JP2015198149A - Mechanical stimulation response element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel energy harvest technology, namely, to provide a novel mechanism stimulation response element for generating power (voltage and current) from a mechanical stimulation such as impact.SOLUTION: The element configured to generate the voltage from the mechanical stimulation includes: a mechanical stimulation response layer 1 and at least a pair of electrodes 2 and 2 holding the mechanical stimulation response layer 1 therebetween. The mechanical stimulation response layer 1 includes a polymer and a compound that plasticizes the polymer, and electric charge is generated in the polymer or the compound by the impact. It is preferable to have one or two or more of characteristics that the electric charge is positive electric charge or negative electric charge, the polymer or the compound has a polarity, the compound is a plasticizer or a solvent, there is a difference in the triboelectric series between the polymer and the compound, and there is a difference in degrees of movement between the polymer and the compound.

Description

  The present invention relates to a mechanical stimulation response element, and more particularly to an energy harvesting technology that contributes to energy saving, and relates to a new mechanical stimulation response element that generates electric power (voltage, current) by mechanical stimulation such as impact. .

  Energy harvesting is a technology that collects energy such as light, vibration, and heat (harvest) to obtain electric power, and in particular, it is a technology that aims to convert and use a small amount of energy around us to electric power. . In recent years, materials for realizing such energy harvesting (also called energy harvesting materials) have been studied in various fields and are highly expected. This energy harvest may also be called energy harvesting, energy harvesting, energy harvesting, or energy harvesting.

  By the way, the present inventor has reported an actuator using a dielectric polymer material. For example, Patent Document 1 provides a polymer flexible actuator that can be driven by a low electric field using a dielectric polymer. This technique includes a gel 1 composed of a dielectric polymer, a plasticizer, and an ionic liquid selected from phosphonium cations and ammonium cations. Further, Patent Document 2 provides a gel-like polymer device that exhibits an electro-optic effect that is small in energy loss and can be applied to new applications, and a method for manufacturing the same. This technique has a high dielectric gel-like polymer material exhibiting an electro-optic effect, and an electrode for applying a bias voltage to the gel-like polymer material, and the gel-like polymer material has a relative dielectric constant of 0. It is configured to be a predetermined value or more at 01 Hz. An actuator using such a dielectric polymer material is expected to be applied to a small, light and flexible artificial muscle, a voltage driving device, and the like.

JP 2009-273204 A JP 2013-190547 A

  An object of the present invention is to provide a new energy harvesting technology, and to provide a new mechanical stimulus response element that generates electric power (voltage, current) by a mechanical stimulus such as an impact.

  A mechanical stimulation response element according to the present invention for solving the above-described problem is an element that generates a voltage by mechanical stimulation, and includes a mechanical stimulation response layer and at least a pair of electrodes sandwiching the mechanical stimulation response layer. The mechanical stimulus responsive layer includes a polymer and a compound that plasticizes the polymer, and the polymer or the compound is charged with an impact.

  In the mechanical stimulus responsive element according to the present invention, (a) the charge is a positive charge or a negative charge, (b) the polymer or the compound has polarity, and (c) the compound is a plasticizer or a solvent. (D) the electric charge is generated at an electrode on the mechanically stimulated response layer of the mechanical stimulation response layer, and (e) the electric charge is generated at an electrode on the non-mechanical stimulation side of the mechanical stimulation response layer. No, (f) The polymer and the compound have one or more characteristics in that there is a difference in charge train, and (g) the polymer and the compound have a difference in mobility.

  The mechanical stimulus response element according to the present invention can provide a new energy harvesting technology. In particular, it is possible to provide a new mechanical stimulus response element that generates electric power (voltage, current) by a mechanical stimulus such as an impact.

It is a schematic cross section showing an example of a mechanical stimulus response element according to the present invention. It is explanatory drawing of the mechanism of the mechanical stimulus response element based on this invention. The left series is an example in which a polymer generates a charge, and the right series is an example in which a compound that plasticizes the polymer generates a charge. It is a schematic graph which shows the example which a voltage changes in the process of increasing the amount of compounds, and carries out positive / negative reversal. It is a schematic graph which shows the example which a voltage changes in the process of increasing a compound amount, but does not invert positive / negative. 6 is a graph showing experimental results of the mechanical stimulus response element obtained in Example 1. 2 is a graph summarizing the results obtained in Example 1. FIG. 6 is a schematic graph showing an example in which the voltage changes in the process of increasing the amount of plasticizer and reverses positive and negative in the mechanical stimulus response element obtained in Example 1. FIG.

