations using triboelectric sensors has sparked the attention of the scientific community by developing advanced electronic skins with haptic perception. In this work, we design and fabricate different flexible tactile sensors based on the triboelectric effect. The triboelectric sensors were evaluated in respect of their ability to identify different materials that were in contact with the sensor. Our results show that the triboelectric signal depends on the nature of the substrate, and a clear distinction among different substrates could be obtained. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sensor fabricated by aluminum deposition on Kapton<sup>®</sup> substrate. (<b>b</b>) Sensors on printed circuit board. (<b>c</b>) Sensor stuck with biocompatible double-sided tape on a human finger covered with a nitrile glove.</p>
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<p>(<b>a</b>) Connecting the sensor to the oscilloscope; (<b>b</b>) output electric signal. (<b>c</b>) Representative signals for each material in contact with a sensor (glass).</p>
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3 pages, 493 KiB  
Abstract
Advanced Analysis of Solutions with a Low-Cost Electronic Device Containing Color Sensor and Programmable Red, Green, and Blue (RGB) LED
by Ondřej Keresteš and Miroslav Pohanka
Proceedings 2024, 97(1), 8; https://doi.org/10.3390/proceedings2024097008 - 13 Mar 2024
Viewed by 685
Abstract
Although methods for point-of-care testing gains are growing in importance, it is still essential to develop alternatives for tests performed centrally on commercial analyzers, thus making photometry cheaper and more accessible to the public. We introduce a low-cost photometer based on the Arduino [...] Read more.
Although methods for point-of-care testing gains are growing in importance, it is still essential to develop alternatives for tests performed centrally on commercial analyzers, thus making photometry cheaper and more accessible to the public. We introduce a low-cost photometer based on the Arduino with APDS9960 sensor and RBG LED in this work. A photometric platform based on a color sensor can gain a four-signal response. Acetylcholinesterase was chosen as the model element for the biosensor. The device can also easily be upgraded for fluorometric assays. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Overview of proposed system. (<b>b</b>) Distribution of signal response to various concentrations of acetylthiocholine. Y-axis shows the color depth of G-channel in 12-bit resolution.</p>
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3 pages, 178 KiB  
Abstract
Development of a Wearable Sweat Sensor Chip Based on Surface-Enhanced Raman Spectroscopy
by Cristiano D’Andrea, Martina Banchelli, Chiara Amicucci, Panagis Polykretis, Filippo Micheletti, Marella de Angelis, Yurim Han, Heebo Ha, Byungil Hwang and Paolo Matteini
Proceedings 2024, 97(1), 9; https://doi.org/10.3390/proceedings2024097009 - 13 Mar 2024
Viewed by 758
Abstract
A wearable sweat sensor chip based on surface-enhanced Raman spectroscopy is developed. The plasmonic core of the chip, obtained by depositing silver nanowires on a PTFE porous membrane, permits the direct and label-free detection of urea and lactate at physiological concentration in combination [...] Read more.
A wearable sweat sensor chip based on surface-enhanced Raman spectroscopy is developed. The plasmonic core of the chip, obtained by depositing silver nanowires on a PTFE porous membrane, permits the direct and label-free detection of urea and lactate at physiological concentration in combination with the evaluation of sweat pH in the range between 4 and 9. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 968 KiB  
Abstract
Driver Position Measured Based on Textile Capacitive Sensor Array
by Marc Martínez-Estrada, Ignacio Gil and Raúl Fernández-García
Proceedings 2024, 97(1), 10; https://doi.org/10.3390/proceedings2024097010 - 13 Mar 2024
Viewed by 584
Abstract
A woven textile capacitive sensor array fully integrated on a car seat is presented to detect the driver’s position. The sensor array consists of two planar interdigital capacitive sensors located on the base and the backrest of the seat. With this sensor array, [...] Read more.
A woven textile capacitive sensor array fully integrated on a car seat is presented to detect the driver’s position. The sensor array consists of two planar interdigital capacitive sensors located on the base and the backrest of the seat. With this sensor array, the position of the driver can be continually measured in real time with potential detection for events such as back detaching or buttocks displacement, which could indicate a risk of traffic accidents. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Sensor array unit.</p>
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<p>Experimental results for four different cases: without driver (<b>a</b>), driver sat correctly (<b>b</b>) and driver detaching from the back in two different cases (<b>c</b>,<b>d</b>). Continuous black line corresponds to base seat sensor and dashed red line corresponds to backrest sensor.</p>
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3 pages, 458 KiB  
Abstract
An Autonomous Multi-Technological LoRa Sensor Network for Landslide Monitoring
by Mattia Ragnoli, Paolo Esposito, Gianluca Barile, Giuseppe Ferri and Vincenzo Stornelli
Proceedings 2024, 97(1), 11; https://doi.org/10.3390/proceedings2024097011 - 13 Mar 2024
Viewed by 819
Abstract
Hazards like landslides have significant economic and societal repercussions; hence, the issue of remote structure health monitoring has grown in significance for geologic applications. Wireless sensor networks (WSNs) stand out among the new sensing architectures as a particularly well-suited solution, thanks to the [...] Read more.
Hazards like landslides have significant economic and societal repercussions; hence, the issue of remote structure health monitoring has grown in significance for geologic applications. Wireless sensor networks (WSNs) stand out among the new sensing architectures as a particularly well-suited solution, thanks to the versatility they offer. This research, necessary for safety reasons, predictive maintenance and emergency evacuation, presents a WSN-based landslide monitoring system with multi-technology sensor implementation. Its goal is to track the land movements on a hillside. The network is composed of long range (LoRa) sensor nodes connected using a LoRaWAN media access control (MAC) layer. The nodes are several and of different natures and help monitor land movements, hydric parameters and rockfall events, and they also offer a camera view of the landslide in case of an emergency. The system is built on an Internet of Things (IoT) framework, enabling online access to data and reports. The final work will include a system description of the hardware and functionality of all the devices, a description of the web section for remote monitoring, a power analysis and statistics from actual scenarios. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) System application scheme; (<b>b</b>) an installation point for one of the sensing stations.</p>
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3 pages, 734 KiB  
Abstract
A Process to Realize 2PP-Based Electrodes in Microfluidic Channels
by Wiebke Gehlken, Melanie Kirsch and Michael J. Vellekoop
Proceedings 2024, 97(1), 12; https://doi.org/10.3390/proceedings2024097012 - 13 Mar 2024
Viewed by 625
Abstract
In this work, a process to realize metallized 2-photon-polymerized (2PP) structures in prefabricated microfluidic channels is presented, aiming at 3D-structured electrodes. The channel is fabricated using a single-layer process of SU-8 to realize vertical sidewalls with a height and width of 300 µm. [...] Read more.
In this work, a process to realize metallized 2-photon-polymerized (2PP) structures in prefabricated microfluidic channels is presented, aiming at 3D-structured electrodes. The channel is fabricated using a single-layer process of SU-8 to realize vertical sidewalls with a height and width of 300 µm. Electrodes in a ring shape with an outer diameter of 250 µm are printed in the channel using 2PP and metallized via sputtering. Using chromium as sacrificial layer, a lift-off is performed to structure the metal. This allows us to fabricate individual electrically controllable 3D electrodes that use the total height and width of the channel. Metallization with good step coverage on ring-shaped 3D structures in the high microchannel was achieved, which was confirmed using conductivity tests. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Process to realize 2PP-based electrodes in a 300 μm high and wide channel.</p>
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<p>2PP ring structures in a 300 μm high SU-8 channel after metallization and lift-off. Ring diameter is 250 μm, thickness 25 μm. The metal on the electrode is visible with digital microscopy (bottom left).</p>
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3 pages, 1283 KiB  
Abstract
Active Conversion of Bubbly Flow into Slug and Annular Flow during Microchannel Flow Boiling Using Thin-Film Platinum Microheaters
by Mark Schepperle, Sebastian Arnold and Peter Woias
Proceedings 2024, 97(1), 13; https://doi.org/10.3390/proceedings2024097013 - 14 Mar 2024
Cited by 2 | Viewed by 622
Abstract
This paper reports, for the first time, on the use of thin-film platinum microheaters to influence the flow boiling of DI water in microchannels with rapid low power heating pulses. A custom-designed control module allows microheaters to be actuated simultaneously and independently, enabling [...] Read more.
This paper reports, for the first time, on the use of thin-film platinum microheaters to influence the flow boiling of DI water in microchannels with rapid low power heating pulses. A custom-designed control module allows microheaters to be actuated simultaneously and independently, enabling precise local control of flow regimes along an entire channel. In this study, bubbly flow was converted into a slug and annular flow. This pioneering technique promises a radical improvement in the heat transfer and performance of flow-boiling cooling devices by actively targeting flow conditions with high heat dissipation. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Pyrex glass lid with 17 platinum microheaters (<b>a</b>); CAD drawing of experimental apparatus consisting of the 3D-printed reactor housing, stainless-steel microchannel, glass lid with microheaters, cartridge heaters, and spring probes for electrical contact formation to the microheaters (<b>b</b>).</p>
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<p>Time frames of a bubbly flow (<b>a</b>) and time frames of a bubbly flow affected by an 870 mW heating pulse from a 0.5 mm long microheater (<b>b</b>). All frames were acquired with DI water at a mass flow rate of 1.5 g min<sup>−1</sup> using a high-speed camera at 2000 frames per second.</p>
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3 pages, 372 KiB  
Abstract
A Transformer-Based Front-End Circuit for Grounded Capacitive Sensors with Square-Wave Excitation
by Marcelo A. Haberman, Enrique M. Spinelli and Ferran Reverter
Proceedings 2024, 97(1), 14; https://doi.org/10.3390/proceedings2024097014 - 14 Mar 2024
Viewed by 620
Abstract
This work proposes and experimentally characterizes a novel front-end circuit for capacitive sensors with one electrode grounded, which are quite common in liquid-level and position measurement applications. The circuit relies on a properly shielded custom transformer, as already suggested in the literature, but [...] Read more.
This work proposes and experimentally characterizes a novel front-end circuit for capacitive sensors with one electrode grounded, which are quite common in liquid-level and position measurement applications. The circuit relies on a properly shielded custom transformer, as already suggested in the literature, but uses a square excitation instead of a sinusoidal excitation, thus being a simpler solution. Furthermore, the sensor signal is read by a charge amplifier with a single supply voltage, instead of a transimpedance amplifier with a split supply voltage. The preliminary experimental results show an input–output characteristic with a non-linearity error lower than 0.5% FSS in the [0, 33] pF measuring range. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) A transformer-based circuit for grounded capacitive sensors (<span class="html-italic">C</span><sub>x</sub>) with a square excitation. (<b>b</b>) Experimental results (in blue, the measured value of capacitance, and in red, the NLE) obtained when characterizing the circuit in (<b>a</b>).</p>
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3 pages, 424 KiB  
Abstract
A Novel Indium Oxide-Based Nanostructured Material Designed for CO2 Detection
by Arianna Rossi, Barbara Fabbri, Elena Spagnoli, Andrea Gaiardo, Matteo Valt and Vincenzo Guidi
Proceedings 2024, 97(1), 15; https://doi.org/10.3390/proceedings2024097015 - 14 Mar 2024
Viewed by 705
Abstract
Low-cost sensors working at low/room temperature for CO2 mapping in indoor–outdoor environments are in growing demand. Solid-state gas sensors are a suitable alternative to expensive optical sensors, but to date, materials designed for chemoresistive devices have not proven functional for CO2 [...] Read more.
Low-cost sensors working at low/room temperature for CO2 mapping in indoor–outdoor environments are in growing demand. Solid-state gas sensors are a suitable alternative to expensive optical sensors, but to date, materials designed for chemoresistive devices have not proven functional for CO2 detection. This work addresses this challenge both in terms of sensing materials research, with the innovative use of alkali metals as dopants in semiconductors, and in terms of deeply understanding the sensing mechanism through DRIFT spectroscopy. The result is a sensor operating at 200 °C that detects CO2 between 250–5000 ppm with a negligible effect of humidity above 17 RH%. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Dynamic response to CO<sub>2</sub> concentrations varying from 2000 to 5000 ppm in dry air. (<b>b</b>) Selectivity in dry air of the sensor towards 5 ppm of CO, 53 ppb of NO<sub>2</sub>, 1 ppm of toluene, and 1000 ppm of CO<sub>2</sub>. The insert shows the influence of RH% on Na:In<sub>2</sub>O<sub>3</sub> response to 500 ppm of CO<sub>2</sub>.</p>
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3 pages, 336 KiB  
Abstract
Available Kinetic Energy Sources on the Human Body during Sports Activities: An Optimization Investigation Using Cantilevered Piezoelectric Harvester Model
by Damien Hoareau, Gurvan Jodin, Abdo-Rahmane Anas Laaraibi, Jacques Prioux and Florence Razan
Proceedings 2024, 97(1), 16; https://doi.org/10.3390/proceedings2024097016 - 14 Mar 2024
Viewed by 572
Abstract
Previous work has shown that the impacts induced by human sport activities are one of the most relevant features to operating a cantilevered piezoelectric harvester. In addition, the optimal orientations of the simulated harvester according to body parts were investigated. In this contribution, [...] Read more.
Previous work has shown that the impacts induced by human sport activities are one of the most relevant features to operating a cantilevered piezoelectric harvester. In addition, the optimal orientations of the simulated harvester according to body parts were investigated. In this contribution, we study the influence of the harvester dimensions on the simulated harvested energy. The results show that for a defined mass of active material and the optimal harvester orientation, a low-frequency harvester is preferred. Thus, the harvester operating frequencies, orientation, and location on the human body are explored. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Normalized harvested energy on different body locations for a constant active material volume. Longer lengths and narrower widths correspond to lower resonance frequencies.</p>
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3 pages, 474 KiB  
Abstract
Atmospheric Particulate Matter Sensing with Commercial Quartz Crystal Microbalance: A Feature Extraction and Evaluation Study
by Ettore Massera, Brigida Alfano, Tiziana Polichetti and Maria Lucia Miglietta
Proceedings 2024, 97(1), 18; https://doi.org/10.3390/proceedings2024097018 - 14 Mar 2024
Viewed by 630
Abstract
This article presents the results of a study of the ability of the vibrating membranes, such as quartz crystal microbalances, to measure particulate matter. This study builds on the feasibility study previously presented using a low-cost commercial product suitable for research and development [...] Read more.
This article presents the results of a study of the ability of the vibrating membranes, such as quartz crystal microbalances, to measure particulate matter. This study builds on the feasibility study previously presented using a low-cost commercial product suitable for research and development purposes. This work shows the results of the treatment of the vibrating surfaces of the membranes, which significantly amplifies their sensitivity. The study provides an analysis of the impedance spectra of the membranes during their exposure to known concentrations of particulate matter. The results of the study show electronic features highly correlated with the concentration of particulate matter in the air. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) PM categories are linked to the intensity of total PM during injection in a controlled environment; (<b>b</b>) spectral phase percentage distortion around the resonant frequency during dust injection as the powder accumulates on the membrane surface.</p>
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3 pages, 432 KiB  
Abstract
Cheap, Tunable and Versatile Nanoparticles for Explosive Detection: Quantum Dots
by Federica Mitri, Andrea De Iacovo, Serena De Santis and Lorenzo Colace
Proceedings 2024, 97(1), 19; https://doi.org/10.3390/proceedings2024097019 - 14 Mar 2024
Viewed by 712
Abstract
In recent years, fluorescent probes based on quantum dots have become a popular tool for explosive detection. However, despite their high sensitivity, these probes still require lab-based instrumentation and procedures that are difficult to be converted into a small, low-power system. Furthermore, they [...] Read more.
In recent years, fluorescent probes based on quantum dots have become a popular tool for explosive detection. However, despite their high sensitivity, these probes still require lab-based instrumentation and procedures that are difficult to be converted into a small, low-power system. Furthermore, they are hardly applied to the detection of vapor-phase explosives, being limited to water samples. Herein, we propose two alternative ways of employing quantum dots as a sensing material to build simple devices for vapor explosive detection. First, we report on a compact optical system where a solid-state QD photoluminescent probe is successfully integrated with a QD photodetector on the same silicon chip. Therefore, a high-performance chemiresistive sensor whose electrical resistance changes proportionally to the target gas concentration is proposed. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Scheme of the optical system architecture; (<b>b</b>) linear fitting of the optical system (blue dots) and chemiresistive sensor (red dots). ΔI = (Ia -Ig) for different NB concentrations.</p>
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3 pages, 1064 KiB  
Abstract
Classification in Early Fire Detection Using Transfer Learning Based on Multi-Sensor Nodes
by Pascal Vorwerk, Jörg Kelleter, Steffen Müller and Ulrich Krause
Proceedings 2024, 97(1), 20; https://doi.org/10.3390/proceedings2024097020 - 14 Mar 2024
Cited by 2 | Viewed by 700
Abstract
Multi-sensor data from a small laboratory setup was used to create a new feature space with linear discriminant analysis (LDA) to improve the classification of different fire materials. The LDA parameters were applied to a real room dataset to evaluate classification models. Data [...] Read more.
Multi-sensor data from a small laboratory setup was used to create a new feature space with linear discriminant analysis (LDA) to improve the classification of different fire materials. The LDA parameters were applied to a real room dataset to evaluate classification models. Data transformation using LDA improved the classification rate by up to 17% compared to principal component analysis (PCA) approaches used in previous studies. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Data pipeline; blue: data sets, green: training data-based transformation parameters, white: derived transformation parameters for new feature space, yellow: classification model.</p>
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<p>(<b>a</b>) Confusion matrix of SVM classifier distinguishing between 4 types of fire materials, (<b>b</b>) class separation of the training dataset using three LDA components, and (<b>c</b>) class separation of the validation data in the same feature space.</p>
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3 pages, 1638 KiB  
Abstract
Co3O4-Based Materials as Catalysts for Catalytic Gas Sensors
by Olena Yurchenko, Patrick Diehle, Katrin Schmitt and Jürgen Wöllenstein
Proceedings 2024, 97(1), 21; https://doi.org/10.3390/proceedings2024097021 - 14 Mar 2024
Viewed by 683
Abstract
The work deals with the development of Co3O4-based catalysts for application in catalytic gas sensors. Among the transition-metal oxide catalysts, cobalt oxide exhibits the highest activity in catalytic combustion. The catalytic activity of the catalysts was examined by Differential [...] Read more.
The work deals with the development of Co3O4-based catalysts for application in catalytic gas sensors. Among the transition-metal oxide catalysts, cobalt oxide exhibits the highest activity in catalytic combustion. The catalytic activity of the catalysts was examined by Differential Scanning Calorimetry (DSC), evaluating the catalyst’s activity by measuring its thermal response to 1% methane (CH4). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>SE-STEM images of (<b>a</b>) mCo<sub>3</sub>O<sub>4</sub>; (<b>b</b>) sCo<sub>3</sub>O<sub>4</sub>; (<b>c</b>) NiCo<sub>2</sub>O<sub>4</sub>; (<b>d</b>) Ni<sub>0.5</sub>Co<sub>2.5</sub>O<sub>4</sub> metal-oxides.</p>
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<p>Temperature dependent DSC response of four investigated catalysts to 1% CH<sub>4</sub>.</p>
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3 pages, 599 KiB  
Abstract
Development of a Compact, Reliable, and Electrostatically Actuated Device for Microfluidic-Based Active Glasses
by Simon Kulifaj, Clément Chauvin, Antoine Bouvier, Solène Meinier, Fengzhi Gu, Jérôme Degouttes, Nicolas Terrier, Patrick Pittet and Bruno Berge
Proceedings 2024, 97(1), 22; https://doi.org/10.3390/proceedings2024097022 - 14 Mar 2024
Viewed by 593
Abstract
We present the development study of a reliable and low-power actuator for microfluidics-based active glasses. The adaptive part of the lens implements two liquids of a specific refractive index separated by a thin membrane, the modification of their relative volumes allowing adaptive optical [...] Read more.
We present the development study of a reliable and low-power actuator for microfluidics-based active glasses. The adaptive part of the lens implements two liquids of a specific refractive index separated by a thin membrane, the modification of their relative volumes allowing adaptive optical power corrections. The proposed actuator is connected to an adaptive lens by microchannels since it is intended to be installed in the temple of the glasses. The actuation is based on the electrostatic displacement of a thin film, which changes the relative volumes of two cavities filled with these liquids. The metalized film is placed slack with an “S-shape” between two electrodes biased with the actuation voltage. Very compact actuator prototypes have been developed and characterized. Power corrections ranging from +0D to +3D can be achieved via liquid volume displacement as low as 120 µL and with a power consumption of a few mW. The prototypes show good reliability without any significant change in their operation after more than 1 million actuations. For RD purposes, we have replaced some electrodes with transparent windows. With this setup, we show experimental results on the interplay between the performances and the film folding inside the actuator. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Sectional view of new concept actuator.</p>
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<p>Evolution of the volume displaced by the actuator after 1 million cycles. A measurement is carried outapproximatively every 10,000 cycles (triangles). The total volume displaced remains stable at around 103 +/− 3 µL.</p>
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3 pages, 1249 KiB  
Abstract
Dielectric Spectroscopy for Non-Invasive Sensing of Multi-Layered Organ-on-Chip Devices
by Tim Hosman, Massimo Mastrangeli and Marco Spirito
Proceedings 2024, 97(1), 23; https://doi.org/10.3390/proceedings2024097023 - 14 Mar 2024
Viewed by 662
Abstract
Organ-on-chip (OoC) is emerging as a key technology for improved pre-clinical drug testing. Monitoring tissues and the artificial microenvironment in OoC devices is critical to recapitulate human physiology; however, sensing is often invasive, superficial, and not continuous over time. This work aims to [...] Read more.
Organ-on-chip (OoC) is emerging as a key technology for improved pre-clinical drug testing. Monitoring tissues and the artificial microenvironment in OoC devices is critical to recapitulate human physiology; however, sensing is often invasive, superficial, and not continuous over time. This work aims to overcome these issues by proposing dielectric spectroscopy as a non-invasive and time-continuous sensing technique capable of extracting information from multi-layer OoC devices, including distinguishable tissue layers. The presented results set the foundations for this goal by proving this technique’s feasibility, showing excellent correspondence between the experimental and modelled data, and providing design guidelines for application-tailored optimization. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) The DS measurement setup. Different probe types are shown in the top left inset. (<b>b</b>,<b>c</b>), respectively, show the real and imaginary dielectric permittivities for different water depths over glass. Measured data (red surface) overlap excellently with the numerical model prediction (blue surface).</p>
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<p>Sensitivity in water over frequency and depth, measured in <math display="inline"><semantics> <mrow> <mfrac> <mrow> <mi>δ</mi> <msub> <mrow> <mi>S</mi> </mrow> <mrow> <mn>11</mn> </mrow> </msub> </mrow> <mrow> <mi>δ</mi> <mi>d</mi> </mrow> </mfrac> </mrow> </semantics></math>, where <span class="html-italic">S</span><sub>11</sub> is the electric field reflection coefficient, and <span class="html-italic">d</span> the distance between the probe surface and the glass container. (<b>a</b>,<b>b</b>) show the sensitivity for probe diameters of 0.94 mm and 3.00 mm, respectively.</p>
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<p>Envisioned measurement setup for benchmarking multi-layer spectrum extraction. (<b>a</b>) Uncoated reference; (<b>b</b>) two-layer extraction with PDMS interposer; (<b>c</b>) three-layer extraction with PDMS and glass.</p>
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3 pages, 845 KiB  
Abstract
Co-Design and Characterization of a Differential Wireless Passive Micro-Electromechanical System Pressure Sensor
by Romain Alcesilas, Jean Claude Bastien, Marc Sansa, Camille Jouvaud, Patrice Rey and Christophe Delaveaud
Proceedings 2024, 97(1), 24; https://doi.org/10.3390/proceedings2024097024 - 15 Mar 2024
Viewed by 756
Abstract
We present a differential wireless passive sensor based on a miniature antenna associated with a MEMS capacitive pressure sensor. In this configuration, a change in the external pressure results in a shift of the antenna resonance frequency and, thus, a variation in the [...] Read more.
We present a differential wireless passive sensor based on a miniature antenna associated with a MEMS capacitive pressure sensor. In this configuration, a change in the external pressure results in a shift of the antenna resonance frequency and, thus, a variation in the antenna Radar Cross Section (RCS) detectable from a distance of a few meters. The MEMS and the antenna are modelled and simulated, and a co-design procedure is developed to optimize their performance. The MEMS are fabricated on a 200-mm technological platform and characterized. A specific setup was conceived to characterize the antenna sensor as a function of pressure in an anechoic chamber. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Overview of the MEMS process flow. (<b>b</b>) A 200 mm silicon wafer with the different MEMS sensors. (<b>c</b>) Working principle of the differential measurement. Dimensions are in mm.</p>
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<p>(<b>a</b>) Measured capacitance of the MEMS. (<b>b</b>) Simulated RCS variation at 868 MHz and equivalence in terms of relative back-propagated power. (<b>c</b>) Picture of the anechoic chamber with the interrogation antenna in the background and the plastic vacuum chamber in the foreground.</p>
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3 pages, 674 KiB  
Abstract
Analysis and Development of Rotational Angle Sensor
by Yu-Wen Chen and Cheng-Yao Lo
Proceedings 2024, 97(1), 25; https://doi.org/10.3390/proceedings2024097025 - 15 Mar 2024
Viewed by 649
Abstract
This research focuses on the rotational angle acquisition of a flexible sensor. A numerical analysis is conducted during design to discuss the sensor’s capacitance changes under rotation. A working range from −4° to 4° is investigated and fittings are predicted. Furthermore, manufacturing processes [...] Read more.
This research focuses on the rotational angle acquisition of a flexible sensor. A numerical analysis is conducted during design to discuss the sensor’s capacitance changes under rotation. A working range from −4° to 4° is investigated and fittings are predicted. Furthermore, manufacturing processes are used to realize the electrode, mold and spacers. After that, the sensor is measured to determine its capacitance signal. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) thickness and layers of the rotational angle sensor; (<b>b</b>) plane and cross-sectional views of the sensor.</p>
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3 pages, 582 KiB  
Abstract
Development of an e-Nose System for the Early Diagnosis of Sepsis in Mechanically Ventilated Patients: A Preliminary Study
by Stefano Robbiani, Aurora Pierantozzi, Louwrina H. te Nijenhuis, Patricia A. C. Specht, Floor A. Harms, Carmen Bax, Willem van Weteringen, Laura Capelli and Raffaele L. Dellacà
Proceedings 2024, 97(1), 26; https://doi.org/10.3390/proceedings2024097026 - 15 Mar 2024
Viewed by 692
Abstract
Sepsis is a severe condition and the major cause of mortality in the ICU. Prompt intervention decreases mortality, and non-invasive systems for early diagnosis in ICU patients are necessary. This work presents a customized e-Nose system based on non-selective chemical sensors for exhaled [...] Read more.
Sepsis is a severe condition and the major cause of mortality in the ICU. Prompt intervention decreases mortality, and non-invasive systems for early diagnosis in ICU patients are necessary. This work presents a customized e-Nose system based on non-selective chemical sensors for exhaled breath analysis. The system comprises two units: a sampling device able to collect exhaled breath from mechanically ventilated patients and an e-Nose in which the gas is analyzed. Preliminary results from a porcine model support the possibility of discriminating between healthy and sepsis subjects. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) PCA: scores and loading plot; (<b>b</b>) example of sensor (TGS2602) responses relevant to the analysis of one control.</p>
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3 pages, 818 KiB  
Abstract
A Cervical Plethysmography System to Monitor Blood Vessel Pulses on the Neck
by Antonino Proto, Anselmo Pagani, Paolo Zamboni and Angelo Taibi
Proceedings 2024, 97(1), 27; https://doi.org/10.3390/proceedings2024097027 - 15 Mar 2024
Viewed by 745
Abstract
A cervical plethysmography system has been developed to monitor blood vessel pulses on the neck area and at the same time to record the electrocardiogram signal. The system was tested on subjects in upright (90°) and supine (0°) position. The proposed cervical plethysmography [...] Read more.
A cervical plethysmography system has been developed to monitor blood vessel pulses on the neck area and at the same time to record the electrocardiogram signal. The system was tested on subjects in upright (90°) and supine (0°) position. The proposed cervical plethysmography system can be used as a biomedical tool for cardiovascular screening in the general population. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Entire data acquisition: grey color for raw signals (<b>A</b>); filtered signals (4.5 s) for subject in upright position (<b>B</b>); filtered signals (4.5 s) for subject in supine position (<b>C</b>).</p>
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3 pages, 499 KiB  
Abstract
Develop a Smart Material Based on Carbon-Aramid Hybrid Composite for Health Monitoring Structure
by Khalid Alblalaihid, Saad Aldoihi, Abdulaziz Alharbi, Meshal Abuobaid, Sabri Alkhaibari, Khalid Khormi, Sami Alsaleh, Khaled S. Almutairi and Majid A. Albahkali
Proceedings 2024, 97(1), 28; https://doi.org/10.3390/proceedings2024097028 - 15 Mar 2024
Viewed by 826
Abstract
This paper discusses the use of Kevlar-carbon hybrid composites in the aerospace industry for structural and non-structural components. By combining the high tensile strength and impact resistance of Kevlar fibers with the high stiffness and dimensional stability of carbon fibers, a material with [...] Read more.
This paper discusses the use of Kevlar-carbon hybrid composites in the aerospace industry for structural and non-structural components. By combining the high tensile strength and impact resistance of Kevlar fibers with the high stiffness and dimensional stability of carbon fibers, a material with enhanced mechanical properties can be achieved. However, the combination of two materials with different properties can cause delamination between layers, making real-time monitoring of structural integrity important. This study investigates the feasibility of embedding sensors into Kevlar-carbon hybrid composites and presents the basic characterization using a mechanical tensile test. It been shown the embedded sensor has a linear response toward the axial stress and the damage can be detected at the turning point where the capacitance begins to decrease. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Image of weaved carbon fiber into aramid (Kevlar) woven fabrics; (<b>b</b>) schematic diagram of inserting two capacitive sensors (sensors A and B) into a carbon-aramid hybrid composite; (<b>c</b>) experimental setup for characterization of the smart material; (<b>d</b>) graph showing the sensor response and the axial stress versus the crosshead displacement of the tensile test.</p>
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3 pages, 808 KiB  
Abstract
A Low-Cost, Self-Powered, Plantar Pressure Distribution Sensing Insole
by Abdo-Rahmane Anas Laaraibi, Gurvan Jodin, Mario Costanza, Damien Hoareau, Samuel Margueron, Nicolas Bideau and Florence Razan
Proceedings 2024, 97(1), 29; https://doi.org/10.3390/proceedings2024097029 - 15 Mar 2024
Viewed by 747
Abstract
Energy-autonomous wireless sensors are a promising solution for developing wearable medical, lifestyle- and performance-monitoring systems. This paper presents a low-cost, low-power and self-powered wearable intelligent pressure monitoring system based on flexible piezoresistive sensors. The encapsulated insole with an 8 × 2 sensor matrix [...] Read more.
Energy-autonomous wireless sensors are a promising solution for developing wearable medical, lifestyle- and performance-monitoring systems. This paper presents a low-cost, low-power and self-powered wearable intelligent pressure monitoring system based on flexible piezoresistive sensors. The encapsulated insole with an 8 × 2 sensor matrix is powered by a flexible solar panel and connected to a rigid electronic board. Data acquisition occurs via Bluetooth low-energy transmission (BLE), and the average power consumption of the insole is 113 µW. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>System diagram. (<b>a</b>) Self-powered encapsulated insole using a flexible solar panel; (<b>b</b>) inverse viscoelastic model [<a href="#B3-proceedings-97-00029" class="html-bibr">3</a>]; (<b>c</b>) plantar pressure distribution sensing.</p>
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<p>Functional evolution of the supply voltage <span class="html-italic">V<sub>stor</sub></span> versus time.</p>
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3 pages, 356 KiB  
Abstract
Development of NOx Gas Sensor Based on Electrospun ZnO Nanofibers for Diagnosing Asthma Disease
by Niloufar Khomarloo, Elham Mohsenzadeh, Roohollah Bagherzadeh, Masoud Latifi, Driss Lahem, Ari Hakgor, Ly Ahmadou and Hayriye Gidik
Proceedings 2024, 97(1), 30; https://doi.org/10.3390/proceedings2024097030 - 15 Mar 2024
Cited by 1 | Viewed by 779
Abstract
Volatile organic compounds (VOCs) have the potential to serve as biomarkers for respiratory diseases such as asthma. Non-invasive respiratory analysis can be used for early detection and disease monitoring. This paper presents the development of a ZnO metal oxide nanofibers sensor as a [...] Read more.
Volatile organic compounds (VOCs) have the potential to serve as biomarkers for respiratory diseases such as asthma. Non-invasive respiratory analysis can be used for early detection and disease monitoring. This paper presents the development of a ZnO metal oxide nanofibers sensor as a cost-effective method for detecting NO, which is an asthma biomarker, and NO2, that can cause asthma. Electrospun metal oxide nanofibers are considered for gas sensor applications due to their unique structural and electrical properties. The results indicate that the amount of zinc acetate and the morphology of the ZnO nanofibers as a sensing medium can affect the sensitivity of the gas sensor. The preparation of electrospinning solutions containing varying amounts of zinc acetate must be carefully considered due to its impact on morphology and thus sensitivity. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Dynamic response curves of sensors S <sub>1Zac-PVA</sub>. (<b>a</b>) Response to NO gas in 1, 2.5, 5, and 10 ppm at 300 °C. (<b>b</b>) Response to NO<sub>2</sub> gas 0.5, 1, and 2.5 ppm at 300 °C.</p>
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3 pages, 507 KiB  
Abstract
A Magnetic Tracking System Featuring Calibrated Three-Axis AMR Sensors
by Thomas Quirin, Corentin Féry, Céline Vergne, Morgan Madec, Luc Hébrard and Joris Pascal
Proceedings 2024, 97(1), 31; https://doi.org/10.3390/proceedings2024097031 - 15 Mar 2024
Viewed by 626
Abstract
This article presents a magnetic tracking system using on-chip anisotropic magnetoresistive (AMR) sensors. The system consists of four air-core coils sequentially generating four dc magnetic fields. The implemented localization algorithm is quadrilateration, and the accuracy of the system is dependent on the accuracy [...] Read more.
This article presents a magnetic tracking system using on-chip anisotropic magnetoresistive (AMR) sensors. The system consists of four air-core coils sequentially generating four dc magnetic fields. The implemented localization algorithm is quadrilateration, and the accuracy of the system is dependent on the accuracy of the sensors and the simulated field maps. The performance of the system was evaluated using an in-house magnetic field camera (MFC), and the results showed that the system exhibits mean Euclidean errors below 1 mm where the source produces strong gradients. Given the dimensions of the sensors (0.82 × 0.82 mm2), this system is suitable for tracking minimally invasive surgical tools. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) Geometry of the magnetic source simulated with Radia, (<b>B</b>) magnetic field camera (MFC) featuring 64 sensors, (<b>C</b>) and Euclidean error of the 64 sensors of the MFC for 20 different locations. The figure written on top of each of the 20 color maps represents the mean Euclidean error.</p>
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3 pages, 701 KiB  
Abstract
Electropolymerized PEDOT:PSS Thin Films for Fabrication of Vertical Organic Electrochemical Transistors
by Andreas Schander, Michael Skowrons, Melanie Kirsch and Björn Lüssem
Proceedings 2024, 97(1), 32; https://doi.org/10.3390/proceedings2024097032 - 18 Mar 2024
Viewed by 1254
Abstract
This paper presents novel vertical organic electrochemical transistors (vOECTs) with thin transistor channels grown by the electropolymerization of the electrically conductive polymer PEDOT:PSS. This new fabrication method avoids the need for the further structuring of the sensitive polymer layers, which will enable the [...] Read more.
This paper presents novel vertical organic electrochemical transistors (vOECTs) with thin transistor channels grown by the electropolymerization of the electrically conductive polymer PEDOT:PSS. This new fabrication method avoids the need for the further structuring of the sensitive polymer layers, which will enable the high-density integration of biosensors, e.g., on neural probes. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Design of the vertical OECT: (<b>a</b>) mask layout with 3 layers; (<b>b</b>) cross-section view.</p>
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<p>Microfabrication results after 180 s PEDOT:PSS coating: (<b>a</b>) microscope image; (<b>b</b>) SEM image; (<b>c</b>) transistor transfer curves for VD = −0.5 V (T1: 1 drain ring—T5: 5 drain rings).</p>
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3 pages, 407 KiB  
Abstract
Enhancing Ozone Monitoring with Low-Cost Sensors and Deep Neural Network: A Novel Approach
by Marco Magoni, Andrea Gaiardo, Matteo Valt, Pietro Tosato, Barbara Fabbri and Vincenzo Guidi
Proceedings 2024, 97(1), 33; https://doi.org/10.3390/proceedings2024097033 - 18 Mar 2024
Viewed by 652
Abstract
Ozone is a crucial component of the Earth’s atmosphere, playing a critical role in protecting the planet from harmful ultraviolet radiation. However, its concentration can vary greatly across different regions with significant impacts on human health and environment equilibrium. The aim of this [...] Read more.
Ozone is a crucial component of the Earth’s atmosphere, playing a critical role in protecting the planet from harmful ultraviolet radiation. However, its concentration can vary greatly across different regions with significant impacts on human health and environment equilibrium. The aim of this work was to calibrate a low-cost sensing platform, based on chemoresistive gas sensors, to monitor the environmental concentration of O3. The ongoing on-field calibration is performed with a deep neural network using the concentration of O3 collected by the local environmental protection agencies through certified tools as the gold standard. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sensing unit placed in the city centre of Trento, Park Santa Chiara; (<b>b</b>) model performance of the calibration method.</p>
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3 pages, 1569 KiB  
Abstract
Two-Dimensional Localization of an Aluminum Tag Using the Electromagnetic Shielding Effect
by Kiera Montgomery and Kean Chin Aw
Proceedings 2024, 97(1), 34; https://doi.org/10.3390/proceedings2024097034 - 18 Mar 2024
Viewed by 552
Abstract
Electromagnetic shielding is an underutilized method for non-invasive proximity sensing that could be useful in automated production lines as a low-cost method to locate products. A strong relationship was shown between the position of a tag and individual sensors. The strength of the [...] Read more.
Electromagnetic shielding is an underutilized method for non-invasive proximity sensing that could be useful in automated production lines as a low-cost method to locate products. A strong relationship was shown between the position of a tag and individual sensors. The strength of the magnetic field generated by the coil was reduced by up to 25% when the tag was above the sensor and started to decay when the tag was within 15 mm of each sensor. These measurements can then be aggregated to provide a greater range of measurement. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Sensing system. The plane the tag moves on exists between the coil and the sensing array.</p>
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<p>Signal strength detected by ground plane sensors. The red square denotes the position of the 30 × 30 mm tag. The index represents the position of the sensor. Index (2, 2) is directly beneath the coil, and the spacing between sensors is 30 mm: (<b>a</b>) signal reading when the tag is at (0, −20, 30); (<b>b</b>) signal reading when the tag is at (0, 0, 30); (<b>c</b>) signal reading when the tag is at (0, 20, 30).</p>
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<p>The signal strength of sensors as a tag moves along the x-axis of the sensor array.</p>
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3 pages, 327 KiB  
Abstract
Energy-Harvesting Smart Tiles for Human–Machine Interface Applications
by Alessandro Zompanti, Paolo Romeo, Anna Sabatini, Luca Vollero, Marco Santonico and Giorgio Pennazza
Proceedings 2024, 97(1), 35; https://doi.org/10.3390/proceedings2024097035 - 18 Mar 2024
Viewed by 622
Abstract
In this work, a human–machine interface with energy harvesting capabilities was developed and a modular floor made of tiles equipped with piezoelectric elements was produced. The developed platform was tested as a position-tracking system for a human user, allowing the tracking of the [...] Read more.
In this work, a human–machine interface with energy harvesting capabilities was developed and a modular floor made of tiles equipped with piezoelectric elements was produced. The developed platform was tested as a position-tracking system for a human user, allowing the tracking of the lower body in a virtual reality environment. Moreover, the energy collected by the device was evaluated. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Block diagram of the overall system.</p>
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3 pages, 499 KiB  
Abstract
Development and Deployment of Portable Sensor Platforms Based on a Micro-Electro-Mechanical-System Chemoresistive Gas Sensor Array for Outdoor Air Quality Monitoring
by Andrea Gaiardo, Matteo Valt, Pietro Tosato, Marco Magoni, Vincenzo Guidi, Claudia Dolci and Pierluigi Bellutti
Proceedings 2024, 97(1), 36; https://doi.org/10.3390/proceedings2024097036 - 18 Mar 2024
Cited by 1 | Viewed by 1023
Abstract
Nowadays, there is a growing demand for a well-distributed sensor network to monitor air quality which can aid policymakers in making decisions. This has led to an increase in the R&D of cost-effective and energy-efficient sensing solutions. In this study, sensing platforms composed [...] Read more.
Nowadays, there is a growing demand for a well-distributed sensor network to monitor air quality which can aid policymakers in making decisions. This has led to an increase in the R&D of cost-effective and energy-efficient sensing solutions. In this study, sensing platforms composed of MEMS chemoresistive gas sensors were developed and deployed in two Italian cities for the detection of pollutants. Over three years of measurements, the sensors have proven to be reliable in detecting CO, NO2 and O3 with high accuracy compared to data collected by local environmental protection agencies, paving the way for their potential validation and future adoption. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Prototype of final sensor platform; (<b>b</b>) comparison between SnTiNbOx (STN) electrical conductance (orange line) and the real concentration of CO (EPA monitored, blue line), from 6 to 16 February 2020.</p>
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3 pages, 145 KiB  
Abstract
Efficient Methods for Training and Validation of Odor Sensors
by Gina Zeh, Maximilian Koehne and Tilman Sauerwald
Proceedings 2024, 97(1), 37; https://doi.org/10.3390/proceedings2024097037 - 18 Mar 2024
Viewed by 769
Abstract
The correlation between a gas sensor pattern and its corresponding odor impression on human noses remains a scientific challenge for the development of technical odor detection systems. Small, inexpensive gas sensors, for example, those based on a metal oxide semiconductor (MOS), offer a [...] Read more.
The correlation between a gas sensor pattern and its corresponding odor impression on human noses remains a scientific challenge for the development of technical odor detection systems. Small, inexpensive gas sensors, for example, those based on a metal oxide semiconductor (MOS), offer a versatile platform for the development of application-specific sensor systems for odor detection or monitoring. The training of MOS sensors for odor detection remains a challenging task that has been addressed by recent advances. We hereby present a comprehensive method and instrumentation for the characterization and validation of MOS sensors using a gas chromatograph with a mass spectrometer and odor detection port. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 1088 KiB  
Abstract
A Low-Cost Solution and Continuous Wavelet Transform Analysis for Structural Health Monitoring
by Bruno Andò, Danilo Greco and Giacomo Navarra
Proceedings 2024, 97(1), 38; https://doi.org/10.3390/proceedings2024097038 - 18 Mar 2024
Cited by 1 | Viewed by 636
Abstract
In this paper, a low-cost solution for Structural Health Monitoring is proposed, exploiting a dedicated embedded sensing system. Signals provided by the sensor node have been processed by Continuous Wavelet Transform. The node behavior to seismic-like solicitations and has been assessed in the [...] Read more.
