CN108855267B - A microfluidic platform for micromanipulation of biological micro-nanoparticles - Google Patents

Abstract

The invention discloses a micro-channel platform for micro-manipulation of biological micro-nano particles, which can realize the position and flow rate constraints of biological micro-nano particles; the platform comprises: a single-channel syringe pump, a conical pipe, and a pipe rack , a cover glass, a microfluidic channel and a base; wherein, the single-channel syringe pump is communicated with the conical pipe; the conical pipe is fixed on the pipe rack, the taper angle of the conical pipe is 6-12°, and the conical pipe is The conical mouth of the pipe is aligned with the flow channel mouth of the micro flow channel; the pipe rack and the cover glass are fixed on the base, and the base is a plug-in structure; the micro flow channel is fixed on the cover glass, and the micro flow channel is wide on both sides A symmetrical double-arc structure with a narrow middle, the radius of curvature of the symmetrical double-arc structure is 10-20mm, and the distance between the closest points of the two arcs is 50-200μm. The invention has the characteristics of convenient operation, high degree of freedom, low cost and mass production.

Description

A microfluidic platform for micromanipulation of biological micro-nanoparticles

technical field

The invention relates to a device for designing a micro-channel structure, in particular to a micro-channel platform for micro-manipulation of biological micro-nano particles.

Background technique

In the past decade, the micromanipulation of biological objects at the micro-nano scale has become an important topic in the field of bio-nanotechnology. Depending on the complexity and scale of the application process, micromanipulation includes a series of increasingly refined manipulations such as three-dimensional capture, translation/rotation, collection or separation, and live cell surgery/microinjection. At scale, there has been more manipulation from the cellular level into subcellular processes. Among several competing 3D micromanipulation techniques (including electrophoresis, magnetic force, mechanics, etc.), microscopic optical tweezers, as an almost non-invasive method, has the outstanding advantage that it can be used in most cells and subtypes. An adjustable control force of 10 ^-14 -10 ^-8 N is applied in the scale range of cellular components for the realization of the micromanipulation process. The manipulation of biological objects using optical tweezers is currently divided into direct and indirect manipulation (ie, whether the laser directly acts on the biological object). In future bioengineering, the use of direct laser beams for cell trapping or micromanipulation should be avoided as much as possible to eliminate the adverse effects of laser light on biological objects. Therefore, indirect micromanipulation of cells and subcellular objects will become an extremely important tool and research topic in bioengineering.

Without being affected by direct laser light, indirect micro-manipulation can complete the process control of biological object positioning, transportation, sorting, etc. In medical research, diagnosis, treatment, and drug delivery can be studied through these processes, which will enable research from different disciplines. It is of great innovation to perform basic and applied research at the living cell and subcellular scales to enable highly accurate discrimination of cell and drug interactions, to develop new drugs and diagnostics, and to detect the onset of deadly diseases at very early stages. basic research work, and has huge biomedical application value and market potential.

In terms of indirect micro-manipulation, a lot of resources have been invested in this topic in the world in recent years. In order to achieve indirect manipulation of biological objects, optical tweezers are used instead to capture dielectric microspheres (such as latex, polystyrene, silica, etc.), and these microspheres are connected to the ends or boundary surfaces of biological objects. to drive various spatial motions of biological objects. Different from magnetic or electrophoretic manipulation techniques, optical tweezers can achieve multiple manipulations without interfering with each other by using several laser beams at the same time. This feature provides good conditions for indirect micromanipulation. With the development of indirect manipulation, the demand for indirect manipulation of micro-channel design is also increasing. Under the conditions of manipulation, the micro-movement and rotation of biological micro-nano particles must be taken into account, so as to realize the manipulation and classification of rare cells.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device for a micro-fluidic platform for micro-manipulation of biological micro-nano particles in view of the deficiencies of the prior art.

The object of the present invention is achieved through the following technical solutions: a micro-channel platform for micro-manipulation of biological micro-nano particles, which can realize the position and flow rate constraints of biological micro-nano particles, and then realize the control of rare cells. Manipulation classification; the platform includes: a single-channel syringe pump, a conical pipe, a pipe rack, a cover glass, a microfluidic channel and a base; wherein, the single-channel syringe pump is communicated with the conical pipe; the conical pipe is fixed on the On the pipe rack, the taper angle of the conical pipe is 6-12°, and the conical mouth of the conical pipe is aligned with the flow channel mouth of the microchannel; the pipe rack and the cover glass are fixed on the base, and the base is a plug-in structure The microchannel is fixed on the cover glass, and the microchannel is a symmetrical double-arc structure with wide sides on both sides and narrow in the middle. The radius of curvature of the symmetrical double-arc structure is 10-20mm, and the distance between the closest points of the two arcs is 50-200μm .