  Hereinafter, the mechanical stimulus response element according to the present invention will be described, but the present invention is not limited only to the contents described in the following description and drawings.

[Mechanical stimulation response element]
As shown in FIG. 1, the mechanical stimulus response element 10 according to the present invention is an element that generates a voltage by mechanical stimulus, and includes a mechanical stimulus response layer 1 and at least a pair of electrodes 2 sandwiching the mechanical stimulus response layer 1. 2. The mechanical stimulus response layer 1 has a polymer and a compound that plasticizes the polymer, and the polymer or the compound is characterized in that an electric charge is generated by impact.

  This mechanical stimulus response element 10 can be used as a new energy harvesting technology. In particular, it is a new mechanical stimulus response element that generates electric power (voltage, current) by a mechanical stimulus such as an impact. This mechanical stimulus response element 10 is a technology that can be easily applied to conventional general-purpose polymers, and is expected to have great potential. When this technology is applied to energy harvesting, the characteristics can be controlled by changing the type and blending amount of the polymer and the compound, so that it has a special advantage that a desired device can be designed.

  Hereinafter, the components of the mechanical stimulus response element 10 will be described.

(electrode)
As shown in FIGS. 1 and 2, at least one pair of electrodes 1 is provided so as to sandwich the mechanical stimulus response layer 1. The form which provides the electrodes 2 and 2 may be provided in the whole surface so that the mechanical stimulus response layer 1 may be pinched | interposed, and may be provided so that a part may be pinched | interposed. Moreover, as long as at least one pair is provided, two pairs or three pairs may be used. One side may be the entire surface, and a plurality of other surfaces may be provided. When a plurality of surfaces are provided, they are provided so as not to overlap in a plan view. In addition, when overlapping in a plan view, since they are electrically integrated, they are no longer separate electrodes.

  The kind of electrode 2 should just be a material with the required electroconductivity, for example, metal materials, such as aluminum, copper, titanium, or its alloy etc. can be used. Moreover, even if it is electroconductive inorganic materials, electroconductive organic materials, etc., such as an indium tin oxide and a carbon material, as long as it has required electrical conductivity, you may select and use from well-known electrode materials. The shape of the electrode 2 is not particularly limited, and may be any shape according to the shape of the mechanical stimulus response layer 1 such as a sheet shape, a film shape, a mesh shape, a net shape, and a comb shape. The thickness of the electrode 2 is not particularly limited, and may be set to an arbitrary thickness in consideration of resistance, electrical conductivity, and the like. As a method for forming the electrode 2, it is preferable that the electrode prepared in advance is bonded to the mechanical stimulus response layer 1 with a conductive paste or the like. However, the electrode 2 may be provided by a film forming means such as low-temperature vapor deposition or other known methods. May be provided.

  Such an electrode 2 is connected to a control device, subjected to signal processing as necessary, and can perform the following processing using the received signal as a trigger. Further, it may be connected to a battery as necessary and stored as electric power.

(Mechanical stimulus response layer)
The mechanical stimulus response layer 1 is mainly composed of a gel-like polymer material (polymer). The reason “mainly” is because it contains a compound (visibility compound) that softens the polymer. This mechanical stimulus response layer 1 is sandwiched between electrodes 2 and 2 as shown in FIG. As shown in FIGS. 1 and 2, the mechanical stimulus response layer 1 generates a potential difference by applying an impact (load) to one of the electrodes 2 (reference numeral 2 a in the examples of FIGS. 1 and 2), thereby generating a voltage. To do.

  The potential difference generation mechanism is considered as follows.

  First, as shown in FIG. 2 (1), the mechanical stimulus response layer 1 has a polymer dispersed in a gel form. This gel-like polymer is not charged until an impact (also referred to as a load) 3 is applied.