In this paper, a low-cost solution for Structural Health Monitoring is proposed, exploiting a dedicated embedded sensing system. Signals provided by the sensor node have been processed by Continuous Wavelet Transform. The node behavior to seismic-like solicitations and has been assessed in the case of frequency sweeps. The results demonstrate the system’s suitability for use in Early Warning frameworks. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) The node schematization; (<b>b</b>) recorded signals by the reference accelerometer (top) and the embedded node (bottom); (<b>c</b>) wavelet coherence.</p>
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<p>(<b>a</b>) Frequency sweep; (<b>b</b>) CWT of (<b>a</b>); (<b>c</b>) repeatability of the test results.</p>
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2 pages, 445 KiB  
Abstract
Electrochemical Performance of WS2-CNT Core–Shell Heterostructures for the Detection of Vitamin B2 
by Rayhane Zribi, Muhammad Hamid Raza, Nicola Pinna and Giovanni Neri
Proceedings 2024, 97(1), 39; https://doi.org/10.3390/proceedings2024097039 - 18 Mar 2024
Viewed by 721
Abstract
In this study, a novel electrochemical sensor was developed for the quantitative determination of riboflavin. The tungsten disulfide (WS2) layer was deposited on carbon nanotubes (CNTs) by atomic layer deposition (ALD), forming a CNTs-WS2 core–shell heterostructure. This material was used [...] Read more.
In this study, a novel electrochemical sensor was developed for the quantitative determination of riboflavin. The tungsten disulfide (WS2) layer was deposited on carbon nanotubes (CNTs) by atomic layer deposition (ALD), forming a CNTs-WS2 core–shell heterostructure. This material was used to modify the commercial screen-printed carbon electrode in order to enhance its electrocatalytic activity toward the detection of vitamin B2. Cyclic voltammetry was performed as a preliminary test in the presence of riboflavin. In addition to this, an extensive electrochemical study was performed using differential pulse voltammetry, demonstrating that modified the CNTs-WS2/SPCE sensor display superior electrochemical performance compared with bare SPCE. The sensor exhibits a linear response in the concentration range from 0 µM to 45 µM, with remarkably enhanced sensitivity (9 μAμM−1cm−2) compared with the bare electrode, with a limit of detection (LOD) of 1.24 µM. This enhancement is attributed to the conformal growth of the WS2 flakes on the CNTs and the high surface area offered by these flakes. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) DPV of CNTs-WS2/SPCE in 0.1 M PBS in the presence of different RF concentrations, (<b>b</b>) calibration curve corresponding to the DPV test. (The red line corresponds to the linear fit of the calibration curve).</p>
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3 pages, 373 KiB  
Abstract
Experimental Development and Validation of an E-Textile Sleeve for Surface Electromyography
by Armando Coccia, Federica Amitrano, Gaetano Pagano, Arcangelo Biancardi, Giuseppe Tombolini and Giovanni D’Addio
Proceedings 2024, 97(1), 40; https://doi.org/10.3390/proceedings2024097040 - 18 Mar 2024
Viewed by 689
Abstract
This work describes the development of a leg sleeve with embedded e-textile electrodes for surface electromyography (sEMG). The novel device is a textile substrate with embedded circular electrodes made of conductive fabric, which can be connected to EMG acquisition systems. The performances of [...] Read more.
This work describes the development of a leg sleeve with embedded e-textile electrodes for surface electromyography (sEMG). The novel device is a textile substrate with embedded circular electrodes made of conductive fabric, which can be connected to EMG acquisition systems. The performances of the novel prototypical device were validated in comparison with standard sEMG electrodes. The experimental study involved 11 healthy volunteers, and general features extracted from the signals were compared using statistical methods. The results underline the absence of significant differences between the two systems, suggesting that the e-textile novel device is a viable alternative to conventional electrodes for collecting sEMG data. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Smart textile sleeve: (<b>a</b>) internal view of textile electrodes; (<b>b</b>) external view of it connected to the acquisition system.</p>
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3 pages, 3579 KiB  
Abstract
Concept and Proof of Principle of an Acoustofluidic Single-Particle Sorting Device Using a Spatially Confined Acoustic Active Region
by Andreas Fuchsluger, Annalisa De Pastina, Tina Mitteramskogler, Rafael Ecker, Thomas Voglhuber-Brunnmaier, Nikolai Andrianov, Alexander Shatalov, Norbert Cselyuszka, Mohssen Moridi and Bernhard Jakoby
Proceedings 2024, 97(1), 41; https://doi.org/10.3390/proceedings2024097041 - 18 Mar 2024
Viewed by 703
Abstract
We present the concept and a proof-of-principle experiment for an acoustofluidic single- particle sorter. In a microfluidic channel, a flow profile with the following three parallel fluid domains is generated: buffer fluid in the center and buffer plus particles in the lateral domains. [...] Read more.
We present the concept and a proof-of-principle experiment for an acoustofluidic single- particle sorter. In a microfluidic channel, a flow profile with the following three parallel fluid domains is generated: buffer fluid in the center and buffer plus particles in the lateral domains. Due to the laminar flow regime present in microfluidics, the particles essentially follow the stream line(s) along the channel. In the spatially confined sorting and detection region, by switching on the standing acoustic wave, particles of interest (POIs) are pushed into the center fluid domain, thus leaving the chip at the center outlet. For particles of non-interest (PONIs), the acoustic region remains silent, so PONIs are not centered and follow their path to the side outlet. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Concept of the acoustofluidic single-particle sorter. A flow profile with three fluid domains is generated in a microfluidic channel with only the lateral domains carrying particles. After detection, POIs are pushed into the center stream in the acoustic sorting region and leave the chip through the center outlet, whereas PONIs stay on their path towards the side outlets.</p>
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<p>Proof-of-principle experiment for the acoustic particle sorter. (<b>a</b>) Photograph of the silicon/glass device, which features trifurcation, a narrow region and a wider cavity, but lacks the three outlets on the right side, which in the following are indicated by yellow drawings. (<b>b</b>) As long as the ultrasound transducer is off, due to the laminar flow regime, polystyrene tracer particles that are introduced through the side inlets would leave through virtual side outlets. (<b>c</b>) When the transducer is switched on (1835 MHz), acoustic particle focusing only takes place in the narrow (400 µm) region, where the resonance condition is met. Particles that are in the wide region are not affected. Only the focused particles would leave through a virtual center outlet.</p>
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3 pages, 479 KiB  
Abstract
Fabricating Acetic Acid Sensors Using PVP Nanofibrous Scaffold Doubly Decorated with Mesoporous Graphene
by Paolo Papa, Emiliano Zampetti, Corrado Di Natale, Fabrizio De Cesare, Giovanna Tranfo and Antonella Macagnano
Proceedings 2024, 97(1), 42; https://doi.org/10.3390/proceedings2024097042 - 18 Mar 2024
Viewed by 814
Abstract
A nanofibrous layer of polyvinylpyrrolidone (PVP) was designed to house, both in the fiber core and onto its outer surface, nanoparticles of mesoporous graphene (MGC), which are able to selectively adsorb acetic acid vapors. When grown on interdigital fingers microelectrodes (IDEs), upon UV-light [...] Read more.
A nanofibrous layer of polyvinylpyrrolidone (PVP) was designed to house, both in the fiber core and onto its outer surface, nanoparticles of mesoporous graphene (MGC), which are able to selectively adsorb acetic acid vapors. When grown on interdigital fingers microelectrodes (IDEs), upon UV-light irradiation taking place in air, the layer proved conductive and stable. Electrical and sensing features were significatively modulated by decorating the fiber surface with MGC (a sandwich-like structure) and polyethyleneimine (PEI). MGC, used both as a conductive filler and to decorate the fiber surface, strengthened the PVP scaffold and acted as a nucleation center for entrapping molecules of acetic acid. PEI improved the adhesion of MGC onto the surface. A preliminary study reported fast responses, high sensitivity with good linearity, selectivity, reversibility, and repeatability towards the acetic acid in ranges of up to hundreds of ppm at room temperature. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>SEM images of (<b>A</b>) PVP nanofibers housing MGC powder dispersion; (<b>B</b>) following decoration with PEI-MGC thin film; (<b>C</b>) transient sensor responses to common VOCs in dynamic modes, where DI is the current change and I<sub>0</sub> the current baseline before VOC exposure; (<b>D</b>) bar plot depicting a comparison between the sensor responses to the same concentration of VOCs; (<b>E</b>) sensors and circuit sides of the sensing device.</p>
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3 pages, 1174 KiB  
Abstract
Equivalent Circuit Models for Impedimetric Sensors
by Eva-Maria Korek, Evanthia Chrysanthi Kounoupioti and Ralf Brederlow
Proceedings 2024, 97(1), 43; https://doi.org/10.3390/proceedings2024097043 - 18 Mar 2024
Cited by 1 | Viewed by 796
Abstract
In this work, equivalent circuit models for conductivity, reference, and potassium ion sensors are introduced and validated. The models help to understand and verify the sensors’ functioning and to determine the selective element of the potassium sensor as a capacitance that occurs below [...] Read more.
In this work, equivalent circuit models for conductivity, reference, and potassium ion sensors are introduced and validated. The models help to understand and verify the sensors’ functioning and to determine the selective element of the potassium sensor as a capacitance that occurs below 1 Hz. Measurements at 100 mHz suggest that the phase response of the sensor reveals advantages concerning response time and stability compared to the typically used magnitude. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Equivalent circuits and fitting results for 1 mM and 25 mM K<sup>+</sup> solutions. (<b>a</b>) A conductivity sensor, (<b>b</b>) a reference sensor and (<b>c</b>) a K<sup>+</sup> sensor that shows cross-sensitivity towards Na<sup>+</sup> below 1 Hz.</p>
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<p>Potassium sensor and its response at 100 mHz. (<b>a</b>) Picture of the potassium sensor. (<b>b</b>) Change in magnitude of the impedance and (<b>c</b>) change in phase for varying K<sup>+</sup> ion concentrations.</p>
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3 pages, 1347 KiB  
Abstract
Fabrication of Wafer-Level Vacuum-Packaged 3C-SiC Resonators with Q-Factor above 250,000
by Sergio Sapienza, Luca Belsito, Matteo Ferri, Ivan Elmi, Marcin Zielinski, Francesco La Via and Alberto Roncaglia
Proceedings 2024, 97(1), 44; https://doi.org/10.3390/proceedings2024097044 - 18 Mar 2024
Cited by 1 | Viewed by 917
Abstract
In this work, the fabrication of wafer-level vacuum-packaged 3C-SiC on Si double- clamped beam resonators via glass–silicon anodic bonding using Ti-based vacuum gettering is reported. Open-loop resonance measurements are performed on the vacuum-packaged devices, showing Q-factor values up to 290,000, a process yield [...] Read more.
In this work, the fabrication of wafer-level vacuum-packaged 3C-SiC on Si double- clamped beam resonators via glass–silicon anodic bonding using Ti-based vacuum gettering is reported. Open-loop resonance measurements are performed on the vacuum-packaged devices, showing Q-factor values up to 290,000, a process yield above 80%, and a maximum vacuum level around 10−2 mbar inside the Ti-gettered encapsulations. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Process flow for the fabrication of the wafer-level vacuum-packaged SiC resonators.</p>
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<p>Q-factor measurements performed on double-clamped beams inside capsules with different geometries and areas.</p>
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3 pages, 497 KiB  
Abstract
Electrochemical Sensors for Animal Welfare
by Ilaria Sorrentino, Claire Verplanck and Yohann R. J. Thomas
Proceedings 2024, 97(1), 45; https://doi.org/10.3390/proceedings2024097045 - 18 Mar 2024
Viewed by 699
Abstract
The WAIT4 (Welfare: Artificial Intelligence and new Technologies for Tracking Key Indicator Traits in Animals Facing Challenges of the Agro-ecological Transition) project aims to increase research-based capacities to quantify and characterize animal welfare (AW) from the agro-ecological (AE) perspective and to revise farming [...] Read more.
The WAIT4 (Welfare: Artificial Intelligence and new Technologies for Tracking Key Indicator Traits in Animals Facing Challenges of the Agro-ecological Transition) project aims to increase research-based capacities to quantify and characterize animal welfare (AW) from the agro-ecological (AE) perspective and to revise farming practices by considering interactions between the animal and its environment. From this perspective, the development of new sensors for assessing the kinetics of physiological variables of interest (Na+, K+, pH) in animals’ interstitial fluid (ISF) by microneedle patches will be a valuable aid for farmers to monitoring AW states and various stressors. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Electrochemical responses and linearity of (<b>A</b>) Na<sup>+</sup> test and (<b>B</b>) K<sup>+</sup> test in artificial ISF.</p>
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3 pages, 322 KiB  
Abstract
A Chipless RFID Humidity Sensor for Smart Packaging Applications
by Viviana Mulloni, Giada Marchi, Andrea Gaiardo, Matteo Valt, Massimo Donelli and Leandro Lorenzelli
Proceedings 2024, 97(1), 46; https://doi.org/10.3390/proceedings2024097046 - 18 Mar 2024
Viewed by 633
Abstract
A chipless RFID humidity sensor suitable for smart packaging is proposed in this work. The sensor is flexible, fast, low-cost, easy to fabricate and can be read wirelessly. The results show a very high sensitivity in the low-humidity range (1–10%), making it especially [...] Read more.
A chipless RFID humidity sensor suitable for smart packaging is proposed in this work. The sensor is flexible, fast, low-cost, easy to fabricate and can be read wirelessly. The results show a very high sensitivity in the low-humidity range (1–10%), making it especially suited to monitor and establish package integrity. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Return loss intensity as a function of frequency in the range 1–2 GHz. (<b>b</b>) Variation in peak intensity and frequency as a function of relative humidity.</p>
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3 pages, 323 KiB  
Abstract
WO3-Pt/Graphene Nanocomposite Sensors for Methane Sensing Applications
by Patricia Arroyo, Tiziana Polichetti, Brigida Alfano, Maria Lucia Miglietta, Ettore Massera and Jesus Lozano
Proceedings 2024, 97(1), 47; https://doi.org/10.3390/proceedings2024097047 - 18 Mar 2024
Viewed by 789
Abstract
This study presents the fabrication and characterization of chemoresistive sensors based on a nanocomposite of WO3-Pt and graphene for methane detection. The graphene was prepared using a liquid-phase exfoliation technique, and the nanocomposite was deposited onto interdigitated gold electrodes using drop-casting. The response [...] Read more.
This study presents the fabrication and characterization of chemoresistive sensors based on a nanocomposite of WO3-Pt and graphene for methane detection. The graphene was prepared using a liquid-phase exfoliation technique, and the nanocomposite was deposited onto interdigitated gold electrodes using drop-casting. The response of the sensors was analyzed by measuring changes in electrical resistance at methane concentrations of 7, 5, 3, and 1 ppm. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Resistive behavior of the material to changes in methane concentration (<b>a</b>) dynamic response to 7 ppm steps; (<b>b</b>) difference in the characteristic values for each measurement and the characteristic value at 0 ppm concentration.</p>
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3 pages, 416 KiB  
Abstract
Fabrication of an Ultrathin PMMA Foil for Sensing Applications in Microfluidic Systems
by Rafael Ecker, Tina Mitteramskogler, Andreas Fuchsluger and Bernhard Jakoby
Proceedings 2024, 97(1), 48; https://doi.org/10.3390/proceedings2024097048 - 19 Mar 2024
Viewed by 661
Abstract
This research work focuses on the fabrication of ultrathin polymethylmethacrylate (PMMA) foils using a spin coating process of in anisole dissolved PMMA on a water-soluble polyvinyl alcohol (PVA) foil. Currently, layer thicknesses as low as 1 µm can be achieved and even thinner [...] Read more.
This research work focuses on the fabrication of ultrathin polymethylmethacrylate (PMMA) foils using a spin coating process of in anisole dissolved PMMA on a water-soluble polyvinyl alcohol (PVA) foil. Currently, layer thicknesses as low as 1 µm can be achieved and even thinner layers appear to be possible. Sensors and actuators can be applied to the foils and directly integrated into the center of the channel of a polymer-based microfluidic chip. Specifically, the foil acts as a supporting structure that helps to position the sensor in the center of the channel. Thermal sensors, in particular, benefit from the low heat capacity of the foil. This will improve the performance and the accuracy of these sensors of which the impact on the fluidic flow is minimized. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) Fabrication procedure of an ultrathin PMMA foil. (<b>a</b>) Cutting and placing of the PVA foil. (<b>b</b>) Clamping of the PVA foil into laser-cut PMMA tensions rings. (<b>c</b>) Spin coating of a PMMA layer. (<b>d</b>) Curing process for solvent evaporation. (<b>e</b>) Clamping to smaller tension rings. (<b>f</b>) Dissolving of the PVA foil in a water-filled glass container. (<b>g</b>) Drying of the foil at room temperature or in the oven. (<b>B</b>) Fabricated sensors using the ultrathin PMMA foil and screen-printed electrodes.</p>
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3 pages, 456 KiB  
Abstract
A Wireless Strain Sensor for Measurement in Composites
by Lukas Bertram, Michael Brink and Walter Lang
Proceedings 2024, 97(1), 49; https://doi.org/10.3390/proceedings2024097049 - 19 Mar 2024
Viewed by 739
Abstract
This paper presents first characterization results of a novel, battery-less sensor for integration into glass fiber-reinforced plastic (FRP) materials. The sensor targets combined usage in both production and structural health monitoring applications. It is shown that wireless measurement of biaxial mechanical strain inside [...] Read more.
This paper presents first characterization results of a novel, battery-less sensor for integration into glass fiber-reinforced plastic (FRP) materials. The sensor targets combined usage in both production and structural health monitoring applications. It is shown that wireless measurement of biaxial mechanical strain inside FRP is possible with the presented approach. The results promise feasibility of industrial application by implementing a sticker-based ‘sensor tag’ approach for easy application and additional advantages in context of ‘smart’ structures. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Specimen with integrated tag and unintegrated tag for reference. Tag coordinate system indicated. (<b>b</b>) Averaged strain readings of a single specimen; n = 5; F<sub>max</sub> = 1 kN. Shaded areas: Std. dev.</p>
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3 pages, 988 KiB  
Abstract
An Acoustically Transparent Electrical Cap for Piezoelectric Ultrasound Transducers on Silicon
by Gandhika K. Wardhana, Tiago L. Costa and Massimo Mastrangeli
Proceedings 2024, 97(1), 50; https://doi.org/10.3390/proceedings2024097050 - 19 Mar 2024
Viewed by 793
Abstract
Bulk piezoelectric ultrasound transducers on integrated circuits offer unique properties for therapeutic applications of ultrasound neuromodulation. However, current implementations of such transducers are not optimized for the high transmit efficiency required to stimulate neurons. This is mainly due to the challenge of implementing [...] Read more.
Bulk piezoelectric ultrasound transducers on integrated circuits offer unique properties for therapeutic applications of ultrasound neuromodulation. However, current implementations of such transducers are not optimized for the high transmit efficiency required to stimulate neurons. This is mainly due to the challenge of implementing a metal layer on top of the piezoelectric film using microfabrication techniques. Here, we propose a micromachined capping structure providing an electrical connection on top of the piezoelectric film with minimal acoustic losses. The structure can potentially be used as a common ground connection in phased-array ultrasound transducers. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Fabrication and assembly of the capping structure. (<b>a</b>) Thinning down of silicon wafer to match the piezoelectric film thickness. (<b>b</b>) Deposition of PECVD SiO2. (<b>c</b>) Sputtering of Al(1%Si) and Ti. (<b>d</b>) Backside patterning of positive photoresist (AZ 12XT-20PL). (<b>e</b>) Backside DRIE of the Si wafer. (<b>f</b>) Spin-coating of PDMS on the front side of the wafer. (<b>g</b>) Etching of SiO2 using BHF (1:7). (<b>h</b>) Filling of the contact groove with conductive paste. (<b>i</b>) Assembly of the top-level connection on a test chip. Lead zirconate titanate (PZT) was used as piezoelectric material. (<b>j</b>) Terminal configuration to drive the transducer. (<b>k</b>) Terminal configuration to measure the electric resistance of the membrane.</p>
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<p>(<b>a</b>) Bottom-view of the proposed cap structure, (<b>b</b>) cap structure assembled on top of a test chip with PZT. (<b>c</b>) Measured pressure profile of the assembled transducer (focal distance: 10 mm).</p>
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3 pages, 942 KiB  
Abstract
A Phenylalanine Ammonia Lyase Capacitive Sensor for Phenylalanine Detection
by Bruno Andò, Salvatore Castorina, Ludovica Maugeri, Salvatore Petralia, Maria Anna Messina, Martino Ruggieri, Giovanni Neri, Angelo Ferlazzo, Emilio Sardini and Mauro Serpelloni
Proceedings 2024, 97(1), 51; https://doi.org/10.3390/proceedings2024097051 - 19 Mar 2024
Cited by 1 | Viewed by 763
Abstract
In this paper, an easy-to-use and fast biosensor for phenylalanine quantification in patients affected by phenylketonuria is investigated. The phenylalanine concentration was indirectly estimated through the ammonia released as a by-product of an enzymatic reaction, which was then detected by exploiting an yttria-stabilized [...] Read more.
In this paper, an easy-to-use and fast biosensor for phenylalanine quantification in patients affected by phenylketonuria is investigated. The phenylalanine concentration was indirectly estimated through the ammonia released as a by-product of an enzymatic reaction, which was then detected by exploiting an yttria-stabilized zirconia layer deposited over an interdigitated capacitive sensor. The latter was manufactured by rapid-prototyping technologies. A sensor limit of detection higher than 1.25 µM was estimated, along with an accuracy better than 18.31 µM. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The sensor: (<b>a</b>) top view (layout), (<b>b</b>) cross section and real view, (<b>c</b>) calibration diagram.</p>
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4 pages, 693 KiB  
Abstract
Additive Manufacturing Electronics for Packaging High-Frequency Aluminum Nitride Piezoelectric Micromachined Ultrasonic Transducer Probes
by Vincenzo Mariano Mastronardi, Antonio Qualtieri, Enrico Boni, Piero Tortoli, Roberto De Fazio, Paolo Visconti, Maria Teresa Todaro and Massimo De Vittorio
Proceedings 2024, 97(1), 52; https://doi.org/10.3390/proceedings2024097052 - 18 Mar 2024
Viewed by 738
Abstract
Additive Manufacturing Electronics (AME) is a promising method that has the potential to directly embed piezoelectric micromachined ultrasonic transducer (PMUT) probes into conventional electronic circuits and boards. It enables fast customized prototyping, three-dimensional circuit boards, and small-series production. In this study, annular probes [...] Read more.
Additive Manufacturing Electronics (AME) is a promising method that has the potential to directly embed piezoelectric micromachined ultrasonic transducer (PMUT) probes into conventional electronic circuits and boards. It enables fast customized prototyping, three-dimensional circuit boards, and small-series production. In this study, annular probes composed of circular suspended Aluminum Nitride (AlN)-based PMUT membranes, addressed in 2-dimensional arrays, were designed, fabricated, and encapsulated using AME technology. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Annular probe with AlN membranes arranged along five circular rings; (<b>b</b>) 3D design of package with final probe encapsulation and transmission measurement in time domain for 1st resonance mode in liquid (Ring 1 is the outer and most populated ring, and Ring 5 is the inner and less populated one).</p>
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3 pages, 896 KiB  
Abstract
Aerosol Measurements by OPC Aided by QCM Mass Sensor
by Emiliano Zampetti, Maria Aurora Mancuso, Papa Paolo, Antonella Macagnano, Andrea Bearzotti and Yi Hsuan Chen
Proceedings 2024, 97(1), 53; https://doi.org/10.3390/proceedings2024097053 - 19 Mar 2024
Viewed by 678
Abstract
Atmospheric aerosols, as well as particulate matters or suspended particulate matters (PMx), impact climate and affect human health, directly or indirectly. PMx is one of the most important pollutants monitored for air quality evaluation. Optical particle counters and quartz crystal microbalances are used [...] Read more.
Atmospheric aerosols, as well as particulate matters or suspended particulate matters (PMx), impact climate and affect human health, directly or indirectly. PMx is one of the most important pollutants monitored for air quality evaluation. Optical particle counters and quartz crystal microbalances are used to measure mass in a fixed volume. However, when used separately, these devices can show some issues. In this work, we propose combining these devices to obtain results that include particle counting, mass measurement, and, in particular cases, discrimination between solid and liquid aerosols. By using both instruments together, we can overcome the limitations of each and obtain more accurate and comprehensive data on air quality. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Results of the measurements of a sample of nebulized NaCl aerosol by OPC (on the <b>left</b>) and QCM (on the <b>right</b>). The red dashed line shows the heating area, highlighting when the heat is on.</p>
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<p>Results of the measurements of a sample of nebulized “e-liquid” aerosol by OPC (on the <b>left</b>) and QCM (on the <b>right</b>). The red dashed line shows the heating area highlighting when the heat is on.</p>
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3 pages, 798 KiB  
Abstract
Enhancing Ammonia Sensor Sensitivity by CuBr Encapsulation in a Mesoporous Host
by Lisa Weber, Virginie Martini, David Grosso, Stephane Burtey and Marc Bendahan
Proceedings 2024, 97(1), 54; https://doi.org/10.3390/proceedings2024097054 - 19 Mar 2024
Viewed by 747
Abstract
A resistive room-temperature ammonia sensor has been developed by CuBr impregnation of a mesoporous SiO2 host prepared by the sol–gel process and deposited by dip-coating. The mesoporous sensor performances are compared with those of a single CuBr layer. The CuBr encapsulation in [...] Read more.
A resistive room-temperature ammonia sensor has been developed by CuBr impregnation of a mesoporous SiO2 host prepared by the sol–gel process and deposited by dip-coating. The mesoporous sensor performances are compared with those of a single CuBr layer. The CuBr encapsulation in a mesoporous host leads to an impressive sensitivity improvement with sub-ppm detection of ammonia at room temperature. The results open new perspectives for the development of highly sensitive chemical sensors and are of great interest for non-invasive health monitoring. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>CuBr-based sensor responses exposed to NH<sub>3</sub>: (<b>a</b>) resistance measurement to 1500 ppb; (<b>b</b>) sensitivities from 200 to 2300 ppb NH<sub>3</sub>.</p>
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<p>Comparison between the gas analyzer and the CuBr mesoporous sensor performances.</p>
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3 pages, 595 KiB  
Abstract
Three-Dimensionally Printed Resonator with Piezoelectric Actuation and Machine Learning Calibration for In-Line Density–Viscosity Sensing
by Víctor Corsino, Víctor Ruiz-Díez, Mario Ramírez-Palma, Javier Toledo, José Manuel Gilpérez and José Luis Sánchez-Rojas
Proceedings 2024, 97(1), 55; https://doi.org/10.3390/proceedings2024097055 - 19 Mar 2024
Viewed by 709
Abstract
Three-dimensionally printed cuboid-shaped flow cells featuring a rectangular vibrating plate in one of the sides, actuated by PZT piezoelectric films, were designed, fabricated, and tested. Instead of oscillator circuits based on single resonances, we use the frequency response of the cell in a [...] Read more.
Three-dimensionally printed cuboid-shaped flow cells featuring a rectangular vibrating plate in one of the sides, actuated by PZT piezoelectric films, were designed, fabricated, and tested. Instead of oscillator circuits based on single resonances, we use the frequency response of the cell in a range with multiple resonances, sensitive to the liquid properties. Machine learning techniques were implemented for training and calibration with water–glycerol mixtures at different temperatures. Various materials, fabrication parameters, and post-treatment processes were investigated. The calibration errors and resolutions are compared for different devices, conditioning circuits, and machine learning algorithms. Our results demonstrate the high potential of the low-cost sensor to monitor density and viscosity in aqueous solutions. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Spectra taken with the <span class="html-italic">N<sub>i</sub></span> solutions with a cross-sectional scheme and a photograph of one of the fabricated cells in the inset. (<b>b</b>) Estimated viscosity of the <span class="html-italic">N<sub>i</sub></span> liquids with the machine learning model. Red symbols show the performance of the model in the training sets, blue symbols show the predictions on the test sets, and yellow symbols show the reference viscosity values for each solution.</p>
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3 pages, 460 KiB  
Abstract
Fabrication of 3D Nanostructures via AFM-Based Nanolithography
by Lorenzo Vincenti, Paolo Pellegrino, Isabella Farella, Mariafrancesca Cascione, Valeria De Matteis, Fabio Quaranta and Rosaria Rinaldi
Proceedings 2024, 97(1), 56; https://doi.org/10.3390/proceedings2024097056 - 19 Mar 2024
Cited by 1 | Viewed by 846
Abstract
The increasing use of nanomaterials in high-tech devices has posed an exciting challenge for the scientific community to develop new, easy, high-throughput nanofabrication approaches. Here, we present an easy AFM-based nanofabrication approach based on Static Plowing Lithography, with which we are able to [...] Read more.
The increasing use of nanomaterials in high-tech devices has posed an exciting challenge for the scientific community to develop new, easy, high-throughput nanofabrication approaches. Here, we present an easy AFM-based nanofabrication approach based on Static Plowing Lithography, with which we are able to realize patterns of 3D nanostructures on a thin PMMA layer. By coupling a wet etching process with ultrasound exposure, we effectively removed the polymer bulges at the nanostructure’s borders, increasing the quality of the patterned 3D nanostructures, and paving the way for their integration into lab-on-a-chip devices. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) SPL of nanosquares array patterned on PMMA; (<b>b</b>) 3D image of the square patterned at setpoint of 1.5 nA, scanning rate of 0.50 µm/s; (<b>c</b>) AFM image of the nanosquare array after the chemical–physical treatment; (<b>d</b>) 3D image of the particular in (<b>c</b>) after the chemical–physical treatment.</p>
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3 pages, 463 KiB  
Abstract
Electrochemical Detection of MMP-2 Using Graphene-Based Aptasensor
by Stefan Jarić, Silvia Schobesberger, Peter Ertl, Nikola Ž. Knežević and Ivan Bobrinetskiy
Proceedings 2024, 97(1), 57; https://doi.org/10.3390/proceedings2024097057 - 19 Mar 2024
Viewed by 912
Abstract
A graphene-based electrochemical biosensor was developed for the detection of matrix metalloproteinase 2 (MMP-2) endopeptidase, whose expression can be significantly related to the occurrence, metastasis, and prognosis of cancer. A specific anti-MMP-2 aptamer was successfully immobilized on the surface of electrochemically reduced graphene [...] Read more.
A graphene-based electrochemical biosensor was developed for the detection of matrix metalloproteinase 2 (MMP-2) endopeptidase, whose expression can be significantly related to the occurrence, metastasis, and prognosis of cancer. A specific anti-MMP-2 aptamer was successfully immobilized on the surface of electrochemically reduced graphene oxide via a pyrene-based linker, enabling the specific capture of MMP-2. The sensor was able to detect 1 ng mL−1, with an overall detection time of less than 20 min. Moreover, the aptamer-based biosensor showed good specificity toward different unspecific proteins. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) Graphene-based aptasensor assembly characterization via CV; (<b>B</b>) EIS spectra of different MMP-2 concentrations in 1× PBS.</p>
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3 pages, 1023 KiB  
Abstract
Contactless Heating Technology for Lab-on-Chip Microfluidic-Based Nucleic Acid Amplification Testing System
by Tomasz Matusiak, Miron Tokarski, Małgorzata Małodobra-Mazur, Henryk Roguszczak, Arkadiusz Dąbrowski, Paweł Sitarz and Matylda Czosnykowska
Proceedings 2024, 97(1), 58; https://doi.org/10.3390/proceedings2024097058 - 20 Mar 2024
Viewed by 1128
Abstract
The miniaturisation of manual systems is reported in this paper. The whole system was based on microfluidic cartridge heated up by a unique contactless system. The presented device utilised fully passive cartridge with required reagents. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Overview of the analyser and microfluidics cartridge.</p>
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<p>The principle of operation of the heating and detecting systems.</p>
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<p>Temperature ramps of four heating zones.</p>
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<p>Fluorescence readings for pathogen presence determination.</p>
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3 pages, 635 KiB  
Abstract
Research by Fondazione Bruno Kessler on Strategies to Improve the Yield in Plasma Focused Ion Beam Circuit Editing
by David Novel, Evgeny Demenev and Lorenza Ferrario
Proceedings 2024, 97(1), 59; https://doi.org/10.3390/proceedings2024097059 - 20 Mar 2024
Viewed by 735
Abstract
This contribution explores the potential of PFIB for the post-production circuit editing of custom ASICs. The reworking of integrated circuits with ion beam is an effective tool for testing design modifications rapidly, and in small-volume productions, it proves to be a valuable substitute [...] Read more.
This contribution explores the potential of PFIB for the post-production circuit editing of custom ASICs. The reworking of integrated circuits with ion beam is an effective tool for testing design modifications rapidly, and in small-volume productions, it proves to be a valuable substitute for the microfabrication of chips with a revised layout, thus reducing the cost and lead time. In the case study in this work, the PFIB intervention resulted in the recovery of ~90% of defective channels in a multichannel ASIC design by disconnecting some parts of the internal circuit. This contribution describes several implemented optimization strategies and their statistical effectiveness. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Large milling area milled with a high beam current. It was used as a reference to find relative coordinates from a surface morphology to the buried trace to be removed. (<b>b</b>) Top view of the crater after milling. The trace to be removed is highlighted. (<b>c</b>) Cross-section of the milling crater that was used to reach the deep metal layer to be removed. The positioning precision needs to be below 500 nm. (<b>d</b>) Map showing the yield in chips for 10 reworked chips.</p>
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3 pages, 417 KiB  
Abstract
Efficient Modeling of Piezoelectric Micromachined Ultrasonic Transducers Using a Combination of Finite and Lumped Element Modeling
by Romain Liechti, Francois Blard, Jean-Rémi Chatroux, Jean-Claude Bastien, Hélène Lhermet and Bruno Fain
Proceedings 2024, 97(1), 60; https://doi.org/10.3390/proceedings2024097060 - 20 Mar 2024
Cited by 1 | Viewed by 713
Abstract
This research paper presents a comprehensive methodology for the efficient modeling of piezoelectric micromachined ultrasonic transducers (PMUTs) using a combination of finite and lumped element models. A single membrane is first studied in air with an eigenfrequency study in order to calibrate the [...] Read more.
This research paper presents a comprehensive methodology for the efficient modeling of piezoelectric micromachined ultrasonic transducers (PMUTs) using a combination of finite and lumped element models. A single membrane is first studied in air with an eigenfrequency study in order to calibrate the lumped element model on the finite element model. From this electrical equivalent circuit, a complete model of the PMUT cell composed of numerous membranes is developed using the propagation, directivity, absorption, mutual and self-impedances, and variability of the resonance frequencies due to manufacturing discrepancies. The calculated acoustic response of the PMUT is then compared with a measured response, in water. The relatively good agreement between the simulation and the measurement, as well as the very low computation time, makes this approach relevant for further optimization of the PMUT design to target larger bandwidth and higher sensitivity. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Distribution of the resonance frequencies of the 228 transducers of one cell calculated using a truncated normal distribution with a maximum deviation of 3% from the nominal value (<b>a</b>), simulation and measurement of the electrical impedance of a cell (<b>b</b>), acoustic pressure of a cell simulated by the analytical model in a plane parallel to the plane of the PMUT at a distance of 2.11 mm, (<b>c</b>) and the corresponding acoustic pressure measured in water (<b>d</b>).</p>
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3 pages, 2446 KiB  
Abstract
Annealed Gallium-Doped Zinc Oxide (ZnO:Ga) Thin Films for Sub-ppm NO2 Sensing
by Benjamin Paret, Philippe Menini, Thierry Camps, Yohann Thimont, Antoine Barnabé, Laurent Mazenq and Lionel Presmanes
Proceedings 2024, 97(1), 61; https://doi.org/10.3390/proceedings2024097061 - 20 Mar 2024
Viewed by 637
Abstract
In this work, gallium-doped zinc oxide was deposited with a Radio Frequency Magnetron sputtering method on test platforms. The NO2 sensing properties of the resulting devices were studied. The sensing properties of ZnO:Ga thin films were successfully stabilized through annealing in dry [...] Read more.
In this work, gallium-doped zinc oxide was deposited with a Radio Frequency Magnetron sputtering method on test platforms. The NO2 sensing properties of the resulting devices were studied. The sensing properties of ZnO:Ga thin films were successfully stabilized through annealing in dry air, and then improved by either a thinning of the layer or an increase in the roughness of the substrate. The sensing response with an Rgas/Rair of 15 for 100 ppb of NO2 under 50% humidity was obtained, with a response time below 10 min. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>STEM capture of a 50 nm thick ZnO:Ga thin film deposited by RF sputtering on a Si substrate covered by smooth thermal SiO<sub>2</sub>.</p>
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3 pages, 751 KiB  
Abstract
A Low-Cost Testbed for Neural Microelectrodes
by Cat-Vu H. Bui, Neethu Maliakal, Hasan Ulusan, Andreas Hierlemann and Fernando Cardes
Proceedings 2024, 97(1), 62; https://doi.org/10.3390/proceedings2024097062 - 21 Mar 2024
Viewed by 714
Abstract
The performances of microelectrode arrays for neural interfaces strongly depend on electrode design. Due to a lack of simulation tools, electrode engineers often have to refine new designs empirically. This process requires setups of electrical and electrophysiological hardware that are not specific to [...] Read more.
The performances of microelectrode arrays for neural interfaces strongly depend on electrode design. Due to a lack of simulation tools, electrode engineers often have to refine new designs empirically. This process requires setups of electrical and electrophysiological hardware that are not specific to electrode testing and unnecessarily costly. We propose a low-cost testbed for specifically targeting metrics relevant to electrode performance and functions, which relies on an off-the-shelf measurement tool and only on components necessary for such testing. We experimentally demonstrate the platform by characterizing microelectrodes by means of impedance spectroscopy and recording the extracellular action potentials from in vitro primary rat neurons. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Testbed schematic and results. (<b>a</b>) An MEA was connected to a 61:4 MUX bank. Two of the outputs were connected to a low-noise amplifier (LNA) and a transimpedance amplifier (TIA). The STEMLab 125-10 hosts a system-on-chip, analog–digital and digital–analog converters (ADC/DAC), and digital outputs (I/Os) to operate the MUXs. Switches S<sub>1–5</sub> set up either EIS or recording mode. For EIS, a frequency-swept voltage signal (V<sub>A</sub>) is applied to the RE, and the current through the WE (I<sub>A</sub>) is measured by the TIA. For electrophysiological recordings, the RE is grounded, and the voltage (V<sub>B</sub>) is recorded from a WE after amplification by the LNA. (<b>b</b>) Spectra of mean impedance magnitudes (|Z|) of electrodes of 4 and 8 μm diameter, with and without Pt-black (<span class="html-italic">n</span> = 15 each). (<b>c</b>) Representative voltage recording of extracellular APs (marked with red triangles) from 31 DIV rat neurons.</p>
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3 pages, 654 KiB  
Abstract
Laser-Induced Graphitization of Polyimide Tape as Modifiable Sensor in Anodic Stripping Voltammetry
by Laura Chirivì, Antonio Serra, Antonio Della Torre, Riccardo Di Corato, Rosaria Rinaldi and Alessandra Aloisi
Proceedings 2024, 97(1), 63; https://doi.org/10.3390/proceedings2024097063 - 21 Mar 2024
Viewed by 820
Abstract
The monitoring of toxic contaminant traces in the environment needs a simple and sensitive method, such as stripping analysis that applies a pre-concentration step to the analyte on the working electrode. The present work focuses on the realization of a two-electrode sensor made [...] Read more.
The monitoring of toxic contaminant traces in the environment needs a simple and sensitive method, such as stripping analysis that applies a pre-concentration step to the analyte on the working electrode. The present work focuses on the realization of a two-electrode sensor made by means of laser-induced graphitization of a polyimide (PI) tape. Moreover, taking advantage of the strong affinity of Bi for metal ions for detection by Anodic Stripping Voltammetry (ASV), the proposed sensor implementation involved the use of Bi2O3 nanopowder as the precursor of Bi film as eco-friendly Hg substitute. Physicochemical analyses were conducted to investigate elemental and structural differences in relation to the shifts recorded in the voltametric behavior. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Focus on direct patterning of a Kapton tape applied on a PVC substrate: the PI film is converted into a conductive material through the carbonization process operated by a 445 nm laser, in N<sub>2</sub> conditioned atmosphere. (<b>b</b>) Representative responses of pristine, bismuth- and chitosan/bismuth- modified LIG sensors in the simultaneous detection of 25 µg/L of Cd(II) and Pb(II) in KCl solution, pH 2.</p>
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3 pages, 743 KiB  
Abstract
Microfluidic Flowmeter Using a Single Hot Wire
by Rafael Ecker and Bernhard Jakoby
Proceedings 2024, 97(1), 64; https://doi.org/10.3390/proceedings2024097064 - 21 Mar 2024
Cited by 1 | Viewed by 766
Abstract
The objective of this study is the design and fabrication of a microfluidic thermal flow sensor using polymethylmethacrylate (PMMA) as a substrate. This enables the simple fabrication process of the channel structure and the sensor itself using a laser engraver/cutter machine and a [...] Read more.
The objective of this study is the design and fabrication of a microfluidic thermal flow sensor using polymethylmethacrylate (PMMA) as a substrate. This enables the simple fabrication process of the channel structure and the sensor itself using a laser engraver/cutter machine and a solvent-based bonding process. A thin platinum wire called a Wollaston wire is directly integrated into the fluidic chip and acts as the only sensor element. The combination of this sensor and customized measurement electronics enables a measurement range at flow velocities from 4 mm/s up to 400 mm/s (volume flow rate range from 10 µL/min up to 1 mL/min). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Etched Wollaston wire in the channel soldered to copper wires at each end; (<b>b</b>) fabricated flow sensor; (<b>c</b>) circuit to switch between two temperature levels.</p>
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<p>Comparison of the measured flow rate with our hot wire sensor and the measured flow rate of an external sensor (<b>a</b>) directly after calibration and (<b>b</b>) two days after calibration.</p>
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3 pages, 1348 KiB  
Abstract
Innovative Silicon-Based Sensing Strategy for the Alzheimer’s Disease Detection by Phage Display
by Paolo Calorenni, Maria Giovanna Rizzo, Laura Maria De Plano, Antonio A. Leonardi, Vincenzo Paratore, Guglielmo Guido Condorelli, Alessia Irrera, Emanuele L. Sciuto, Salvatore Oddo and Sabrina Conoci
Proceedings 2024, 97(1), 65; https://doi.org/10.3390/proceedings2024097065 - 21 Mar 2024
Viewed by 817
Abstract
An innovative biosensing strategy for the diagnosis of Alzheimer’s disease (AD) in human sera has been developed. The technology relied on a silicon flat substrate that was functionalized to perform a phage display detection of anti-amyloid beta (Aβ) antibodies, as AD markers, among [...] Read more.