Further, the injection speed of the single-channel syringe pump is 0.1-1 ml/h.

Further, the single-channel syringe pump and the conical pipeline are communicated through a hose, the hose is fixed on the X-shaped metal frame, and the liquid flow rate in the hose is reduced by screwing in the end screw of the X-shaped metal frame, so as to realize the Micro-adjustment of flow rate.

Further, the material of the tapered pipe is glass, and the tapered angle is produced by an electric coil heating method.

Further, the inclination angle of the slope of the pipe rack is consistent with the taper angle of the conical pipe, so that the liquid flows forward into the microfluidic channel.

Further, the pipe rack and the base are integrally formed and realized by 3D printing technology.

Further, the 3D printing technology material is ABS or PBS.

Further, the gluing between the cover glass, the micro-channel and the base and the gluing between the tapered pipes and the pipe racks are specifically: using UV glue to connect and fix the components.

The beneficial effects of the present invention are:

1. The present invention has the characteristics of low cost, and its plug-in structure provides the possibility of mass production, and has the characteristics of one-time replacement.

2. The present invention has the potential of commercial miniaturization, and can be combined with a microfluidic chip to realize Lab-on-a-chip integration.

3. The symmetrical double-arc structure of the micro flow channel in the present invention facilitates the observation of liquid flow, and the selection of flow velocity and cone angle reduces the influence of liquid surface tension and improves the accuracy of the position and flow rate constraints of biological micro-nano particles.

4. The present invention has the development potential of indirectly manipulating the micro-movement and rotation of micro-nano particles, manipulating, detecting, and separating rare cells, and is the core component of nano-particle micro-manipulation.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the micro-channel platform used for the micro-manipulation of biological micro-nano particles according to the present invention;

Fig. 2 is the tapered pipe schematic diagram of the microfluidic platform;

3 is a schematic diagram of a micro-manipulation system that utilizes the micro-channel platform of the present invention to constrain the position and flow rate of biological micro-nano particles;

Figure 4 is an assembly diagram of a microchannel platform;

Figure 5 is an exploded view of the microchannel platform;

In the figure, single-channel syringe pump 1, hose 2, tapered pipe 3, pipe rack 4, cover glass 5, microchannel 6, base 7, optical fiber operation rack 8, microchannel platform 9, microscope objective 10 , fiber 11.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

The working principle of the present invention is as follows:

According to the continuity equation, Navier-stokes equation of motion, energy conservation equation and rheological constitutive equation in microfluidic fluid dynamics, the influence of the cross-sectional shape of the flow channel on the fluid is analyzed:

可知：当流体在流道中处于稳定层流状态时，流体的压力损失为：

其中λ为沿程阻力系数；v为流体动力粘度；ρ为流体密度；d为流道直径；l为流道长度；Re为雷诺数。According to Navier-stokes equation of motion

It can be seen that when the fluid is in a stable laminar flow state in the flow channel, the pressure loss of the fluid is:

Where λ is the resistance coefficient along the way; v is the fluid dynamic viscosity; ρ is the fluid density; d is the diameter of the flow channel; l is the length of the flow channel; Re is the Reynolds number.

In the process of microfluidic flow, due to the microscale effect, the surface force is enhanced, the viscous force far exceeds the inertial force, the reduction of the diameter of the flow channel leads to the reduction of the microfluidic Reynolds number, the increase of the resistance coefficient along the path, and the microfluidic channel The length-to-jing ratio increases. It can be seen from the pressure loss formula: the smaller the diameter of the microfluidic channel, the greater the pressure loss of the microfluid during the flow process, and the worse the fluidity of the fluid;

Therefore, the flow length of the microfluid in the microfluidic channel is inversely proportional to the specific surface area of the channel section (the ratio of the perimeter of the section to the cross-sectional area). When the specific surface area of the microfluidic channel is small, the fluid temperature and injection pressure have a great influence on the flow length.

Specifically, the present invention provides a micro-channel platform for micro-manipulation of biological micro-nano particles, as shown in Figures 1 and 2, the platform can realize the position and flow rate constraints of biological micro-nano particles, and then realize the control of biological micro-nano particles. Manipulation and classification of rare cells; the platform includes: a single-channel syringe pump 1, a conical pipe 3, a pipe rack 4, a coverslip 5, a microfluidic channel 6 and a base 7; wherein, the single-channel syringe pump 1 and the conical The pipes 3 are connected; the conical pipes 3 are fixed on the pipe frame 4, the cone angle of the conical pipes 3 is 6-12°, and the conical mouths of the conical pipes 3 are aligned with the flow passages of the microchannels 6; the pipes The frame 4 and the cover glass 5 are fixed on the base 7, and the base 7 is a plug-in structure; the micro-channel 6 is fixed on the cover glass 5, and the micro-channel 6 is a symmetrical double arc structure with wide and middle narrow on both sides. It is easy to observe the flow of liquid and control it. The radius of curvature of the symmetrical double arc structure is 10-20mm, and the distance between the closest points of the two arcs is 50-200μm.