  Next, in the polymer-rich example in FIG. 2 (2a), when an impact 3 is applied to one electrode 2a, the gel polymer in the vicinity of the electrode 2a is distorted, and the intermolecular distance between the polymer chain and the compound is increased. The polymer is charged by friction. Thus, in the mechanical stimulus response layer 1, the polymer near the electrode 2a is in a state of being charged to a negative charge, for example. At this time, in order to neutralize the charge, the electrode 2a is positively charged as shown in FIG. 2 (3a). An electromotive force is generated between the positively charged electrode 2a and the other electrode 2b that is not charged at the other side, and a potential difference is generated between the electrodes to generate a voltage. With this principle, a voltage is generated by the impact 3.

  On the other hand, in the compound-rich example in FIG. 2 (2b), when an impact 3 is applied to one electrode 2a, the gel polymer in the vicinity of the electrode 2a is distorted, and intermolecular friction between the polymer chain and the compound occurs. As a result, the compound is charged. In this way, the compound near the electrode 2a in the mechanical stimulus response layer 1 is in a state of being charged to a positive charge, for example. At this time, in order to neutralize the charge, the electrode 2a is negatively charged as shown in FIG. 2 (3b). An electromotive force is generated between the negatively charged electrode 2b and the other electrode 2b that is not charged at the other side, and a potential difference is generated between the electrodes to generate a voltage. With this principle, a voltage is generated by the impact 3.

  As described above, electric charges are generated at the mechanically stimulated electrode 2a of the mechanical stimulus response layer 1 and are not generated at the non-mechanically stimulated electrode 2b. For this reason, a potential difference is generated between the electrodes and a voltage is generated. In the above example, “polymer-rich” and “compound-rich” are referred to. However, this is not to say that the amount is large, and in terms of which charge is generated by impact 3 in either the polymer or the compound ( Rich) or poor (poor).

  FIG. 3A is an example of a mechanical stimulus response element 10 having the same characteristics as FIG. 7 described in Example 2 described later. A polymer is negatively charged by impact, and a compound is positive by impact. It is an example using what is electrically charged. On the other hand, FIG. 3B shows an example in which the polymer is positively charged by impact and the compound is negatively charged by impact. FIG. 4A shows an example in which the polymer is negatively charged by impact and the compound is not positively or negatively charged by impact. On the other hand, FIG. 4B shows an example in which the polymer is positively charged by impact and the compound is not positively or negatively charged by impact. As described above, by changing the types of the polymer and the compound, the mechanical stimulus response element 10 can have arbitrary characteristics as shown in FIGS. 3 and 4.

  In the mechanical stimulus response element 10 that operates according to such a principle, the charge generated in the mechanical stimulus response layer 1 in the vicinity of the electrode 2 subjected to the impact 3 may be a positive charge or a negative charge. And depending on the type of compound.

  Moreover, it is preferable that any one or both of a polymer and a compound have polarity. When they have polarity, they are polarized by the impact 3 and charges are easily generated.

  In order to generate a large potential difference, it is preferable that the polymer and the compound have a difference in the charge train. The charge train is a sequence of positive and negative when two materials are rubbed together and static electricity occurs to charge positively or negatively, respectively, and is also referred to as a frictional charge train. Although this charged column is publicly disclosed, strong static electricity is generated by rubbing an object located at a distance from the column. The polymer and the compound constituting the mechanical stimulus response layer 1 also generate a larger electrostatic charge if the charged trains are separated from each other. Therefore, a large charge is generated near the electrode on the side subjected to the impact 3, and a large charge is generated. Voltage is generated.

  Moreover, it is preferable that a polymer and a compound have a difference in mobility. When there is a difference in mobility, when one of the mobility becomes relatively large and an impact 3 is applied to one of the electrodes 2a, either the polymer or the compound in the vicinity of the electrode 2a moves greatly, and there is a large gap between the two. Friction is likely to occur. As a result, a larger electrostatic charge is generated, so that a large charge is generated near the electrode on the side subjected to the impact 3 and a large voltage is generated.

  The mechanical stimulus response element 10 that operates by such a mechanism can extract energy from the gel-like mechanical stimulus response layer 1. The degree of freedom in selecting polymers and compounds is high, familiar materials can be used, and there are no special considerations, and control is extremely easy. In addition, it can be handled in the same manner as a normal film and is excellent in convenience. In addition, although piezoelectric materials and the like are widely used, only limited materials are used, and the application range is not necessarily large. However, the mechanical stimulus response element proposed in the present invention is a novel element discovered in the process of developing an electrostrictive actuator of dielectric gel, and has a wide range of applications in that it exhibits extremely unique characteristics. The degree of freedom in device design is also great.