An innovative biosensing strategy for the diagnosis of Alzheimer’s disease (AD) in human sera has been developed. The technology relied on a silicon flat substrate that was functionalized to perform a phage display detection of anti-amyloid beta (Aβ) antibodies, as AD markers, among the pool of IgGs of human sera. The substrate was derivatized with an interface able to bind and orient the IgGs for the detection operated by an engineered selective probe phage. The interface chemistry and its discrimination activity of healthy and AD sera have been fully characterized. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Silicon interface: (<b>a</b>) complete view; (<b>b</b>) detail of interface derivatization with (<b>I</b>) GOPS layer bound to (<b>II</b>) protein G array; (<b>c</b>) anti-Aβ IgG target; and (<b>d</b>) detection system based on (<b>I</b>) probe M13 phage and (<b>II</b>) anti-M13 HRP-conjugated antibody.</p>
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<p>(<b>a</b>) Silicon interface SEM characterization. (<b>b</b>) Sensing activity validation by ELISA test on Abs450nm signal of no serum (NS), healthy serum (HS) and AD serum (AS) sample.</p>
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3 pages, 614 KiB  
Abstract
Neural Network Approaches for Distributional Shifts in Environmental Sensors
by Tobias Sukianto, Sebastian A. Schober, Cecilia Carbonelli, Simon Mittermaier and Robert Wille
Proceedings 2024, 97(1), 66; https://doi.org/10.3390/proceedings2024097066 - 21 Mar 2024
Viewed by 683
Abstract
Harmful pollutants in the air have become a severe concern in our health-conscious society. Consequently, deploying low-cost environmental sensors and the application of machine learning algorithms to the sensor raw data are crucial to enabling an overall assessment of the air quality around [...] Read more.
Harmful pollutants in the air have become a severe concern in our health-conscious society. Consequently, deploying low-cost environmental sensors and the application of machine learning algorithms to the sensor raw data are crucial to enabling an overall assessment of the air quality around us. Due to the distributional shift between the training and operational environment induced by sensor ageing and drift processes, the algorithms that predict air quality suffer from performance degradation during the products’ lifetime. We propose a novel transformer-based model architecture inspired by the field of natural language processing, showing advantages compared to other architectures in the presence of distributional shifts. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Transformer algorithm, (<b>b</b>) transfer learning results, (<b>c</b>) architecture comparison.</p>
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3 pages, 409 KiB  
Abstract
HyperTaste Lab—A Notebook with a Machine Learning Pipeline for Chemical Sensor Arrays
by Gianmarco Gabrieli, Michal Muszynski, Matteo Manica, Joris Cadow-Gossweiler and Patrick W. Ruch
Proceedings 2024, 97(1), 67; https://doi.org/10.3390/proceedings2024097067 - 21 Mar 2024
Viewed by 723
Abstract
The cross-sensitivity of materials in low-selective sensor arrays, namely e-noses and e-tongues, results in a convoluted sensor array response, which renders traditional analytical methods for data processing ineffective. Machine learning approaches can help discover the latent information in such data, and various data [...] Read more.
The cross-sensitivity of materials in low-selective sensor arrays, namely e-noses and e-tongues, results in a convoluted sensor array response, which renders traditional analytical methods for data processing ineffective. Machine learning approaches can help discover the latent information in such data, and various data processing methods, including unsupervised and supervised techniques, have been proposed to calibrate those devices. In this study, we demonstrate HyperTaste Lab—a notebook with a machine learning pipeline for potentiometric sensor arrays. The ability of the notebook to process raw data produced by model sensor arrays comprising cross-sensitive and/or ion-selective electrodes is demonstrated for the characterization of drinking water and consumer beverages. We describe the modular data processing and machine learning framework that can be applied by sensor researchers to accommodate different signal modalities and perform various downstream tasks, such as the verification of a product’s originality, the estimation of ion concentrations, and the quantitative prediction of sensory descriptors. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Machine learning pipeline for processing sensor array data in HyperTaste Lab.</p>
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3 pages, 470 KiB  
Abstract
Modified Local Regression for Signal Resampling
by Reiner Jedermann, Yogesh Kapoor and Walter Lang
Proceedings 2024, 97(1), 68; https://doi.org/10.3390/proceedings2024097068 - 21 Mar 2024
Viewed by 604
Abstract
The resampling of sensor signals to compensate for deviating sampling intervals, clock jitter, or missing samples is still challenging. Real-time applications demand low latency and restriction of the input data window to past samples. Furthermore, most practical sensor signals are overlaid with noise. [...] Read more.
The resampling of sensor signals to compensate for deviating sampling intervals, clock jitter, or missing samples is still challenging. Real-time applications demand low latency and restriction of the input data window to past samples. Furthermore, most practical sensor signals are overlaid with noise. A new resampling method that provides a lower error than four other common interpolation methods under such conditions is introduced. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>RMSE as a function of the band-limit test signal. Reconstruction for real-time mode with only past samples known. (<b>a</b>) Clean input signal. (<b>b</b>) Input signal overlaid with −60 dB white noise.</p>
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3 pages, 415 KiB  
Abstract
Morpho-Mechanical Characterization and Removal Strategy of Pile-Ups in AFM-Based Nanolithography
by Paolo Pellegrino, Isabella Farella, Lorenzo Vincenti, Mariafrancesca Cascione, Valeria De Matteis, Fabio Quaranta and Rosaria Rinaldi
Proceedings 2024, 97(1), 69; https://doi.org/10.3390/proceedings2024097069 - 21 Mar 2024
Viewed by 781
Abstract
Nowadays, mechanical AFM-based nanolithography has emerged as the most promising nanolithography technique, allowing the patterning of nanostructures on polymer layers with a sub-nanometer resolution. In such a stimulating context, we developed the Pulse-AFM method to obtain continuous structures with a controlled depth profile, [...] Read more.
Nowadays, mechanical AFM-based nanolithography has emerged as the most promising nanolithography technique, allowing the patterning of nanostructures on polymer layers with a sub-nanometer resolution. In such a stimulating context, we developed the Pulse-AFM method to obtain continuous structures with a controlled depth profile, either constant or variable, on a polymer layer. However, those nanostructures are contoured by polymer pile-ups that limit their integration into high-tech devices. Since pile-up removal is still an open challenge, AFM force–distance curve analysis was performed to characterize the stiffness of bulges, and an effective strategy to easily remove pile-ups while preserving the shape and morphology of nanostructures was then developed. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) P-AFL-patterned nanochannels; (<b>b</b>) details of PMMA pile-ups contouring the nanochannel; (<b>c</b>–<b>f</b>) effect of the pile-up removal for increasing times.</p>
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3 pages, 443 KiB  
Abstract
Non-Stationary Gas Sensors Based on WSe2 or MoS2 Calibrated upon NH3 Exposure
by Filiberto Ricciardella, Kangho Lee, Niall McEvoy, Mark McCrystall and Georg S. Duesberg
Proceedings 2024, 97(1), 70; https://doi.org/10.3390/proceedings2024097070 - 21 Mar 2024
Viewed by 779
Abstract
We report on the calibration of gas sensors based on two transition metal dichalcogenides, molybdenum disulfide or tungsten diselenide, grown by the thermally assisted conversion of patterned Mo or W. The sensors showed non-stationary behavior when exposed to ammonia (NH3) in [...] Read more.
We report on the calibration of gas sensors based on two transition metal dichalcogenides, molybdenum disulfide or tungsten diselenide, grown by the thermally assisted conversion of patterned Mo or W. The sensors showed non-stationary behavior when exposed to ammonia (NH3) in the range of 10–100 parts per million at room temperature. This drawback hampered the calibration of the sensors. Applying the time-differential signal output (TDSO) enabled us to overcome the issue since the maxima of TDSO were uniquely and linearly correlated to the NH3 concentration. The outcomes show that TDSO is a powerful, reliable, and valid approach when gas sensors are exposed to both oxidizing and reducing atmospheres. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Real-time percentage current variation (black curve) of MoS<sub>2</sub>-sensor exposed to pulses of NH<sub>3</sub> at increasing concentrations (red rectangles). Each pulse lasts 150 s while dry N<sub>2</sub> is used as a buffer gas. Pressure and temperature were kept constant at 150 Torr and RT, respectively. Maxima of the differential curves as a function of the NH<sub>3</sub> concentration for (<b>b</b>) MoS<sub>2</sub>- and (<b>c</b>) WSe<sub>2</sub>-based sensors. The WSe<sub>2</sub>-based sensor is calibrated in a narrower range because of the scarce response at concentrations lower than 40 ppm and TDSO peaks not being well defined.</p>
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3 pages, 960 KiB  
Abstract
Optically Induced Dielectrophoresis and Machine Learning Algorithms for the Identification of the Circulating Tumor Cells
by Joanna Filippi, Francesca Corsi, Paola Casti, Gianni Antonelli, Michele D’Orazio, Francesco Capradossi, Rosamaria Capuano, Giorgia Curci, Lina Ghibelli, Arianna Mencattini and Eugenio Martinelli
Proceedings 2024, 97(1), 71; https://doi.org/10.3390/proceedings2024097071 - 21 Mar 2024
Viewed by 864
Abstract
Detecting circulating tumor cells (CTCs) is a challenge in cancer research. Their dissemination into the blood stream represents a crucial event in the formation of the metastases from the primary tumor. For this reason, targeting CTCs in human liquid biopsies is a warning [...] Read more.
Detecting circulating tumor cells (CTCs) is a challenge in cancer research. Their dissemination into the blood stream represents a crucial event in the formation of the metastases from the primary tumor. For this reason, targeting CTCs in human liquid biopsies is a warning event for cancer invasiveness, progression, and prognosis. In this regard, by means of the optically induced dielectrophoresis (ODEP) technique, we investigated the response to the electric field, at different frequencies, of human prostatic carcinoma PC3 cells, which mimic CTCs derived from prostate cancer, and human leukemia monocytic THP-1 cells, which simulate circulating monocytes. The obtained spectra of the cell motion descriptors represent the unique identification signature of each cell type. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Schematic representation of the ODEP system setup with details on the cell measurement strategy.</p>
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<p>Spectra of cumulative displacement (<b>a</b>) and maximum DEP force (<b>b</b>). Average values and standard deviations are reported. Dotted lines indicate the crossover frequency (f<sub>co</sub>). (<b>c</b>) Confusion matrix of the LDA model.</p>
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3 pages, 889 KiB  
Abstract
Low-Voltage Tri-Electrode Electrostatic Actuator Using Solid Gap-Spacing Materials
by Mehdi Allameh, Byoungyoul Park and Cyrus Shafai
Proceedings 2024, 97(1), 72; https://doi.org/10.3390/proceedings2024097072 - 21 Mar 2024
Viewed by 734
Abstract
Employing a tri-electrode electrostatic actuator revealed a significant improvement in reducing the controlling voltage. However, the primary electrode fixed voltage can be a few times higher than the conventional topology. In this work, materials with relative permittivity of εr = 4.2, 6.2 [...] Read more.
Employing a tri-electrode electrostatic actuator revealed a significant improvement in reducing the controlling voltage. However, the primary electrode fixed voltage can be a few times higher than the conventional topology. In this work, materials with relative permittivity of εr = 4.2, 6.2 and 10 were explored as the spacing material to reduce the primary voltage, and the results are compared with using air. Simulations showed that the controlling voltage can be reduced more than two times (at εr = 4.2) compared to the conventional topology while the primary electrode voltage required is lower than for air spacing and not more than two times larger than the conventional. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Conventional parallel plate electrostatic actuator topology with V<sub>C</sub> varying controlling voltage and (<b>b</b>) tri-electrode electrostatic actuator topology with fixed V<sub>P</sub> and varying V<sub>I</sub> controlling voltage.</p>
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<p>Displacement vs. V<sub>P</sub> for (<b>a</b>) unipolar, (<b>b</b>) bipolar and (<b>c</b>) max displacement at D<sub>2</sub> = 1.67D<sub>1</sub> and W<sub>S</sub> = 3W<sub>E</sub>.</p>
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3 pages, 1299 KiB  
Abstract
MEMS Valves with Molecular Flow Regime Orifices
by Alvise Bagolini, Raffaele Correale, Antonino Picciotto and Leandro Lorenzelli
Proceedings 2024, 97(1), 73; https://doi.org/10.3390/proceedings2024097073 - 21 Mar 2024
Viewed by 1346
Abstract
In this work, a novel, silicon-based micro-electromechanical valve that includes a submicrometric orifice and can operate at pressure gradients of 1 bar was used to enhance sampling for gas chromatograph mass spectrometers. The valve is based on a membrane-in-membrane design and operates with [...] Read more.
In this work, a novel, silicon-based micro-electromechanical valve that includes a submicrometric orifice and can operate at pressure gradients of 1 bar was used to enhance sampling for gas chromatograph mass spectrometers. The valve is based on a membrane-in-membrane design and operates with thermomechanical actuation. It includes a pin to enable self-cleaning. Prototypes were fabricated and preliminary testing was performed. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Membrane and bridge valve section.</p>
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<p>SEM image of the fabricated membrane with a bridge valve.</p>
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3 pages, 693 KiB  
Abstract
Ecoresorbable Radio-Frequency Platform for Humidity and Temperature Sensing
by James Bourely, Jaemin Kim, Xavier Aeby, Gilberto Siqueira, Gustav Nyström, Oleksandr Vorobyov, Christian Beyer, David Schmid and Danick Briand
Proceedings 2024, 97(1), 74; https://doi.org/10.3390/proceedings2024097074 - 22 Mar 2024
Viewed by 908
Abstract
Aiming to reduce electronic waste in sensing applications, we report on an eco-friendly printed microstrip line to sense relative humidity (RH) and temperature. The device is made of zinc resonators on paper used as transducers, which are coated with beeswax as an encapsulant, [...] Read more.
Aiming to reduce electronic waste in sensing applications, we report on an eco-friendly printed microstrip line to sense relative humidity (RH) and temperature. The device is made of zinc resonators on paper used as transducers, which are coated with beeswax as an encapsulant, and uses konjac as a humidity sensitive coating. The multi-resonating structure, operating in the S-band, shows reproducible temperature and humidity sensing from 15 °C to 35 °C and 30% to 70% RH with sensitivities up to 1.9 MHz/°C and 2.0 MHz/%RH, respectively. This combination of transducing and sensing materials is promising for the realization of disposable environmental sensors. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>S12 signal of the ecoresorbable microstrip platform (noise at 3 GHz due to climatic chamber operation. (<b>a</b>) S12 temperature response of the multi-resonating structure cycling from 15 °C to 35 °C and down, with device schematic; (<b>b</b>) S12 relative humidity response of the multi-resonating structure cycling from 30% RH to 70% RH and down, with device schematic.</p>
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3 pages, 359 KiB  
Abstract
Colour Catcher®: A Low-Cost Support for Developing Colorimetric Sensors for PFOA Detection
by Fabrizio Caroleo, Francesco Pizzoli, Gabriele Magna, Valerio Allegra, Sara Nardis, Corrado Di Natale, Emma Gallo and Roberto Paolesse
Proceedings 2024, 97(1), 75; https://doi.org/10.3390/proceedings2024097075 - 22 Mar 2024
Viewed by 814
Abstract
In this work, we report the development of an optical sensor based on the colour variation of a silicon corrole upon interaction with specific emerging pollutants belonging to the PFAS family in water samples. The solid support on which the receptor is deposited [...] Read more.
In this work, we report the development of an optical sensor based on the colour variation of a silicon corrole upon interaction with specific emerging pollutants belonging to the PFAS family in water samples. The solid support on which the receptor is deposited consists of Colour Catcher® paper strips. An optical portable platform composed of low-cost electronic devices, such as an LED as a light source and a webcam as a detector, was developed to digitalize the strip colour changes during the measurements. This instrument is able to perform in situ analysis of water sources to determine the perfluoroalkyl substance (PFASs) content. Data analysis using the hue parameter allowed for the calculation, with great sensitivity, of the PFOA concentration depending on colour changes. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) The PT-like instrument setup used for optical measurements (webcam, LED, and homemade holder). (<b>b</b>) The optical responses of the <span class="html-italic">CC</span>-SiTTC(OH), ordered from left to right: distilled water, PFOA (0.1 mM), and PFOA (1 mM).</p>
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3 pages, 866 KiB  
Abstract
Development of an Indirect Photoacoustic Sensor Concept for Highly Accurate Low-ppm Gas Detection
by Ananya Srivastava, Achim Bittner and Alfons Dehé
Proceedings 2024, 97(1), 76; https://doi.org/10.3390/proceedings2024097076 - 22 Mar 2024
Viewed by 711
Abstract
Indirect photoacoustic sensing (PAS) offers accurate low-ppm gas measurements, with an inverse relation of the obtained signal to the measured gas concentration. The gas is sealed in transistor outline (TO) housing using a new method. This provides a relatively a very small volume [...] Read more.
Indirect photoacoustic sensing (PAS) offers accurate low-ppm gas measurements, with an inverse relation of the obtained signal to the measured gas concentration. The gas is sealed in transistor outline (TO) housing using a new method. This provides a relatively a very small volume for the reference gas signal. The gas sensing system features a black body source, highly reflective measurement volumes and TO housing sealed with gas and multiple sensors. CO2 is used for testing and characterizing the sensor sealing and working concepts in the measurement range 0–2000 ppm, with other gases, such as CO, methane, etc., planned to be tested. A PAS signal corresponding to a 4 ppm minimum gas concentration is measured. Allan Deviation measurements provide a theoretical limit of detection of 3.14 ppm, with the integration time of 5.2 × 103 s. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sealed TO package in a sensor setup, (<b>b</b>) placement of detector elements on a TO housing base, (<b>c</b>) Allan Deviation plot with an integration time of 5.2 × 10<sup>3</sup> s, and (<b>d</b>) PAS signal output between 0 and 2000 ppm fits the negative exponential trend with an R2 score of 0.9992.</p>
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3 pages, 822 KiB  
Abstract
Optical Interference Analysis of ZIF-8 Films for Chemical Vapor Detection
by Anna Estany-Macià, Sachin Navale, Ignasi Fort-Grandas, Nirav Joshi, Albert Romano-Rodríguez and Mauricio Moreno-Sereno
Proceedings 2024, 97(1), 77; https://doi.org/10.3390/proceedings2024097077 - 22 Mar 2024
Viewed by 806
Abstract
Metal–organic frameworks (MOFs) are materials that feature a large surface area with permanent porosity, which is an attractive property for chemical and gas sensing, making them a good candidate for sensor fabrication. In this paper, we present a sensor that employs zeolitic-imidazolate-based MOFs [...] Read more.
Metal–organic frameworks (MOFs) are materials that feature a large surface area with permanent porosity, which is an attractive property for chemical and gas sensing, making them a good candidate for sensor fabrication. In this paper, we present a sensor that employs zeolitic-imidazolate-based MOFs (ZIF-8) to detect ethanol vapors via refractive index-dependent optical interference. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Interference fringes’ red shift (arrow) for increasing ethanol/water concentrations (volume percentage in water). (<b>b</b>) Comparison of the monitored dynamic interference peak shift in an 8 min time frame. The figure inset shows the interference peak shift at t = 5 min for the different concentrations.</p>
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2 pages, 499 KiB  
Abstract
Comparative Assessment of Gold Nanoparticle–Antibody Conjugates with Two Differently Shaped Particles for Multimodal Colorimetric Lateral Flow Assay
by Vinayak Sharma, Bilal Javed and Furong Tian
Proceedings 2024, 97(1), 78; https://doi.org/10.3390/proceedings2024097078 - 21 Mar 2024
Viewed by 891
Abstract
Novel detection strategies that exploit the unique properties of gold nanoparticles (AuNPs) hold great potential for the advancement of point-of-care (POC) diagnostics, such as lateral flow and dipstick immunoassay [...] Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Gold nanoparticle based lateral flow assay for the detection of mycotoxins in food samples.</p>
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3 pages, 513 KiB  
Abstract
Efficient Methane Monitoring with Low-Cost Chemical Sensors and Machine Learning
by Guillem Domènech-Gil, Nguyen Thanh Duc, J. Jacob Wikner, Jens Eriksson, Donatella Puglisi and David Bastviken
Proceedings 2024, 97(1), 79; https://doi.org/10.3390/proceedings2024097079 - 22 Mar 2024
Viewed by 1090
Abstract
We present a method to monitor methane at atmospheric concentrations with errors in the order of tens of parts per billion. We use machine learning techniques and periodic calibrations with reference equipment to quantify methane from the readings of an electronic nose. The [...] Read more.
We present a method to monitor methane at atmospheric concentrations with errors in the order of tens of parts per billion. We use machine learning techniques and periodic calibrations with reference equipment to quantify methane from the readings of an electronic nose. The results obtained demonstrate versatile and robust solution that outputs adequate concentrations in a variety of different cases studied, including indoor and outdoor environments with emissions arising from natural or anthropogenic sources. Our strategy opens the path to a wide-spread use of low-cost sensor system networks for greenhouse gas monitoring. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Results from partial least squares regression model trained and tested with data acquired outdoors in a private garden in a suburban area close to a forest during autumn in Sweden, and (<b>b</b>) temporal evolution of the test data compared to data reported by means of reference equipment.</p>
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3 pages, 709 KiB  
Abstract
Optical Detection System of Heavy Metals Based on Microplasma Excitation
by Tomasz Matusiak, Arkadiusz Dąbrowski and Leszek Golonka
Proceedings 2024, 97(1), 80; https://doi.org/10.3390/proceedings2024097080 - 22 Mar 2024
Viewed by 652
Abstract
This paper presents the outcome of a study on the reliability of sensors utilizing microplasma to analyze the amount of selected elements in aqueous solutions. Increasing environmental pollution poses new challenges for protective services through real-time monitoring. The aim of this work was [...] Read more.
This paper presents the outcome of a study on the reliability of sensors utilizing microplasma to analyze the amount of selected elements in aqueous solutions. Increasing environmental pollution poses new challenges for protective services through real-time monitoring. The aim of this work was to develop miniature plasma generators for the excitation and then analysis of aqueous solutions. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Optical system: (<b>a</b>) block diagram and (<b>b</b>) front view of the device.</p>
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3 pages, 430 KiB  
Abstract
Low-Cost, Low-Footprint X-ray Sensors Based on Colloidal Quantum Dots
by Marco Ruggieri, Elisabetta Colantoni, Eleonora Marconi, Andrea Fabbri, Paolo Branchini, Andrea De Iacovo, Lorenzo Colace and Luca Tortora
Proceedings 2024, 97(1), 81; https://doi.org/10.3390/proceedings2024097081 - 22 Mar 2024
Viewed by 704
Abstract
Development of novel and inexpensive X-ray detectors is of key importance for numerous applications, such as dosimetry in nuclear and medical facilities, diagnostics in cultural heritage, and homeland security. Solution-processed materials are being investigated as novel x-ray sensing materials, with constant improvements that [...] Read more.
Development of novel and inexpensive X-ray detectors is of key importance for numerous applications, such as dosimetry in nuclear and medical facilities, diagnostics in cultural heritage, and homeland security. Solution-processed materials are being investigated as novel x-ray sensing materials, with constant improvements that are rapidly approaching commercial standards. Here, we demonstrate a detector based on PbS colloidal quantum dots (QD) fabricated in air with simple drop-casting techniques on a Si substrate with pre-patterned Au interdigitated electrodes. The device showed good linearity in the tested dose range and a maximum sensitivity value of 2370 µC Gy−1 cm−1, which is higher than typically reported values for commercial a-Se and poly-CZT detectors. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) SEM picture of the final QDs layer. The scale bar represents 100 um. (<b>b</b>) Photogenerated current during X-ray illumination at different dose rates. (<b>c</b>) Dose–charge line; the inset is a sketch of the device.</p>
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3 pages, 570 KiB  
Abstract
Gas Sensing Capabilities of CuInS2/ZnO Core–Shell Quantum Dot
by Antonio Orlando, Guglielmo Trentini, Pietro Tosato, Soufiane Krik, Matteo Valt, Andrea Gaiardo and Luisa Petti
Proceedings 2024, 97(1), 82; https://doi.org/10.3390/proceedings2024097082 - 22 Mar 2024
Viewed by 1686
Abstract
Chemoresistive gas sensors are surely one of the easiest and most commonly used methods to monitor the presence of different polluting gases. Nevertheless, there are still several challenges to overcome in order for these sensors to be widely used. In particular, the selectivity [...] Read more.
Chemoresistive gas sensors are surely one of the easiest and most commonly used methods to monitor the presence of different polluting gases. Nevertheless, there are still several challenges to overcome in order for these sensors to be widely used. In particular, the selectivity and sensitivity of chemoresistive gas sensors towards a wide range of analytes need to be improved. This is why new sensing materials capable of detecting different analytes in a sensitive and selective manner are being investigated. In this regard, this work is focused on the development and characterization of a new sensing material based on the quantum dot (QD) core–shell of CuInS2/ZnO (CIS-ZO). Optimized films of the QD core–shell of CIS-ZO were integrated into a micro-electromechanical system (MEMS)-based gas sensor platform, showing excellent sensing performance versus different gases and especially towards ethanol (C2H5OH). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) SEM image on CIS-ZO powder. (<b>b</b>) Response of CIS-ZO–based gas sensors calculated as <math display="inline"><semantics> <mrow> <mi mathvariant="italic">Response</mi> <mo>=</mo> <mo stretchy="false">(</mo> <mfrac> <mrow> <msub> <mi>R</mi> <mn>0</mn> </msub> </mrow> <mrow> <msub> <mi>R</mi> <mi>g</mi> </msub> </mrow> </mfrac> <mo stretchy="false">)</mo> <mo>−</mo> <mn>1</mn> </mrow> </semantics></math> with different concentrations of ethanol (5, 10, 15, and 20 ppm) at 0 RH% and 400 °C.</p>
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3 pages, 732 KiB  
Abstract
Multispectral Integrated System with Discrete Light Sources for Material Classification
by Anju Manakkakudy Kumaran, Federica Mitri, Emanuele Maiorana, Andrea De Iacovo and Lorenzo Colace
Proceedings 2024, 97(1), 83; https://doi.org/10.3390/proceedings2024097083 - 22 Mar 2024
Viewed by 670
Abstract
This paper presents a compact and portable classification system that utilizes a discrete light source method combining near-infrared (NIR) reflectance spectroscopy with a Support Vector Machine (SVM) to identify and classify waste materials. The system operates by sequentially activating 10 light-emitting diodes (LEDs) [...] Read more.
This paper presents a compact and portable classification system that utilizes a discrete light source method combining near-infrared (NIR) reflectance spectroscopy with a Support Vector Machine (SVM) to identify and classify waste materials. The system operates by sequentially activating 10 light-emitting diodes (LEDs) of different wavelengths and measuring their reflectance using a photodetector. This system incorporates a DAQ card using the LabView program for data acquisition and system control. The proposed model achieved an identification accuracy of up to 98% using different input features and training batches. This efficient and cost-effective solution provides an innovative approach to waste management. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Confusion matrix of experimental model.</p>
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3 pages, 567 KiB  
Abstract
Integration of Printed PVDF-Based Force Sensors into a Printed Circuit Board Stack
by Sebastian Lang, Wolfgang Hilber, Herbert Enser and Bernhard Jakoby
Proceedings 2024, 97(1), 84; https://doi.org/10.3390/proceedings2024097084 - 22 Mar 2024
Cited by 1 | Viewed by 715
Abstract
This work reports on the fabrication and testing of force sensors integrated directly into a printed circuit board (PCB). For this purpose, a layer of poly(vinylidene fluoride-trifluoroethylen) (P(VDF-TrFE)) is printed onto two pieces of two two-layer PCBs, which are then stacked together to [...] Read more.
This work reports on the fabrication and testing of force sensors integrated directly into a printed circuit board (PCB). For this purpose, a layer of poly(vinylidene fluoride-trifluoroethylen) (P(VDF-TrFE)) is printed onto two pieces of two two-layer PCBs, which are then stacked together to create a four-layer PCB. The devised and fabricated sensor with the described measurement setup features a nearly linear measurement characteristic in the range between 0.3 and 1.2 N and a detection limit of approximately 10 mN. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Evaluation and measurement setup: (<b>a</b>) cross-section of the PCB-P(VDF-TrFE) sensor design; (<b>b</b>) picture of a finished sample; (<b>c</b>) actual picture of the setup and the fabricated sensor stack.</p>
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<p>Measurement data using an early sample: (<b>a</b>) sensor signal and force applied on the sensor during one measurement; (<b>b</b>) force-charge curve created using the data shown in (<b>a</b>) (averaged steps).</p>
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3 pages, 1014 KiB  
Abstract
Comparison of Bacterial Cellulose Deformation Sensors Based on Choline Malonate and EMIM-BF4 Ionic Liquids
by Santhosh Kurukunda, Salvatore Cerruto, Salvatore Graziani, Carlo Trigona, Giovanna Di Pasquale, Antonino Pollicino, Kaija Põhako-Esko and Alvo Aabloo
Proceedings 2024, 97(1), 85; https://doi.org/10.3390/proceedings2024097085 - 25 Mar 2024
Cited by 1 | Viewed by 670
Abstract
Sensors and transducers are essential components of measurement systems. The achievement of a sustainable economy requires environmentally friendly solutions and processes in order to develop sensors and transducers that are capable of being recycled, disposed, and, degraded without releasing pollutants into the environment. [...] Read more.
Sensors and transducers are essential components of measurement systems. The achievement of a sustainable economy requires environmentally friendly solutions and processes in order to develop sensors and transducers that are capable of being recycled, disposed, and, degraded without releasing pollutants into the environment. In this context, we propose a comparative analysis of deformation sensors based on bacterial cellulose impregnated with choline malonate and EMIM-BF4 ionic liquids (ILs). Their features and performance will be compared while also considering the green aspect of the proposed sensors. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The time domain graphs of the deformation and the output voltages for the BC-based composites when the shaker is driven at 400 mV and 10 Hz. (<b>a</b>) EMIM-BF<sub>4</sub>; (<b>b</b>) CH MAL.</p>
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<p>Characterization of RMS deformation for BC-based composites: (<b>a</b>) EMIM-BF<sub>4</sub> and (<b>b</b>) CH MAL.</p>
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3 pages, 915 KiB  
Abstract
Energy-Autonomous Tread Wear Wireless Sensor System for Tire Monitoring
by Robert A. Lockhart, Pattanaphong Janphuang, Francisco Molina-Lopez, Andres Vasquez Quintero, Gabriele Tasselli, Patrick Favre, Cyril Botteron, Pierre-André Farine and Danick Briand
Proceedings 2024, 97(1), 86; https://doi.org/10.3390/proceedings2024097086 - 25 Mar 2024
Viewed by 802
Abstract
Technologies are going through a digitalization process. Convergence of 2D printing with 3D printing is leading to 3D structural electronics. Implementation during their fabrication of sensing components in objects using printing would make these 3D-printed objects smarter. At the same time, sensors production [...] Read more.
Technologies are going through a digitalization process. Convergence of 2D printing with 3D printing is leading to 3D structural electronics. Implementation during their fabrication of sensing components in objects using printing would make these 3D-printed objects smarter. At the same time, sensors production would benefit, thanks to their digital manufacturing in the 3rd dimension, from customization, self-packaging, and better integration into products. We are proposing to apply digital printing of functional and structural inks addressing the challenges of the whole processing in a single tool. Developments in the field of smart wearables are presented. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The full system architecture of the tread wear wireless sensor node and position in the tire.</p>
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<p>Prototypes of the different components developed and evaluated, from left to right: wear sensors, packaged PVDF vibration and PZT compression energy harvesters, 434 MHz antenna.</p>
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3 pages, 454 KiB  
Abstract
Machine Learning for Enhanced Operation of Underperforming Sensors in Humid Conditions
by Guillem Domènech-Gil and Donatella Puglisi
Proceedings 2024, 97(1), 87; https://doi.org/10.3390/proceedings2024097087 - 25 Mar 2024
Viewed by 735
Abstract
Using a single sensor as a virtual electronic nose, we demonstrate the possibility of obtaining good results with underperforming sensors that, at first glance, would be discarded. For this aim, we characterized chemical gas sensors with low repeatability and random drift towards both [...] Read more.
Using a single sensor as a virtual electronic nose, we demonstrate the possibility of obtaining good results with underperforming sensors that, at first glance, would be discarded. For this aim, we characterized chemical gas sensors with low repeatability and random drift towards both dangerous and innocuous volatile organic compounds (VOCs) under different levels of relative humidity. Our results show classification accuracies higher than 90% when differentiating harmful from harmless VOCs and coefficients of determination, R2, higher than 80% when determining their concentration in the parts per billion to parts per million range. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Support vector machine classification results for formaldehyde (0.25 to 1.5 ppm), acetic acid (0.25 to 15 ppm), and synthetic air under relative humidity ranging from 20 to 50%; (<b>b</b>) principal component regression quantification results for formaldehyde under relative humidity ranging from 20 to 50%.</p>
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3 pages, 333 KiB  
Abstract
Investigation on the Development, Stabilization and Impact of Thermally Induced Oxygen Vacancies on the Chemoresistive Sensing Properties of MOX
by Andrea Gaiardo, Lia Vanzetti, Andrea Pedrielli, Matteo Valt and Soufiane Krik
Proceedings 2024, 97(1), 88; https://doi.org/10.3390/proceedings2024097088 - 25 Mar 2024
Viewed by 616
Abstract
Gas sensors based on metal oxide (MOX) semiconductors doped with oxygen vacancies (VO) have many advantages over stoichiometric MOX, such as higher surface reactivity and lower operating temperature. However, preparing reduced MOX is challenging, and the impact of different VO types and concentration [...] Read more.
Gas sensors based on metal oxide (MOX) semiconductors doped with oxygen vacancies (VO) have many advantages over stoichiometric MOX, such as higher surface reactivity and lower operating temperature. However, preparing reduced MOX is challenging, and the impact of different VO types and concentration on sensing performance is still unclear. In this work, we developed a tailored reducing thermal treatment for creating controlled VO in MOX. The effect of the length and temperature of the treatment was investigated using several characterization methods. Finally, measurements were performed to evaluate the impact of VO type and concentration on reduced MOX sensing performance. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sensing responses, at a working temperature of 70 °C, of (<b>a</b>) stoichiometric and reduced (R) WO<sub>3</sub> powders vs. NH<sub>3</sub> and (<b>b</b>) stoichiometric and reduced (R) SnO<sub>2</sub> powders vs. NO<sub>2</sub>.</p>
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3 pages, 2415 KiB  
Abstract
Engineered Porous Metal Structures via Electroplating in Two-Photon Polymerized Molds
by Ana Luiza Silveira Fiates, Sina Reede, Franziska Bollhorst, Lukas Hansen, Klaus Froehner and Michael J. Vellekoop
Proceedings 2024, 97(1), 89; https://doi.org/10.3390/proceedings2024097089 - 25 Mar 2024
Viewed by 686
Abstract
We report the realization of metallic 3D microstructures, electroplated in two-photon polymerized molds. These molds are typically 150 × 150 × 30 µm3 in size and the smallest feature size is about 1 µm. After the electroplating process, the mold is removed [...] Read more.
We report the realization of metallic 3D microstructures, electroplated in two-photon polymerized molds. These molds are typically 150 × 150 × 30 µm3 in size and the smallest feature size is about 1 µm. After the electroplating process, the mold is removed by means of CF4/O2 etching (1 h). The vertical electroplating growth is about two times higher than the horizontal growth, which creates voids. A new design to prevent voids was tested where the pores were arranged at a 35° angle to the chip surface. The remaining structures consisted of a copper base with a palladium finish, or of pure palladium. They were analyzed through SEM and were shown to be a good reproduction of the mold design, resulting in metallic porous structures with a specific surface area of about 6 mm2/mm2. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Borosilicate glass chip: Cr/Au metallic layers, and OrmoComp as a passivation layer.</p>
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<p>The SEM images (<b>a</b>,<b>c</b>) show Cu/Pd and Pd-electroplated structures, respectively, after the removal of the polymer mold. (<b>b</b>) A FIB cut realized in the structure in (<b>a</b>) after the electroplating process with Pd (white layer). (<b>d</b>) A FIB cut realized in (<b>c</b>).</p>
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3 pages, 348 KiB  
Abstract
Influence of Ultrasonic Bath on Mold-Assisted Electrodeposition of Gold Microelectrode Arrays
by Neeraj Yadav, Flavio Giacomozzi, Alessandro Cian, Damiano Giubertoni and Leandro Lorenzelli
Proceedings 2024, 97(1), 90; https://doi.org/10.3390/proceedings2024097090 - 25 Mar 2024
Viewed by 655
Abstract
This study investigates the potential of ultrasonic baths to enhance mold-assisted electrodeposition for fabricating three-dimensional (3D) microelectrode arrays (MEAs) with improved quality and reliability. Focusing on gold microstructures, commonly employed in 3D MEAs due to their biocompatibility and electrical conductivity, we explore how [...] Read more.
This study investigates the potential of ultrasonic baths to enhance mold-assisted electrodeposition for fabricating three-dimensional (3D) microelectrode arrays (MEAs) with improved quality and reliability. Focusing on gold microstructures, commonly employed in 3D MEAs due to their biocompatibility and electrical conductivity, we explore how ultrasonic vibrations impact the electrodeposition process. Through the formation of microscopic bubbles and reactive sites, ultrasonic baths accelerate deposition, offering potential benefits such as increased deposition rates, uniformity, and cost-effectiveness. Our experimental findings demonstrate significant improvements in deposition rate and uniformity, highlighting the potential of ultrasonic baths to advance the fabrication of 3D MEAs for various biomedical applications. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Bar graph representing gold electrodeposition rate for various tests with percentage standard deviation for the thickness of microstructures as error bars. (<b>b</b>) Bar graph representing mean adhesion strength of the electrodeposited microstructures with standard deviation as error bars.</p>
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3 pages, 355 KiB  
Abstract
From Gas Sensors to Artificial Neural Networks: A New Precision Farming Approach for Crop Coefficient Determination
by Francesco Tralli, Barbara Fabbri, Matteo Valt, Alessandro Drago and Vincenzo Guidi
Proceedings 2024, 97(1), 91; https://doi.org/10.3390/proceedings2024097091 - 25 Mar 2024
Viewed by 665
Abstract
This study aims to utilize gaseous emissions from cultivation to predict the crop coefficient, an indirect measure of plant water stress. An array of chemiresistive gas sensors was used to collect the data, which were then processed by a simple artificial neural network [...] Read more.
This study aims to utilize gaseous emissions from cultivation to predict the crop coefficient, an indirect measure of plant water stress. An array of chemiresistive gas sensors was used to collect the data, which were then processed by a simple artificial neural network algorithm. The results highlighted that the gas emissions from tomato crops can be used as a reliable indicator for determining the crop coefficient, allowing for more efficient and effective irrigation management. This research offers a potential solution to the growing issue of water scarcity in agriculture by providing a cost-effective and practical method for monitoring crop water status. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Test phase of the neural network (last two entries of the legend).</p>
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3 pages, 501 KiB  
Abstract
From a Memory Sensor to a Sensor without Memory: Trigger Mechanism
by Giada Marchi, Viviana Mulloni, Andrea Gaiardo, Matteo Valt, Massimo Donelli and Leandro Lorenzelli
Proceedings 2024, 97(1), 92; https://doi.org/10.3390/proceedings2024097092 - 25 Mar 2024
Viewed by 672
Abstract
In the context of environmental monitoring, maximum levels of nitrogen dioxide (NO2) are internationally regulated since long exposure impacts health. In general, very low concentrations in the sub-ppm range are found for NO2, which implies the need for very [...] Read more.
In the context of environmental monitoring, maximum levels of nitrogen dioxide (NO2) are internationally regulated since long exposure impacts health. In general, very low concentrations in the sub-ppm range are found for NO2, which implies the need for very sensitive detection systems. Here, we demonstrate a chipless RFID sensing cell with both threshold detection and re-usability capabilities. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>A non-volatile NO<sub>2</sub> chipless memory sensor turned into a reusable sensor. (<b>a</b>) Measurement setup; (<b>b</b>) response and recovery trend for the non-volatile memory sensor; (<b>c</b>) response and recovery trend when the sensor is turned into a sensor without memory using a UV LED source.</p>
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3 pages, 476 KiB  
Abstract
Humidity Impact on Thermal Conductivity Sensors
by Sophie Emperhoff, Matthias Eberl, Tim Dwertmann and Jürgen Wöllenstein
Proceedings 2024, 97(1), 93; https://doi.org/10.3390/proceedings2024097093 - 25 Mar 2024
Cited by 2 | Viewed by 785
Abstract
The thermal conductivity of humid air at different saturation levels has been investigated at 70 °C. A MEMS-based thermal conductivity sensor was calibrated and used to measure the thermal conductivity of humid air. The obtained results were compared to different equations for calculating [...] Read more.
The thermal conductivity of humid air at different saturation levels has been investigated at 70 °C. A MEMS-based thermal conductivity sensor was calibrated and used to measure the thermal conductivity of humid air. The obtained results were compared to different equations for calculating the thermal conductivity of gas mixtures, in this case, dry air and water vapor. The selected equations predict contradicting behaviors of humid air at different temperatures and saturation levels. A semi-empirical equation by Melling et al. for the temperature range of 100 °C to 200 °C has shown the best agreement with the experimental data. We intend to study the temperature range from 0 to 100 °C in more detail and plan to adapt the interpolation to fit this temperature range. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Calibration of the thermal conductivity sensor based on a measurement of different concentrations of hydrogen in synthetic air at 70 °C using an equation by Mason and Saxena to calculate the thermal conductivity of the used gas mixture [<a href="#B5-proceedings-97-00093" class="html-bibr">5</a>]. (<b>b</b>) The measured signal is converted to a thermal conductivity value for different relative humidities at 70 °C and compared to calculated values with equations from Tsilingiris, Udoetok and Melling et al. [<a href="#B1-proceedings-97-00093" class="html-bibr">1</a>,<a href="#B2-proceedings-97-00093" class="html-bibr">2</a>,<a href="#B3-proceedings-97-00093" class="html-bibr">3</a>].</p>
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3 pages, 1347 KiB  
Abstract
Multi-Micro-Sensor Platform for Monitoring Toxic Algal Blooms and Pollution in Coastal Marine Waters: Transducer Integration in Micro-Technology
by Pierre Groc, Guy Cathébras, Vincent Kerzerho, Adrian Laborde, Fabien Soulier, Pierre Temple-Boyer, Jérôme Launay and Serge Bernard
Proceedings 2024, 97(1), 94; https://doi.org/10.3390/proceedings2024097094 - 25 Mar 2024
Viewed by 665
Abstract
This work presents the design of a multisensor platform for the in situ monitoring of physico-chemical parameters in seawater. As a result, we propose an 8.5 × 8.5 mm2 silicon chip that integrates a MOSFET and two ISFETs (Metal Oxide Semiconductor and [...] Read more.
This work presents the design of a multisensor platform for the in situ monitoring of physico-chemical parameters in seawater. As a result, we propose an 8.5 × 8.5 mm2 silicon chip that integrates a MOSFET and two ISFETs (Metal Oxide Semiconductor and Ion-Sensitive Field-Effect Transistor) and four microelectrodes (two Ag electrodes and two Pt electrodes). The device allows measurements to be taken in liquid phase of temperature, pH, nitrate concentrations and conductivity. These silicon transducers could be integrated with conditioning electronics to achieve an autonomous environmental sensor device. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Crab-chip with (A) ISFETs, (B) MOSFET, and (C) electrodes.</p>
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<p>Temperature measurement with a MOSFET.</p>
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<p>pH measurement with an ISFET.</p>
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<p>Measurement of nitrate concentration.</p>
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3 pages, 757 KiB  
Abstract
Inductive Sensor with Contactless Interrogation for Conductive Target Detection
by Marco Zini, Marco Baù, Alessandro Nastro, Marco Ferrari and Vittorio Ferrari
Proceedings 2024, 97(1), 95; https://doi.org/10.3390/proceedings2024097095 - 25 Mar 2024
Cited by 1 | Viewed by 636
Abstract
The contactless interrogation of an inductive sensor (IS) for conductive target detection is presented. The IS comprises a solenoidal coil of copper wire wrapped around a plastic pipe which is connected to a series capacitor to form an LC circuit resonating at the [...] Read more.