Further, the injection speed of the single-channel syringe pump 1 is 0.1-1 ml/h.

Further, the single-channel syringe pump 1 and the conical pipe 3 are communicated through a hose 2, the hose 2 is fixed on the X-shaped metal frame, and the hose 2 is reduced by screwing into the end screw of the X-shaped metal frame. Liquid flow rate, to achieve micro-adjustment of the flow rate.

Further, the material of the tapered pipe 3 is glass, and the tapered angle is produced by an electric coil heating method.

Further, the inclination angle of the slope of the pipe rack 4 is consistent with the taper angle of the conical pipe 3 , so that the liquid can flow forward into the micro-channel 6 .

Further, the pipe frame 4 and the base 7 are integrally formed and realized by 3D printing technology.

Further, the 3D printing technology material is ABS or PBS.

Further, the gluing between the cover glass 5 , the micro-channel 6 , and the base 7 and the gluing between the tapered pipes 3 and the pipe racks 4 are specifically: using UV glue to connect and fix the components.

As shown in FIG. 3 , in the micro-manipulation system using the micro-channel platform of the present invention to constrain the position and flow rate of biological micro-nano particles, the optical fiber 11 is manipulated by the optical fiber operating frame 8 to focus the light spot on the micro-channel plane, and the The flow channel platform 9 constrains the flow position and velocity of the biological micro-nano particles, so that the light spot can be aligned with the biological micro-nano particles to achieve manipulation and capture. The experimental phenomenon is observed and recorded through the microscope objective lens 10 . The micro-channel plug-in structure is directly inserted into the grooves in Figures 4 and 5 .

The above-mentioned embodiments are used to explain the present invention, rather than limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modifications and changes made to the present invention all fall into the protection scope of the present invention.

Claims (7)

1. A micro-channel platform for micro-manipulation of biological micro-nano particles is characterized in that the platform can realize position and flow velocity constraint on the biological micro-nano particles, and further realize manipulation and classification of rare cells; the platform includes: the device comprises a single-channel injection pump (1), a conical pipeline (3), a pipeline rack (4), a cover glass (5), a micro-channel (6) and a base (7); wherein the single-channel injection pump (1) is communicated with the conical pipeline (3); the conical pipeline (3) is fixed on the pipeline frame (4), the cone angle of the conical pipeline (3) is 6-12 degrees, and the cone opening of the conical pipeline (3) is aligned with the runner opening of the micro-channel (6); the pipeline rack (4) and the cover glass (5) are fixed on a base (7), and the base (7) is of a plug-in sheet type structure; the micro-channel (6) is fixed on the cover glass (5), the micro-channel (6) is a symmetrical double-arc structure with two wide sides and a narrow middle part, the curvature radius of the symmetrical double-arc structure is 10-20mm, and the distance between the closest points of the two arcs is 50-200 mu m; single channel syringe pump (1) and conical duct (3) pass through hose (2) intercommunication, hose (2) are fixed on X type metal frame, reduce the liquid velocity of flow in hose (2) through precession X type metal frame tail end screw, realize the fine-tuning to the velocity of flow.

2. The micro flow channel platform for micro manipulation of biological micro-nano particles according to claim 1, wherein the injection speed of the single-channel injection pump (1) is 0.1-1 ml/h.

3. The micro flow channel platform for micro-manipulation of biological micro-nano particles according to claim 1, wherein the conical channel (3) is made of glass, and a cone angle is manufactured by an electric coil heating method.

4. The micro flow channel platform for micro manipulation of biological micro-nano particles according to claim 1, wherein the slope inclination angle of the pipeline frame (4) is consistent with the cone angle of the conical pipeline (3) so as to facilitate forward flow of liquid into the micro flow channel (6).

5. The micro flow channel platform for micro manipulation of biological micro-nano particles according to claim 1, wherein the channel frame (4) and the base (7) are integrally formed and realized by a 3D printing technology.

6. The micro flow channel platform for micro manipulation of biological micro-nano particles according to claim 5, wherein the 3D printing technical material is ABS or PBS.

7. The micro flow channel platform for micro-manipulation of biological micro-nano particles according to claim 1, wherein the gluing among the cover glass (5), the micro flow channel (6) and the base (7) and the gluing among the conical pipeline (3) and the pipeline rack (4) are specifically as follows: and the uv glue is adopted for gluing, so that the connection and the fixation of each component are realized.

Images