(polymer)
The polymer should just be what is easily plasticized with the compound mentioned later. As an example of such a polymer, it is preferable that it is a material that mainly contains a polymer, does not contain an ionic material or a conductive material, and does not exhibit ionic conductivity or electrical conductivity. Such a polymer is likely to generate a charge by impact 3.

  This polymer is a general insulating polymer compound before it is gelled by adding a gelling agent such as a plasticizer or a solvent described later to the polymer. Such a polymer has a small dielectric constant, and usually has a relative dielectric constant of about 2 to 9. However, since the polymer gelled material does not contain an ionic material or a conductive material, energy loss such as heat generation due to a current flowing based on the ionic material or the conductive material is extremely small.

  Examples of the polymer include polyvinyl chloride (PVC), polyacrylonitrile (PAN), nylon (Nylon), polyethylene terephthalate (PET), polypropylene (PP), polyethylene (PE), polyketone (PK), and polyvinyl alcohol (PVA). Any one or two or more polymer compounds selected from the group consisting of polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), poly nbutyl acrylate (PnBA), cellulose, wool and the like can be used.

(Compound)
The compound is a plasticizer or solvent that can be plasticized to such an extent that the above-mentioned polymer is gelled. As such a plasticizer, a known insulating plasticizer can be used. For example, dioctyl phthalate, diisononyl phthalate, diisodecyl phthalate, dibutyl phthalate (di-n-butyl phthalate); adipic acid esters such as dioctyl adipate, diisononyl adipate; trioctyl trimellitic acid, etc. Trimellitic acid ester; Polyester; Phosphate ester such as tricresyl phosphate; Maleic acid ester; benzoic acid ester and the like.

  Which plasticizer is used is selected depending on the type of polymer. Moreover, although the blending ratio of the plasticizer is also set depending on the kind of polymer, it is usually preferable to blend a large amount of plasticizer. The blending ratio is preferably in the range of polymer: plasticizer (mass ratio) = 1: 0.5 to 1:10.

  As a solvent to be blended for gelation, a solvent having a low dielectric constant (ε = 2 to 8) such as benzene or toluene may be used, or a high dielectric constant such as dimethyl sulfoxide (DMSO) or dimethylformamide (DMF). A solvent of (ε = 20 to 40) may be used.

  Which solvent is used is selected depending on the type of polymer. Further, the blending ratio of the solvent is also set depending on the type of polymer, but usually the solvent is not blended as much as the plasticizer described above. The blending ratio is preferably in the range of polymer: solvent (mass ratio) = 1: 0.5 to 1: 5.

  The gel-like mechanical stimulus response layer 1 is a gel formed by adding a compound or solvent for imparting plasticity to the polymer. Gelation can be performed by adding a gelling agent to the polymer. Although the gelling agent depends on the type of polymer, for example, a plasticizer or a solvent can be used. The amount of the gelling agent such as a plasticizer or a solvent is determined so as to obtain a desired gel strength.

  As another configuration, it is desirable that a protective film is provided so as to cover the electrodes 2 and 2 of the mechanical stimulus response element 10. Since this mechanical stimulus response element 10 generates a voltage by applying a mechanical shock from the electrode side, a protective film is provided to protect the electrode from being broken or cracked by the shock. . Although it does not specifically limit as a protective film, An organic type protective film may be sufficient and an inorganic type protective film may be sufficient.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
Polyvinyl chloride having a polymerization degree of 1700 (Ryuron paste 810: registered trademark, Toyo Soda Kogyo Co., Ltd.) and dibutyl adipate (DBA) were blended at a mass ratio (PVC: DBA) of 1: 1 and sufficiently stirred. . Each solution was poured into a glass cell preheated at 150 ° C. Aluminum electrodes were previously placed on the opposing wall surfaces of the glass cell, and the injected solution was heated at 150 ° C. for 30 minutes to produce a gel-like plasticized PVC having a length of 2 cm and a width of 1 cm between the electrodes. . Nine types of gel-like mechanical stimulus response elements were thus obtained.