The contactless interrogation of an inductive sensor (IS) for conductive target detection is presented. The IS comprises a solenoidal coil of copper wire wrapped around a plastic pipe which is connected to a series capacitor to form an LC circuit resonating at the frequency fr. A conductive target placed at different positions inside the pipe modifies the inductance of the coil, and in turn, fr. An external interrogation coil (IC) electromagnetically coupled to the IS allows the fr to be read through a contactless interrogation technique. The approach has been tested by varying both the position of a lead sphere adopted as the target and the interrogation distance d between the IS and IC. Without the sphere, the LC circuit has fr0 = 2.51 MHz. The target sphere has been detected at up to |x| = 7.5 mm from the center of the IS coil with a frequency variation ∆ fr = 180 kHz at x = 0. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Block diagram of the readout system based on impedance measurement. <span class="html-italic">R</span><sub>1</sub> = 15.2 Ω, <span class="html-italic">L</span><sub>1</sub> = 36.4 µH, <span class="html-italic">R</span><sub>2</sub> = 72 Ω, <span class="html-italic">L</span><sub>2</sub> = 144 µH without the sphere; (<b>b</b>) developed setup used to test the proposed IS for conductive particle detection.</p>
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<p>(<b>a</b>) Measured <span class="html-italic">R</span>(<span class="html-italic">f</span>) with the conductive sphere placed at <span class="html-italic">x</span><sub>1</sub> = −0.5 mm and <span class="html-italic">x</span><sub>2</sub> = −7.5 mm for different values of <span class="html-italic">d</span>; (<b>b</b>) measured <span class="html-italic">f</span><sub>r</sub> as a function of <span class="html-italic">x</span> for different values of <span class="html-italic">d</span>.</p>
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3 pages, 651 KiB  
Abstract
Housing Molecularly Imprinted Polymer Nanoparticles in Polyvinylpyrrolidone/Multiwall Carbon Nanotube Nanofibers to Detect Chiral Terpene Vapors
by Fabricio N. Molinari, Fabrizio De Cesare and Antonella Macagnano
Proceedings 2024, 97(1), 96; https://doi.org/10.3390/proceedings2024097096 - 26 Mar 2024
Cited by 1 | Viewed by 831
Abstract
This study proposes a two-step process to design a chiral sensor combining MIP (molecularly imprinted polymer) and electrospinning technologies. First, stereoselective S(-)-limonene molecularly imprinted polymer nanoparticles (MINPs) were fabricated and dispersed into polyvinylpyrrolidone–carbon nanotube (PVP-MWCNT) conductive nanofibers to cover resistive interdigitated electrodes (IDEs). [...] Read more.
This study proposes a two-step process to design a chiral sensor combining MIP (molecularly imprinted polymer) and electrospinning technologies. First, stereoselective S(-)-limonene molecularly imprinted polymer nanoparticles (MINPs) were fabricated and dispersed into polyvinylpyrrolidone–carbon nanotube (PVP-MWCNT) conductive nanofibers to cover resistive interdigitated electrodes (IDEs). The electrical and sensing performances of the resulting sensor confirmed its capacity to discriminate and quantify the two limonene enantiomers. The sensor’s response to terpene gases appeared completely reversible, probably due to the peculiarity of the nanostructure. The sensor characteristics were influenced by the polymer matrix’s composition ratio, the cavity shape and the interfaces with carbon nanotubes. The morphological properties of the nanofibers were investigated by microscopy (optical, SEM, TEM and AFM). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) TEM image of a cluster of NIMPs (bar: 100 nm) and (<b>B</b>) MINPs (bar: 100 nm).</p>
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<p>(<b>A</b>) MINP-ESNF sensor response when exposed to 15 ppm of vapors of the enantiomers of limonene (S and R_), linalool and alpha pinene (<b>B</b>) MINP-ESNF and NINP-ESNF sensor response when exposed to 15 ppm of vapors of S limonene.</p>
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3 pages, 732 KiB  
Abstract
Low-Cost Sensors Based on Nanoparticles of Tin Dioxide Decorated with Graphene Used to Detect Ultra-Low NO2 Concentrations at Room Temperature
by Isabel Sayago, Carlos Sánchez-Vicente and José Pedro Santos
Proceedings 2024, 97(1), 97; https://doi.org/10.3390/proceedings2024097097 - 25 Mar 2024
Viewed by 722
Abstract
Chemical nanosensors based on nanoparticles (NPs) of pure tin dioxide (SnO2) and graphene-decorated tin dioxide were developed and characterized for the detection of pollutant gases. Sensitive layers were prepared by a drop casting method. The photoactivation of the sensors allows for [...] Read more.
Chemical nanosensors based on nanoparticles (NPs) of pure tin dioxide (SnO2) and graphene-decorated tin dioxide were developed and characterized for the detection of pollutant gases. Sensitive layers were prepared by a drop casting method. The photoactivation of the sensors allows for the detection of ultra-low NO2 concentrations (50 ppb) at room temperature. The sensors show strong responses to NO2 and weak ones to the other tested polluting gases (CO, CH4 and CO2). The effect of humidity and the presence of graphene on the sensors’ response were studied. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Dynamic response curves (black curve) of the sensors’ sensitivity to different NO<sub>2</sub> concentrations (blue curve) at room temperature in humid air (50% RH) and under UV-LED lighting conditions.</p>
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<p>Calibration curves of sensors’ sensitivity in dry and humid air (50% RH) to NO<sub>2</sub>, at room temperature in humid air (50% RH), and under UV-LED lighting conditions.</p>
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3 pages, 794 KiB  
Abstract
New SiC Microwire-Based Ion Sensitive Junction Field Effect Transistors (SiC ISJFETs) for pH Sensing
by Olfa Karker, Konstantinos Zekentes, Nicolaos Makris, Edwige Bano and Valérie Stambouli
Proceedings 2024, 97(1), 98; https://doi.org/10.3390/proceedings2024097098 - 26 Mar 2024
Viewed by 602
Abstract
For the first time, we have implemented new kinds of ISFETs based on silicon carbide (SiC). Thanks to its chemical inertness, SiC is an interesting semiconductor for the development of chemically robust and biocompatible ISFETs. The challenge is to replace Si NWFETs for [...] Read more.
For the first time, we have implemented new kinds of ISFETs based on silicon carbide (SiC). Thanks to its chemical inertness, SiC is an interesting semiconductor for the development of chemically robust and biocompatible ISFETs. The challenge is to replace Si NWFETs for biochemical sensing due to the lack of long-term stability of Si NWs in aqueous solutions. More particularly, we fabricated a micro/nanowire SiC-based ion-sensitive junction field-effect transistor (SiC-ISJFET) and studied its sensitivity to pH variations. The obtained sensitivity reaches 500 mV/pH, making it the first SiC pH sensor with performance equaling that of the latest NWFET Si-based pH sensors. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>3D schematic of the SiC ISJFET.</p>
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<p>pH sensitivity obtained from IDS-Vref curves.</p>
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3 pages, 489 KiB  
Abstract
FOCV-MPPT Power Management Unit for Submilliwatt Indoor PV Cells
by Marc Azlor, Eduard Ferré, Manel Gasulla and Ferran Reverter
Proceedings 2024, 97(1), 99; https://doi.org/10.3390/proceedings2024097099 - 26 Mar 2024
Viewed by 742
Abstract
This work proposes and experimentally characterizes a low-power circuit to track the maximum power point (MPP) of submilliwatt photovoltaic (PV) cells intended for indoor applications. The circuit relies on a low-power conventional indirect tracking technique: the fractional open circuit voltage (FOCV). The experimental [...] Read more.
This work proposes and experimentally characterizes a low-power circuit to track the maximum power point (MPP) of submilliwatt photovoltaic (PV) cells intended for indoor applications. The circuit relies on a low-power conventional indirect tracking technique: the fractional open circuit voltage (FOCV). The experimental results presented herein show that power losses due to the tracking inaccuracy of the FOCV technique are much lower (at least a factor of 10) than those due to the ensuing micropower DC/DC converter. Accordingly, the application of more accurate yet more power-demanding tracking techniques seems unnecessary in such scenarios, since they could incur even higher power losses. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Proposed PMU for a low-power PV cell applying the FOCV-MPPT method. (<b>b</b>) Experimental results obtained when characterizing the circuit in <a href="#proceedings-97-00099-f001" class="html-fig">Figure 1</a>a.</p>
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3 pages, 385 KiB  
Abstract
Magnetic Field Sensors for Non-Invasive Current Monitoring in Wire-Bond-Less Power Modules
by Perla Malagò, Stefano Lumetti, Dominik Holzmann, Michael Ortner and Ali Roshanghias
Proceedings 2024, 97(1), 100; https://doi.org/10.3390/proceedings2024097100 - 27 Mar 2024
Cited by 1 | Viewed by 674
Abstract
A non-invasive implementation of a planar magnetoresistive sensor on top of copper interconnected power modules is proposed. This solution allows for the real-time monitoring of the electrical current flowing across the power modules. Anisotropic magnetoresistive (AMR) sensors made of Permalloy were designed through [...] Read more.
A non-invasive implementation of a planar magnetoresistive sensor on top of copper interconnected power modules is proposed. This solution allows for the real-time monitoring of the electrical current flowing across the power modules. Anisotropic magnetoresistive (AMR) sensors made of Permalloy were designed through finite-difference and finite-element simulations in the so-called barber-pole configuration and microfabricated via patterning by laser lithography and thin film deposition by electron-beam evaporation. Finally, the sensor performance was tested by measuring the magnetic field generated by the electrical current in a specific range of interest. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Top view of the PM sub-assembly together with the planar interconnects and magnetic field sensor. (<b>b</b>) ΔV measured for different values of <span class="html-italic">i</span> and <span class="html-italic">i<sub>s</sub></span>.</p>
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3 pages, 1156 KiB  
Abstract
Electrostatic Microelectromechanical System Speaker Array with Out-of-Plane Piston Displacement and Simplified Microfabrication
by Diogo E. Aguiam, Inês S. Garcia, Edoardo Sotgiu and Filipe S. Alves
Proceedings 2024, 97(1), 101; https://doi.org/10.3390/proceedings2024097101 - 27 Mar 2024
Viewed by 756
Abstract
This study presents a new design for a MEMS electrostatic speaker array with out-of-plane piston-like diaphragm displacement using a simplified silicon-on-insulator microfabrication process. The device comprises an array of parallel actuating membranes with small circular mechanically open but acoustically sealed apertures that enable [...] Read more.
This study presents a new design for a MEMS electrostatic speaker array with out-of-plane piston-like diaphragm displacement using a simplified silicon-on-insulator microfabrication process. The device comprises an array of parallel actuating membranes with small circular mechanically open but acoustically sealed apertures that enable controlled etching of the buried oxide to be released directly from the front side, but retain a high acoustic impedance acting as a flat membrane. This approach simplifies the microfabrication process, requiring only two lithography masks and increasing process tolerances. Preliminary experimental measurements validate the concept and demonstrate the electromechanical and acoustic performance compared with theoretical models. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic of the microspeaker array and single diaphragm element. (<b>b</b>) COMSOL simulation of vibration modes for a single membrane showing a piston-like fundamental mode.</p>
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<p>(<b>a</b>) SEM image of one microspeaker membrane and etch openings. (<b>b</b>) Piston-like RMS deflection measurement. Membrane deflection for a sinusoidal actuation (<b>c</b>,<b>d</b>) and compensated (<b>e</b>,<b>f</b>) voltage signal. Frequency response of the (<b>g</b>) membrane deflection and (<b>h</b>) SPL of the microspeaker.</p>
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3 pages, 1196 KiB  
Abstract
A Novel Sensor Effect Applicable in Seismically Active Regions
by Siya Lozanova, Martin Ralchev, Avgust Ivanov and Chavdar Roumenin
Proceedings 2024, 97(1), 102; https://doi.org/10.3390/proceedings2024097102 - 27 Mar 2024
Viewed by 572
Abstract
This paper reports a novel sensor effect in solid non-regular materials with the following formula: a previously unknown phenomenon in solid disordered structures, such as rocks and building concrete, has been experimentally established, which is expressed in the emission of micro-sized particles under [...] Read more.
This paper reports a novel sensor effect in solid non-regular materials with the following formula: a previously unknown phenomenon in solid disordered structures, such as rocks and building concrete, has been experimentally established, which is expressed in the emission of micro-sized particles under the action of uniaxial pressures. The obtained results are an integrated technology indicator for pre-emergency and emergency conditions in mountain massifs and are applicable in seismically active regions. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Arrangement for detection of microparticles: rock test specimen 1; box 2; air filter 3; laser counter 4; press 5; flexible muffs 6; air conductors 7 and 8. The parallelepiped samples with a height of 80 mm and equal lateral ribs measuring 50 mm are subjected to uniaxial loading.</p>
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<p>Intensity of particle emission on uniaxial pressure for granite samples in the range of 0.3–0.5 μm. The experimental error is no more than 5–6%.</p>
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<p>Particle emission for granite, &gt;5.0 μm.</p>
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<p>Implementation of the novel effect for seismic purposes: rock massif 1; tectonic plate 2; vertical borehole 3; hermetic stopper 4; air conductors 5 and 6; air filter 7; aerosol particle laser counter 8.</p>
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3 pages, 860 KiB  
Abstract
Multi-Sensor System for Saffron Quality Identification
by Rosamaria Capuano, Chiara Serafini, Leonardo Papale, Valerio Allegra, Corrado Di Natale and Alexandro Catini
Proceedings 2024, 97(1), 103; https://doi.org/10.3390/proceedings2024097103 - 27 Mar 2024
Viewed by 692
Abstract
The high commercial value of saffron prompts attempts to adulterate this commodity. Thus, there is growing interest in fast and simple methods of identifying quality products. Color and aroma are the most appreciated characteristics of saffron that make this spice widely used. On [...] Read more.
The high commercial value of saffron prompts attempts to adulterate this commodity. Thus, there is growing interest in fast and simple methods of identifying quality products. Color and aroma are the most appreciated characteristics of saffron that make this spice widely used. On these bases, we developed a multisensor approach to saffron quality identification based on VIS spectrometry and volatile compound detection. For scopes, a miniaturized spectrophotometer and an electronic nose were used to identify high-quality saffron with respect to less-valuable commercial products and adulterant agents. The outer product of the spectra and electronic nose patterns was demonstrated to be effective at clustering samples according to their purity. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Example of an outer product matrix obtained by combining the spectral signals (256 values) and electronic nose signals (12 values) for a single sample.</p>
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<p>A <span class="html-italic">p</span>-value map of the outer product of the spectral and electronic nose signals. Representative spectra are shown. The values of the color bar are in a logarithmic scale.</p>
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<p>Scores plot of the PCA calculated using the outer product matrix elements with a <span class="html-italic">p</span>-value of less than 0.01.</p>
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2 pages, 128 KiB  
Abstract
Construction of an Array of Antibody–Gold Nanoparticle Conjugates for Their Comparative Assessment on Multiplex Lateral Flow Test to Detect Mycotoxins
by Bilal Javed, Vinayak Sharma and Furong Tian
Proceedings 2024, 97(1), 104; https://doi.org/10.3390/proceedings2024097104 - 27 Mar 2024
Viewed by 806
Abstract
A multiplex lateral flow immuno-biosensor for rapid, simple, and ultrasensitive on-site quantification of aflatoxin B1, type B-Fumonisin, and zearalenone in food requires the conjugation of their anti-toxin antibodies to the gold nanoparticles of various colors and sizes to obtain different color test lines [...] Read more.
A multiplex lateral flow immuno-biosensor for rapid, simple, and ultrasensitive on-site quantification of aflatoxin B1, type B-Fumonisin, and zearalenone in food requires the conjugation of their anti-toxin antibodies to the gold nanoparticles of various colors and sizes to obtain different color test lines [...] Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 647 KiB  
Abstract
Microengineered Flexible Pressure Sensors with Sacrificial Molding Layer: A Novel Fabrication Approach for Improved Performance
by Maria Brites Atalaia Rosa and Michael Kraft
Proceedings 2024, 97(1), 105; https://doi.org/10.3390/proceedings2024097105 - 27 Mar 2024
Viewed by 659
Abstract
Recent research aims to improve the performance of flexible pressure sensors by microengineering their active layer. However, current fabrication approaches often require a trade-off between scalability, miniaturization, and performance. To overcome these limitations, we propose a novel technique that involves stacking all sensor [...] Read more.
Recent research aims to improve the performance of flexible pressure sensors by microengineering their active layer. However, current fabrication approaches often require a trade-off between scalability, miniaturization, and performance. To overcome these limitations, we propose a novel technique that involves stacking all sensor layers on a carrier wafer and shaping the active layer into micro-cones using a sacrificial mold. Precise miniaturization through photolithography techniques improves mapping resolution, useful for object recognition applications. This method offers enhanced ease of fabrication, versatility in shape and size, and tunability, potentially improving the efficacy of flexible pressure sensors for various applications. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Proposed fabrication process for the flexible pressure sensor: (<b>a</b>) Si carrier wafer; (<b>b</b>) deposition of PDMS bottom substrate; (<b>c</b>) deposition of bottom Ti/Pt/Ti electrode; (<b>d</b>) deposition of PDMS lamination layer; (<b>e</b>) deposition and patterning of the sacrificial molding layer; (<b>f</b>) deposition and molding of the active layer; (<b>g</b>) deposition of top Ti/Pt/Ti electrode and sacrificial layer etching; and (<b>h</b>) deposition of top PDMS substrate.</p>
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<p>(<b>a</b>) Fabricated row–column flexible pressure sensor; (<b>b</b>) SEM image of the active layer with 150× magnification; (<b>c</b>) SEM image of the active layer with 500× magnification; and (<b>d</b>) SEM image of the conical shape obtained with 2000× magnification.</p>
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3 pages, 183 KiB  
Abstract
An Innovative Layer on Surface Acoustic Wave Sensors Integrated in a Cascade Impactor to Optimize PM10 Detection for Air Pollution Monitoring
by Ghida Fawaz, Meddy Vanotti, Fatima-Ezzahraa Dbibih, Valérie Soumann, Sacha Poisson and Virginie Blondeau-Patissier
Proceedings 2024, 97(1), 106; https://doi.org/10.3390/proceedings2024097106 - 27 Mar 2024
Viewed by 623
Abstract
A cascade impactor coupled with Surface Acoustic Wave (SAW) sensors was developed in our laboratory to detect Particulate Matters with an aerodynamic diameter of less or equal to 2.5 and 10 µm (PM2.5 and PM10). To improve the collection of PM10, a layer [...] Read more.
A cascade impactor coupled with Surface Acoustic Wave (SAW) sensors was developed in our laboratory to detect Particulate Matters with an aerodynamic diameter of less or equal to 2.5 and 10 µm (PM2.5 and PM10). To improve the collection of PM10, a layer was added to the SAW sensors, which was later on tested to check its effectiveness. These tests were carried out using polystyrene (PS) and silicon carbide (SiC) particles in order to have a representative sample of sizes. Results analysis was conducted quantitatively using a digital microscope. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 406 KiB  
Abstract
Optimization of Dielectric Excitation for Metal Oxide Sensors: Simulation and Experimental Results
by Alessandro Benegiamo, Meryl Cruz, Stefano Robbiani, Raffaele Dellacá and Santiago Marco
Proceedings 2024, 97(1), 107; https://doi.org/10.3390/proceedings2024097107 - 27 Mar 2024
Viewed by 705
Abstract
This study assesses the agreement in terms of linearity errors between simulated and experimental data from MOX sensors operated in dielectric excitation mode. Both simulated and experimental reactance spectra exhibit high linearity with respect to gas concentration in the high-frequency shoulder of the [...] Read more.
This study assesses the agreement in terms of linearity errors between simulated and experimental data from MOX sensors operated in dielectric excitation mode. Both simulated and experimental reactance spectra exhibit high linearity with respect to gas concentration in the high-frequency shoulder of the relaxation peak. The results demonstrate strong agreement between simulated and experimental 95% CI of absolute linearity errors as a function of frequency. As expected, the empirical errors are slightly bigger compared to the simulation prediction, since the latter only considers the linearity errors. The good correspondence between simulations and empirical results supports the use of simulation to optimize the tuning capacitor and the selection of the optimal operating frequency. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>Left</b>) Reactance spectra of a single sensor during an experimental day, with different colors indicating varying ethanol gas concentrations. The close-up highlights the region where the reactance response demonstrates maximum linearity with respect to the gas concentration. (<b>Right</b>) The 95% CIs of the absolute error relative to the full scale are shown as a function of the operational frequency, comparing experimental and simulated data for the same sensor during the same experimental day.</p>
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3 pages, 673 KiB  
Abstract
Measuring Exhaled Propofol in an Ex Vivo Lung Model with Low-Cost Metal Oxide Gas Sensors
by Christian Bur, Ksenia Karst, Andreas Schütze, Felix Maurer, Stefan Radermacher, Klaus Hoffmann and Sascha Kreuer
Proceedings 2024, 97(1), 108; https://doi.org/10.3390/proceedings2024097108 - 27 Mar 2024
Viewed by 712
Abstract
Herein, commercially available MOS gas sensors running in temperature cycling operations are studied for the online monitoring of propofol in an ex vivo ventilation and perfusion lung model. A porcine lung was connected to a heart–lung machine and propofol was added into the [...] Read more.
Herein, commercially available MOS gas sensors running in temperature cycling operations are studied for the online monitoring of propofol in an ex vivo ventilation and perfusion lung model. A porcine lung was connected to a heart–lung machine and propofol was added into the blood reservoir. The MOS sensor was able to quantitatively detect exhaled propofol in the very low ppb range. The results are in accordance with those obtained by a propofol-sensitive ion mobility spectrometer. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Schematic of the experimental setup.</p>
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<p>Sensor response of the ZMOD4510 (<b>top</b>), model estimate (<b>middle</b>), and P-IMS (<b>bottom</b>).</p>
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2 pages, 568 KiB  
Abstract
Optimization of a Drone-Based System for Instrumental Odor Monitoring Using Feature Selection
by Alessandro Benegiamo, Javier Burgués, Javier Alonso-Valdesueiro, Beatrice Julia Lotesoriere, Lara Terrén, Lidia Sauco, Mª Deseada Esclapez, Silvia Doñate, Agustín Gutiérrez-Gálvez and Santiago Marco
Proceedings 2024, 97(1), 109; https://doi.org/10.3390/proceedings2024097109 - 27 Mar 2024
Viewed by 617
Abstract
The application of Instrumental Odor Monitoring Systems (IOMS) for odor concentration estimation in wastewater treatment plants remains a challenge. We present the optimization of a heterogeneous gas sensor array mounted on a small drone to be used in dynamic conditions. The proposed method [...] Read more.
The application of Instrumental Odor Monitoring Systems (IOMS) for odor concentration estimation in wastewater treatment plants remains a challenge. We present the optimization of a heterogeneous gas sensor array mounted on a small drone to be used in dynamic conditions. The proposed method is based on the use of feature selection during the estimation of the best calibration model. The results show that the selection of an optimal sensor array and the proper time window decreases the multiplicative error a 25%. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>Left</b>) Bar plot displaying the RMSECV at iteration 8 for the addition of a new interval. Red bars are the selected interval. The intervals are 20 s long for each sensor. The first interval for each sensor is synchronized with the activation of the sampler. (<b>Right</b>) Predicted odor concentration vs. real odor concentration (in OuE/m<sup>3</sup>) for the optimal sensor configuration.</p>
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3 pages, 3976 KiB  
Abstract
Development of Fluid Handling Capabilities for Autonomous Sampling Capsule
by Bharathesh Badadamath, Desmond Brennan, Paul D. Cotter and Paul Galvin
Proceedings 2024, 97(1), 110; https://doi.org/10.3390/proceedings2024097110 - 21 Mar 2024
Viewed by 604
Abstract
This work focusses on the design of a swallowable smart capsule to collect rumen samples from a cow’s rumen and small intestine. The capsule (60 mm long × 25 mm diameter) passively travels along the cow’s GI tract, identifies the region of interest, [...] Read more.
This work focusses on the design of a swallowable smart capsule to collect rumen samples from a cow’s rumen and small intestine. The capsule (60 mm long × 25 mm diameter) passively travels along the cow’s GI tract, identifies the region of interest, collects a sample, and chemically stabilizes it for offline omics analysis. Key components in the fluidic system include (i) a micro pump, (ii) valves, and (iii) a fluidic reservoir. As a preliminary design step, we investigated sample collection and reagent mixing protocols on a bench-top fluidic system. A model rumen sample (80% glycerol/water) of similar viscosity to rumen fluid was used in our research to evaluate pumping and mixing with a stabilizing reagent. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Fluidic system under microscope to study mixing; (<b>b</b>) schematic of mixing configuration; (<b>c</b>) impeller designed for mechanical mixing inside the reservoir.</p>
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<p>Graphs showing time taken to mix: (<b>a</b>) time taken by mp6liq micropump to mix; (<b>b</b>) time taken to mix when a mixing impeller is used.</p>
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3 pages, 1362 KiB  
Abstract
Development of a Potentiometric Nitrate Ion Microsensor Improved Using Conductive Polymer Doped with Carbon Nanotubes as a Transducing Layer
by Camille Bene, Emmanuel Flahaut, Morgan Legnani, Pierre Temple-Boyer and Jérôme Launay
Proceedings 2024, 97(1), 111; https://doi.org/10.3390/proceedings2024097111 - 27 Mar 2024
Cited by 2 | Viewed by 641
Abstract
An all-integrated on-chip electrochemical microcell (10 × 11 mm2) is developed using silicon technology. The potentiometric nitrate ion detection is based on the functionalization of the working microelectrode array with a polymer membrane in fluoropolysiloxane (FPSX) containing ionophore tetradodecylammoniumnitrate (TDDAN) and [...] Read more.
An all-integrated on-chip electrochemical microcell (10 × 11 mm2) is developed using silicon technology. The potentiometric nitrate ion detection is based on the functionalization of the working microelectrode array with a polymer membrane in fluoropolysiloxane (FPSX) containing ionophore tetradodecylammoniumnitrate (TDDAN) and ionic additive potassium tetrakis[3,5-bis(trifuoromethyl)phenyl]borate (KTFPB) to form an all-solid-state ion selective electrode (ISE). The addition of an ion-to-electron transducing layer between the platinum working electrode and the polymer membrane helped to improve the sensor performances, especially the response time, the sensitivity, and the stability. Composites formed with two conductive polymers were compared: Polyethylenedioxythiophène (PEDOT) and Polypyrrole (PPy), doped with Poly(styrene sulfonate) or double-walled carbon nanotubes (DWCNTs). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Ultra-microelectrode array integrated on silicon wafer.</p>
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<p>SEM images respectively of PEDOT:PSS, PEDOT:DWCNT, and PPy:CNT deposits on an ultramicroelectrode of the array.</p>
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<p>Open circuit potential value of the different nitrate ion sensors with pNO<sub>3</sub>.</p>
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3 pages, 785 KiB  
Abstract
Optical System Design and Characterization of MEMS Mirror-Based SPAD LiDAR System for Smart Factory Applications
by Jeong-Yeon Hwang, Paul Raschdorf, Andre Henschke, Manuel Ligges, Sara Weyer and Shanshan Gu-Stoppel
Proceedings 2024, 97(1), 112; https://doi.org/10.3390/proceedings2024097112 - 28 Mar 2024
Viewed by 850
Abstract
This paper presents the optical system design for the MEMS mirror-based SPAD LiDAR system. The transmitter of the proposed LiDAR system consists of related optics for incident beam expansion and a piezoelectric MEMS mirror for a wide-scanning field of view. For the receiver [...] Read more.
This paper presents the optical system design for the MEMS mirror-based SPAD LiDAR system. The transmitter of the proposed LiDAR system consists of related optics for incident beam expansion and a piezoelectric MEMS mirror for a wide-scanning field of view. For the receiver unit, an SPAD array is utilized to collect the laser beam reflected from the target objects at a smart factory. The optical system of the proposed LiDAR system is presented, designed, and analyzed in various ways. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic description of the proposed LiDAR system; (<b>b</b>) RMS beam diameter and beam proportion within various diameters of MEMS mirrors depending on the location of the MEMS mirror device; (<b>c</b>) comparisons of spot diagrams with different divergence angles of Lens 3; (<b>d</b>) resultant reflected ray trajectories; and (<b>e</b>) distributions at ROI under a MEMS mirror rotation of ±45°.</p>
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3 pages, 643 KiB  
Abstract
Functionalization of Indium Tin Oxide with Noble Metals Nanoparticles in Hydrogen Sensing
by Brigida Alfano, Maria Lucia Miglietta, Ettore Massera, Patricia Arroyo, Jesus Lozano and Tiziana Polichetti
Proceedings 2024, 97(1), 113; https://doi.org/10.3390/proceedings2024097113 - 25 Mar 2024
Viewed by 605
Abstract
This work presents a simple method of synthesis of hydrogen-sensitive composites, starting from commercial materials, namely ITO, Rh, Pd and Pt nanoparticles. These composites, prepared by mechanical mixture and tested vs. 0.5% H2 showed promising results at temperatures below 250 °C, in line [...] Read more.
This work presents a simple method of synthesis of hydrogen-sensitive composites, starting from commercial materials, namely ITO, Rh, Pd and Pt nanoparticles. These composites, prepared by mechanical mixture and tested vs. 0.5% H2 showed promising results at temperatures below 250 °C, in line with those obtained in the literature on similar materials, prepared with more energy- and time-consuming methods. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Dynamic response of the prepared nanocomposite (<b>a</b>) ITO-Rh n; (<b>b</b>) ITO-Pd; (<b>c</b>) ITO-Pt. Devices were biased at 1 V. Sensing tests towards 0.5% of H2 were performed in synthetic air with RH 50%.</p>
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3 pages, 1275 KiB  
Abstract
Piezoelectric Layer Transfer Process for MEMS
by Gwenael Le Rhun, Franklin Pavageau, Timothée Rotrou, Christel Dieppedale and Laurent Mollard
Proceedings 2024, 97(1), 114; https://doi.org/10.3390/proceedings2024097114 - 27 Mar 2024
Viewed by 609
Abstract
Piezoelectric MEMS devices were fabricated on 200 mm Si wafers using both deposited and layer-transferred PZT films. In both cases, the PZT-based devices showed ferroelectric and piezoelectric properties at the level of current state-of-the-art devices. The wafer-to-wafer piezoelectric layer transfer process that was [...] Read more.
Piezoelectric MEMS devices were fabricated on 200 mm Si wafers using both deposited and layer-transferred PZT films. In both cases, the PZT-based devices showed ferroelectric and piezoelectric properties at the level of current state-of-the-art devices. The wafer-to-wafer piezoelectric layer transfer process that was developed can thus be useful to bypass the thermal budgeting issue associated with the high crystallization temperature of PZT (~700 °C). It allows the integration of PZT capacitors on any kind of layer stack or substrate, for either actuator or sensor applications. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Wafer to wafer layer transfer process.</p>
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<p>Photos of released piezoelectric MEMS structures fabricated using 200 mm Si technology.</p>
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<p>(<b>a</b>) Displacement of PZT films, and deflection curves of 500 µm long PZT beams (<b>b</b>) without and (<b>c</b>) with normalization of the deflection. For all 3 figures: PZT deposited (−), PZT reported via Au bonding (<span style="color:#E26B0A">−</span>), and PZT reported via SiO<sub>2</sub> bonding (<span style="color:#00AF50">−</span>).</p>
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3 pages, 2956 KiB  
Abstract
Parameters Affecting Single ZnO Nanowire Assembly by Dielectrophoresis
by Achilleas Bardakas and Christos Tsamis
Proceedings 2024, 97(1), 115; https://doi.org/10.3390/proceedings2024097115 - 27 Mar 2024
Viewed by 553
Abstract
This study aims to examine the dielectrophoretic assembly of single ZnO nanowires, focusing on the effect of electrode geometry, AC frequency and solvent medium on the alignment performance. Experimental results indicate that the electrode geometry significantly affects the capturing performance due to the [...] Read more.
This study aims to examine the dielectrophoretic assembly of single ZnO nanowires, focusing on the effect of electrode geometry, AC frequency and solvent medium on the alignment performance. Experimental results indicate that the electrode geometry significantly affects the capturing performance due to the electric field distribution. Utilizing ethanol as the solvent medium resulted in repeatable nanowire alignment at the optimal AC voltage frequency. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>SEM images of single ZnO NWs assembled via DEP: (<b>a</b>) using DIW as a solvent and (<b>b</b>) using ethanol as a solvent; (<b>c</b>) a single ZnO NW arrested on one electrode, unable to bridge the gap due to its length. The scale bars are 1 μm.</p>
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3 pages, 932 KiB  
Abstract
LIG/ZnO/Porphyrin-Functionalized EGFET-Based Electronic Tongue
by Kishore Pushparaj, Alexandro Catini, Rosamaria Capuano, Leonardo Papale, Valerio Allegra, Gabriele Magna, Gianni Antonelli, Eugenio Martinelli, Yuvaraj Sivalingam, Roberto Paolesse and Corrado di Natale
Proceedings 2024, 97(1), 116; https://doi.org/10.3390/proceedings2024097116 - 28 Mar 2024
Viewed by 809
Abstract
The use of laser cutter machines to produce porous graphene films is an innovative method for a low-cost production of flexible electrodes for electronics and sensing applications. Here, laser-induced graphene (LIG) is used to produce the gate electrodes of EGFET sensors. LIG electrodes [...] Read more.
The use of laser cutter machines to produce porous graphene films is an innovative method for a low-cost production of flexible electrodes for electronics and sensing applications. Here, laser-induced graphene (LIG) is used to produce the gate electrodes of EGFET sensors. LIG electrodes and LIG electrodes functionalized with ZnO and metalloporphyrin-coated ZnO are used as elements of the electronic tongue. The array is tested in a classical experiment aimed at identifying complex food matrices, such as fruit juices. The results demonstrate the feasibility of the approach and provide a solid basis for further array developments. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Experimental setup and electronic circuits.</p>
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<p>Example of normalized sensor signals during exposure to orange juice. Vertical lines indicate the times at which the features are calculated.</p>
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<p>PCA of the sensor signals is represented by the first and the second principal components that account for about 85% of the total variance. Left side: score plot; right side: loading plot; each sensor is represented by three features.</p>
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3 pages, 919 KiB  
Abstract
A New Hall Microdevice with Minimal Complexity
by Siya Lozanova, Avgust Ivanov, Martin Ralchev and Chavdar Roumenin
Proceedings 2024, 97(1), 117; https://doi.org/10.3390/proceedings2024097117 - 28 Mar 2024
Viewed by 573
Abstract
A new Hall microdevice with minimal complexity and orthogonal magnetic field activation is suggested. The microsensor contains a rectangular n-type silicon substrate. On the long sides, three ohmic contacts are formed symmetrically and opposite each other. The first two opposite electrodes are [...] Read more.
A new Hall microdevice with minimal complexity and orthogonal magnetic field activation is suggested. The microsensor contains a rectangular n-type silicon substrate. On the long sides, three ohmic contacts are formed symmetrically and opposite each other. The first two opposite electrodes are connected and the second two are fed in the same way, and third ones are the outputs. The increased sensitivity constituting 40 V/AT is due to the reduced parasitic surface currents. Furthermore, output electrodes are moved out of the area where the supply currents flow. The 80 × 135 μm2 size of the sensor increases the resolution and provides detailed mapping of the magnetic field’s topology. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Schematically plan-view of the new Hall configuration. In the <span class="html-italic">x-y</span> plane, the length of contacts C<sub>1</sub>–C<sub>6</sub> is 30 μm, their width is 10 μm, and the depth is about 2 μm. The distance between electrodes C<sub>1</sub>, C<sub>2</sub>, and C<sub>4</sub> varies: C<sub>5</sub> is 20 μm, while <span class="html-italic">l</span><sub>C2,3</sub> and <span class="html-italic">l</span><sub>C5,6</sub> are 15 μm (on the mask). The width of the <span class="html-italic">p</span>-ring on the chip surface is about 20 μm.</p>
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<p>Offset voltage versus bias of current IS at T = 20 °C.</p>
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<p>Internal noise power spectral density with the current IS as a parameter.</p>
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3 pages, 1211 KiB  
Abstract
Electrochemical Diffusion Study in Hydrogels
by Eva Melnik, Steffen Kurzhals, Valerio Beni, Giorgio C. Mutinati and Rainer Hainberger
Proceedings 2024, 97(1), 118; https://doi.org/10.3390/proceedings2024097118 - 28 Mar 2024
Viewed by 723
Abstract
In this study, poly(ethylene glycol) dimethacrylate (PEG-DMA)-based hydrogels were investigated with respect to the diffusion properties of methylene blue (MB) and MB conjugated proteins (MB-BSA and MB-IgG). Electrochemical sensors were used to monitor the diffusion process via the redox-active MB-label. All tested molecules [...] Read more.
In this study, poly(ethylene glycol) dimethacrylate (PEG-DMA)-based hydrogels were investigated with respect to the diffusion properties of methylene blue (MB) and MB conjugated proteins (MB-BSA and MB-IgG). Electrochemical sensors were used to monitor the diffusion process via the redox-active MB-label. All tested molecules showed good mobility in the hydrogel. Also, the release of MB-BSA could be demonstrated after drying the hydrogel containing MB-BSA, which is a promising result for the development of hydrogel-based reagent reservoirs for biosensing. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Sensors covered with hydrogel (<b>A</b>) were overlayed with an MB(–conjugate) solution (<b>B</b>) for electrochemical diffusion monitoring via DPV (<b>C</b>).</p>
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<p>Diffusion study of MB-BSA for wet (<b>A</b>) and dry hydrogel (<b>B</b>).</p>
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3 pages, 454 KiB  
Abstract
Effect of Heat Treatment on Electrical Insulation of Strain Sensors for Aluminum Cast Parts
by Marco Cen-Puc, Tim de Rijk, Dirk Lehmhus and Walter Lang
Proceedings 2024, 97(1), 119; https://doi.org/10.3390/proceedings2024097119 - 29 Mar 2024
Viewed by 672
Abstract
This work presents the effect of thermal treatment on the electrical insulation of strain sensors on aluminum substrates. The sensors are meant to be embedded into cast aluminum parts, which are heat-treated for strengthening via precipitation hardening. For sensor manufacturing, thick film materials [...] Read more.
This work presents the effect of thermal treatment on the electrical insulation of strain sensors on aluminum substrates. The sensors are meant to be embedded into cast aluminum parts, which are heat-treated for strengthening via precipitation hardening. For sensor manufacturing, thick film materials are used for the electrical insulation and its connection tracks, whereas sensing platinum structures are produced by sputtering. The effectiveness of different insulation thicknesses was tested for a treatment regime of 7 h at 535 °C, which matches solution heat treatment conditions as the most demanding part of the precipitation hardening process. The results showed that insulation is partially lost after treatment, and six consecutive insulating layers are required to produce an insulation capable of withstanding an extended heat treatment. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Strain sensor for temperature resistance test: (<b>a</b>) Fabrication elements layers of sensors and actual sample (without top insulation); (<b>b</b>) Percentage of sensor with intact insulation before and after heat treatment.</p>
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3 pages, 436 KiB  
Abstract
Preparation of Antibody-Conjugated Gold Nanotriangles for Immunochromatographic Test
by Asahi Kimura, Mao Hamamoto and Hiromasa Yagyu
Proceedings 2024, 97(1), 120; https://doi.org/10.3390/proceedings2024097120 - 29 Mar 2024
Viewed by 732
Abstract
Gold nanotriangles (GNTs) for producing a test strip of human chorionic gonadotropin (hCG) tests were reported in this paper. The GNTs were simply synthesized by non-thermal liquid-phase reduction with sodium citrate and tannic acid composition as a reducing reagent. The antibody-conjugated GNTs were [...] Read more.
Gold nanotriangles (GNTs) for producing a test strip of human chorionic gonadotropin (hCG) tests were reported in this paper. The GNTs were simply synthesized by non-thermal liquid-phase reduction with sodium citrate and tannic acid composition as a reducing reagent. The antibody-conjugated GNTs were prepared using the synthesized GNTs and anti-hCG beta antibodies. The experimental results confirmed that the use of GNTs can decrease the volume of antibodies required for the use of a labeling reagent compared with spherical GNPs for the first time. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) TEM images of GNTs and GNPs. (<b>b</b>) Absorption spectra of the synthesized GNTs and GNPs solution. (<b>c</b>) Difference in absorbance ratio DR of antibody-conjugated GNTs and GNPs as a function of the molar ratio of antibody to Au.</p>
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3 pages, 423 KiB  
Abstract
Rational Design of a Planar Junctionless Field-Effect Transistor for Sensing Biomolecular Interactions
by Rajendra P. Shukla, Johan G. Bomer, Daniel Wijnperle, Naveen Kumar, Janwa El Maiss, Divya Balakrishanan, Aruna Chandra Singh, Vihar P. Georgiev, Cesar Pascual Garcia, Sivashankar Krishnamoorthy and Sergii Pud
Proceedings 2024, 97(1), 121; https://doi.org/10.3390/proceedings2024097121 - 29 Mar 2024
Viewed by 962
Abstract
In the ElectroMed project, we are interested in screening certain peptide sequences for their ability to selectively interact with antibodies or MHC proteins. This poses a combinatorial challenge that requires a highly multiplexed setup of label-free immunosensors. Label-free FET-based immunosensors are good candidates [...] Read more.
In the ElectroMed project, we are interested in screening certain peptide sequences for their ability to selectively interact with antibodies or MHC proteins. This poses a combinatorial challenge that requires a highly multiplexed setup of label-free immunosensors. Label-free FET-based immunosensors are good candidates due to their high multiplexing capability and fast response time. Nanowire-based FET sensors have shown high sensitivity but are unreliable for clinical applications due to drift and gate stability issues. To address this, a label-free immuno-FET architecture based on planar junctionless FET devices is proposed. This geometry can improve the signal-to-noise ratio due to its larger planar structure, which is less prone to defects that cause noise and is better suited to the functionalization of different receptor molecules. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Microfabrication and surface functionalization: (<b>a</b>) microfabricated device with open gate area; (<b>b</b>) surface functionalization of Au/SiO2 SPR chips with APTES, peptide, and protein.</p>
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3 pages, 422 KiB  
Abstract
Rapid Determination of Hexane Residues in Refined Vegetable Oils Using Semiconducting Metal Oxide-Based Sensors
by Asia Kalinichenko, Benjamin Junker, Udo Weimar and Nicolae Bârsan
Proceedings 2024, 97(1), 122; https://doi.org/10.3390/proceedings2024097122 - 29 Mar 2024
Viewed by 854
Abstract
A simple, direct method for the determination residual hexane content in refined oils was developed, which makes use of commercial Semiconducting Metal Oxides (SMOX) sensors and is proposed as an alternative to the currently used standards (ISO 9832:2002, ISO 2719:2016). The main advantages [...] Read more.
A simple, direct method for the determination residual hexane content in refined oils was developed, which makes use of commercial Semiconducting Metal Oxides (SMOX) sensors and is proposed as an alternative to the currently used standards (ISO 9832:2002, ISO 2719:2016). The main advantages are related to the direct measurement of the headspace of oil samples. The measurements are performed at an oil sample temperature of 30 °C and by spiking the samples with hexane in the 8–132 mg·kg−1 range, which is in line with the requirements of current standard for the maximum residue limit set by European Union regulation. Using separate measurements performed with the help of a computer-controlled gas mixing system it is possible to determine the relationship between the concentration of hexane in oil and in the headspace. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Calibration curves based on the DC resistance measurements for the FIS SB-AQ1-06 sensor using GMS (<b>a</b>) and the model sunflower oils from different manufacturers (<b>b</b>); the use of the transfer function obtained from GMS (<b>a</b>) to predict the equivalent hexane concentration in the headspace (<b>c</b>) of sunflower oils (<b>b</b>).</p>
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3 pages, 166 KiB  
Abstract
Inkjet-Printed Split Ring Resonators for the Detection of Analyte Binding to a Gold Surface
by Matthias Paul, Doris Pollhammer, Christoph Mehofer, Rudolf Oberpertinger, Harald Kühnel and Markus Wellenzohn
Proceedings 2024, 97(1), 123; https://doi.org/10.3390/proceedings2024097123 - 29 Mar 2024
Viewed by 799
Abstract
This work focuses on demonstrating the working principle of inkjet-printed Au nanoparticle (NP) split-ring resonators (SRRs) as a novel platform for the detection of analytes on flexible substrates. Potential applications of this technology include rapid and reusable near-patient diagnostics. In the method, a [...] Read more.
This work focuses on demonstrating the working principle of inkjet-printed Au nanoparticle (NP) split-ring resonators (SRRs) as a novel platform for the detection of analytes on flexible substrates. Potential applications of this technology include rapid and reusable near-patient diagnostics. In the method, a microwave electromagnetic wave is coupled into the Au SRR via a printed Cu-NP stripline sintered photonically on a solid FR1 substrate. This coupling mechanism facilitates the detection of analytes by inducing resonance shifts in the SRR. To demonstrate the sensing principle of the platform, biomolecules are attached to the SRR and the resulting resonance shift is measured. All experiments show resonance frequency shifts in the range of approximately 20–30 MHz. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 3174 KiB  
Abstract
Development of Piezoelectrically Driven Quasi-Static 2D MEMS Mirrors with Extremely Large FoV for Scanning LiDARs
by Paul Raschdorf, Jeong-Yeon Hwang, Lena Wysocki, Lianzhi Wen, Jörg Albers, Gunnar Wille, Erdem Yarar and Shanshan Gu-Stoppel
Proceedings 2024, 97(1), 124; https://doi.org/10.3390/proceedings2024097124 - 29 Mar 2024
Viewed by 2751
Abstract
In this paper, a piezoelectrically driven quasi-static MEMS mirror is developed for a scanning LiDAR system. Finite element method (FEM) simulations are used to optimize the design of the MEMS scanner. With special emphasis on the shape and thickness of the actuators, they [...] Read more.
In this paper, a piezoelectrically driven quasi-static MEMS mirror is developed for a scanning LiDAR system. Finite element method (FEM) simulations are used to optimize the design of the MEMS scanner. With special emphasis on the shape and thickness of the actuators, they are optimized to reach a maximum static total optical scan angle (TOSA) of 30°. Their influence on the resonance frequency at dynamic modes and the material stress are investigated. In this study, two designs are compared with respect to their FEM simulation results. Currently, the devices are manufactured in the cleanroom. The manufactured samples will be characterized and the measurement results will be published in future works. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Static tilting of the quasi-static MEMS scanner. It amounts to 30° TOSA at ±100 V DC voltage applied across the piezoelectric actuators. A cross-section of the deposited thin film stack on the actuators is shown on the right. (<b>b</b>) Left: Quasi-static MEMS scanner, as seen from below. The mirror plate is not visible since it is covered by the actuators. Right: Driving voltage for static (<b>i</b>) and resonant (<b>ii</b>) modes. The left actuators move outward and the right ones move inward under positive and negative voltage, respectively. This leads to a tilting of the mirror plate along the vertical axis.</p>
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3 pages, 1069 KiB  
Abstract
Zinc-Based Electrically Conductive Adhesive for the Transfer of SMD Components on Paper PCB
by James Bourely, Nicolas Fumeaux, Marie Sanglé-Ferrière and Danick Briand
Proceedings 2024, 97(1), 125; https://doi.org/10.3390/proceedings2024097125 - 1 Apr 2024
Viewed by 625
Abstract
We report on an eco-friendly zinc-based electrically conductive adhesive (ECA). The composition and process for the implementation of the paste to fix surface-mounted devices (SMDs) components were investigated and optimized. The ECA was used to transfer SMD resistors onto paper with printed zinc [...] Read more.
We report on an eco-friendly zinc-based electrically conductive adhesive (ECA). The composition and process for the implementation of the paste to fix surface-mounted devices (SMDs) components were investigated and optimized. The ECA was used to transfer SMD resistors onto paper with printed zinc contact pads. The stability of the paste was assessed for 1 month at room temperature with less than 1% change in resistance. Mechanical bending of SMDs bonded onto the substrate was evaluated. The paste was also implemented to fabricate a zinc paper-based RFID card. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Test structure schematic and photo of SMD resistor fixed using the ECA; (<b>b</b>) evolution of the resistance using the zinc ECA on polyimide for 30 days for various acetic acid concentrations.</p>
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<p>(<b>a</b>) Stability of the zinc ECA with 12.5% acetic acid over one month for different substrate and transducing materials; (<b>b</b>) evolution of the resistance for various radii.</p>
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3 pages, 712 KiB  
Abstract
ZIF-8 Films and Surface Plasmon Resonance for Chemical Vapor Detection
by Anna Estany-Macià, Ignasi Fort-Grandas, Nirav Joshi, Winnie E. Svendsen, Maria Dimaki, Albert Romano-Rodríguez and Mauricio Moreno-Sereno
Proceedings 2024, 97(1), 126; https://doi.org/10.3390/proceedings2024097126 - 1 Apr 2024
Viewed by 750
Abstract
In this paper, we present a sensor that employs Zeolitic Imidazolate Frameworks (ZIF-8) on a Surface Plasmon Resonance sensor based on diffraction gratings to detect ethanol vapors via refractive index change in the porous structure. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Dip wavelengths of the samples’ gratings with and without ZIF-8. (<b>b</b>) Dip wavelengths with different liquids and bulk sensitivities of the Λ = 400 nm (blue) and Λ = 500 nm (red) grating periods. (<b>c</b>) Dip shift for Λ = 400 nm (blue) and Λ = 500 nm (red) from nitrogen to a saturated ethanol atmosphere.</p>
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3 pages, 527 KiB  
Abstract
Refractive Index Sensitivity of Localized Surface Plasmon Resonance Sensor Using Gold Nanotriangles Synthesized by Seedless Non-Thermal Liquid-Phase Reduction
by Mao Hamamoto and Hiromasa Yagyu
Proceedings 2024, 97(1), 127; https://doi.org/10.3390/proceedings2024097127 - 1 Apr 2024
Viewed by 722
Abstract
This paper reported the refractive index sensing ability of localized surface plasmon resonance (LSPR) sensors using synthesized GNTs by a seedless and non-thermal synthesis method. The synthesized GNTs were a blue solution, and the edge length of the GNTs was 127 nm. The [...] Read more.
This paper reported the refractive index sensing ability of localized surface plasmon resonance (LSPR) sensors using synthesized GNTs by a seedless and non-thermal synthesis method. The synthesized GNTs were a blue solution, and the edge length of the GNTs was 127 nm. The refractive index sensitivity of the LSPR sensor using GNTs showed 162 nm/RIU, and the results confirmed that the LSPR sensor using GNTs realized high refractive index sensitivity compared with that using spherical gold nanoparticles (GNPs) with a Au concentration of 0.186 mM and a diameter of 10 nm. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) UV–vis absorption spectra of GNPs and GNTs solution. (<b>b</b>) TEM image of GNPs and GNTs. (<b>c</b>) LSPR peak shift of LSPR sensors using GNPs and GNTs as a function of refractive index.</p>
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3 pages, 1184 KiB  
Abstract
Screen-Printed Ceramic MEMS for Metal Oxide Gas Sensor
by Oleg Kul, Alexey Vasiliev, Andrey Nikitin, Anna Dmitrieva and Alexandr Bolshakov
Proceedings 2024, 97(1), 128; https://doi.org/10.3390/proceedings2024097128 - 1 Apr 2024
Viewed by 2985
Abstract
We developed a new approach to the fabrication of MEMS (Microelectromechanical system) substrates for gas sensors. This full screen-printing approach consists in the application of sacrificial material, which is solid at the near-room temperature of printing and becomes powder after firing of the [...] Read more.
We developed a new approach to the fabrication of MEMS (Microelectromechanical system) substrates for gas sensors. This full screen-printing approach consists in the application of sacrificial material, which is solid at the near-room temperature of printing and becomes powder after firing of the elements of the sensor and, therefore, can be removed from under the suspended elements of the MEMS structure in an ultrasonic bath. The glass–ceramic MEMS is a cantilever structure equipped with a Pt-based microheater on the end edge with the sensing layer. Screen-printing provides cheap fabrication, robustness, and low power (~120 mW at 450 °C) for the sensing element. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Photo of ceramic MEMS sensors fabricated using screen-printing technology. (<b>a</b>) Top view of the microchip with a thin (20 μm) ceramic cantilever, microheater, and contacts to the sensing layer. (<b>b</b>) Sensor chip packaged into the TO5 housing. (<b>c</b>) Temperature distribution over the microheater and cantilever.</p>
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3 pages, 3263 KiB  
Abstract
Noise Analysis of MEMS Microphones as a Gas-Sensing Element
by Gabriel Rodriguez Gutierrez and Stefan Palzer
Proceedings 2024, 97(1), 129; https://doi.org/10.3390/proceedings2024097129 - 1 Apr 2024
Viewed by 2982
Abstract
In recent years, micromachined microphones have evolved into versatile transducers for gas-sensing applications in the fields of both direct and indirect photoacoustics. However, their noise properties have not yet caught much attention. In this contribution, we present an analysis of the noise spectrum [...] Read more.
In recent years, micromachined microphones have evolved into versatile transducers for gas-sensing applications in the fields of both direct and indirect photoacoustics. However, their noise properties have not yet caught much attention. In this contribution, we present an analysis of the noise spectrum of a MEMS microphone and show how it may be employed as a gas-sensing tool and to characterize photoacoustic detectors. The results highlight the potential to determine the speed of sound, ambient temperature, and gas composition via Fourier analysis of the microphone noise. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>Left</b>): Noise spectrum measured for an ICS-40720 microphone encapsulated in a synthetic-air atmosphere. (<b>Right</b>): The first resonant peak of the microphone’s noise fitted to a Lorentzian shape. The resonant frequency was determined by its geometry, the speed of sound in the gas, and the temperature.</p>
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<p>(<b>Left</b>): Noise spectrum recorded for microphones encapsulated in atmospheres with different gas compositions. (<b>Right</b>): Relationship between the resonance frequency at the first peak and the speed of sound in the atmosphere of each sensor. Note the rather exact 0.5 exponent in the proportionality.</p>
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3 pages, 1442 KiB  
Abstract
Sensing Material Temperature Effect on the Multiple Gas Sensor Sensing Response
by Anze Sitar, Elia Scattolo, Matteo Valt, Alvise Bagolini, Pietro Tosato and Andrea Gaiardo
Proceedings 2024, 97(1), 130; https://doi.org/10.3390/proceedings2024097130 - 1 Apr 2024
Viewed by 727
Abstract
The temperature of the sensing material has a large impact on the tin-oxide gas sensor performance. However, the thermal analysis of gas sensors is often overlooked or only partially included in the studies. The aim of this research was to employ numerical simulations [...] Read more.
The temperature of the sensing material has a large impact on the tin-oxide gas sensor performance. However, the thermal analysis of gas sensors is often overlooked or only partially included in the studies. The aim of this research was to employ numerical simulations to investigate the temperature effect on the detection of the ethanol in an ethanol/air mixture by positioning multiple electrodes on a single heated membrane. The experimental results validated the electrothermal simulation and indicated a significant temperature effect on the sensor responsivity. Indeed, the decrease in the average sensor temperature from 427 °C to 411 °C increased the sensing response by approximately 75 % during the 5 ppm ethanol mixture flow over the sensor array. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Micro-fabricated sensor structure, (<b>b</b>) Thermal simulation of the tin-oxide and the M1–M4 sensor locations, (<b>c</b>) Thermal simulation presented in a 3D plot at a heating power of 120 mW.</p>
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<p>The M1–M4 sensor response after injection of 5ppm of ethanol/air mixture at a constant membrane heating power of 120 mW.</p>
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3 pages, 448 KiB  
Abstract
UV Light Stereoselective Limonene Sensor Using Electrospun PVP Composite Nanofibers
by Antonella Macagnano, Fabricio N. Molinari, Tiziana Mancini, Stefano Lupi and Fabrizio De Cesare
Proceedings 2024, 97(1), 131; https://doi.org/10.3390/proceedings2024097131 - 1 Apr 2024
Cited by 1 | Viewed by 841
Abstract
This study explored the design of an innovative stereoselective S-(-)-limonene sensor according to the molecular imprinting polymer (MIP) strategy using UV light to generate in situ polymer cross-linking. A conductive composite nanofibrous fabric of polyvinylpyrrolidone (PVP), polyacrylic acid (PAA) and carbon nanotubes (MWCNTs) [...] Read more.
This study explored the design of an innovative stereoselective S-(-)-limonene sensor according to the molecular imprinting polymer (MIP) strategy using UV light to generate in situ polymer cross-linking. A conductive composite nanofibrous fabric of polyvinylpyrrolidone (PVP), polyacrylic acid (PAA) and carbon nanotubes (MWCNTs) was deposited on purpose in a single step by electrospinning onto interdigital microelectrodes. The nanostructured layer was investigated by microscopy (SEM, TEM, AFM) and infrared transmission measurements (FTIR). The resulting sensing features (carried out in environmental air) seemed to be mainly dependent on the peculiarity of the nanostructure and the phenomena occurring at the interfaces between the cross-linked PVP–PAA/cavity shape and MWCNTs. Furthermore, the specificity of the host–guest interaction was proven by the sensitivity, selectivity and stereoselectivity of the sensor when exposed to similar monoterpenes ((±)-α-pinene and (±)-linalool) and the enantiomer of limonene (R(+)), respectively. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) TEM and (<b>B</b>) SEM of one and a network of the treated nanocomposite fibers, respectively; (<b>C</b>) response curves of the ES-MIP-sensor to increasing concentration of S(-)- and R-(+)-limonene (ranging between 5 and 165 ppm).</p>
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3 pages, 1205 KiB  
Abstract
Sensitivity Characterization of an Impedance-Based Platform for Viability Analysis of 3D Spheroids
by Claudia Sampaio da Silva, Christian Beyer, Julia Boos, Sreedhar Kumar, Mario Modena, Thomas Valentin, Andreas Hierlemann and Vincent Revol
Proceedings 2024, 97(1), 132; https://doi.org/10.3390/proceedings2024097132 - 1 Apr 2024
Viewed by 718
Abstract
Electrical impedance spectroscopy (EIS) is a promising label-free tool for high-throughput analysis of 3D cellular constructs, also called spheroids. Here, we used an EIS platform featuring facing electrodes to characterize the viability of hepatic spheroids, which are used for bioprinting applications. By using [...] Read more.
Electrical impedance spectroscopy (EIS) is a promising label-free tool for high-throughput analysis of 3D cellular constructs, also called spheroids. Here, we used an EIS platform featuring facing electrodes to characterize the viability of hepatic spheroids, which are used for bioprinting applications. By using principal component analysis (PCA), we show that this simple impedance sensor enables us to successfully distinguish healthy spheroids from spheroids exposed to toxic conditions. The sensitivity of the impedance sensor will be further characterized by using spheroids exposed to varying stress conditions like different drug concentrations and temperatures. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) Top view of the microfluidic EIS chip and close-up schematic detailing its critical dimensions. (<b>B</b>) Schematic of the measurement setup.</p>
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<p>(<b>A</b>) Fluorescence images of the two populations, healthy spheroids and spheroids exposed to DMSO, showing fractions of dead (red) and live (green) cells. Scale bar: 100 µm. (<b>B</b>) Plot of the first two PCs retrieved after performing PCA on multifrequency EIS data for healthy (green) and DMSO-exposed (red) spheroids.</p>
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3 pages, 1116 KiB  
Abstract
ZnO/WS2 Hybrid Material, for NO2 Detection, via the Combination of AACVD and APCVD Techniques
by Shuja Bashir Malik, Eduard Llobet and Fatima Ezahra Annanouch
Proceedings 2024, 97(1), 133; https://doi.org/10.3390/proceedings2024097133 - 1 Apr 2024
Cited by 1 | Viewed by 782
Abstract
We report for the first time the successful synthesis of ZnO/WS2 hybrid material using a combination of aerosol-assisted chemical vapor deposition (AA-CVD) and atmospheric pressure CVD techniques. The morphology and the composition of the grown films were investigated and the results confirm [...] Read more.
We report for the first time the successful synthesis of ZnO/WS2 hybrid material using a combination of aerosol-assisted chemical vapor deposition (AA-CVD) and atmospheric pressure CVD techniques. The morphology and the composition of the grown films were investigated and the results confirm the co-existence of both materials. Moreover, gas-sensing results against 500 ppb of NO2 revealed the influence of WS2 material on the ZnO gas-sensing performance. The operating temperature shifted towards lower values, from 300 °C to 150 °C. Furthermore, at room temperature, the ZnO/WS2 sensor was able to detect NO2 at ppb level. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>FESEM images of (<b>a</b>) ZnO, (<b>b</b>) WS<sub>2</sub>, (<b>c</b>,<b>d</b>) ZnO/WS2, (<b>e</b>,<b>f</b>) Raman spectra and (<b>g</b>) EDX anaysis of ZnO/WS<sub>2</sub>.</p>
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<p>Sensor response as a function of temperature (<b>a</b>) ZnO, (<b>b</b>) ZnO/WS<sub>2</sub> and (<b>c</b>) example of ZnO/WS<sub>2</sub> resistance change in response to 500 ppb of NO<sub>2</sub>.</p>
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3 pages, 546 KiB  
Abstract
Selectivity Enhancement of an Acetone-Monitoring SPR Sensor: Theoretical Evaluation
by Gabriel B. M. Fernandes, Villeneve O. Soares, Jefferson L. B. Marques and Cleumar S. Moreira
Proceedings 2024, 97(1), 134; https://doi.org/10.3390/proceedings2024097134 - 1 Apr 2024
Viewed by 714
Abstract
A numerical investigation of a sensor for acetone monitoring using surface plasmon resonance (SPR) is proposed. We evaluate the effects of polyaniline (PANI), graphene, or chitosan acting as a chemisorption binding layer for the selective sensing of acetone. Our findings suggest that these [...] Read more.
A numerical investigation of a sensor for acetone monitoring using surface plasmon resonance (SPR) is proposed. We evaluate the effects of polyaniline (PANI), graphene, or chitosan acting as a chemisorption binding layer for the selective sensing of acetone. Our findings suggest that these materials present suitable responses when applied as an overlayer to the sensor. Their thicknesses, however, should be maintained close to a monolayer level to preserve performance. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>SPR curves for silver-based sensor as a function of affinity layer thickness.</p>
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3 pages, 1000 KiB  
Abstract
Electrical Conductivity Sensor for Plant Substrates
by Yawar Abbas, Milou Jaspers, Rached Moalla, Joris van Nieuwstadt and Marcel A. G. Zevenbergen
Proceedings 2024, 97(1), 135; https://doi.org/10.3390/proceedings2024097135 - 1 Apr 2024
Viewed by 854
Abstract
Measuring the electrical conductivity (EC) of plant substrates is an effective way to assess their nutrient content. This study aims to compare the performance of EC sensors with varying electrode sizes and spacings when embedded in a plant substrate. The range of electrode [...] Read more.
Measuring the electrical conductivity (EC) of plant substrates is an effective way to assess their nutrient content. This study aims to compare the performance of EC sensors with varying electrode sizes and spacings when embedded in a plant substrate. The range of electrode sizes and spacings varied from 0.1 mm to 10 mm. The EC electrodes were embedded in a porous plant substrate and subjected to wet–dry cycles. The results showed that the electrodes with larger electrode dimensions and spacing produce valid EC values. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) The sensor with different EC electrode combinations E1 and E2; (<b>b</b>) cell constant of each pair; (<b>c</b>) experimental setup for EC measurement in a plant substrate for watering–drying cycle.</p>
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<p>EC measurements of the electrode designs: (<b>a</b>) E1; (<b>b</b>) E2; (<b>c</b>) E1 and E2 in aqueous solution.</p>
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3 pages, 3142 KiB  
Abstract
The Improvement of Tamm Interface State Detection by Using a Porous Layer between a Metal Nanostructured Grating and a DBR
by Oumaima Haidar, Baptiste Mathmann, Yannick Dusch, Mohamed El Barghouti, Gaëtan Lévêque, Abdellatif Akjouj, Abdellah Mir and Abdelkrim Talbi
Proceedings 2024, 97(1), 136; https://doi.org/10.3390/proceedings2024097136 - 2 Apr 2024
Viewed by 789
Abstract
In this work, we propose a sensor based on Tamm plasmonic resonance; the structure is composed of gold nanoribbons deposited on a Distributed Bragg Reflector (DBR) (SiO2/Si3N4)6. We have enhanced the sensitivity of our sensor [...] Read more.
In this work, we propose a sensor based on Tamm plasmonic resonance; the structure is composed of gold nanoribbons deposited on a Distributed Bragg Reflector (DBR) (SiO2/Si3N4)6. We have enhanced the sensitivity of our sensor from 40 nm/RIU to 200 nm/RIU for a refractive index change of 1% by replacing the last layer of Si3N4 in contact with gold with porous Si3N4 with a porosity of p = 40%. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic representation of the Tamm plasmon structure constituted of double period Tamm structure, with <span class="html-italic">p</span> = 0%. (<b>b</b>) Reflection spectrum of Tamm structure. (<b>c</b>) Norm of the electric field of peaks A and B.</p>
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<p>Reflection spectra as a function of wavelength for different refractive indices of the double period Tamm structure (<b>a</b>) without a porous layer and (<b>b</b>) with a porous Si3N4 layer of porosity <span class="html-italic">p</span> = 40%.</p>
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3 pages, 392 KiB  
Abstract
Zn-Based Triphenylene Metal–Organic Frameworks as a Chemiresistive Platform for Methane Detection
by Sachin Navale, Ignasi Fort-Grandas, Yuzelfy Mendoza, Paolo Pellegrino, Mauricio Moreno, Daniel Sainz, Anton Vidal-Ferran and Albert Romano-Rodriguez
Proceedings 2024, 97(1), 137; https://doi.org/10.3390/proceedings2024097137 - 1 Apr 2024
Viewed by 811
Abstract
Methane (CH4) emissions are a leading cause of global warming, and precise monitoring of and reduction in these emissions are important. To achieve these goals, miniaturized low-power sensor systems with improved precision are necessary. To this end, we present a novel [...] Read more.
Methane (CH4) emissions are a leading cause of global warming, and precise monitoring of and reduction in these emissions are important. To achieve these goals, miniaturized low-power sensor systems with improved precision are necessary. To this end, we present a novel room-temperature chemiresistive CH4 gas sensor that employs Zn-hexahydroxytriphenylene-based metal–organic frameworks (Zn-HHTP MOFs) as detection materials. The high surface area and porosity of Zn-HHTP MOFs enable effective detection of low atmospheric levels (1.2 ppm) of CH4. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Chemical structure of Zn-HHTP MOF; (<b>b</b>) chemiresistive study of Zn-HHTP MOF sensor to 6.2 and 1.2 ppm of CH<sub>4</sub> at room temperature, proving its reversibility.</p>
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3 pages, 1496 KiB  
Abstract
Platform for Weakly Coupled Electro-Mechanical Resonators with Arbitrary Tunability
by Ruopeng Chen, Bernardo Pereira, Chen Wang, Michael Kraft and Georges Gielen
Proceedings 2024, 97(1), 138; https://doi.org/10.3390/proceedings2024097138 - 1 Apr 2024
Viewed by 664
Abstract
This paper presents a platform for weakly coupled mechanical and electrical resonators with arbitrary tunability. Two- and three-degree-of-freedom (DoF) weakly coupled resonator systems are demonstrated experimentally with this platform, showing excellent tuning and matching flexibility. Fully electrical coupling logic circuitry gives the proposed [...] Read more.
This paper presents a platform for weakly coupled mechanical and electrical resonators with arbitrary tunability. Two- and three-degree-of-freedom (DoF) weakly coupled resonator systems are demonstrated experimentally with this platform, showing excellent tuning and matching flexibility. Fully electrical coupling logic circuitry gives the proposed system better adjustability and lower susceptibility to fabrication tolerances compared to purely mechanical weakly coupled resonators. Due to its mother/daughter board structure and the simplicity of the coupling logic, the proposed system can easily be extended to any-DoF systems. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Proposed tunable platform for weakly coupled electro-mechanical resonator systems: (<b>a</b>) simplified schematic of the proposed system; (<b>b</b>) PCB implementation of the proposed system.</p>
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<p>Measurement results of the proposed tunable weakly coupled resonator system: (<b>a</b>) frequency response of Resonator <math display="inline"><semantics> <mrow> <msub> <mi>R</mi> <mn>1</mn> </msub> </mrow> </semantics></math> with different coupling factors in the 2-DoF coupled resonator system; (<b>b</b>) frequency response of Resonator <math display="inline"><semantics> <mrow> <msub> <mi>R</mi> <mn>1</mn> </msub> </mrow> </semantics></math> with different coupling factors in the 3-DoF coupled resonator system; (<b>c</b>) frequency response of Resonator <math display="inline"><semantics> <mrow> <msub> <mi>R</mi> <mn>1</mn> </msub> </mrow> </semantics></math> with capacitance value perturbation in electrical resonator <math display="inline"><semantics> <mrow> <msub> <mi>R</mi> <mn>2</mn> </msub> </mrow> </semantics></math> in the 3-DoF coupled resonator system.</p>
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3 pages, 328 KiB  
Abstract
Biaxial Piezoelectrically Driven MEMS Mirror with Large Design Flexibility
by Lena Wysocki, Patrick Schütt, Jörg Albers, Gunnar Wille, Erdem Yarar, Paul Raschdorf, Lianzhi Wen and Shanshan Gu-Stoppel
Proceedings 2024, 97(1), 139; https://doi.org/10.3390/proceedings2024097139 - 1 Apr 2024
Viewed by 2883
Abstract
In this work, a biaxial, piezoelectrically driven resonant MEMS mirror with large design flexibility is presented. After FEM-based design optimization to reduce material stress and thereby maximize the achievable total optical scanning angles, fabricated MEMS mirrors were electrically, mechanically, and optically characterized. While [...] Read more.
In this work, a biaxial, piezoelectrically driven resonant MEMS mirror with large design flexibility is presented. After FEM-based design optimization to reduce material stress and thereby maximize the achievable total optical scanning angles, fabricated MEMS mirrors were electrically, mechanically, and optically characterized. While the achievable optical scanning angles were determined using a home-built optical setup, a laser Doppler vibrometer was used to characterize the resonance frequencies of the rotational modes and their respective quality factors. The encapsulation of the mirror by a glass window ensures its operation in vacuum, which increases the Q-factor up to 15,000. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The results of the FEM-based eigenfrequency study of the active wafer of the MEMS scanner. Presented are the slow rotational mode (<b>a</b>) and fast rotational mode (<b>b</b>). The color code represents the z-component of the deflection in arbitrary units. (<b>c</b>) A photograph of the final optical MEMS scanner.</p>
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3 pages, 390 KiB  
Abstract
Increasing Safe Water Availability via a Multisensor System for Water Monitoring and Filtration
by Anna Sabatini, Alessandro Zompanti, Simone Grasso, Marco Santonico and Giorgio Pennazza
Proceedings 2024, 97(1), 140; https://doi.org/10.3390/proceedings2024097140 - 2 Apr 2024
Viewed by 634
Abstract
The availability and quality of water have become major concerns worldwide due to the impact of climate change and pollution. To ensure safe water consumption, a monitoring and filtration system comprising a Miniwell Filter 360 passive filter, a multisensorial system with an electrochemical [...] Read more.
The availability and quality of water have become major concerns worldwide due to the impact of climate change and pollution. To ensure safe water consumption, a monitoring and filtration system comprising a Miniwell Filter 360 passive filter, a multisensorial system with an electrochemical sensor and spectrophotometer, was designed. Water samples were collected in two locations on the north coast of Rome, and analyses were conducted before and after filtration. Multivariate statistical analyses were performed to assess the instruments’ ability. The results indicate that the implemented system can increase the availability of safe water. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>BIONOTE-L responses (<b>upper panel</b>) and the spectrophotometer responses (<b>lower panel</b>) to a pre-filter (red) and post-filter (blue) water sample.</p>
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3 pages, 391 KiB  
Abstract
Toward Material-Integrated Wireless Electronics for SHM in Fiber Metal Laminates
by Sarah Bornemann, Liv Rittmeier, Thomas Roloff, Jan N. Haus, Christoph Polle, Axel S. Herrmann, Andreas Dietzel, Michael Sinapius, Walter Lang and Björn Lüssem
Proceedings 2024, 97(1), 141; https://doi.org/10.3390/proceedings2024097141 - 2 Apr 2024
Viewed by 764
Abstract
A self-sufficient wireless electronic sensor node for the acquisition of guided ultrasonic waves (GUW) is introduced. The system presents a step toward a structural health monitoring (SHM) system fully integrated into fiber metal laminates. It removes the need for complex wiring to transfer [...] Read more.
A self-sufficient wireless electronic sensor node for the acquisition of guided ultrasonic waves (GUW) is introduced. The system presents a step toward a structural health monitoring (SHM) system fully integrated into fiber metal laminates. It removes the need for complex wiring to transfer energy and data and reduces electromagnetic actuator excitation interference observable in wired GUW measurements. The functionality of the integrated system, e.g., to monitor the structural health of FMLs, is tested with the help of magnets used as pseudo defects. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Pseudo defect positions during experimental investigation; (<b>b</b>) Experimental results.</p>
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3 pages, 1550 KiB  
Abstract
Temperature Effect of the Synthesis of Gold Nanoparticles by Microfluidics
by Sheng Shu, Mao Hamamoto and Hiromasa Yagyu
Proceedings 2024, 97(1), 142; https://doi.org/10.3390/proceedings2024097142 - 2 Apr 2024
Viewed by 1028
Abstract
We clarified the effect of mixing temperature on the synthesis of gold nanoparticles by a microfluidic device using tannic acid and citric acid as reducing reagents. In this study, gold nanoparticles were synthesized on the microfluidic device with a flow rate of 0.05 [...] Read more.
We clarified the effect of mixing temperature on the synthesis of gold nanoparticles by a microfluidic device using tannic acid and citric acid as reducing reagents. In this study, gold nanoparticles were synthesized on the microfluidic device with a flow rate of 0.05 mL/min at the temperature of room temperature (23 °C) and 80 °C. The results confirmed that the mean diameter and coefficient of variation of gold nanoparticles synthesized at 80 °C were 13.7 nm and 0.28 and the coefficient of variation increased by 65% in comparison with that at room temperature. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Photograph of (<b>a</b>) the fabricated microfluidic device and (<b>b</b>) experimental setup.</p>
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<p>(<b>a</b>) Photograph and (<b>b</b>) absorbance spectrum of GNPs. (<b>c</b>) TEM images of the synthesized GNPs at the flow rate of 0.05 mL/min.</p>
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3 pages, 336 KiB  
Abstract
Indoor Air Quality CO2 Thermally Modulated SMR Sensor
by Siavash Esfahani, Thomas Dawson, Barbara Urasinska Wojcik, Marina Cole and Julian W. Gardner
Proceedings 2024, 97(1), 143; https://doi.org/10.3390/proceedings2024097143 - 2 Apr 2024
Viewed by 3215
Abstract
This paper reports on a CO2 solidly mounted resonator (SMR)-based sensor with an integrated heater. The SMR device is CMOS compatible and operates at a resonant frequency of 2 GHz. To increase the sensitivity and selectivity, the SMR devices were functionalized with [...] Read more.
This paper reports on a CO2 solidly mounted resonator (SMR)-based sensor with an integrated heater. The SMR device is CMOS compatible and operates at a resonant frequency of 2 GHz. To increase the sensitivity and selectivity, the SMR devices were functionalized with a 20 μm CO2 sensitive layer. Two SMR sensors were employed in a differential configuration; one sensor was uncoated and used as a reference and the other was coated and used as a sensing device. The frequency shift of ~8 kHz/% CO2 in dry air was observed after temperature and humidity compensation; demonstrating its potential application in indoor air quality (IAQ) monitoring. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Photograph of an uncoated SMR device with the active area above a Bragg reflector [<a href="#B4-proceedings-97-00143" class="html-bibr">4</a>].</p>
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<p>(<b>a</b>) Responses to 1%, 3%, and 5% CO<sub>2</sub> in dry air. (<b>b</b>) Repeatability of the device (two experiments a few days apart).</p>
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3 pages, 2560 KiB  
Abstract
A Comprehensive Characterization Procedure for Resonant MEMS Scanning Mirrors
by Clement Fleury, Markus Bainschab, Gianluca Mendicino, Roberto Carminati, Pooja Thakkar, Dominik Holzmann, Sara Guerreiro and Adrien Piot
Proceedings 2024, 97(1), 144; https://doi.org/10.3390/proceedings2024097144 - 3 Apr 2024
Viewed by 3136
Abstract
We demonstrate an experimental assessment of a high-Q, high-angle piezoelectric (2 µm PZT) MEMS scanning micromirror featuring distributed backside reinforcement, suitable for applications demanding energy-efficient and high-quality image projection. Frequency response measurements at 10 different vacuum levels ranging from atmospheric pressure to 10 [...] Read more.
We demonstrate an experimental assessment of a high-Q, high-angle piezoelectric (2 µm PZT) MEMS scanning micromirror featuring distributed backside reinforcement, suitable for applications demanding energy-efficient and high-quality image projection. Frequency response measurements at 10 different vacuum levels ranging from atmospheric pressure to 10−6 mbar allow for the quantitative separation of damping mechanisms (air and structural). Stroboscopic digital holographic microscopy was used to assess the static and dynamic deformation of the mirror surface. The experimental results are in good agreement with simulations and models. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Measured Q factor vs. pressure, (<b>b</b>) 1/Q vs. optical amplitude in the vacuum regime.</p>
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<p>Measured static (<b>a</b>), measured total (<b>b</b>), and simulated dynamic (<b>c</b>) mirror deformation at 14° mech. angle (56° opt.).</p>
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3 pages, 403 KiB  
Abstract
Electronic Nose for Early Diagnosis of Ovarian Cancer
by Jens Eriksson, Donatella Puglisi and Christer Borgfeldt
Proceedings 2024, 97(1), 145; https://doi.org/10.3390/proceedings2024097145 - 3 Apr 2024
Viewed by 1012
Abstract
We present an electronic nose that detects ovarian cancer based on gas emissions from blood plasma. There is currently no test available for screening or diagnostic testing of this disease, which is therefore often detected at aa late stage, resulting in a poor [...] Read more.
We present an electronic nose that detects ovarian cancer based on gas emissions from blood plasma. There is currently no test available for screening or diagnostic testing of this disease, which is therefore often detected at aa late stage, resulting in a poor prognosis. Our approach correctly detected 85 out of 87 ovarian cancers, ranging from borderline to stage IV. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sensor signal of one out of 32 sensors after preprocessing for four cancer samples (dashed) and four negative controls (solid); (<b>b</b>) confusion matrix showing true class vs. predicted class for 113 samples (87 cancers and 26 negative controls).</p>
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2 pages, 458 KiB  
Abstract
Room Temperature CO2 Detection by Metal Oxide-Based Nanosensors
by José Pedro Santos, Isabel Sayago and Júlia González
Proceedings 2024, 97(1), 146; https://doi.org/10.3390/proceedings2024097146 - 3 Apr 2024
Viewed by 869
Abstract
Carbon dioxide is considered a greenhouse gas and is the main cause of global warming. CO2 emissions have increased more and more each year. It is therefore important to be able to detect these levels of CO2 at room temperature. Chemical [...] Read more.
Carbon dioxide is considered a greenhouse gas and is the main cause of global warming. CO2 emissions have increased more and more each year. It is therefore important to be able to detect these levels of CO2 at room temperature. Chemical sensors consisting of FR-4 substrates with four membranes on which Fe2O3, SnO2, ZnO, and CuO nanoparticles have been deposited, were used in this experiment. The method used to create the sensors was the drop-casting technique. Two types of experiments were performed using these sensors, with each measurement considering a relative humidity value of either 0% or 50% in air. Based on the results, we have observed a significant improvement in detection for measurements with humidity. These sensors can detect concentration as low as 250 ppm with 50% humidity, compared to 700 ppm without humidity in air. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Response curves of the SnO<sub>2</sub> and ZnO sensors to different CO<sub>2</sub> concentrations at room temperature: (<b>a</b>) response curves in dry air (without humidity); (<b>b</b>) response curves in wet air (with 50% humidity).</p>
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3 pages, 872 KiB  
Abstract
Resistive Gas Dosimeters as a Novel Method to Measure Small Gas Concentrations and Quantities, Both Accumulative and Timely Resolved
by Ralf Moos, Andrea Groß and Daniela Schönauer-Kamin
Proceedings 2024, 97(1), 147; https://doi.org/10.3390/proceedings2024097147 - 3 Apr 2024
Viewed by 754
Abstract
Resistive gas dosimeters are a novel method to accurately measure timely intervals like hourly mean values even for small gas concentrations. This measuring principle overcomes the disadvantageously low recovery times of conventional chemiresistive sensors. Applications for the detection of nitrogen oxides in ambient [...] Read more.
Resistive gas dosimeters are a novel method to accurately measure timely intervals like hourly mean values even for small gas concentrations. This measuring principle overcomes the disadvantageously low recovery times of conventional chemiresistive sensors. Applications for the detection of nitrogen oxides in ambient air in the ppb range demonstrate the feasibility. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Scheme of the processes that occur in a resistive gas dosimeter during one cycle consisting of a long measurement phase and a very short regeneration phase. From [<a href="#B1-proceedings-97-00147" class="html-bibr">1</a>], permitted by the authors.</p>
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<p>A typical example of an earlier sensor that demonstrates the capability to operate a dosimeter continuously for almost one hour. From [<a href="#B2-proceedings-97-00147" class="html-bibr">2</a>], permitted by the authors.</p>
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3 pages, 1114 KiB  
Abstract
Printed PEDOT:PSS Sensing Labels for Real-Time Monitoring of Hydrogen Peroxide Vapors
by Silvia Demuru, Jaemin Kim, Martin Novák, Gregor Hommes and Danick Briand
Proceedings 2024, 97(1), 148; https://doi.org/10.3390/proceedings2024097148 - 3 Apr 2024
Viewed by 768
Abstract
This work reports on printed organic PEDOT:PSS sensors for the detection of hydrogen peroxide (H2O2) vapors. Compared to commercial devices, the proposed sensors are thin and flexible, allowing their simple integration into an industrial process for multilocation decontamination monitoring. [...] Read more.
This work reports on printed organic PEDOT:PSS sensors for the detection of hydrogen peroxide (H2O2) vapors. Compared to commercial devices, the proposed sensors are thin and flexible, allowing their simple integration into an industrial process for multilocation decontamination monitoring. The sensors show a reproducible behavior in a laboratory environment using chambers containing a concentration of 130 ppm of H2O2, measuring an increase in resistance of ~1200% for 1 h exposure. The results highlight the importance of contact interfaces and their encapsulation for reproducible sensing behavior. These devices are promising as low-cost disposable devices for decontamination process monitoring. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Printed PEDOT:PSS resistors. (<b>a</b>) The fabricated flexible sensors and (<b>b</b>) schematic of the cross-section of the device, including materials used and the application for H<sub>2</sub>O<sub>2</sub> detection.</p>
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<p>Setup and results. (<b>a</b>) Picture of the test setup. (<b>b</b>) Image of sensors with wiring. (<b>c</b>) Image of a sensor with ZIF connector. (<b>d</b>–<b>f</b>) Response to H<sub>2</sub>O<sub>2</sub> vapor for sensors with different connections.</p>
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3 pages, 526 KiB  
Abstract
Systematic Experimental Evaluation of Submilliwatt PV Cells for Indoor Applications
by Eduard Ferré, Marc Azlor, Manel Gasulla and Ferran Reverter
Proceedings 2024, 97(1), 149; https://doi.org/10.3390/proceedings2024097149 - 3 Apr 2024
Viewed by 722
Abstract
In the context of energy harvesting for tiny autonomous sensors placed indoors, this work carries out a systematic experimental evaluation of low-power, low-area photovoltaic (PV) cells. The evaluation involves several cell technologies and types of illumination and, for each technology–illumination pair, a sweep [...] Read more.
In the context of energy harvesting for tiny autonomous sensors placed indoors, this work carries out a systematic experimental evaluation of low-power, low-area photovoltaic (PV) cells. The evaluation involves several cell technologies and types of illumination and, for each technology–illumination pair, a sweep of different levels of illuminance and temperature expected indoors is performed. The information extracted from this work will enable a better selection of the cell technology for a given type of indoor illumination, and a better design of the ensuing maximum power point (MPP) tracker oriented to the cell technology–illumination pair. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Experimental results for an amorphous PV cell (Panasonic AM1454, with an active area of around 11 cm<sup>2</sup>) subjected to cold white LED at (<b>a</b>) different levels of illuminance with a constant temperature (25 °C), and (<b>b</b>) different temperatures with a constant illuminance (1000 lux).</p>
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3 pages, 367 KiB  
Abstract
The Role of Convection and Size Effects in Sensor Microhotplate Heat Exchange
by Alexey Vasiliev, Alexey Shaposhnik and Oleg Kul
Proceedings 2024, 97(1), 150; https://doi.org/10.3390/proceedings2024097150 - 3 Apr 2024
Viewed by 722
Abstract
The analysis of the influence of microhotplate size on the convective heat exchange of gas sen-sors is presented. It is demonstrated that there is a minimum size leading to the formation of convection heat exchange flow. Below this minimum, only the thermal conductivity [...] Read more.
The analysis of the influence of microhotplate size on the convective heat exchange of gas sen-sors is presented. It is demonstrated that there is a minimum size leading to the formation of convection heat exchange flow. Below this minimum, only the thermal conductivity of ambient air and IR radiation should be considered as channels for heat dissipation by microhotplate. This limit expression contains only fundamental constants of air, d~4·ν·Dg3, where ν is the kinematic viscosity of air, D is the diffusion coefficient, and g is the acceleration of free fall, d~0.5 cm. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Microhotplate and convection tube over it.</p>
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3 pages, 816 KiB  
Abstract
Freeform Optimization of an Ultrasonic Horn Coupled to an Airborne MEMS Transducer
by Gabriele Bosetti, Stefan Hofstetter-Spona and Gabriele Schrag
Proceedings 2024, 97(1), 151; https://doi.org/10.3390/proceedings2024097151 - 8 Apr 2024
Viewed by 3125
Abstract
We designed an ultrasonic horn using a physics-based freeform optimization method to achieve the target frequency response of an airborne ultrasonic MEMS transducer operating in transmitting mode. The radial profile of the ultrasonic horn was parametrized using a Bezier curve, and its shape [...] Read more.