(Measurement)
The obtained mechanical stimulus response element was placed on a table, and the electrodes were connected to a PC data logger. A steel ball (diameter: 11 cm, weight: 5.5 g) was dropped from a position 10 cm above the mechanical stimulus response element, and a voltage value and a current value were measured. The results at that time are shown in FIG. “1st” in FIG. 5 is the voltage and current when the steel ball first falls on the mechanical stimulus response element, “2nd” is the second drop after bouncing, and “3rd” is bounced. It is the time of the third fall after, and “4th” is the time of the fourth fall after bouncing. FIG. 6 is a graph using the voltage value and the current value obtained in FIG. 5, the horizontal axis is the generated voltage obtained in FIG. 5, and the vertical axis is 2 of the current value at the generated voltage. The result is obtained by multiplying the power by time (E = (current) ² × time). From the result of FIG. 6, when an impact was applied to the mechanical stimulus response element, a negative voltage was generated, and the generated voltage value was directly proportional to the energy E. This result indicates that mechanical stimulation is converted into electric energy (power generation).

[Example 2]
In Example 2, the weight ratio of PVC: DBA was 1: 0, 1: 0.5, 1: 0.6, 1: 0.7, 1: 0.8, 1: 0.9, 1: 1. 1: 2, 1: 3. Otherwise, each mechanical stimulus response element was fabricated in the same manner as in Example 1. In addition, the thing of PVC: DBA = 1: 0 was produced by the solvent cast method.

  FIG. 7 is a schematic diagram showing an example in which the abscissa indicates the mass ratio of “plasticizer / PVC polymer”, the ordinate indicates the voltage value, and the voltage changes in the process of increasing the amount of the plasticizer and is reversed between positive and negative. It is a simple graph. As shown in FIG. 7, a positive voltage was generated up to P2 with less plasticizer as shown in FIGS. This positive voltage causes the PVC polymer to be distorted by impact, the PVC polymer is negatively charged due to intermolecular friction between the polymer chain and the plasticizer, and the electrode is positively charged to neutralize the charge. It is considered a thing. In addition, up to P1 where the plasticizer is increased, the plasticizer is relatively increased, and the positive charge of the plasticizer starts to be generated, and the negative charge of the PVC polymer and the positive charge of the plasticizer are offset. It is thought that the voltage value of decreased.

  It is considered that the voltage is zero at P1 in FIG. 7, the positive / negative is reversed at the boundary of 0, the plasticizer is positively charged, and the electrode is negatively charged in order to neutralize the charge. Further, up to P3 where the plasticizer was increased, the plasticizer increased relatively, the positive charge of the plasticizer further increased, and the negative voltage further increased. However, when the plasticizer is further increased, the fluidity of the gel is increased, the agent is further increased, the intermolecular friction between the polymer chain and the plasticizer is decreased, the voltage is decreased, and the voltage approaches zero. It is thought that it will go.

1 Mechanical stimulus response layer 2, 2a, 2b Electrode 3 Impact (load)
10 Mechanical stimulus response element 20 Steel ball

Claims (8)

An element that generates a voltage by mechanical stimulation,
A mechanical stimulation response layer, and at least a pair of electrodes sandwiching the mechanical stimulation response layer,
The mechanical stimulus response layer includes a polymer and a compound that plasticizes the polymer, and the polymer or the compound generates an electric charge by impact.   The mechanical stimulation response element according to claim 1, wherein the charge is a positive charge or a negative charge.   The mechanical stimulus responsive element according to claim 1, wherein the polymer or the compound has polarity.   The mechanical stimulus responsive element according to claim 1, wherein the compound is a plasticizer or a solvent.   The mechanical stimulation response element according to claim 1, wherein the electric charge is generated at an electrode on the mechanical stimulation side of the mechanical stimulation response layer.   5. The mechanical stimulus response element according to claim 1, wherein the electric charge is not generated at an electrode on the non-mechanically stimulated side of the mechanical stimulus response layer. 6.   The mechanical stimulus response element according to any one of claims 1 to 6, wherein the polymer and the compound are different from each other in a charge train. The mechanical stimulus responsive element according to claim 1, wherein the polymer and the compound have a difference in mobility.

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