We designed an ultrasonic horn using a physics-based freeform optimization method to achieve the target frequency response of an airborne ultrasonic MEMS transducer operating in transmitting mode. The radial profile of the ultrasonic horn was parametrized using a Bezier curve, and its shape was optimized using a genetic algorithm. A computationally fast compact model of the full system, wherein the horn was described analytically using transmission line theory, was used to calculate the frequency response of the transducer and evaluate the optimization objective. The result shows very good agreement with the experimental measurement of a realized prototype. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Laser Doppler vibrometer measurements of the center displacement of the transducer under electrical actuation in vacuum and in air when attached to a cylindrical ultrasonic horn. (<b>b</b>) Freeform modeling of the ultrasonic channel. The radial profile is described with Bezier curves.</p>
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<p>(<b>a</b>) Input acoustic impedance of the ultrasonic horn: comparison between analytical calculation and FEM results. (<b>b</b>) System response of the optimized ultrasonic system. Comparison between compact model and measurements.</p>
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2 pages, 169 KiB  
Abstract
Swelling Behavior of an Ethanol-Sensitive Hydrogel Immobilized on a Plasmonic Sensor Substrate
by Julia Herzog, Martin Sobczyk, Marisa Rio, Christiane Schuster, Thomas Härtling and Gerald Gerlach
Proceedings 2024, 97(1), 152; https://doi.org/10.3390/proceedings2024097152 - 5 Apr 2024
Viewed by 641
Abstract
Refractive index-sensitive plasmonic sensors are suitable for the on-site detection of fluid parameters in process engineering applications. The functionalization of optically sensitive nanostructured surfaces with stimuli-responsive hydrogels enables the selective determination of parameters of complex liquids. Thereby, the degree of swelling of the [...] Read more.
Refractive index-sensitive plasmonic sensors are suitable for the on-site detection of fluid parameters in process engineering applications. The functionalization of optically sensitive nanostructured surfaces with stimuli-responsive hydrogels enables the selective determination of parameters of complex liquids. Thereby, the degree of swelling of the hydrogel gives indications to liquid parameters like pH or molecule concentrations. In this study, the influence of the swelling degree of an immobilized ethanol-sensitive hydrogel on the sensor signal is investigated. The application of both a measuring and reference area allows differentiation of the refractive index change induced by the swelling effect from the refractive index change of the analyte due to concentration changes. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 1114 KiB  
Abstract
Flexible, Fan-Out, Wafer-Level Packaging Using Polydimethylsiloxane and Printed Redistribution Layers
by Muhammad Hassan Malik, Muhammad Khan, Sherjeel Khan and Ali Roshanghias
Proceedings 2024, 97(1), 153; https://doi.org/10.3390/proceedings2024097153 - 7 Apr 2024
Viewed by 809
Abstract
The hybrid integration of electronics in flexible substrates using fanned-out, wafer-level packaging (FOWLP) has recently gained significant attention, with numerous applications in wearable electronics, foldable displays, robotics, medical implants, and healthcare monitoring. In this study, a fully additive and scalable manufacturing process flow [...] Read more.
The hybrid integration of electronics in flexible substrates using fanned-out, wafer-level packaging (FOWLP) has recently gained significant attention, with numerous applications in wearable electronics, foldable displays, robotics, medical implants, and healthcare monitoring. In this study, a fully additive and scalable manufacturing process flow to realize a low-cost, flexible FOWLP system was introduced. Here, the integration of 36 LED chips in a biocompatible polydimethylsiloxane (PDMS) substrate was demonstrated using a stencil-printed silver (Ag) redistribution layer (RDL). The processes for the integration of chips, i.e., chip first (exposed die embedding), chip first (deep embedding with filled valleys) and chip last (RDL first), were implemented, and the corresponding samples were evaluated electrically. The bendability of the samples was also characterized at different bending diameters. Conclusively, it was shown that by using surface-modified PDMS as a flexible substrate and stretchable Ag paste as interconnect, flexible FOWLP can be produced. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) The three approaches to realize flexible FOWLP; (<b>b</b>) an example of the demonstrator.</p>
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<p>(<b>a</b>) Electrical characterization of the fabricated samples at different loop diameters. (<b>b</b>) A demonstration of the lighting LEDS under bending condition.</p>
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3 pages, 518 KiB  
Abstract
Plasmonic Nanopores as Tunable Optical Platforms for Single-Molecule Detection
by Adriano Colombelli, Daniela Lospinoso and Maria Grazia Manera
Proceedings 2024, 97(1), 154; https://doi.org/10.3390/proceedings2024097154 - 7 Apr 2024
Viewed by 713
Abstract
Tunable plasmonic nanostructures are of the utmost importance in sensing applications due to their ability to precisely manipulate and control light–matter interactions at the nanoscale. The easy control of geometrical features enables the optimization of their optical properties, such as the resonance frequency, [...] Read more.
Tunable plasmonic nanostructures are of the utmost importance in sensing applications due to their ability to precisely manipulate and control light–matter interactions at the nanoscale. The easy control of geometrical features enables the optimization of their optical properties, such as the resonance frequency, intensity, and spectral width, to match the specific requirements of the sensing system. Enhanced sensing performances are thus achieved in terms of the sensitivity and selectivity towards target analytes, leading to improved detection limits and accuracy. Additionally, tunable plasmonic nanostructures offer the flexibility to adapt to different sensing conditions and analytes, making them versatile platforms for a wide range of sensing applications. In this work, a low-cost and optimized fabrication protocol was developed to realize highly ordered nanopores in thin gold films with tunable plasmonic features. Performances of the realized nanostructures were tested by different metal-enhanced spectroscopies, in particular Surface-Enhanced Raman Spectroscopies. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>–<b>d</b>) Simulated (dashed lines) and experimental transmittance spectra shown together for comparison. Vertical lines indicate the position of the excitation wavelength (red), the strongest minimum wavelength λ3 (blue), and the Raman band position of the selected Raman probe (green). (<b>e</b>–<b>h</b>) Horizontal cross sections of the local field distribution at the strong minimum position λ3.</p>
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3 pages, 1604 KiB  
Abstract
High-Frequency Grating-Based Microelectromechanical Systems Actuator
by Inês Pires, Inês S. Garcia, João Vieira, Zeev Zalevsky, Carlos Calaza, Filipe S. Alves and Rosana A. Dias
Proceedings 2024, 97(1), 155; https://doi.org/10.3390/proceedings2024097155 - 7 Apr 2024
Viewed by 3227
Abstract
A silicon mechanical-photonic wavelength converter, not based on absorption, has been recently proposed to address the need for all-silicon photodetectors in the infrared spectrum. Its implementation requires high-frequency modulation, from hundreds of kHz to 1 MHz, of a light beam over an area [...] Read more.
A silicon mechanical-photonic wavelength converter, not based on absorption, has been recently proposed to address the need for all-silicon photodetectors in the infrared spectrum. Its implementation requires high-frequency modulation, from hundreds of kHz to 1 MHz, of a light beam over an area of a few hundred microns. Since the displacement amplitudes of tens of microns at these frequencies are unfeasible, a moving grate is proposed to locally modulate the light. The MEMS actuator, an array of 1 µm-wide 1 µm-spaced beams (100 × 100 µm2 area), achieved displacements of 70 nm at atmospheric pressure and 350 nm under low vacuum, with 10 Vpp actuation at 290 kHz (FOM displacement × frequency2 above previously reported works). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic representation of MPWC device with MEMS optical modulator, (<b>b</b>) MEMS optical modulator devices layout, and (<b>c</b>) SEM images of the fabricated devices.</p>
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<p>(<b>a</b>) Experimental setup, (<b>b</b>) bode plots at different pressures, and (<b>c</b>) magnitude displacement in low-pressure conditions for different amplitude actuation signals.</p>
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3 pages, 1172 KiB  
Abstract
Towards Next-Generation Glucose Sensors: Reactively Sputtered Nanostructured Nickel Nitrides for CMOS Integration
by Filippo Franceschini, Catarina Fernandes and Irene Taurino
Proceedings 2024, 97(1), 156; https://doi.org/10.3390/proceedings2024097156 - 7 Apr 2024
Viewed by 661
Abstract
A facile and clean-room compatible approach to Ni nitride (NixNy) synthesis is proposed, based on a reactive sputtering deposition technique. NixNy thin films were deposited at different N2 partial pressures, after which their electrocatalytic properties [...] Read more.
A facile and clean-room compatible approach to Ni nitride (NixNy) synthesis is proposed, based on a reactive sputtering deposition technique. NixNy thin films were deposited at different N2 partial pressures, after which their electrocatalytic properties towards glucose oxidation were investigated. Relative to the bare Ni, NixNy thin films sputtered at low N2 partial pressures exhibited a decreased linear range (0–5 mM) and sensitivity. Contrarily, NixNy thin films sputtered at high N2 partial pressures displayed an increase in sensitivity of ≈30% in the same linear range (0–10 mM) as for Ni. The NixNy films showed a clear morphological change from a flat thin film (Ni) to a faceted nanostructure whose characteristic dimensions decreased with increasing N2. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(From <b>left</b> to <b>right</b>) SEM images of Ni, Ni<sub>x</sub>N<sub>y</sub> (20%), Ni<sub>x</sub>N<sub>y</sub> (50%).</p>
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<p>Cyclic voltammograms of Ni (<b>A</b>) Ni<sub>x</sub>N<sub>y</sub> 20% (<b>B</b>), Ni<sub>x</sub>N<sub>y</sub> 50% (<b>C</b>) in 0.1 M KOH at 0, 1, 2, 4, 8, 10 mM of glucose.</p>
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3 pages, 600 KiB  
Abstract
Questioning Breath: A Digital Dive into CO2 Levels
by Silvia Casalinuovo, Alessio Buzzin, Antonio Mastrandrea, Marcello Barbirotta, Donatella Puglisi, Giampiero de Cesare and Domenico Caputo
Proceedings 2024, 97(1), 157; https://doi.org/10.3390/proceedings2024097157 - 7 Apr 2024
Viewed by 704
Abstract
This work presents a smart mask for real-time monitoring of carbon dioxide (CO2) levels as a reference tool for diagnosis, sports training and mental health status. A printed circuit board was projected and fabricated to gain data with real-time visualization and [...] Read more.
This work presents a smart mask for real-time monitoring of carbon dioxide (CO2) levels as a reference tool for diagnosis, sports training and mental health status. A printed circuit board was projected and fabricated to gain data with real-time visualization and storage on a database, enabling remote monitoring as a needed skill for telemedicine purposes. The electronics were inserted in a wearable device—shaped like a mask—and 3D-printed with biocompatible materials. The whole device was used for analyzing CO2 on a breath volunteer in three kinds of measurement. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Image of a printed circuit board (PCB)-based breath sensing system. The figure highlights the small size of the device compared to a coin; (<b>b</b>) Prototype of the wearable device useful for encapsulating the PCB. In order (i), (ii), (iii), (iv) insets represent the top-, front-, lateral- and back- side views; (<b>c</b>) Plot showing CO<sub>2</sub> levels (ppm) vs. samples (s) in three measurement conditions.</p>
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3 pages, 2464 KiB  
Abstract
Transparent PZT Capacitors on Glass for Actuating Applications
by Franklin Pavageau, Christel Dieppedale, Kevin Benedetto, Christophe Licitra, Laurent Frey, Fabrice Casset and Gwenaël Le Rhun
Proceedings 2024, 97(1), 158; https://doi.org/10.3390/proceedings2024097158 - 7 Apr 2024
Viewed by 3118
Abstract
Fully integrated transparent ITO/PZT/ITO capacitors on glass were obtained thanks to a recently developed wafer-to-wafer layer-transfer process to bypass the thermal budget issue associated with the high crystallization temperature of PZT (~700 °C). The fabricated devices show an average transparency of around 80% [...] Read more.
Fully integrated transparent ITO/PZT/ITO capacitors on glass were obtained thanks to a recently developed wafer-to-wafer layer-transfer process to bypass the thermal budget issue associated with the high crystallization temperature of PZT (~700 °C). The fabricated devices show an average transparency of around 80% (and up to 94%) in the visible spectrum thanks to the use of SiO2 passivation acting as an anti-reflector and a transverse piezoelectric coefficient of up to 10.25 C/m2, which is suitable for the actuating purpose. The actuation of a vibrating glass plate (3.12 cm × 3.12 cm) was highlighted using a PZT capacitor (35.9 mm2) in agreement with the modeling. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Piezoelectric stack (5 mask levels integration). (<b>b</b>) Transparency of capacitors evidenced.</p>
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<p>(<b>a</b>) Simulation of the plate’s vibration mode. (<b>b</b>) Photography of the actuator device and its connector. (<b>c</b>) Comparison of the simulated resonance frequency (COMSOL) and the measured one.</p>
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3 pages, 575 KiB  
Abstract
Light-Emitting Silicon Nanowires (Si NWs) as a Novel Sensing Platform for SARS-CoV-2 Detection
by Antonio Alessio Leonardi, Emanuele Luigi Sciuto, Maria José Lo Faro, Barbara Fazio, Maria Giovanna Rizzo, Luca Francioso, Rosaria Anna Picca, Francesco Nastasi, Alessia Irrera and Sabrina Conoci
Proceedings 2024, 97(1), 159; https://doi.org/10.3390/proceedings2024097159 - 7 Apr 2024
Viewed by 956
Abstract
Silicon nanowires (Si NWs) are considered an outstanding material for several applications. We have realized quantum-confined and room-temperature luminescent Si NWs. These Si NWs exhibit a high-aspect ratio, and high sensitive and selective label-free detection has been demonstrated for proteins, small extracellular vesicles, [...] Read more.
Silicon nanowires (Si NWs) are considered an outstanding material for several applications. We have realized quantum-confined and room-temperature luminescent Si NWs. These Si NWs exhibit a high-aspect ratio, and high sensitive and selective label-free detection has been demonstrated for proteins, small extracellular vesicles, and DNAs. The realization of a SARS-CoV-2 Si NW sensor able to detect a few virus copies and remain unaffected by the variant (such as Omicron) is reported, paving the way for new, cheap, optical label-free devices for the primary health care diagnosis with an industrially compatible approach. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Commercial Si wafer, (<b>b</b>) Au discontinuous layer, (<b>c</b>) Si NWs. SEM images Si NWs in the circular cavities in (<b>d</b>) plan view and (<b>e</b>) cross-section. (<b>f</b>) Functionalization protocol. (<b>g</b>) Calibration curve.</p>
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3 pages, 648 KiB  
Abstract
3D Bioprinted Hydrogel Sensor towards Rapid Salivary Diagnostics Based on pH Colorimetric Detection
by Magdalena Beata Łabowska, Agnieszka Krakos (Podwin) and Wojciech Kubicki
Proceedings 2024, 97(1), 160; https://doi.org/10.3390/proceedings2024097160 - 7 Apr 2024
Cited by 1 | Viewed by 840
Abstract
In this paper, a novel solution of 3D bioprinted hydrogel sensor towards rapid diagnostics of saliva based on pH colorimetric detection is proposed. The hydrogel ink of unique composition of sodium alginate and polyvinylpyrrolidone was developed and printed on biocompatible substrates to achieve [...] Read more.
In this paper, a novel solution of 3D bioprinted hydrogel sensor towards rapid diagnostics of saliva based on pH colorimetric detection is proposed. The hydrogel ink of unique composition of sodium alginate and polyvinylpyrrolidone was developed and printed on biocompatible substrates to achieve a repeatable and robust sensor structure. A colorimetric method was applied to visualize the hydrogel color tunability in a pH range of 5.5–7.5. The biosensor calibration curve was determined showing appropriate performance, as well as experiments with artificial saliva samples containing green tea in different proportions were conducted. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Process of 3D bioprinting-example: (<b>a</b>); Front panel of application for colorimetric detection; plate with hydrogel areas selected for analysis—green boxes (left), RGB component analysis for 5 samples—ROI 1 to ROI 5 (right): (<b>b</b>).</p>
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<p>Repeatability tests of sensor fabrication–results (5 hydrogel structures shown at the top): (<b>a</b>), Calibration curve (real-view of the sensor shown at the top): (<b>b</b>), Analysis of artificial saliva samples mixed with green tea in different ratios (reference–no saliva; saliva; saliva with green tea mixed in a ratio 1:5 <span class="html-italic">v</span>/<span class="html-italic">v</span>): (<b>c</b>).</p>
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2 pages, 394 KiB  
Abstract
Sensor Protection Caps: Development Aspects and Verification
by Gunter Hagen, Julia Herrmann, Thomas Kern, Thomas Wöhrl and Ralf Moos
Proceedings 2024, 97(1), 161; https://doi.org/10.3390/proceedings2024097161 - 8 Apr 2024
Viewed by 764
Abstract
High-temperature gas sensors are often affected by non-constant ambient conditions, especially with respect to mass flow variations. Steady operation conditions are essential for attaining stable results. So, appropriate protection caps must provide an optimum level of gas access to the sensors’ functional structures [...] Read more.
High-temperature gas sensors are often affected by non-constant ambient conditions, especially with respect to mass flow variations. Steady operation conditions are essential for attaining stable results. So, appropriate protection caps must provide an optimum level of gas access to the sensors’ functional structures to allow for a sufficient response but also maximal homogeneity. Therefore, cap design was carried out through modelling and simulations. For verification, we used a specially developed sensor structure with screen-printed thermocouples to measure temperature homogeneity inside individually designed caps, which were created via additive manufacturing. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Example of a verification measurement: Sensor transducer (<b>a</b>) with screen-printed Pt-Au-thermocouples protected by individual modelled and additive-manufactured cap (<b>b</b>). Temperature characteristics on the sensors surface were measured under varying gas flows (<b>c</b>). The temperatures were even unaffected by twisting the sensor orientation.</p>
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3 pages, 1551 KiB  
Abstract
Embedded Sensing System for Wireless Sleep Apnea Monitoring
by Gabriel Rodriguez Gutierrez, Chenchen Shen, Daniel Rau, Alvaro Ortiz Perez, Jürgen Götze and Stefan Palzer
Proceedings 2024, 97(1), 162; https://doi.org/10.3390/proceedings2024097162 - 8 Apr 2024
Viewed by 984
Abstract
Sleep apnea syndrome is a breathing disorder with a prevalence exceeding 20% in the overall population, and it can seriously affect health and well-being. However, this condition usually remains undetected because suitable monitoring solutions are lacking. This contribution presents an approach to facilitate [...] Read more.
Sleep apnea syndrome is a breathing disorder with a prevalence exceeding 20% in the overall population, and it can seriously affect health and well-being. However, this condition usually remains undetected because suitable monitoring solutions are lacking. This contribution presents an approach to facilitate apnea diagnosis using a battery-powered, wireless, miniaturized sensing system embedded in a patient’s mask. It combines a photoacoustic-based carbon dioxide detector with temperature and humidity sensors as well as embedded algorithms to automatically detect apnea episodes. The results show the feasibility of detecting apnea using an easily deployable analysis system. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic overview of the wireless, embedded system design for apnea diagnosis. (<b>b</b>) The system concept including a highly selective, miniatured CO<sub>2</sub> sensing module.</p>
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<p>The real time values of the apnea indicator (black line) during a laboratory test and simulated apnea events. The system’s algorithm reliably detected patterns in line with OSA. The blue line represents the threshold value under which an apnea episode is detected, the red lines are time intervals in which a simulated apnea event occurred.</p>
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2 pages, 361 KiB  
Abstract
TinyML with Meta-Learning on Microcontrollers for Air Pollution Prediction
by I Nyoman Kusuma Wardana, Suhaib A. Fahmy and Julian W. Gardner
Proceedings 2024, 97(1), 163; https://doi.org/10.3390/proceedings2024097163 - 8 Apr 2024
Viewed by 962
Abstract
Tiny machine learning (tinyML) involves the application of ML algorithms on resource-constrained devices such as microcontrollers. It is possible to improve tinyML performance by using a meta-learning approach. In this work, we proposed lightweight base models running on a microcontroller to predict air [...] Read more.
Tiny machine learning (tinyML) involves the application of ML algorithms on resource-constrained devices such as microcontrollers. It is possible to improve tinyML performance by using a meta-learning approach. In this work, we proposed lightweight base models running on a microcontroller to predict air pollution and show how performance can be improved using a stacking ensemble meta-learning method. We used an air quality dataset for London. Deployed on a Raspberry Pi Pico microcontroller, the tinyML file sizes were 3012 bytes and 5076 bytes for the two base models we proposed. The stacked model could achieve RMSE improvements of up to 4.9% and 14.28% when predicting NO2 and PM2.5, respectively. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Stacking ensemble concept; (<b>b</b>) Base-1 and Base-2 model architectures.</p>
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3 pages, 885 KiB  
Abstract
Self-Diagnostic Method for Resistive Displacement Sensors
by Federico Mazzoli, Davide Alghisi and Vittorio Ferrari
Proceedings 2024, 97(1), 164; https://doi.org/10.3390/proceedings2024097164 - 8 Apr 2024
Cited by 1 | Viewed by 753
Abstract
Displacement sensors play a key role in the control of dynamic processes. Such sensors can be endowed with self-diagnostic capabilities to identify both the degradation of their conditions and the possible process anomalies that caused them, thus allowing researchers to monitor the process [...] Read more.
Displacement sensors play a key role in the control of dynamic processes. Such sensors can be endowed with self-diagnostic capabilities to identify both the degradation of their conditions and the possible process anomalies that caused them, thus allowing researchers to monitor the process efficiency and therefore its sustainability. Within this scope, a self-diagnostic method is proposed to infer the conditions of a resistive displacement sensor by estimating its model parameters online during operation. Experimental results confirm the effectiveness of the presented method. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Circuit model of a generic resistive displacement sensor (<b>a</b>). Images obtained with digital microscopy system (Leica DMS300, Wetzlar, Germany) of the sensor resistive track in undamaged (<b>b</b>) and worn (<b>c</b>) conditions.</p>
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<p>Estimated values of the parameters <b><span class="html-italic">p</span><sub>0</sub></b> = [<span class="html-italic">R<sub>c</sub></span><sub>0</sub>; ξ<sub>0</sub>] and <b><span class="html-italic">p</span><sub>w</sub></b> = [<span class="html-italic">R<sub>c</sub></span><sub>w</sub>; ξ<sub>w</sub>] obtained from resistances <span class="html-italic">R</span><sub>12<span class="html-italic">k</span></sub>, <span class="html-italic">R</span><sub>23<span class="html-italic">k</span></sub> and <span class="html-italic">R</span><sub>13<span class="html-italic">k</span></sub> measured at <span class="html-italic">n</span> = 500 different random positions in the initial and worn conditions (<b>a</b>). Position errors <span class="html-italic">e</span><sub>pos</sub> of the worn sensor versus cursor position derived with reference to both <b><span class="html-italic">P</span><sub>0</sub></b> and <b><span class="html-italic">P</span><sub>w</sub></b> (<b>b</b>).</p>
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3 pages, 572 KiB  
Abstract
Selective Detection of Toxic Gases by Arrays of Single-Layer Graphene Sensors Functionalized with Nanolayers of Different Oxides
by Margus Kodu, Martin Lind, Valter Kiisk, Indrek Renge and Raivo Jaaniso
Proceedings 2024, 97(1), 165; https://doi.org/10.3390/proceedings2024097165 - 8 Apr 2024
Viewed by 866
Abstract
Graphene provides an ideal platform for chemiresistive gas sensors as the material is fully exposed to the surrounding environment. For practical use in an ambient atmosphere, its sensitivity and selectivity should be evoked by functionalization by defects and dopants or by decoration with [...] Read more.
Graphene provides an ideal platform for chemiresistive gas sensors as the material is fully exposed to the surrounding environment. For practical use in an ambient atmosphere, its sensitivity and selectivity should be evoked by functionalization by defects and dopants or by decoration with nanophases of metals or metal oxides. Here, we demonstrate a few successful cases of selectivity enhancement by functionalizing the graphene with different oxide layers and applying machine learning to the resulting sensor array. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Responses of an array (inset) of graphene sensors functionalized with different PLD films for differentiating NH3 and NO2 gases. Measured at RT under UV light excitation. (<b>b</b>) Responses of an array of graphene sensors functionalized with different PLD films for differentiating O3 and NO2 gases. The inset shows clustering of the data points in the 2D feature space of the response amplitudes.</p>
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3 pages, 1374 KiB  
Abstract
Integration of a Bead-Based Immunoassay on a Commercial PCR-Performing POC Device
by Benita Johannsen, Desirée Baumgartner, Michal Karpíšek, David Stejskal, Nils Paust, Roland Zengerle and Konstantinos Mitsakakis
Proceedings 2024, 97(1), 166; https://doi.org/10.3390/proceedings2024097166 - 8 Apr 2024
Viewed by 3504
Abstract
Point-of-care (POC) infectious disease diagnostic devices typically detect either only pathogens or only protein biomarkers, while they provide a low throughput of samples (one to two) tested per run. In this work, we demonstrate the adaptation of a bead-based competitive immunoassay method to [...] Read more.
Point-of-care (POC) infectious disease diagnostic devices typically detect either only pathogens or only protein biomarkers, while they provide a low throughput of samples (one to two) tested per run. In this work, we demonstrate the adaptation of a bead-based competitive immunoassay method to be compatible with a commercial POC PCR-performing device without modifications to its hardware. In addition, the assay integration in two half disk-shaped cartridges with seven identical structures on each provides a considerable throughput of 14 samples per 20 min run. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Left: Schematic of the BFPD-IA. The grey arrow and yellow symbol in step 2 indicate the separation of the MB (e.g., via centrifugation) and the fluorescence detection, respectively. Middle: Design of two half-disks with 14 multipurpose chambers. The dashed box indicates the repeated structure. Bottom right: a Rhonda device.</p>
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<p>Left: Standard curves with varying FB volumes. Right: The table indicates the number of samples that were classified in each concentration zone A, B, and C (values in mg/L), based on the MTP and the disk on Rhonda.</p>
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3 pages, 689 KiB  
Abstract
Measuring the Thermal Conductivity of Humid Air over a Broad Temperature and Water Content Range
by Hans-Fridtjof Pernau, Mike Benkendorf, Martin Jägle, Stephan Heinrich, Thorsten Knittel and Jürgen Wöllenstein
Proceedings 2024, 97(1), 167; https://doi.org/10.3390/proceedings2024097167 - 8 Apr 2024
Viewed by 919
Abstract
The knowledge of the thermal conductivity of humid air between 0 and 100 °C and 0 and 100% relative humidity is of great interest for various applications. However, direct measurement of the thermal conductivity of gaseous substances is challenging. Using an adapted version [...] Read more.
The knowledge of the thermal conductivity of humid air between 0 and 100 °C and 0 and 100% relative humidity is of great interest for various applications. However, direct measurement of the thermal conductivity of gaseous substances is challenging. Using an adapted version of the 3-omega method, we show that direct measurement is possible within a reasonable error limit. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Calculated thermal conductivity [<a href="#B3-proceedings-97-00167" class="html-bibr">3</a>] of humid air as a function of water mol ratio and temperature.</p>
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<p>Calculated virtual shift in the thermal conductivity when the sensor temperature is 15 K higher than the actual gas temperature. Depending on the starting point in <a href="#proceedings-97-00167-f001" class="html-fig">Figure 1</a>, the shift in thermal conductivity is strongly affected by the absolute humidity (60 °C gas temperature).</p>
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3 pages, 1022 KiB  
Abstract
Cu Ferrospinel Thin Films for Sub-ppm NO2 Sensing
by Sabah Zahaf, Lionel Presmanes, Antoine Barnabé, Thierry Camps and Philippe Menini
Proceedings 2024, 97(1), 168; https://doi.org/10.3390/proceedings2024097168 - 9 Apr 2024
Viewed by 792
Abstract
The paper reports the synthesis and characterization of a copper ferrospinel thin layer. The thin layer (25 nm) was synthesized by RF sputtering of a pure CuFe2O4 target. The material structure and microstructure were characterized using X-ray diffraction and transmission [...] Read more.
The paper reports the synthesis and characterization of a copper ferrospinel thin layer. The thin layer (25 nm) was synthesized by RF sputtering of a pure CuFe2O4 target. The material structure and microstructure were characterized using X-ray diffraction and transmission electron microscopy. Simplified test substrates were microfabricated with interdigitated Pt electrodes to investigate electrical properties in a controlled atmosphere. The sensitive layer was stabilized by annealing at 550 °C under air. NO2 responses at a low concentration (<1 ppm) and 50% relative humidity were measured between 100 and 500 °C. The optimal response was obtained at 250 °C. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Electrical microdevice design used for sensing performance evaluation with 16 Pt electrodes of 100 µm width. The distance between each electrode is 50 µm.</p>
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<p>XRD pattern of copper ferrospinel thin film.</p>
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<p>NO<sub>2</sub>-sensing performance.</p>
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2 pages, 156 KiB  
Abstract
Gas Sensors: A Non-Contact and Non-Invasive Solution for Checking the Hydraulic Fluid Degradation
by Ambra Fioravanti, Pietro Marani, Luigi Sequino, Fulvio Palmieri, Francesca Rapparini, Achill Holzer, Zita Tappeiner, Katharina Schmitz, Sara Morandi, Stefano Lettieri and Maria Cristina Carotta
Proceedings 2024, 97(1), 169; https://doi.org/10.3390/proceedings2024097169 - 9 Apr 2024
Viewed by 941
Abstract
Chemiresistive gas sensors based on metal oxide (MOX) semiconductors are attractive devices used to detect gaseous compounds in many applications. In fluid power systems, they could be exploited to monitor the odor changes of the hydraulic fluid that occur with aging. In this [...] Read more.
Chemiresistive gas sensors based on metal oxide (MOX) semiconductors are attractive devices used to detect gaseous compounds in many applications. In fluid power systems, they could be exploited to monitor the odor changes of the hydraulic fluid that occur with aging. In this work, an extensive investigation has been performed for many kinds of hydraulic fluids aged in different conditions with the aim to develop a portable device to be installed in every system for performing predictive maintenance increasing system efficiency, reliability, and sustainability. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 317 KiB  
Abstract
Surface Enhanced Raman Scattering (SERS) for the Detection of Oxidative Stress Markers Using Si Nanowires (SiNWs)/Ag Nanostructures Fabricated by Metal Assisted Chemical Etching (MACE)
by Ioannis Kochylas, Anastasia Kanioura, Georgia Geka, Vlassios Likodimos, Spiros Gardelis, Anastasios Dimitriou, Nikolaos Papanikolaou, Sotirios Kakabakos and Panagiota Petrou
Proceedings 2024, 97(1), 170; https://doi.org/10.3390/proceedings2024097170 - 9 Apr 2024
Viewed by 969
Abstract
In this work, silicon nanowires were constructed by metal-assisted chemical etching and decorated with silver nanoparticles and used as substrates for the SERS determination of oxidative stress markers, namely glutathione, malondialdehyde and catalase. The assays were sensitive, with detection limits of 50 and [...] Read more.
In this work, silicon nanowires were constructed by metal-assisted chemical etching and decorated with silver nanoparticles and used as substrates for the SERS determination of oxidative stress markers, namely glutathione, malondialdehyde and catalase. The assays were sensitive, with detection limits of 50 and 3.2 nM for glutathione and malondialdehyde, respectively, and 0.5 μg/mL for catalase, indicating the capability of the proposed substrates to be implemented for the determination of various oxidative stress markers. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) SERS spectra of CV upon incubation with 0 (dark blue line) and 1 μM GSH (red line). (<b>b</b>) SERS spectra of TBA-MDA adduct for 0 (blue line) and 32 nM MDA (purple line). (<b>c</b>) SERS spectra of catalase at concentrations of 5 (black line) and 50 μg/mL (green line).</p>
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3 pages, 999 KiB  
Abstract
SiO2/Platinum Monolith Aerogels Realized in Closed µfluidic Channels
by Ana Luiza Silveira Fiates, Oliver Thüringer, Thorsten M. Gesing and Michael J. Vellekoop
Proceedings 2024, 97(1), 171; https://doi.org/10.3390/proceedings2024097171 - 9 Apr 2024
Viewed by 829
Abstract
Aerogels with noble metals have a wide range of applications such as sensing and catalysis, but research needs to be done to improve the integration of these materials in µ-channels. We realize silica aerogels without shrinkage and with high specific surface area (~600 [...] Read more.
Aerogels with noble metals have a wide range of applications such as sensing and catalysis, but research needs to be done to improve the integration of these materials in µ-channels. We realize silica aerogels without shrinkage and with high specific surface area (~600 m2/g) inside of closed channels. Further, Pt nanoparticles are deposited via capillary forces, into the complete network. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>View of the chip filled with aerogel, (<b>a</b>) adhesion between glass and aerogel (<b>b</b>) between silicon and aerogel (<b>c</b>) EDX from the middle of the aerogel sample, red dots are Pt nanoparticles.</p>
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3 pages, 756 KiB  
Abstract
Smart Odour Sensing for Automated Monitoring of Bread Products
by Carmen Bax, Bianca di Diodoro, Alessandro Ticozzi, Nicolò Dellarosa, Flavio Corazza, Giacomo Langfelder and Laura Capelli
Proceedings 2024, 97(1), 172; https://doi.org/10.3390/proceedings2024097172 - 9 Apr 2024
Cited by 1 | Viewed by 816
Abstract
This work proposes an electronic nose (e-nose) system based on resistive gas sensors to predict the cooking evolution of different types of bread. The e-nose includes six metal-oxide semiconductor (MOS) gas sensors, a low-noise electronic system for signal conditioning and data acquisition, and [...] Read more.
This work proposes an electronic nose (e-nose) system based on resistive gas sensors to predict the cooking evolution of different types of bread. The e-nose includes six metal-oxide semiconductor (MOS) gas sensors, a low-noise electronic system for signal conditioning and data acquisition, and a classification algorithm for real-time detection of the cooking stage. Baking tests with five different recipes were carried out, and the system performances were evaluated by a panel of tasters, obtaining a -88% accuracy for the automatic detection of cooking time. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Measured noise density of a TGS2620. (<b>b</b>) Temperature, humidity and resistance values of three of the gas sensors during the bread baking process.</p>
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<p>(<b>a</b>) PCA score plot of the dataset. (<b>b</b>) Sensorial evaluation of bread samples.</p>
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3 pages, 544 KiB  
Abstract
Portable Fluorescence Biosensing System for Low-Cost, Quantitative, and Multiplexed Allergen Screening
by Hui Chai-Gao, Yevhen Shynkarenko, Silvia Demuru, Nicola Hermann, Patricia-Daiana Boia, Peter Cristofolini, Bradley Petkus, Silvia Generelli, Stefano Cattaneo and Loïc Burr
Proceedings 2024, 97(1), 173; https://doi.org/10.3390/proceedings2024097173 - 10 Apr 2024
Viewed by 879
Abstract
A miniaturized multi-array system is being developed for immune-signature testing. The presented system includes microfluidic chips functionalized with allergens for IgE detection and a custom-made portable reader for fast (~1 s), quantitative, and sensitive (500 dye molecules/μm2) detection, with a high [...] Read more.
A miniaturized multi-array system is being developed for immune-signature testing. The presented system includes microfluidic chips functionalized with allergens for IgE detection and a custom-made portable reader for fast (~1 s), quantitative, and sensitive (500 dye molecules/μm2) detection, with a high spatial resolution (~50–100 μm). The developed solution enables the rapid sensing of allergic reactions at the point of care with a low-cost portable device. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Multiplex system for allergen screening. (<b>a</b>) Images showing the microfluidic system (1.), the system for sample handling (2.), the fluorescent signals on the micropillars (3.), and the portable fluorescent reader (4.). (<b>b</b>) Signal corresponding to specific IgEs recorded with InnoScan reader. The arrows inducate a high IgE response for common birch (green bars), cat epithelium (pink bars), and house dust mite (Der. pter-onyssinus, yellow bars).</p>
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3 pages, 658 KiB  
Abstract
Pull-In Voltage and Stress in Fixed-Fixed Beams of RF MEMS Switches
by Anna Persano, Girolamo Tagliapietra, Jacopo Iannacci, Alvise Bagolini, Fabio Quaranta and Pietro Siciliano
Proceedings 2024, 97(1), 174; https://doi.org/10.3390/proceedings2024097174 - 10 Apr 2024
Cited by 1 | Viewed by 3305
Abstract
Electrostatically actuated microelectromechanical system (MEMS) switches with fixed- fixed beams were fabricated. FEM modeling was used to calculate the contributions of stress in the fabricated beams from the measured values of pull-in voltage. The reported study provides useful guidelines to optimize the design [...] Read more.
Electrostatically actuated microelectromechanical system (MEMS) switches with fixed- fixed beams were fabricated. FEM modeling was used to calculate the contributions of stress in the fabricated beams from the measured values of pull-in voltage. The reported study provides useful guidelines to optimize the design of fixed-fixed beams, in order to reduce the stress contributions for the successful development of efficient and reliable electrostatically actuated MEMS devices. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Typical SEM image of a fabricated RF MEMS switch. The labels <span class="html-italic">l</span>, <span class="html-italic">r</span>, and <span class="html-italic">s</span> are used to indicate the different sections of the beam and are equal to 65 µm, 100 µm, and 95 µm, respectively. The width of the beam is 100 µm.</p>
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<p>Diagram of the deformation (<b>a</b>) and of the stress (<b>b</b>) that are induced by the electrostatic actuation of the beam.</p>
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3 pages, 396 KiB  
Abstract
Microhotplate as a Platform for Calorimetry
by Rebeka Gy. Kiss, Lajos Harasztosi, István A. Szabó and Gábor Battistig
Proceedings 2024, 97(1), 175; https://doi.org/10.3390/proceedings2024097175 - 10 Apr 2024
Viewed by 3165
Abstract
Calorimetry is a powerful method for characterising materials. The heat of a reaction can be directly measured with good accuracy. The established method usually requires large amounts of materials, which is a major drawback when studying thin film reactions. A MEMS microhotplate-based microcalorimeter [...] Read more.
Calorimetry is a powerful method for characterising materials. The heat of a reaction can be directly measured with good accuracy. The established method usually requires large amounts of materials, which is a major drawback when studying thin film reactions. A MEMS microhotplate-based microcalorimeter is developed in this study; it allows us to investigate thin film reactions by using a very small amount of materials. The temperature scale is calibrated by a well-known heat method of melting of two metal films. Energy calibration is also solved, and thus real information can be extracted for various solid-phase thin film reactions. In order to study reactions taking place close to room temperature, a cooled sample holder is developed, and the measurements can be started well below 0 °C. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Layout of the Pt heater element with a diameter of 150 mm with enhanced temperature homogeneity over the surface (<b>a</b>); Microcalorimeter chip with two independent heater elements embedded in separated dielectric membranes (<b>b</b>).</p>
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3 pages, 505 KiB  
Abstract
Reliable Damping Simulation of Highly Perforated Micro-Electro-Mechanical Systems through Physical Compact Modeling
by Friederike Michael, Barbara Leikam and Gabriele Schrag
Proceedings 2024, 97(1), 176; https://doi.org/10.3390/proceedings2024097176 - 11 Apr 2024
Viewed by 3221
Abstract
We present an approach to estimate damping in highly and irregularly perforated microplates over a wide range of pressures applying physics-based compact models implemented in a flux-conserving finite network. The models are coded in Verilog A, which allows for simulation using a standard [...] Read more.
We present an approach to estimate damping in highly and irregularly perforated microplates over a wide range of pressures applying physics-based compact models implemented in a flux-conserving finite network. The models are coded in Verilog A, which allows for simulation using a standard circuit simulator. This provides an efficient and customizable way to determine damping beyond the state of the art, and thus, to tailor and design the dynamic operation of MEMS in a predictive manner. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Top view of the “chessboard” test structure. (<b>b</b>) Pressure-dependent damping ratio due to SQFD: comparison of simulation results with experimentally extracted data of three different test structures. Non-viscous damping (e.g., structural damping) is subtracted from the measurement as in [<a href="#B5-proceedings-97-00176" class="html-bibr">5</a>].</p>
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3 pages, 1261 KiB  
Abstract
Printed Anisotropic Magnetoresistive Sensors on Flexible Polymer Foils
by Clemens Voigt, Sindy Mosch, Eduardo Sergio Oliveros-Mata, Denys Makarov, Conrad Schubert, Morris Ott, Thomas Preußner and Mykola Vinnichenko
Proceedings 2024, 97(1), 177; https://doi.org/10.3390/proceedings2024097177 - 11 Apr 2024
Viewed by 889
Abstract
The experimental approach to the fabrication of flexible anisotropic magnetoresistive (AMR) sensors for magnetic field detection in the mT range is validated. It is based upon a combination of screen printing with high-power diode laser array post-processing, both of which are scalable and [...] Read more.
The experimental approach to the fabrication of flexible anisotropic magnetoresistive (AMR) sensors for magnetic field detection in the mT range is validated. It is based upon a combination of screen printing with high-power diode laser array post-processing, both of which are scalable and high-throughput methods. The whole process chain is evaluated, including powder preparation, paste formulation, screen printing, laser sintering, and characterization of microstructure and magnetoresistive response of the resulting sensors. Using high-quality permalloy powder with platelet geometry, the sensors with an AMR effect of 0.5–0.6% at 2–3 mT were realized on polymer substrates. The further optimization of the sensors’ preparation steps is in progress. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematics of process chain. (<b>b</b>) Photo of printed and laminated meander structure on polyimide foil and (<b>c</b>) photo of printed, laminated, and sintered structure on also printed contacts.</p>
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<p>MR plots of meander structure sintered with an optimal fluence of 17.4 J/cm² where the magnetic field is parallel to the long axis (<b>a</b>) and perpendicular (<b>b</b>).</p>
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2 pages, 851 KiB  
Abstract
Prediction of Atmospheric Ozone Concentrations with a Temperature-Modulated Gas Sensor Array
by Arne Kobald, Udo Weimar and Nicolae Bârsan
Proceedings 2024, 97(1), 178; https://doi.org/10.3390/proceedings2024097178 - 11 Apr 2024
Viewed by 764
Abstract
Ozone is one of the most important pollutant gases. The excellent sensitivity and low limit of detection of gas sensors based on Semiconducting Metal Oxides (SMOXs) make them ideal candidates to accurately monitor outdoor air quality. We present a convolutional neural network (CNN) [...] Read more.
Ozone is one of the most important pollutant gases. The excellent sensitivity and low limit of detection of gas sensors based on Semiconducting Metal Oxides (SMOXs) make them ideal candidates to accurately monitor outdoor air quality. We present a convolutional neural network (CNN) architecture that is trained on the resistance readout of a multi-pixel SMOX gas sensor array operated in temperature modulation. The trained model outperforms a ridge regressor in the quantification of ozone concentrations in real outdoor air. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Predicted vs. real concentrations of ozone for (<b>a</b>) the CNN model and (<b>b</b>) the ridge regression.</p>
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3 pages, 619 KiB  
Abstract
Real-Time Tracking of the Dynamic Viscosity of Bitumen with Piezoelectric MEMS Resonators
by Suresh Alasatri, Michael Schneider, Johannes Mirwald, Bernhard Hofko and Ulrich Schmid
Proceedings 2024, 97(1), 179; https://doi.org/10.3390/proceedings2024097179 - 12 Apr 2024
Viewed by 2954
Abstract
This work demonstrates lab-scale monitoring of the dynamic viscosity of bitumen with piezoelectric MEMS resonators over a period of 120 h at an elevated temperature of 100 °C in air. The aluminium nitride-based MEMS resonator is excited in a high-order roof-tile-shaped mode to [...] Read more.
This work demonstrates lab-scale monitoring of the dynamic viscosity of bitumen with piezoelectric MEMS resonators over a period of 120 h at an elevated temperature of 100 °C in air. The aluminium nitride-based MEMS resonator is excited in a high-order roof-tile-shaped mode to provide high-quality factors while immersed in bitumen. The results demonstrate the robustness of the MEMS sensor, as it is capable of performing at elevated temperatures continuous measurements for a long time even in harsh environments like bitumen. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Top and bottom images show the raw and corrected conductance with fitted LCR conductance, respectively; (<b>b</b>) <span class="html-italic">f</span><sub>0</sub> as a function of time for submerged sensor in bitumen.</p>
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<p>(<b>a</b>,<b>b</b>) Q and <span class="html-italic">µ</span> as a function of time for immersed sensor in bitumen, respectively.</p>
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2 pages, 150 KiB  
Abstract
RFID Autonomous Sensors for Monitoring Corrosion on Prestressed Concrete Bridges
by Karim Bouzaffour, Philippe Talbot, Benoit Lescop, Stephane Rioual, Yannick Falaise, Cheikh Sarr, Sylvain Chataigner and Laurent Gaillet
Proceedings 2024, 97(1), 180; https://doi.org/10.3390/proceedings2024097180 - 12 Apr 2024
Viewed by 818
Abstract
Steel corrosion in concrete infrastructures is of worldwide interest. This paper reports the monitoring of concrete prestressed bridge infrastructures by autonomous sensors based on the RFID technology. Embedded autonomous sensors in concrete were produced for this purpose and tested in a laboratory environment. [...] Read more.
Steel corrosion in concrete infrastructures is of worldwide interest. This paper reports the monitoring of concrete prestressed bridge infrastructures by autonomous sensors based on the RFID technology. Embedded autonomous sensors in concrete were produced for this purpose and tested in a laboratory environment. Subsequent tests in real environments are in progress. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 644 KiB  
Abstract
Surface-Enhanced Raman Spectroscopy on Ag−WO3/TiO2 Inverse Opal Film Substrates
by Maria-Athina Apostolaki, Elias Sakellis, Polychronis Tsipas, Spiros Gardelis and Vlassis Likodimos
Proceedings 2024, 97(1), 181; https://doi.org/10.3390/proceedings2024097181 - 12 Apr 2024
Viewed by 984
Abstract
The synergetic effects of electromagnetic and chemical enhancements via the combination of semiconductor nanomaterials with noble metal nanoparticles is crucial to the performance of surface-enhanced Raman scattering (SERS). Here, WO3/TiO2 photonic crystal films in the form of three-dimensional inverse opals [...] Read more.
The synergetic effects of electromagnetic and chemical enhancements via the combination of semiconductor nanomaterials with noble metal nanoparticles is crucial to the performance of surface-enhanced Raman scattering (SERS). Here, WO3/TiO2 photonic crystal films in the form of three-dimensional inverse opals were fabricated via the co-assembly of polymer colloidal templates with water-soluble precursors in order to simultaneously grow both constituent metal oxides with tailored electronic properties and photonic band gaps. The surface modification of compositionally tuned WO3/TiO2 inverse opals by Ag nanoparticles is demonstrated to be an efficient method to boost SERS efficiency in the detection of 4−mercaptobenzoic acid via the synergy of plasmonic effects with charge transfer and slow-light trapping. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) (Upper) Top view and cross-section SEM images and (Lower) TEM image and elemental EDX maps of Ti and W for PC287 1:0.25; (<b>b</b>) specular reflectance (R%) spectra for PC287 films; (<b>c</b>,<b>d</b>) SERS spectra of 4−MBA on Ag−PC287 WO<sub>3</sub> and 1:2 substrates.</p>
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3 pages, 924 KiB  
Abstract
Small Footprint Temperature Sensing NFC Tag
by Jorge Pereira, Inês S. Garcia, Gabriel Ribeiro, José Fernandes, Filipe S. Alves, Marco Martins, André Cardoso and Rosana A. Dias
Proceedings 2024, 97(1), 182; https://doi.org/10.3390/proceedings2024097182 - 12 Apr 2024
Viewed by 895
Abstract
Smart NFC tags are seeing many interesting applications and can benefit from further miniaturization. A passive temperature sensing tag with 5.1 mm diameter is demonstrated, comprising a thin-film microfabricated antenna and an NFC chip. The microantenna/coil comprises two 15 µm-thick electroplated copper layers [...] Read more.
Smart NFC tags are seeing many interesting applications and can benefit from further miniaturization. A passive temperature sensing tag with 5.1 mm diameter is demonstrated, comprising a thin-film microfabricated antenna and an NFC chip. The microantenna/coil comprises two 15 µm-thick electroplated copper layers embedded in SU-8, withstanding the soldering process of a BGA NFC IC. The µ-antenna design challenge is to miniaturize while minimizing performance impairment (inductive-coupling distance), while the micromachining process is very dependent on topography propagation. Fabricated coils were successfully characterized (2.32 µH inductance; 13.76 MHz self-resonance) and temperature was read (after assembly) with a mobile phone at distances of up to 7 mm. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic representation of NFC μ-antenna, (<b>b</b>) main micromachining process steps, and (<b>c</b>) photograph and microscope image (close-up) of the fabricated devices. Microfabrication includes (i) SiO<sub>2</sub> deposition on silicon wafer, (ii) SiO<sub>2</sub> patterning and SU-8 lithography (iii) Seed layer deposition, thick resist lithography and copper electroplating, (iv) resist removal (v) SU-8 lithography, (vi) thick resist lithography and copper electroplating, (vii) resist removal, (viii) SU-8 lithography and (ix) HF vapor release.</p>
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<p>(<b>a</b>) Temperature sensing tag before encapsulation, (<b>b</b>) encapsulation schematic, (<b>c</b>) picture of encapsulated tag, and (<b>d</b>) NFC tag temperature measurements against thermal camera readings.</p>
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3 pages, 985 KiB  
Abstract
Capacitive Biosensor Based on a Peptide Hybrid Substrate for the Detection of MMP-13 in Chronic Wounds
by Amandine Sandoval, Brice Sorli, Arnaud Vena, Cécile Echalier, Ahmad Mehdi and Gilles Subra
Proceedings 2024, 97(1), 183; https://doi.org/10.3390/proceedings2024097183 - 12 Apr 2024
Viewed by 817
Abstract
This work focuses on a capacitive biosensor based on a hydride peptide for the detection of MMP-13. Indeed, the enzyme MMP-13 is a remarkable indicator of inflammation in chronic wounds. To achieve specific detection of this enzyme, a metallocene was added to the [...] Read more.
This work focuses on a capacitive biosensor based on a hydride peptide for the detection of MMP-13. Indeed, the enzyme MMP-13 is a remarkable indicator of inflammation in chronic wounds. To achieve specific detection of this enzyme, a metallocene was added to the peptide which amplifies the electrical variation allowing for proof of concept and reliability. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) Peptide-based sensor for MMP-13 activity detection. (<b>B</b>) Electrical model used for measurement.</p>
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<p>Curves representing the degradation of the S4 material (green curve) by MMP-13 (S4-MMP, pink curve). (<b>A</b>) capacitance versus frequency. (<b>B</b>) Tan δ versus frequency.</p>
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3 pages, 165 KiB  
Abstract
Optimizing Polyaniline-Based Gas Sensors for Hydrogen Sulfide Detection: The Crucial Role of Solvent Choice
by Maria L. Braunger, Edilene A. da Silva, Igor Fier, Nathalie Redon and Caroline Duc
Proceedings 2024, 97(1), 184; https://doi.org/10.3390/proceedings2024097184 - 12 Apr 2024
Cited by 1 | Viewed by 814
Abstract
Hydrogen sulfide (H2S) gas poses a significant risk and thus demands continuous monitoring using reliable sensors. Chemiresistive sensors can serve this purpose, and the utilization of conducting polymeric materials, particularly polyaniline (PAni), has demonstrated significant potential. To fabricate chemiresistors based on [...] Read more.
Hydrogen sulfide (H2S) gas poses a significant risk and thus demands continuous monitoring using reliable sensors. Chemiresistive sensors can serve this purpose, and the utilization of conducting polymeric materials, particularly polyaniline (PAni), has demonstrated significant potential. To fabricate chemiresistors based on PAni, the materials must be dispersed in an organic solvent like dimethylformamide (DMF), which has several hazardous properties. Fortunately, dimethyl sulfoxide (DMSO) is a safer alternative with similar properties to DMF, and may be used instead of DMF. In this study, we aim to compare the efficacy of DMF and DMSO solvents in fabricating PAni and metal chloride composite films for detecting H2S gas. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 1754 KiB  
Abstract
Flexural Plate Wave Piezoelectric MEMS Pressure Sensor
by Alessandro Nastro, Stefano Bertelli, Marco Ferrari, Libor Rufer, Skandar Basrour and Vittorio Ferrari
Proceedings 2024, 97(1), 185; https://doi.org/10.3390/proceedings2024097185 - 15 Apr 2024
Cited by 1 | Viewed by 3011
Abstract
A piezoelectric MEMS pressure sensor that exploits the first antisymmetric vibration mode (A0) of Lamb waves is presented. The 6 mm × 6 mm diaphragm used to sense the applied pressure is composed of a stack of doped silicon (Si) and aluminum nitride [...] Read more.
A piezoelectric MEMS pressure sensor that exploits the first antisymmetric vibration mode (A0) of Lamb waves is presented. The 6 mm × 6 mm diaphragm used to sense the applied pressure is composed of a stack of doped silicon (Si) and aluminum nitride (AlN) layers with metal interdigital transducers (IDTs) to generate flexural plate waves (FPWs). The working principle has been validated through 2D finite element analysis within the frequency range 10–15 MHz and experimentally verified. A variable pressure has been applied across the diaphragm while measuring the electrical admittance of a single IDT. Experimental data are in good agreement with simulations showing a frequency shift of the admittance peaks when pressure acts on the MEMS diaphragm. For an applied pressure of 170 Pa, a relative frequency variation of 0.25% has been achieved. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Cross-section views of the proposed piezoelectric MEMS pressure sensor without (<b>a</b>) and with (<b>b</b>) the pressure <span class="html-italic">P</span> applied.</p>
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<p>Simplified schematic view of the proposed MEMS device configured for the simulation of the electrical admittance (<b>a</b>). Simulated conductance G(<span class="html-italic">f</span>) of a single IDT as a function of the excitation frequency <span class="html-italic">f</span> at different pressure <span class="html-italic">P</span> (<b>b</b>). Enlarged view of a single peak of G(<span class="html-italic">f</span>) (inset).</p>
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<p>Experimental setup employed to test the MEMS pressure sensor (<b>a</b>). Enlarged view of the sealed chamber (<b>b</b>). Top (<b>c</b>) and bottom (<b>d</b>) views of the fabricated MEMS device. Comparison (<b>e</b>) of the simulated (blue circles) and measured (green circles) relative resonant frequency variation and non-linear fittings (dotted curves) as a function of the applied pressure <span class="html-italic">P</span>.</p>
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3 pages, 921 KiB  
Abstract
Triboelectric Energy Harvesting Shoe Insole
by Zifan Li, Lihua Tang, Wee Chen Gan and Kean Chin Aw
Proceedings 2024, 97(1), 186; https://doi.org/10.3390/proceedings2024097186 - 15 Apr 2024
Viewed by 919
Abstract
Harvesting power from walking-related motions can be a sustainable energy source for powering wearables. This paper proposes a shoe insole with a 3D stackable self-supporting structure and energy harvesting capability based on triboelectrification. Initial tests showed that a unit cell of the structure [...] Read more.
Harvesting power from walking-related motions can be a sustainable energy source for powering wearables. This paper proposes a shoe insole with a 3D stackable self-supporting structure and energy harvesting capability based on triboelectrification. Initial tests showed that a unit cell of the structure could produce an open-circuit voltage of 164.5 V with a charge density of 2.02 nC/cm2, and the performance can be further improved with a higher force and a structure of multiple cells. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Conceptual design of the shoe insole; (<b>b</b>) illustration of H-TENG structure under compression; (<b>c</b>) unit cell of the shoe insole; (<b>d</b>) TENG configuration on the unit cell.</p>
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<p>(<b>a</b>) Conceptual design of the shoe insole; (<b>b</b>) illustration of H-TENG structure under compression; (<b>c</b>) unit cell of the shoe insole; (<b>d</b>) TENG configuration on the unit cell.</p>
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<p>The unit cell (<b>a</b>) open-circuit voltage and (<b>b</b>) charge density under different excitation forces.</p>
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3 pages, 461 KiB  
Abstract
Microfluidic System with Integrated Electrode Array for High-Throughput Electrochemical Impedance Spectroscopy Analysis of Localised Cells
by Lilia Bató and Péter Fürjes
Proceedings 2024, 97(1), 187; https://doi.org/10.3390/proceedings2024097187 - 16 Apr 2024
Viewed by 817
Abstract
A multi-channel microfluidic system was designed and fabricated with an integrated electrode array to be capable of trapping and analysing single cells or populations in the individual channels in a controlled chemical environment. The analytical system was interfaced with a dedicated printed circuit [...] Read more.
A multi-channel microfluidic system was designed and fabricated with an integrated electrode array to be capable of trapping and analysing single cells or populations in the individual channels in a controlled chemical environment. The analytical system was interfaced with a dedicated printed circuit board designed for parallel EIS and optical screening. The continuous impedance measurement also monitors the adequate filling of the channels and the cell trapping events. Yeast cells were characterised by recording the EIS spectra of individual channels, allowing the differentiation between the populations considering their size, viability, or proliferation. The EIS analysis was supported by fluorescent optical microscopy, also using cell staining. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The layout and electrode design of the microfluidic chip (<b>a</b>) and the assembled device (<b>b</b>) the EIS spectra of trapped yeast cells (<b>c</b>) and a single cell trapped between the electrodes (<b>d</b>).</p>
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2 pages, 458 KiB  
Abstract
Wearable Prototype for Smart Personal Protective Equipment
by Fabrizio Formisano, Antonio Del Giudice, Michele Dellutri and Girolamo Di Francia
Proceedings 2024, 97(1), 188; https://doi.org/10.3390/proceedings2024097188 - 16 Apr 2024
Viewed by 3088
Abstract
Smart personal protective equipment (PPE) broadens the ways to enhance security in workplaces. Using active systems with communication capabilities, it is possible to continuously monitor workers and environmental parameters to prevent undesirable events or to quickly intervene in case of accident. This work [...] Read more.
Smart personal protective equipment (PPE) broadens the ways to enhance security in workplaces. Using active systems with communication capabilities, it is possible to continuously monitor workers and environmental parameters to prevent undesirable events or to quickly intervene in case of accident. This work describes the latest improvements in the design of an upgraded version of our earlier laboratory prototype. The enhancements concern a more compact form factor, reduced power consumption and replacements with the latest products available on the market. In this work, the design solution and results will be presented. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Naked 3D rendering of final wearable prototype based on wiring of the PCB motherboard.</p>
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3 pages, 872 KiB  
Abstract
Controlled Contact between Beads and Cells for the Characterization of Receptor–Ligand Bonds
by Clémentine Lipp, Laure Koebel, Romain Loyon, Aude Bolopion, Laurie Spehner, Michaël Gauthier, Christophe Borg, Arnaud Bertsch and Philippe Renaud
Proceedings 2024, 97(1), 189; https://doi.org/10.3390/proceedings2024097189 - 16 Apr 2024
Viewed by 762
Abstract
The controlled contact between two micro-sized objects, such as beads and cells, and the assessment of their adhesion status is demonstrated in this research. The controlled contact is carried out in a microfluidic channel under flow conditions and makes use of a combination [...] Read more.
The controlled contact between two micro-sized objects, such as beads and cells, and the assessment of their adhesion status is demonstrated in this research. The controlled contact is carried out in a microfluidic channel under flow conditions and makes use of a combination of hydrodynamic traps, flow drag force and dielectrophoretic (DEP) force to maintain the two objects in contact for the desired duration in a first step. Then, the pair objects are separated in the second step in order to explore their adhesion status. Adhesion events are mediated by the bond formed between a receptor and its ligand, and their binding kinetic parameters can be extracted from the measurements using the proposed device. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>–<b>d</b>) Process for the controlled contact between two cells and the exploration of their adhesion status after a defined, forced contact time. (<b>e</b>) SEM image of the proposed device with the hydrodynamic trap highlighted in the inset and the electrodes used for the DEP manipulation patterned in their vicinity.</p>
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<p>This microscopy picture represents the controlled contact between a cancer cell (in the hydrodynamic trap) and a T-cell (manipulated by DEP) using the proposed device.</p>
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3 pages, 1155 KiB  
Abstract
Two-Dimensional Layered Amorphous Metal Oxide Gas Sensors (LAMOS) Perspectives and Gas Sensing Properties
by Valentina Paolucci, Jessica De Santis, Vittorio Ricci, Giacomo Giorgi and Carlo Cantalini
Proceedings 2024, 97(1), 190; https://doi.org/10.3390/proceedings2024097190 - 17 Apr 2024
Viewed by 898
Abstract
Two-dimensional Layered Amorphous Metal Oxide Sensors (LAMOS) represent a new class of 2D amorphous oxide (a-MOx) interfaces with unveiled properties in gas sensing applications. Herein, we report the humidity and gas sensing response of p- and n-type chemoresistive few-layered [...] Read more.
Two-dimensional Layered Amorphous Metal Oxide Sensors (LAMOS) represent a new class of 2D amorphous oxide (a-MOx) interfaces with unveiled properties in gas sensing applications. Herein, we report the humidity and gas sensing response of p- and n-type chemoresistive few-layered (2D) amorphous a-SnO2, a-In2O3, and a-Cr2O3, discussing their reaction mechanisms using DFT modelling and electrical tests. LAMOS interfaces can be easily prepared by controlled oxidation in air of a large class of exfoliated 2D TMDs, MCs, and TMTH (Transition Metal Dichalcogenides, Chalcogenides, and Trihalides) like WS2, MoS2, SnSe2, In2Se3, NiCl2, and CrCl3, yielding 2D amorphous a-MOx interfaces. LAMOS platforms preserving all the surface-to-volume advantages of their 2D precursors show excellent gas sensing properties representing a new class of material for gas sensing applications. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) SEM picture of <span class="html-italic">a</span>-SnO2 spin-coated flakes over Si3N4 substrates with Pt-finger-type electrodes; (<b>b</b>) high-magnification SEM of terraced as-exfoliated SnSe<sub>2</sub> flake; (<b>c</b>) lateral size distribution of exfoliated SnSe<sub>2</sub>; (<b>d</b>) HRTEM of the as exfoliated crystalline 2D-SnSe2; (<b>e</b>) HRTEM of the <span class="html-italic">a</span>-SnO2 flake after oxidation of the 2D-SnSe2.</p>
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<p>(<b>a</b>) Schematization of H2O dissociative chemisorption mechanism over <span class="html-italic">a</span>-SnO2 at a 100 °C operating temperature; (<b>b</b>,<b>c</b>) adsorption/desorption responses to 1 ppm NO2 and 100 ppm H2 with increasing RH.</p>
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3 pages, 403 KiB  
Abstract
Optimization of Micro-Electromechanical Lorentz Actuator Using a Surrogate Model Accelerated Genetic Algorithm
by Phiona Buhr, Cyrus Shafai, Byoungyoul Park, Yunli Wang and Miroslav Belov
Proceedings 2024, 97(1), 191; https://doi.org/10.3390/proceedings2024097191 - 17 Apr 2024
Viewed by 2927
Abstract
A surrogate model (SM)-assisted multi-objective genetic algorithm (GA) is presented that is used to accelerate the performance optimization of a MEMS actuator. The GA employs both finite element method (FEM) simulations and the SM together to undertake the multi-objective optimization. The algorithm evolves [...] Read more.
A surrogate model (SM)-assisted multi-objective genetic algorithm (GA) is presented that is used to accelerate the performance optimization of a MEMS actuator. The GA employs both finite element method (FEM) simulations and the SM together to undertake the multi-objective optimization. The algorithm evolves the actuator geometry to meet a required 1 µm displacement while seeking to achieve the objectives of minimal temperature rise and resonant frequency over 5 kHz. The result is a continuous surface of Pareto optimal designs for the decision maker to choose from. The SM was found to compute similar solutions as the FEM with a 100,000× faster computation speed. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Original starting device that the GA undertakes to improve. (<b>b</b>) The design with the lowest mechanical stress and highest first resonance frequency, f<sub>0</sub>. (<b>c</b>) The design with the smallest temperature increase.</p>
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3 pages, 1024 KiB  
Abstract
Silver-Based Plasmonic Grating with PDMS Microchannel for Biological Sensors
by Pongsak Sarapukdee, Dirk Schulz and Stefan Palzer
Proceedings 2024, 97(1), 192; https://doi.org/10.3390/proceedings2024097192 - 17 Apr 2024
Viewed by 765
Abstract
The label-free approach streamlines sample analysis by eliminating the need for fluorescent markers or labels, thus improving accuracy and speed. This contribution explores the potential of silver-based plasmonic gratings as central building blocks for developing biological sensors using label-free detection techniques. It presents [...] Read more.
The label-free approach streamlines sample analysis by eliminating the need for fluorescent markers or labels, thus improving accuracy and speed. This contribution explores the potential of silver-based plasmonic gratings as central building blocks for developing biological sensors using label-free detection techniques. It presents the design, fabrication, and optimization of plasmonic gratings, including showcasing their application in biological molecule detection. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic overview of the silver grating geometry with a grating period of <span class="html-italic">P</span> = 800 nm, a height of <span class="html-italic">h</span> = 50 nm, and a thickness of <span class="html-italic">b</span> = 100 nm. (<b>b</b>) The silver grating with PDMS microchannel was mounted in the sample holder with laser beam alignment on the grating area. The experimental setup indicating the incident and reflected waves is shown in (<b>c</b>).</p>
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<p>The effect of PDMS microchannel on the relative reflection and plasmon excitation angle change induced by various fluid solutions.</p>
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3 pages, 461 KiB  
Abstract
Non-Stoichiometric Titanium-Oxide Gate Electrodes for EGFET Based pH Sensors
by Zsombor Szomor, Lilia Bató, Silvia Stágl, Orsolya Hakkel, Attila Sulyok, Csaba Dücső, Zsófia Baji and Péter Fürjes
Proceedings 2024, 97(1), 193; https://doi.org/10.3390/proceedings2024097193 - 17 Apr 2024
Viewed by 796
Abstract
A compact pH measuring electrochemical sensor module was developed for Smart Multi-Well Plates (SMWP) applicable for highly parallelized cell culture analysis using incorporated Organ-on-Chip devices. A specific electronic architecture was designed and manufactured containing an extended gate field effect transistor as the transducer [...] Read more.
A compact pH measuring electrochemical sensor module was developed for Smart Multi-Well Plates (SMWP) applicable for highly parallelized cell culture analysis using incorporated Organ-on-Chip devices. A specific electronic architecture was designed and manufactured containing an extended gate field effect transistor as the transducer device. Electrochemical electrodes were functionalized using pH sensitive metal-oxides and applied as the gate material. The composition and the related pH sensitivity of differently deposited materials were characterized and the suitability of ALD-deposited, non-stoichiometric titanium oxide (TiOx) for sensitive pH measurement was verified showing excellent responses close to the ideal Nernstian slope (59 mV/pH). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Schematic measurement setup representing the electronic architecture of EGFET-based pH sensor (<b>a</b>), the manufactured read-out electronics (<b>b</b>), and the MO<sub>x</sub>-functionalized working electrode (<b>c</b>). The pH sensitivity of the non-stoichiometric TiO<sub>x</sub> layer was close to the Nernstian response (<b>d</b>).</p>
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3 pages, 770 KiB  
Abstract
Multianalyte-Compatible Lysis for the Detection of P. aeruginosa and IL-6 via Lateral Flow Immunoassay
by Anna Klebes, Bianka Pfefferle, Anna-Sophia Kittel, Bastian Breiner, Nadine Borst and Felix von Stetten
Proceedings 2024, 97(1), 194; https://doi.org/10.3390/proceedings2024097194 - 17 Apr 2024
Viewed by 2967
Abstract
The development of new multianalyte biosensors that can detect multiple classes of biomolecules is highly desirable and will greatly improve medical diagnostics. In the field of infectious diseases, for example, it is beneficial to detect pathogens via nucleic acid analysis together with host [...] Read more.
The development of new multianalyte biosensors that can detect multiple classes of biomolecules is highly desirable and will greatly improve medical diagnostics. In the field of infectious diseases, for example, it is beneficial to detect pathogens via nucleic acid analysis together with host immune response markers. In this work, we present a multianalyte-compatible lysis using antimicrobial peptides (AMPs). This strategy enables the simultaneous detection of bacterial DNA and inflammatory biomarkers via multianalyte lateral flow immunoassay (LFIA). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Workflow for the simultaneous detection of <span class="html-italic">P. aeruginosa</span> and IL-6. (<b>A</b>) Multianalyte-compatible lysis via AMPs. (<b>B</b>) Protein-compatible isothermal amplification and labeling of bacterial DNA and internal amplification control (IAC). (<b>C</b>) Simultaneous detection of IL-6 and labeled amplification products via LFIA.</p>
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<p>AMP-based lysis for the simultaneous detection of <span class="html-italic">P. aeruginosa</span> and IL-6. (<b>A</b>) Intensity of protein-TL and DNA-TL for samples with (w) or without (w/o) IL-6 and/or <span class="html-italic">P. aeruginosa</span>. The solid and dashed lines represents the fluorescence intensity at the DNA-TL of non-lysed samples and samples lysed via bead beating (BB). Depicted are the mean and standard deviations; n = 3. (<b>B</b>) Corresponding fluorescence images of the multianalyte LFIA.</p>
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3 pages, 464 KiB  
Abstract
Soft Optomechanical Devices Featuring Intrinsic Redox Activity
by Ferran Pujol-Vila and Mar Álvarez
Proceedings 2024, 97(1), 195; https://doi.org/10.3390/proceedings2024097195 - 19 Apr 2024
Viewed by 823
Abstract
Soft optomechanical sensors have the ability to combine the high tunability and elasticity of soft polymers with the distinctive optical properties of photonic structures, thus offering unprecedented opportunities for the development high-performance colorimetric sensors. Herein, we demonstrate for the first time the use [...] Read more.
Soft optomechanical sensors have the ability to combine the high tunability and elasticity of soft polymers with the distinctive optical properties of photonic structures, thus offering unprecedented opportunities for the development high-performance colorimetric sensors. Herein, we demonstrate for the first time the use of optomechanical devices made of off-stoichiometry thiol-ene (OSTE), a polymeric material that features intrinsic redox activity, overcoming some limitations of conventional materials (e.g., polydimethylsiloxane or silicon). Remarkably, this work provides the foundation for a new generation of highly tunable and versatile optomechanical sensors, enabling unexplored functionalities. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Image of the OSTE optomechanical bridges and optical microscopy image (50×) of the periodical surface structure. (<b>b</b>) Color imaging setup. (<b>c</b>) Working principle of the sensors. (<b>d</b>) Color changes during the reduction of MTT for pristine sensors and sensors coated on one side with PEI.</p>
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2 pages, 660 KiB  
Abstract
Merging Surface Plasmon Optical Detection with Electronic Sensing
by Wolfgang Knoll
Proceedings 2024, 97(1), 196; https://doi.org/10.3390/proceedings2024097196 - 19 Apr 2024
Viewed by 3276
Abstract
In one of the “classical” configurations of electrolyte-gated field effect transistors (EGOFETs) for biosensing, the planar gate electrode is functionalized by (a monolayer of) receptors, to which the analyte molecules of interest bind from the analyte solution, thereby modifying the gate potential, which [...] Read more.
In one of the “classical” configurations of electrolyte-gated field effect transistors (EGOFETs) for biosensing, the planar gate electrode is functionalized by (a monolayer of) receptors, to which the analyte molecules of interest bind from the analyte solution, thereby modifying the gate potential, which in turn modifies the source drain current as the sensor output signal [...] Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>SPR-EGO-FET combination setup for simultaneous surface plasmon optical and electronic monitoring of surface reactions.</p>
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<p>Electronic (<b>top</b>) and surface plasmon optical (<b>bottom</b>) protocol of the multilayer formation by the layer-by-layer deposition of polyelectrolytes, taken at two different potentials applied to the gate substrate.</p>
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2 pages, 632 KiB  
Abstract
Recent Improvements on Double-Parametric Optical Sensing of O2 Exploiting Near-Infrared Luminescence of Mixed-Phase Anatase/Rutile TiO2 Nanoparticles
by Romina Rega, Ambra Fioravanti, Pietro Marani, Sara Morandi, Laura Giordano, Stefano Lettieri, Maria Cristina Carotta and Pasquale Maddalena
Proceedings 2024, 97(1), 197; https://doi.org/10.3390/proceedings2024097197 - 19 Apr 2024
Viewed by 1040
Abstract
Mixed-phase titanium dioxide (TiO2) can be effectively employed as photoluminescence (PL) based ratiometric optical sensor of O2, thanks to its peculiar “anti-correlated” PL responses to O2 of anatase and rutile TiO2 polymorphs. We discuss how to exploit [...] Read more.
Mixed-phase titanium dioxide (TiO2) can be effectively employed as photoluminescence (PL) based ratiometric optical sensor of O2, thanks to its peculiar “anti-correlated” PL responses to O2 of anatase and rutile TiO2 polymorphs. We discuss how to exploit the simultaneous detection of luminescence arising from anatase and rutile TiO2 nanoparticles to obtain a responsivity which is, by construction, larger than the one obtainable through other gas-responsive oxides via the same PL-based approach. Furthermore, we illustrate our recent improvements on sensor sensitivity and stability for O2 concentrations ranging in the 10–100 ppm interval. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Example of anti-correlated PL intensity of rutile (near-infrared PL) and anatase (visible PL) response to different O<sub>2</sub> concentrations (time t = 1200 s, 1500 s, and 1800 s), alternated with O<sub>2</sub> desorption in N<sub>2</sub> flow.</p>
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3 pages, 946 KiB  
Abstract
AMR Sensor Array Design for the Realization of a 3D Magnetic Tactile Sensor
by Stefano Lumetti, Perla Malagò, Peter-Andreas Stürmer, Francisco Ferreira Relvão and Michael Ortner
Proceedings 2024, 97(1), 198; https://doi.org/10.3390/proceedings2024097198 - 22 Apr 2024
Viewed by 902
Abstract
The design of arrays of anisotropic magnetoresistive (AMR) sensors capable of detecting and reconstructing the 3D motion of a permanent magnet, and thus, suitable for the development of a 3D magnetic tactile sensor, is reported. The proposed structure allows for probing the 3D [...] Read more.
The design of arrays of anisotropic magnetoresistive (AMR) sensors capable of detecting and reconstructing the 3D motion of a permanent magnet, and thus, suitable for the development of a 3D magnetic tactile sensor, is reported. The proposed structure allows for probing the 3D magnet displacements—and, hence, to infer the three components of the applied force—via a purely planar arrangement of monolithically microfabricated AMR sensors. The concept presented here also holds potential for the realization of a wide spectrum of easy-to-fabricate, miniaturized and low-cost sensors suitable for the detection of a broad variety of physical observables. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Three-dimensional tactile sensor structure. (<b>b</b>) First AMR sensor array design. (<b>c</b>) Second AMR sensor array design. (<b>d</b>) Three-dimensional magnet motion reconstruction via the first AMR sensor array design.</p>
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3 pages, 427 KiB  
Abstract
Automated Allergen Sample Preparation and Detection via Centrifugal Microfluidic Lateral Flow Assay
by Bastian Breiner, Daniel M. Kainz, Stefan Wagner, Maxime Gavage, Serhat Sahakalkan, Riccardo Marega, Felix von Stetten and Anna Klebes
Proceedings 2024, 97(1), 199; https://doi.org/10.3390/proceedings2024097199 - 22 Apr 2024
Viewed by 1040
Abstract
Food allergies are a severe burden for affected individuals and healthcare systems. To tackle the need for simple food allergen detection, we developed a system for the detection of the soy protein glycinin via a centrifugal microfluidics-assisted lateral flow immunoassay (LFIA). Glycinin is [...] Read more.
Food allergies are a severe burden for affected individuals and healthcare systems. To tackle the need for simple food allergen detection, we developed a system for the detection of the soy protein glycinin via a centrifugal microfluidics-assisted lateral flow immunoassay (LFIA). Glycinin is a complex allergen requiring extensive sample preparation. The presented workflow includes a manual denaturing extraction, followed by automated centrifugal microfluidic desalting, metering and detection via LFIA. The functionality of the microfluidic cassettes was tested on prototypes produced via microthermoforming before an injection molding tool was designed, which added a cylindrical lens to improve the readout. Overall, this system aims to aid in food allergen detection with high sensitivity and minimized manual steps. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Depicted is the workflow of the glycinin extraction, desalting and detection with the corresponding automated steps for the design of the centrifugal microfluidic cassette.</p>
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3 pages, 725 KiB  
Abstract
A Hybrid Piezoelectric and Reverse Electrowetting Energy Harvester for Wearable Biosensors
by Sotiria D. Psoma, Ihor Sobianin and Antonios Tourlidakis
Proceedings 2024, 97(1), 200; https://doi.org/10.3390/proceedings2024097200 - 23 Apr 2024
Viewed by 804
Abstract
Wearable biosensors play a critical role in healthcare monitoring. However, the reliance of biosensors on batteries has serious drawbacks. Although the human body’s energy can be converted into electricity with energy harvesters, the hybridisation of multiple energy harvesters is a prominent way of [...] Read more.
Wearable biosensors play a critical role in healthcare monitoring. However, the reliance of biosensors on batteries has serious drawbacks. Although the human body’s energy can be converted into electricity with energy harvesters, the hybridisation of multiple energy harvesters is a prominent way of increasing power output. In this work, a hybrid piezoelectric and reverse electrowetting (REWOD) energy harvester is proposed. Its main working principle is based on the presence of an electrical double layer in the REWOD component and coupling with a piezoelectric nanogenerator via an electret. The proposed energy harvester design was tested numerically and in a series of experiments. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The hybrid harvester working principle.</p>
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<p>Empirical data on the influence of piezoelectric material on harvester output.</p>
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3 pages, 2200 KiB  
Abstract
A Flexible PCB-Based MEMS Field Mill with a Vertical Movement Shutter Driven by an Electrostatic Actuator
by Tao Chen and Cyrus Shafai
Proceedings 2024, 97(1), 201; https://doi.org/10.3390/proceedings2024097201 - 23 Apr 2024
Viewed by 2250
Abstract
This paper describes a simulated MEMS field mill that utilizes a vertical movement shutter powered by an electrostatic actuator. The design is based upon a Flexible PCB substrate to enable faster prototyping and lower cost. The simulation results show that if the system [...] Read more.
This paper describes a simulated MEMS field mill that utilizes a vertical movement shutter powered by an electrostatic actuator. The design is based upon a Flexible PCB substrate to enable faster prototyping and lower cost. The simulation results show that if the system operates at a resonance, a 10 kV/m field will induce a current of 53 pA, resulting in a charge induction efficiency of 5.3 pA/(kV/m). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Operation principle.</p>
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<p>Sensor design.</p>
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<p>Shutter movement.</p>
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<p>Driving electric-field distribution.</p>
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3 pages, 1258 KiB  
Abstract
A Simple Method for Extracting Piezoelectric Coefficient d31 by Fitting Experimental Data with an Analytical Model
by Yangyang Guan, Mustafa Mert Torunbalci, Sanjog Vilas Joshi, Sina Sadeghpour, Aojie Quan, Chen Wang and Michael Kraft
Proceedings 2024, 97(1), 202; https://doi.org/10.3390/proceedings2024097202 - 16 Apr 2024
Viewed by 2183
Abstract
This work presents a simple method to extract the piezoelectric coefficient d31 based on analytical model fitting. A theoretical circuit model is developed for a piezoelectric circular membrane actuator based on PZT thin film. The circular diaphragm consists of a 12 µm [...] Read more.
This work presents a simple method to extract the piezoelectric coefficient d31 based on analytical model fitting. A theoretical circuit model is developed for a piezoelectric circular membrane actuator based on PZT thin film. The circular diaphragm consists of a 12 µm silicon layer, an 800 nm thick PZT layer, and a 200 nm Ti/Pt layer, featuring a single 50% inner top electrode coverage. The proposed model is validated by the finite element method with a 2D axisymmetric model of a PZT piezoelectric membrane. Further, piezoelectric coefficient d31 is extracted by fitting the Laser Doppler Vibrometer (LDV) experimental result with the analytical model. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic of the piezoelectric actuator; (<b>b</b>) Optical photograph of the fabricated PZT device. (<b>c</b>) The equivalent circuit model of the piezoelectric membrane actuator.</p>
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<p>(<b>a</b>) Comparison of the theoretical and simulated results of the membrane displacement. (<b>b</b>) Results measured by LDV and predicted by the theoretical model. (<b>c</b>) P−E hysteresis loop of deposited PZT film at 1 kHz.</p>
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5 pages, 2715 KiB  
Abstract
Systematic Review on Biosensor Systems for COVID-19 Aerosol Detection
by Divya Pragna Mulla, Mario Alessandro Bochicchio and Antonella Longo
Proceedings 2024, 97(1), 203; https://doi.org/10.3390/proceedings2024097203 - 24 Apr 2024
Viewed by 2401
Abstract
Timely detection and diagnosis are crucial for outbreak measures and infection control. This review discusses the types of biosensor systems developed so far for the detection of COVID-19 aerosols in the air for the risk assessment and identification of gaps in the field. [...] Read more.
Timely detection and diagnosis are crucial for outbreak measures and infection control. This review discusses the types of biosensor systems developed so far for the detection of COVID-19 aerosols in the air for the risk assessment and identification of gaps in the field. Data were collected from four academic databases, including IEEE Xplore, Scopus, Web of Science, and MDPI. The results suggest the development of very few sensors for the aerosol detection of COVID-19, and most of the sensors are immune based. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Study Selection Flow Diagram.</p>
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<p>Types Of Data Sources.</p>
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<p>Types of sensors.</p>
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<p>Geographical Distribution of the articles.</p>
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<p>Co-occurrence of keywords.</p>
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<p>Co-Authoship of the authors.</p>
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3 pages, 474 KiB  
Abstract
Graphene Oxide-Based Flexible Sensors for Detection of Volatile Organic Compounds at Room Temperature
by Anna Maria Laera, Gennaro Cassano, Emiliano Burresi, Maria Lucia Protopapa and Michele Penza
Proceedings 2024, 97(1), 204; https://doi.org/10.3390/proceedings2024097204 - 24 Apr 2024
Viewed by 1014
Abstract
Flexible sensors, with an active layer made of graphene oxide (GO), were produced to detect volatile organic compounds (VOCs) at room temperature. Copper interdigitated electrodes were inkjet-printed on a substrate of bimatted polyester, and the direct drop-casting of a GO water solution was [...] Read more.
Flexible sensors, with an active layer made of graphene oxide (GO), were produced to detect volatile organic compounds (VOCs) at room temperature. Copper interdigitated electrodes were inkjet-printed on a substrate of bimatted polyester, and the direct drop-casting of a GO water solution was carried out to coat the devices. The performance of both commercial GO and GO synthesized by a modified Hummers’ method was investigated and compared. The oxygenated functional groups on the GO surface mainly enhance the selective sensing of polar analytes. The fabricated sensors exhibit the highest response towards alcohols, and minor sensitivity to esters, ketones, ethers and apolar petroleum ether. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sensor responses towards several VOCs with different dipole moments; (<b>b</b>) sensor resistance versus time upon exposure to decreasing ethanol concentrations of 147, 103 and 76 ppm.</p>
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2 pages, 348 KiB  
Abstract
A New Active Antenna Unit for Portable Microwave Bio-Dosimeters
by Andrey Simakov, Igor Vodokhlebov and Yuriy Voronov
Proceedings 2024, 97(1), 205; https://doi.org/10.3390/proceedings2024097205 - 24 Apr 2024
Viewed by 776
Abstract
Today, the growing ecological contamination by microwave irradiation requires new devices and information systems to monitor dangerous situations, especially in big cities, and provide safety for the population. This work is focused on the design of anew antenna unit for advanced portable personal [...] Read more.
Today, the growing ecological contamination by microwave irradiation requires new devices and information systems to monitor dangerous situations, especially in big cities, and provide safety for the population. This work is focused on the design of anew antenna unit for advanced portable personal microwave dosimeters and irradiation monitoring systems. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Photograph of antenna unit; (<b>b</b>) antenna unit on electronic board of mobile GEO-DOSE dosimeter; (<b>c</b>) mobile dosimeter.</p>
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3 pages, 420 KiB  
Abstract
Noble Metal-Loaded WO3-Based Gases—The Gold Anomaly
by Anna Staerz, Udo Weimar and Nicolae Barsan
Proceedings 2024, 97(1), 206; https://doi.org/10.3390/proceedings2024097206 - 24 Apr 2024
Viewed by 842
Abstract
Tungsten oxide is one of the most commonly used materials for metal oxide-based gas sensors. In order to tune the sensing behavior, small clusters of noble metals are often added to the surface of WO3. Previously, it has been found that [...] Read more.
Tungsten oxide is one of the most commonly used materials for metal oxide-based gas sensors. In order to tune the sensing behavior, small clusters of noble metals are often added to the surface of WO3. Previously, it has been found that in the case of oxidized metal clusters, e.g., Rh and Pt additives, the Fermi-level pinning mechanism dominates. Unlike other noble metal surface clusters, gold seems to remain metallic under sensor operation. As a result, the behavior of WO3-based sensors was found to be significantly enhanced for all reducing gases and decreased for NO2. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sensor profile and (<b>b</b>) response to oxygen of the pristine and the 5 wt% WO<sub>3</sub> sensor with Au additive.</p>
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3 pages, 388 KiB  
Abstract
Isotope-Selective Gas Sensing Using Photoacoustic Non-Dispersive Spectroscopy
by Gabriel Rodriguez Gutierrez, Loay Marouani, Alvaro Ortiz Perez, Peter Kreuzaler and Stefan Palzer
Proceedings 2024, 97(1), 207; https://doi.org/10.3390/proceedings2024097207 - 24 Apr 2024
Viewed by 2239
Abstract
The flow of carbons into the citric acid cycle can be readily traced by supplementation with 13C stable isotope labelled nutrients. However, the quantification of the amount of fully oxidised nutrients to carbon dioxide is a challenging task. This contribution presents an [...] Read more.
The flow of carbons into the citric acid cycle can be readily traced by supplementation with 13C stable isotope labelled nutrients. However, the quantification of the amount of fully oxidised nutrients to carbon dioxide is a challenging task. This contribution presents an isotope-selective, miniaturized gas detection scheme based on indirect photoacoustic spectroscopy. The results show that low-cost, continuous, in situ monitoring of the isotope ratio in gaseous samples is feasible. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The sensor response to varying CO<sub>2</sub> concentrations in dry synthetic air: (<b>a</b>) Using the standard isotope ratio of CO<sub>2</sub>, the sensitivity of the standard CO<sub>2</sub> channel is considerably higher than for the <sup>13</sup>CO<sub>2</sub> channel. (<b>b</b>) For the gas sensitive characterization, using pure <sup>13</sup>CO<sub>2</sub> gas, the situation is reversed.</p>
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3 pages, 1567 KiB  
Abstract
Sample Preparation and qPCR Detection of Tuberculosis on a Centrifugal Microfluidic Cartridge Enabling Molecular Downstream Resistance Profiling
by Judith Schlanderer, Markus Beutler, Jan Lüddecke, Harald Hoffmann and Nils Paust
Proceedings 2024, 97(1), 208; https://doi.org/10.3390/proceedings2024097208 - 26 Apr 2024
Viewed by 2481
Abstract
Tuberculosis (TB) is still one of the world’s deadliest infections. Fast detection of the pathogen M. tuberculosis (MTB) and its genetic resistance markers substantially improves treatment success and outcome. A key element for rapid genetic diagnostics is the efficient extraction of DNA from [...] Read more.
Tuberculosis (TB) is still one of the world’s deadliest infections. Fast detection of the pathogen M. tuberculosis (MTB) and its genetic resistance markers substantially improves treatment success and outcome. A key element for rapid genetic diagnostics is the efficient extraction of DNA from sputum for qPCR detection at the point of care. We present the fully automated sample preparation of MTB DNA from 3 mL of liquefied sputum and qPCR detection of MTB on a centrifugal microfluidic cartridge. Our method achieves a limit of detection (LoD) between 17 and 57 CFU/mL and provides a purified DNA solution for molecular downstream testing, such as targeted NGS. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>A</b>) Exploded view of the FL module. (<b>B</b>) Microfluidic cartridge. (<b>C</b>) Top-side view of the DNA tube.</p>
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<p><b>(A)</b> Sample preparation steps automated by the cartridge. (<b>B</b>) LoD achieved with the automated sample preparation and qPCR detection of the microfluidic cartridge with H37Rv spiked in sputum.</p>
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3 pages, 525 KiB  
Abstract
Microfluidic Cuvette for Near-Infrared Spectroscopy
by Zoltán Szabó, Kitti Pankász, János Bozorádi, Orsolya Hakkel, Szabolcs Bella, Bianka Fabinyi, Sandro Meucci and Péter Fürjes
Proceedings 2024, 97(1), 209; https://doi.org/10.3390/proceedings2024097209 - 6 May 2024
Viewed by 799
Abstract
We intend to develop an in situ near-infrared spectroscopic solution for monitoring the nutrient composition (e.g., lactate concentration) in microfluidic channels of organ-on-chip devices. In this work, the effects of the geometry, surface quality, and architecture of the micro-volume cuvettes were characterized and [...] Read more.
We intend to develop an in situ near-infrared spectroscopic solution for monitoring the nutrient composition (e.g., lactate concentration) in microfluidic channels of organ-on-chip devices. In this work, the effects of the geometry, surface quality, and architecture of the micro-volume cuvettes were characterized and optimized considering the signal-to-noise ratio and sensitivity of the proposed spectroscopic method in case of aqueous solutions. The applicability of the micro-volume near-infrared spectroscopy method using this specially designed microfluidic cuvette was proven. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Concentration-dependent near-IR transmittance spectra for ethanol solutions (0.05, 0.1, 0.5, 1.0, 5.0, 10% <span class="html-italic">v</span>/<span class="html-italic">v</span>) compared to water as a reference in macroscopic (<b>a</b>) and microfluidic (<b>b</b>) HE (100 µm, transmittance) cuvettes. Relative intensities (<b>c</b>) demonstrate a signal loss over a wavelength of 1400 nm.</p>
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4 pages, 1316 KiB  
Abstract
Numerically Stable Magnetic Field Expressions for End-of-Shaft Angle Sensing Systems
by Peter Leitner, Lukas Rauber and Michael Ortner
Proceedings 2024, 97(1), 210; https://doi.org/10.3390/proceedings2024097210 - 6 May 2024
Viewed by 684
Abstract
The design of end-of-shaft angle sensing magnetic positioning systems (MPS) requires accurate field computations in the sensing area for the magnetostatic inversion procedure. Highly resolved field computations on a 3-D domain make FEM simulations unfeasible and favour analytical solutions. Analytical textbook field solutions [...] Read more.
The design of end-of-shaft angle sensing magnetic positioning systems (MPS) requires accurate field computations in the sensing area for the magnetostatic inversion procedure. Highly resolved field computations on a 3-D domain make FEM simulations unfeasible and favour analytical solutions. Analytical textbook field solutions of a number of standard magnet shapes are however numerically unstable along symmetry axes, body edges as well as in the far field. For the particular application of an end-of-shaft system, only a particular instability close to the symmetry axis, ρ → 0 plays a detrimental role. We stabilize the field equation by mathematical reformulation of naturally occurring numerically unstable combinations of elliptic integrals in the derivation. The resulting formulas or even their ready-to-use implementation in the freely available Python package Magpylib can be used without limitations for end-of-shaft MPS designs. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>End-of-shaft magnetic positioning system. A magnet is mounted at the end of a rotating shaft whose field is detected in the subjacent sensor array.</p>
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<p>Precision (number of significant figures) of the analytic field computation (B<sub><span class="html-italic">ρ</span></sub>, B<sub><span class="html-italic">φ</span></sub>, B<sub><span class="html-italic">z</span></sub>) (<b>left</b>, <b>middle</b>, <b>right</b>) in the sensing area (indicated by blue frames). The complete loss of precision for <span class="html-italic">ρ</span> → 0 (<b>upper</b> panel) is successfully remedied by our numerical stabilization (<b>lower</b> panel), giving at least 10 significant figures in the area of interest.</p>
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3 pages, 534 KiB  
Abstract
Pulsed Temperature Operation of SnO2-Based Gas Sensors
by Larissa Egger, Lisbeth Reiner, Alessandro Togni, Christian Mitterer and Anton Köck
Proceedings 2024, 97(1), 211; https://doi.org/10.3390/proceedings2024097211 - 6 May 2024
Viewed by 779
Abstract
We herein demonstrate the pulsed-mode temperature operation of chemical sensor devices based on thin SnO2 films, which were synthesized by magnetron sputtering. The gas-sensitive films were integrated on SiN-based micro-hotplate (µhp) chips, which enable operation temperatures up to 500 °C. We compared [...] Read more.
We herein demonstrate the pulsed-mode temperature operation of chemical sensor devices based on thin SnO2 films, which were synthesized by magnetron sputtering. The gas-sensitive films were integrated on SiN-based micro-hotplate (µhp) chips, which enable operation temperatures up to 500 °C. We compared the gas sensor performance in constant temperature mode with pulsed temperature mode operation towards the test gases carbon monoxide and toluene. In contrast to constant temperature, the pulsed temperature mode operation reveals additional information about the type of test gas. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Typical resistance measurement in DC- and pulsed-mode T operation for CO and C<sub>7</sub>H<sub>8</sub> (5, 10, and then 20 ppm). (<b>b</b>) Comparison of pulsed-mode T operation for 5 ppm of CO and C<sub>7</sub>H<sub>8</sub>.</p>
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3 pages, 411 KiB  
Abstract
Electrochemical Analysis of Rationally Designed ZnO Nanostructures for Biodegradable Cellular Scaffolds
by Giuseppe Arrabito, Vittorio Ferrara, Giuseppe Prestopino, Pier Gianni Medaglia, Michelangelo Scopelliti and Bruno Pignataro
Proceedings 2024, 97(1), 212; https://doi.org/10.3390/proceedings2024097212 - 6 May 2024
Viewed by 749
Abstract
This work is a preliminary analysis of a wet-chemistry synthesized platform based on ZnO nanostructures (n-ZnO) for application in regenerative medicine. n-ZnO stability is investigated by electrochemical in situ sensing of zinc ions released by n-ZnO soaked in simulated biofluids. Impedance analysis allows [...] Read more.
This work is a preliminary analysis of a wet-chemistry synthesized platform based on ZnO nanostructures (n-ZnO) for application in regenerative medicine. n-ZnO stability is investigated by electrochemical in situ sensing of zinc ions released by n-ZnO soaked in simulated biofluids. Impedance analysis allows detection of subtle changes in the bulk solution impedance up to 50 kHz, which can be ascribed to the release of ionic species in solution, among which are Zn2+ ions. In parallel, a voltammetry analysis using low-cost, mercury-free, screen-printed sensors shows the release of Zn2+ ions at concentrations that are not harmful. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Direct sensing of n-ZnO effect in aqueous fluids. (<b>a</b>) Time-dependent analysis of the impedance of solution containing n-ZnO. (<b>b</b>) Preliminary voltammetric determination of zinc ions.</p>
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3 pages, 492 KiB  
Abstract
Shape Memory Polymer Microstructures Using Melt Electrowriting
by Biranche Tandon, Nasim Sabahi, Reza Farsi, Taavet Kangur, Xiaopeng Li and Jürgen Brugger
Proceedings 2024, 97(1), 213; https://doi.org/10.3390/proceedings2024097213 - 10 May 2024
Viewed by 929
Abstract
Melt electrowriting is a relatively new additive manufacturing technique capable of the controlled deposition of polymeric fibers to manufacture pre-programmed structures at micron scale. In this research, a blend of poly (ε-caprolactone) and thermoplastic urethane displaying shape memory properties is processed using melt [...] Read more.
Melt electrowriting is a relatively new additive manufacturing technique capable of the controlled deposition of polymeric fibers to manufacture pre-programmed structures at micron scale. In this research, a blend of poly (ε-caprolactone) and thermoplastic urethane displaying shape memory properties is processed using melt electrowriting. The bulk material at macro scale shows a transition temperature of around 60 °C. Fibers with diameter less than 60 µm were deposited as sinusoids and grid-like scaffolds. A high strain fixity ratio of 92% was obtained for the polymer, which is in accordance with the literature on shape memory polymers. These shape memory structures can be used for applications such as micro-sensing and actuating. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic of the MEW process; (<b>b</b>) DMA data obtained and process steps used; (<b>c</b>) grid-like structure; (<b>d</b>) sinusoid structure obtained for SMP; (<b>e</b>) shape memory effect in printed fibers. Scale bars: 200 µm.</p>
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3 pages, 1013 KiB  
Abstract
TITAN Project: Microfluidic and Sensing Tools for Immunotherapy
by Maria Serena Chiriacò, Elisabetta Primiceri, Antonio Turco, Valeria Garzarelli, Giulia Siciliano, Alessia Foscarini, Ahmed Alsadig, Annunziata Carbonara, Benedetta Stampone, Gianluca Trotta, Marco Cereda, Marco de Tullio, Giuseppe Gigli and Francesco Ferrara
Proceedings 2024, 97(1), 214; https://doi.org/10.3390/proceedings2024097214 - 10 May 2024
Viewed by 863
Abstract
The TITAN project aims to improve immunotherapy, targeting the efficiency of methods to obtain genetically engineered T cells. Immunotherapy has achieved great success in clinical trials, but it is currently very expensive in terms of time required for analysis, reagents, and samples. TITAN [...] Read more.
The TITAN project aims to improve immunotherapy, targeting the efficiency of methods to obtain genetically engineered T cells. Immunotherapy has achieved great success in clinical trials, but it is currently very expensive in terms of time required for analysis, reagents, and samples. TITAN aims to the continuous sampling of critical quality attributes, in order to quickly recognize deviations from the desired range and take appropriate corrective actions on process parameters for an optimal outcome. To achieve its aims, TITAN is currently developing microfluidic and sensing tools for the accurate and efficient real-time monitoring of the T cells amplification process. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Sketch of the qPCR assay procedure.</p>
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<p>(<b>A</b>,<b>B</b>) Spiral channel for cell focusing. Red cycle highlight the position of cells in the channel (<b>C</b>) Interleukin detection by DPV. (<b>D</b>) Simulated device for droplets generation with emulsion of oil (green) in water (blue); (<b>E</b>) plastic device realized for droplet generation (red) in water.</p>
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3 pages, 653 KiB  
Abstract
Design and Integration of an Elastic Sensor Sheet for Pressure Ulcer Prediction: Materials, Methods, and Network Connections
by Mohammad Mohammad Amini, Davood Fanaei Sheikholeslami, Rogério Dionísio, Ahmadreza Heravi and Mahdi Faghihi
Proceedings 2024, 97(1), 215; https://doi.org/10.3390/proceedings2024097215 - 14 May 2024
Viewed by 773
Abstract
This paper discusses the design and integration of an elastic sensor sheet for SENSOMATT, a smart device that predicts pressure ulcers caused by prolonged skin pressure. It covers the mechanical and electrical aspects of the sensor sheet design, including material selection, mould and [...] Read more.
This paper discusses the design and integration of an elastic sensor sheet for SENSOMATT, a smart device that predicts pressure ulcers caused by prolonged skin pressure. It covers the mechanical and electrical aspects of the sensor sheet design, including material selection, mould and tooling design, and network design. The paper describes testing of different configurations of the sensor sheet and various network structures. The final design of the sensor sheet is successfully constructed and tested, and the article provides a brief introduction to the printed circuit board design and manufacturing process. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Flexible sensor sheet with 40 × 10 sensors arrangement. (<b>b</b>) Master board PCB design to receive and analyze signal data.</p>
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3 pages, 630 KiB  
Abstract
Polymer-Mediated Increase in Sensitivity and Stability of CNT-FET pH Sensor
by Letícia Alves da Silva, Martin Hartmann and Sascha Hermann
Proceedings 2024, 97(1), 216; https://doi.org/10.3390/proceedings2024097216 - 15 May 2024
Viewed by 1037
Abstract
There has been an increasing interest in pH sensors based on nanomaterials in environmental and biological sensing. This work addresses persistent challenges in the development of stable and sensitive pH measurements. We present a CNT-FET-based pH sensor with a hybrid encapsulation stack consisting [...] Read more.
There has been an increasing interest in pH sensors based on nanomaterials in environmental and biological sensing. This work addresses persistent challenges in the development of stable and sensitive pH measurements. We present a CNT-FET-based pH sensor with a hybrid encapsulation stack consisting of poly(4-vinylpyridine)/HfO2 layers. The resulting liquid-gated sensors feature an excellent sensitivity of up to 50 mV/pH in an operation regime below 1 V, which is within the electrochemical window of most biological species. Moreover, the P4VP encapsulation results in a 1000× higher on-off-current ratio and nearly 83% smaller drift compared to devices encapsulated in only HfO2. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Sketch of CNT-FET with P4VP passivation and liquid cell on top. (<b>b</b>) Transistor curves with and without P4VP encapsulation were measured in a buffer solution with a pH of 5. (<b>c</b>) Time evolution of the voltage at the minimum current and the drain current upon pH stimulus measured at a gate voltage of 1 V for the P4VP modified transistor. (<b>d</b>) The normalized current of the P4VP encapsulated and not-encapsulated sensors upon pH stimulation at a gate voltage of 1 V, including a linear fit for the drift determination.</p>
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3 pages, 539 KiB  
Abstract
Highly Sensitive Plasmon-Enhanced Spectroscopic Detection of Peptide-Antibody Interactions
by Aruna Chandra Singh, Divya Balakrishnan, Hugo Payen, Clara Sidhoum, Thomas Østerbye and Sivashankar Krishnamoorthy
Proceedings 2024, 97(1), 217; https://doi.org/10.3390/proceedings2024097217 - 16 May 2024
Viewed by 878
Abstract
We demonstrate a highly sensitive plasmon-enhanced fluorescence sensor to detect antibodies to Cytomegalovirus (CMV), using their specific interaction with a peptide identified through in silico methods. The results show high promise for sensor miniaturization, ease of spatial multiplexing, high sensitivity, and quick response [...] Read more.
We demonstrate a highly sensitive plasmon-enhanced fluorescence sensor to detect antibodies to Cytomegalovirus (CMV), using their specific interaction with a peptide identified through in silico methods. The results show high promise for sensor miniaturization, ease of spatial multiplexing, high sensitivity, and quick response times. The developments are readily applicable to detect antibodies to range of other viruses (e.g., SARS-CoV-2 virus, Bird and Swine Flu). Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Plasmonic detection of peptide–protein interactions (<b>a</b>) Gold nanoarrays (SEM-top view), and numerically simulated electromagnetic field profiles showing sub-10 nm electromagnetic hotspots; plot compares fluorescence intensities on MEF sensors and on control surface (equivalent to the gold SPR chips used in (<b>b</b>)) (<b>b</b>) Illustration of the assay steps and the corresponding experimentally measured SPR shifts.</p>
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3 pages, 3477 KiB  
Abstract
Mechanochemical Approach to Carbon Nanotubes-Based Piezoresistive Sensors’ Fabrication
by Elisabetta Primiceri, Anna Grazia Monteduro, Francesco Montagna, Maria Serena Chiriacò, Francesco Ferrara, Mariaenrica Frigione, Giuseppe Maruccio and Antonio Turco
Proceedings 2024, 97(1), 218; https://doi.org/10.3390/proceedings2024097218 - 27 May 2024
Viewed by 666
Abstract
The development of 3D porous nanocarbon composites has improved the performance of piezoresistive sensors. However, the functionalization and surface distribution of nanocarbon may limit conductivity and mechanical stability. In this study, a mechanochemical approach was developed to create an elastomeric/CNTs 3D porous nanocomposite. [...] Read more.
The development of 3D porous nanocarbon composites has improved the performance of piezoresistive sensors. However, the functionalization and surface distribution of nanocarbon may limit conductivity and mechanical stability. In this study, a mechanochemical approach was developed to create an elastomeric/CNTs 3D porous nanocomposite. By changing parameters such as CNT length and polymer amount, different composites with improved piezoresistive properties can be produced for wearables or fluidic devices. The material can withstand compressive stress up to 150 Kpa and has a sensitivity of up to 330 Kpa−1 and a limit of detection of 0.2 Pa and 50 nm for pressure and extension, respectively. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Fabrication scheme of the PDMS/CNTs foams. (<b>b</b>) Scheme of the finger sensing device; (<b>c</b>) signals recorded during vortex movement.</p>
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3 pages, 959 KiB  
Abstract
Magnetic Nanoparticles and Magnetic Sensors for Ultrasensitive and Fast Diagnostics
by Alessandro Surpi, Luca Gnoli, Tatiana Shelykova, Gianluca Giavaresi, Manuel A. González-Gómez, Yolanda Piñeiro, José Rivas and Valentin Alek Dediu
Proceedings 2024, 97(1), 219; https://doi.org/10.3390/proceedings2024097219 - 27 May 2024
Viewed by 622
Abstract
A novel methodology for the sizing of magnetic nanoparticles (MNPs) based on diffusion is described herein. The sensing core is an electrical coil wrapped around a capillary filled by an MNP solution. We show that it is possible to determine MNPs’ hydrodynamic radius [...] Read more.
A novel methodology for the sizing of magnetic nanoparticles (MNPs) based on diffusion is described herein. The sensing core is an electrical coil wrapped around a capillary filled by an MNP solution. We show that it is possible to determine MNPs’ hydrodynamic radius by employing off-the-shelf electronic equipment by measuring the decrease in coil inductance when MNPs diffuse out of the coil by Brownian motion. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Concept of the sensor. At the beginning of the experiment (<b>a</b>), MNPs are magnetically confined in the coil and it has a high inductance. When the MNPs are free to diffuse, they leave the coil and its inductance decreases (<b>b</b>). The decrease in inductance follows the equation shown in the picture. In the plot, inductance (y-axis) and time (x-axis) are given in arbitrary units.</p>
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3 pages, 1028 KiB  
Abstract
Development of Pheromone-Receptor-Based Biosensors for the Early Detection of Pest Insects
by Oumaima Zaki, Emmanuel Scorsone, Gaëlle Lissorgues, Olivier Français and Lionel Rousseau
Proceedings 2024, 97(1), 220; https://doi.org/10.3390/proceedings2024097220 - 28 May 2024
Viewed by 692
Abstract
Insects destroy approximately one third of the world’s annual crop production. Their early detection enables the implementation of appropriate measures to prevent excessive infestation. Insects use species-specific chemical signals known as pheromones to communicate and attract their conspecifics. Interestingly, these pheromones are used [...] Read more.
Insects destroy approximately one third of the world’s annual crop production. Their early detection enables the implementation of appropriate measures to prevent excessive infestation. Insects use species-specific chemical signals known as pheromones to communicate and attract their conspecifics. Interestingly, these pheromones are used to lure insects into traps for pest control purposes. Despite its effectiveness, this method is laborious and time-consuming as it requires frequent observations to identify and count the captures. As an alternative, the detection of pheromones is a promising solution for insect surveillance. In this context, we are developing biosensors based on pheromone receptors (PRs) immobilized on diamond-based capacitive micromachined ultrasonic transducers (CMUT) with the aim of achieving highly selective detection of pest insect pheromones. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) SEM image of a cross section of a CMUT cell; (<b>b</b>) Nyquist plots obtained in the frequency range from 100 kHz to 0.1 Hz at 0 V vs. Ag/AgCl by applying 10 mV (AC mode) in 1 mM [Fe(CN)6]3/4-. (<b>c</b>) The evolution of electron transfer resistance (Ret) values after each immobilization step.</p>
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3 pages, 484 KiB  
Abstract
All-Solid-State Optodes: Recent Developments and Applications
by Larisa Lvova, Fabrizio Caroleo, Gabriele Magna, Federica Mandoj, Sara Nardis, Manuela Stefanelli, Roberto Paolesse and Corrado Di Natale
Proceedings 2024, 97(1), 221; https://doi.org/10.3390/proceedings2024097221 - 29 May 2024
Viewed by 728
Abstract
The development of novel sensing materials and analytical systems remains challenging nowadays. Among various transduction principles employed in chemical sensors, the optical transduction is often preferred, due to the fast response time, simplicity of preparation, and easy signal acquisition of optodes. In this [...] Read more.
The development of novel sensing materials and analytical systems remains challenging nowadays. Among various transduction principles employed in chemical sensors, the optical transduction is often preferred, due to the fast response time, simplicity of preparation, and easy signal acquisition of optodes. In this contribution, the main aspects of novel optical sensor development and their application in both single and array configurations for liquid sample analysis will be discussed. The applications of fluorimetric and colorimetric all-solid-state optical sensors and sensory arrays recently developed or under investigation for ecological monitoring, quality assessment, and medical and health care will be illustrated. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The schematics of optical sensor operating principles.</p>
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3 pages, 1736 KiB  
Abstract
Tilted Triangular Springs with Constant-Force Reaction
by Lisa Schmitt, Philip Schmitt and Martin Hoffmann
Proceedings 2024, 97(1), 222; https://doi.org/10.3390/proceedings2024097222 - 6 Jun 2024
Viewed by 3439
Abstract
Guiding mechanisms are among the most elementary components of in-plane micro-electro-mechanical systems (MEMS). Usually, a spring is desired that is compliant in only one direction and stiff in other directions. We introduce triangular springs with a preset tilting angle. The tilting angle lowers [...] Read more.
Guiding mechanisms are among the most elementary components of in-plane micro-electro-mechanical systems (MEMS). Usually, a spring is desired that is compliant in only one direction and stiff in other directions. We introduce triangular springs with a preset tilting angle. The tilting angle lowers the force reaction in the displacement direction and implements a constant-force reaction whereby the maximum selectivity of the tilted triangular spring is shifted to larger displacements. Thus, the tilted triangular springs can increase the lateral stability of comb-drive actuators. We show tilted triangular springs exhibiting constant forces in a deflection range of about 75 µm to 175 µm. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Tilted triangular spring. (<b>a</b>) Setup; (<b>b</b>) constant-force range (CFR) arising from the proceeding displacement; (<b>c</b>) fabricated SOI chip; (<b>d</b>) setup for experimental spring force reaction characterization.</p>
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<p>(<b>a</b>) Simulated force reaction <span class="html-italic">F<sub>x</sub></span> as a function of <span class="html-italic">β</span>; (<b>b</b>) simulated selectivity <span class="html-italic">S</span> as a function of <span class="html-italic">β</span>; (<b>c</b>) position of maximum selectivity <span class="html-italic">x</span>(<span class="html-italic">S</span><sub>max</sub>) depending on the projected length <span class="html-italic">L</span><sub>proj</sub>. of the tilted triangular spring; (<b>d</b>) experimental force reaction, for the experiment where <span class="html-italic">L</span> = 400 µm, <span class="html-italic">α</span> = 20°, <span class="html-italic">n</span> = 6, <span class="html-italic">d</span> = 5 µm/3.6 µm.</p>
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3 pages, 3130 KiB  
Abstract
Thermal Behavior of Biaxial Piezoelectric MEMS Scanner
by Laurent Mollard, Christel Dieppedale, Antoine Hamelin, François Gardien, Gwenael Le Rhun, Jean Hue, Laurent Frey and Gael Castellan
Proceedings 2024, 97(1), 223; https://doi.org/10.3390/proceedings2024097223 - 14 Jun 2024
Viewed by 3208
Abstract
This paper presents the thermal behavior of a non-resonant (quasi-static) biaxial piezoelectric MEMS scanner [...] Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Two-dimensional scanning/optical angles—2 × 2 mm<sup>2</sup> squared mirror with Bragg reflector (<span class="html-italic">n</span> = 2).</p>
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<p>FoM values (fe, θe.de) previously reported in [<a href="#B2-proceedings-97-00223" class="html-bibr">2</a>] (▲) and this work with <span style="color:orange">◘</span> Bragg (<span class="html-italic">n</span> = 2) and <span style="color:blue">◘</span> gold reflector for 2 × 2 mm<sup>2</sup>, 1 × 1 mm<sup>2</sup>, and 0.5 × 0.5 mm<sup>2</sup> side-squared mirrors.</p>
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<p>Variation in reflector absorption (%) with p- and s-type polarization at 550 nm incident wavelength; 45° incident laser; Bragg and gold reflector; ambient temperature (○, ◊) and after 400 °C annealing (<span style="color:red">○</span>, <span style="color:red">◊</span>).</p>
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<p>Scanner deformation of a Bragg reflector (<span class="html-italic">n</span> = 2) along the Z-axis near ambient temperature (30 °C).</p>
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3 pages, 439 KiB  
Abstract
Using Mono-, Bi- and Tri-Metallic Nanoparticles to Improve Selectivity and Sensitivity of CMOS-Integrated SnO2 Thin-Film Gas Sensors
by Florentyna Sosada-Ludwikowska, Larissa Egger, Jerome Vernieres, Vidyadhar Singh, Panagiotis Grammatikopoulos, Stephan Steinhauer and Anton Köck
Proceedings 2024, 97(1), 224; https://doi.org/10.3390/proceedings2024097224 - 14 Jun 2024
Viewed by 879
Abstract
We demonstrate the systematic optimization of SnO2-based thin-film chemical sensors by using mono-, bi- and tri metallic nanoparticles (NPs) composed of Ag, Pd, and Ru, which are deposited via magnetron sputtering inert gas condensation. The ultrathin SnO2 films are integrated [...] Read more.
We demonstrate the systematic optimization of SnO2-based thin-film chemical sensors by using mono-, bi- and tri metallic nanoparticles (NPs) composed of Ag, Pd, and Ru, which are deposited via magnetron sputtering inert gas condensation. The ultrathin SnO2 films are integrated on CMOS-based micro-hotplate devices, where each chip contains 16 sensor devices in total. We found that the response of the sensor device can be significantly tuned to specific target gases, such as CO and VOCs, by using various types of NPs. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Typical measurements for the bare and functionalized sensors for CO and HCMix (5 ppm, 50 ppm). The inset shows the CMOS-integrated µhp device for 16 sensors in total.</p>
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3 pages, 1496 KiB  
Abstract
Indoor Fire Prevention Based on Miniaturized Sensor Drones and Stationary Sensor Nodes
by Roland Pohle and Oliver Freudenberg
Proceedings 2024, 97(1), 225; https://doi.org/10.3390/proceedings2024097225 - 19 Jun 2024
Viewed by 752
Abstract
Miniature drones for indoor use and stationary sensor nodes have been equipped with thermal imaging and sensors for temperature, humidity, and relevant gas components to enable preventive analysis of indoor environments in order to identify pre-fire events. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Drone platform equipped with Sciosense ENS160/210 multi-gas sensor and the multi-ranger board for obstacle avoidance; (<b>b</b>) mobile drone landing platform with integrated charging.</p>
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<p>(<b>a</b>) Response of the ENS160 VOC sensor to an open flame during flight; (<b>b</b>) hot object detection by thermal image recorded during flight.</p>
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3 pages, 499 KiB  
Abstract
Nitrogen Monoxide Detection with Pentacene-Based Film Bulk Acoustic Resonators
by José Manuel Carmona-Cejas, Teona Mirea, Ricardo Hervás, Jimena Olivares and Marta Clement
Proceedings 2024, 97(1), 226; https://doi.org/10.3390/proceedings2024097226 - 2 Jul 2024
Viewed by 622
Abstract
Exposure to hazardous gases like NOx can have a negative effect on our health. High-performance sensors that are also able to sustain harsh environments are needed to control high levels of these contaminants, which in most cases, are generated by automotive exhaust or [...] Read more.
Exposure to hazardous gases like NOx can have a negative effect on our health. High-performance sensors that are also able to sustain harsh environments are needed to control high levels of these contaminants, which in most cases, are generated by automotive exhaust or industrial factories. In this work, we prove NO detection in the ppm level, employing an AlN-based FBAR with pentacene as the active layer. FBARs are potential candidates as they have also proven operation and stability in harsh environments as well as temperature and humidity discrimination with a single sensor. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Cross−section of an SMR. (<b>b</b>) Frequency shifts due to RH variations in the gas chamber. (<b>c</b>) Frequency shifts and temperature variation of the SMR with 33.3 ppm NO exposures. Red and black arrows show when NO flow starts and stops. (<b>d</b>) Relative humidity variation for the same experiment.</p>
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3 pages, 491 KiB  
Abstract
Film Bulk Acoustic Resonators for Nitrogen Monoxide Detection at 250 °C
by José Manuel Carmona-Cejas, Teona Mirea, Ricardo Hervás, Jimena Olivares and Marta Clement
Proceedings 2024, 97(1), 227; https://doi.org/10.3390/proceedings2024097227 - 9 Jul 2024
Viewed by 436
Abstract
Exposure to hazardous gases like NOx can have a negative impact on our health. High-performance sensors are needed to control high levels of these contaminants, which, in most cases, are generated by automotive exhaust or industrial factories. In this work we demonstrate [...] Read more.
Exposure to hazardous gases like NOx can have a negative impact on our health. High-performance sensors are needed to control high levels of these contaminants, which, in most cases, are generated by automotive exhaust or industrial factories. In this work we demonstrate NO detection below the ppm level by employing an AlScN-based FBAR covered with a sputtered WO3 active layer. FBARs are potential candidates as they have also proved operation and stability in harsh environments as well as temperature and humidity discrimination with a single sensor. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Cross section of an SMR; (<b>b</b>) frequency response of the SMRs before and after the annealing; (<b>c</b>) frequency shifts upon 50 ppm of NO exposure cycles for resonant (black line) and antiresonant frequency (red line).</p>
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3 pages, 535 KiB  
Abstract
Effect of Aesthetic Images on a Population with Mild Cognitive Decline: An Electroencephalography/Functional Near-Infrared Spectroscopy Study
by Livio Clemente, Marianna La Rocca, Marianna Delussi, Giusy Tancredi, Katia Ricci, Giuseppe Procida, Antonio Brunetti, Vitoantonio Bevilacqua and Marina de Tommaso
Proceedings 2024, 97(1), 228; https://doi.org/10.3390/proceedings2024097228 - 19 Sep 2024
Viewed by 478
Abstract
Neuroaesthetics is a relatively young field that connects neuroscience with empirical aesthetics and originates in the neurological theory of aesthetic experience. It investigates brain structures and activity during the phenomena of artistic perception and production and, at the same time, attempts to understand [...] Read more.
Neuroaesthetics is a relatively young field that connects neuroscience with empirical aesthetics and originates in the neurological theory of aesthetic experience. It investigates brain structures and activity during the phenomena of artistic perception and production and, at the same time, attempts to understand the influence of neurological pathologies on these mechanisms. For each participant (six subjects with mild cognitive decline and ten controls), electroencephalography (EEG) and functional near-infrared spectroscopy (fNIRS) data were acquired thanks to a wearable EEG–fNIRS system during the execution of a P300 task. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>The figure shows the preliminary results of the study: (<b>a</b>) IA group P300 latency under different conditions (ugly dynamic = UD; beautiful dynamic = BD; ugly static = US; beautiful static = BS); (<b>b</b>) NA group P300 latency in the different conditions; (<b>c</b>) control group shows elevated haemodynamic cortical activation in the left hemisphere.</p>
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3 pages, 878 KiB  
Abstract
A Portable Gold-Nanoparticle-Enhanced Surface Plasmon Resonance Sensor for Highly Sensitive β-Bungarotoxin Quantification in Snake Poisoning Diagnosis
by Samuel Husin Surya Mandala, Mochamad Januar, Chien-Chun Liu, Jau-Song Yu and Kou-Chen Liu
Proceedings 2024, 97(1), 229; https://doi.org/10.3390/proceedings2024097229 - 25 Sep 2024
Viewed by 578
Abstract
This study introduces a portable gold-nanoparticle-enhanced surface plasmon resonance (SPR) biosensor for the swift and highly sensitive detection of β-bungarotoxin in krait venom. Demonstrating a 103-fold increase in sensitivity over traditional SPR sensors, this compact tool underscores the potential of portable [...] Read more.
This study introduces a portable gold-nanoparticle-enhanced surface plasmon resonance (SPR) biosensor for the swift and highly sensitive detection of β-bungarotoxin in krait venom. Demonstrating a 103-fold increase in sensitivity over traditional SPR sensors, this compact tool underscores the potential of portable SPR biosensors for efficient point-of-care venom diagnostics. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic illustration of the operation procedure of the handheld SPR sensor for directly detecting β-btx in serum samples. (<b>b</b>) Comparison of different SPR reflection spectra either with or without AuNPs. (<b>c</b>) A comparison of two different SPR responses either with or without AuNPs at a fixed β-btx concentration of 500 fg mL<sup>−1</sup>. (<b>d</b>) SPR response as a function of β-btx concentration either with or without AuNPs. (<b>e</b>) SPR responses for reading and scoring the krait bite severity level.</p>
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3 pages, 756 KiB  
Abstract
UV Light-Induced Response Degradation Characteristics of Silicon-Based Detectors
by Daniel Gäbler and Pablo F. Siles
Proceedings 2024, 97(1), 230; https://doi.org/10.3390/proceedings2024097230 - 25 Sep 2024
Viewed by 685
Abstract
High energy radiation is known to potentially impact silicon-based optical sensors adversely, either permanently or reversibly [...] Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Intensity spectrum of a first mercury lamp (HBO 100) [<a href="#B2-proceedings-97-00230" class="html-bibr">2</a>] and a second mercury lamp (UV-Eraser with Grid Lamp G750NO2).</p>
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<p>(<b>left</b>): Photon-Energy related UV degradation for the case of two typical photodiodes (doe and doeher, not specialized on UV robustness), compared to two UV specialized devices, all manufactured in a 0.18 µm CMOS process, with epi wafer material. Dashed lines serve solely as a guide to the eye to observe the data tendency. (<b>right</b>): High sensitivity UVC response achieved by a CMOS integrated device (Technology XS018) compared to a reference CMOS device (Technology XH018) and a discrete backside illuminated device (Hamamatsu).</p>
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3 pages, 1291 KiB  
Abstract
Stimulation of the Nasal Cavity Using Flexible PCB Electrodes
by Clémentine Lipp, Evgenii Glushkov, Halina B. Stanley, Camille Ferdenzi, Maxime Fieux, Arnaud Bertsch, Jürgen Brugger and Moustafa Bensafi
Proceedings 2024, 97(1), 231; https://doi.org/10.3390/proceedings2024097231 - 10 Oct 2024
Viewed by 504
Abstract
The loss of the sense of smell has not produced as many technological developments to mitigate the inconvenience it causes compared to the loss of vision or hearing. Anosmia or hyposmia concerns approximately 20% of the current European population and is associated with [...] Read more.
The loss of the sense of smell has not produced as many technological developments to mitigate the inconvenience it causes compared to the loss of vision or hearing. Anosmia or hyposmia concerns approximately 20% of the current European population and is associated with a loss of quality of life and an increased rate of household accidents. Restoring olfaction would therefore be beneficial, but it represents a technological challenge. Electrical stimulation of the nasal cavity triggers sensations that may be helpful to patients in detecting environmental odorant stimuli. We present an electrical stimulator fabricated using commercial flexible PCB technology and compare two different placement designs: A standard design based on existing medical technology that uses a metallic rod, bent to ensure contact with the nasal cavity; and a self-holding design featuring two magnets, placed across the nasal septum to ensure contact. The detection thresholds were measured for both configurations on seven normosmic individuals and show a good correlation between the two designs. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>Scheme representing the setup for electrical stimulation of the nose: the stimulator comprises electrodes and is connected via a cable to a microcontroller and a pulse generator. The computer sends the stimulation parameters to the controller, which is powered by a 9V battery.</p>
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<p>(<b>a</b>,<b>b</b>) Stimulator in the rod configuration. (<b>c</b>) Patient with the rod stimulator in contact with the nasal mucosa as shown by the inset. (<b>d</b>) Stimulator in the magnetic clip configuration shown with the two branches opened to show the electrodes. (<b>e</b>) Stimulator in the magnetic clip configuration shown with the two branches closed by the two magnets. (<b>f</b>) Patient with the magnetic clip stimulator placed on either side of the nasal septum with the inset showing the contact with the mucosa.</p>
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<p>Perceptual ratings. (<b>a</b>) Comparison of threshold for electrical stimulation with best fit linear regression and standard error. (<b>b</b>) Comparison of perceptual ratings for seven normosmic participants to electrical stimulation at threshold at the anterior septum using the magnetic clip versus rod designs.</p>
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2 pages, 145 KiB  
Abstract
Smart Sensor for Mercury Detection in Novel Food
by Ilaria Antonia Vitale, Giulia Selvolini, Cristina Truzzi and Giovanna Marrazza
Proceedings 2024, 97(1), 232; https://doi.org/10.3390/proceedings2024097232 - 18 Oct 2024
Viewed by 450
Abstract
In this work, we present a simple, fast, and cheap procedure for the determination of mercury [Hg(II)] by square wave anodic stripping voltammetry (SWASV) at nanocomposite screen-printed graphite electrodes. The nanocomposite surfaces were obtained by the electrodeposition of poly(L-aspartic acid) on graphite screen-printed [...] Read more.
In this work, we present a simple, fast, and cheap procedure for the determination of mercury [Hg(II)] by square wave anodic stripping voltammetry (SWASV) at nanocomposite screen-printed graphite electrodes. The nanocomposite surfaces were obtained by the electrodeposition of poly(L-aspartic acid) on graphite screen-printed working electrodes using cyclic voltammetry (CV) and, then, of gold nanoparticles using chronoamperometry. A calibration curve by SWASV was obtained with a wide dynamic range (1–60 μg/L) and a limit of detection of 0.25 μg/L. The developed sensor was applied for the analysis of novel food samples. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
3 pages, 1054 KiB  
Abstract
A Gas Sensor Based on Fully Tuneable and Electrically Coupled Bulk Acoustic Wave Resonators
by Bernardo Madeira, Linlin Wang, Chen Wang and Michael Kraft
Proceedings 2024, 97(1), 233; https://doi.org/10.3390/proceedings2024097233 - 28 Oct 2024
Viewed by 465
Abstract
This paper reports on a gas sensor based on two bulk acoustic wave (BAW) resonators electrically coupled with a tuneable capacitor. The weak coupling strength was tuned to its optimal value (achieving maximum sensitivity) by varying the capacitance (without complex filtering, a control [...] Read more.
This paper reports on a gas sensor based on two bulk acoustic wave (BAW) resonators electrically coupled with a tuneable capacitor. The weak coupling strength was tuned to its optimal value (achieving maximum sensitivity) by varying the capacitance (without complex filtering, a control circuit as required in the state of the art). A gas sensor was developed based on the electrically coupled BAW resonators by functionalizing one of the resonators with zeolitic imidazolate framework-8 (ZIF-8). It featured a quality (Q) factor of ~2.2 k in air and a resonance frequency of ~6.32 MHz. Such a simple coupling mechanism can be tuned and further extended to coupled resonators in other domains. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Schematic of the 1-DoF BAW resonator, (<b>b</b>) displacement of the in-phase contour extensional mode, (<b>c</b>) image of the 1-DoF resonator, (<b>d</b>) image of back side of the ZIF-8 coating, (<b>e</b>) schematic of the experimental setup.</p>
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<p>(<b>a</b>) The AR change and ∆f under different ethanol concentration before drift cancellation post processing and (<b>b</b>) the relation between AR change and ethanol concentration after drift cancellation post processing.</p>
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Jump to: Research

9 pages, 3295 KiB  
Proceeding Paper
Design and Demonstration of Radio Frequency Micro Electro-Mechanical System Switches with Meandered Beams for Reduced Actuation Voltage
by Girolamo Tagliapietra, Jacopo Iannacci, Flavio Giacomozzi and Leandro Lorenzelli
Proceedings 2024, 97(1), 17; https://doi.org/10.3390/proceedings2024097017 - 14 Mar 2024
Cited by 2 | Viewed by 800
Abstract
In this paper, a class of three series ohmic switches is presented, including its design principles, the simulation results, and the outcomes of the measurements performed on the first batch of fabricated samples. The design of the adopted membranes is based on meandered [...] Read more.
In this paper, a class of three series ohmic switches is presented, including its design principles, the simulation results, and the outcomes of the measurements performed on the first batch of fabricated samples. The design of the adopted membranes is based on meandered beams, targeting a reduced actuation voltage. The initial and promising electro-mechanical simulations, performed in an Ansys Workbench environment, predicted actuation voltages in the 5–8 V range, whereas the measurements highlighted slightly greater values. The electro-magnetic behavior of such devices demonstrated a general and qualitative agreement with the simulations performed in the Ansys HFSS environment, with a satisfying performance in terms of return loss (<−20.22 dB) and isolation (<−14.86 dB) along the 5–30 GHz interval. Full article
(This article belongs to the Proceedings of XXXV EUROSENSORS Conference)
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<p>(<b>a</b>) Complete layout of <span class="html-italic">Dev1</span> switch, characterized by uniform meanders. (<b>b</b>) Detailed representation of <span class="html-italic">Dev1</span> switch, including its main dimensional parameters.</p>
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<p>(<b>a</b>) Description of beams employed in <span class="html-italic">Dev2</span> switch in their main dimensional parameters. (<b>b</b>) Beams employed in <span class="html-italic">Dev3</span> switch in their main dimensional parameters.</p>
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<p>(<b>a</b>) Simulated displacements of <span class="html-italic">Dev1</span>, <span class="html-italic">Dev2</span>, and <span class="html-italic">Dev3</span> switches showing actuation voltage. (<b>b</b>) Measured actuation voltages of <span class="html-italic">Dev1</span>, <span class="html-italic">Dev2</span>, <span class="html-italic">Dev3</span> by resistance drop along RF signal line.</p>
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<p>(<b>a</b>) A comparison between the simulated and measured performances of <span class="html-italic">Dev1</span> in its OFF state. (<b>b</b>) A comparison between the simulated and measured performances of <span class="html-italic">Dev1</span> in its ON state.</p>
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<p>(<b>a</b>) A comparison between the simulated and measured performances of <span class="html-italic">Dev2</span> in its OFF state. (<b>b</b>) A comparison between the simulated and measured performances of <span class="html-italic">Dev2</span> in its ON state.</p>
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<p>(<b>a</b>) A comparison between the simulated and measured performances of <span class="html-italic">Dev3</span> in its OFF state. (<b>b</b>) A comparison between the simulated and measured performances of <span class="html-italic">Dev3</span> in its ON state.</p>
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