CN112326996A - Micro-fluidic flow velocity detection device based on micro-capacitor - Google Patents
Micro-fluidic flow velocity detection device based on micro-capacitor Download PDFInfo
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- CN112326996A CN112326996A CN202011207244.9A CN202011207244A CN112326996A CN 112326996 A CN112326996 A CN 112326996A CN 202011207244 A CN202011207244 A CN 202011207244A CN 112326996 A CN112326996 A CN 112326996A
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
- G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
- G01P5/08—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring variation of an electric variable directly affected by the flow, e.g. by using dynamo-electric effect
- G01P5/086—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring variation of an electric variable directly affected by the flow, e.g. by using dynamo-electric effect by using special arrangements and constructions for measuring the dynamo-electric effect
Abstract
The invention provides a micro-fluidic flow velocity detection device based on a micro-capacitor, which comprises: the micro-fluidic chip comprises a micro-fluidic chip, a flexible layer, a first conductive part, a second conductive part, a first polar plate, a second polar plate, a first electrode and a second electrode, wherein a fluid channel is arranged on the surface of the micro-fluidic chip, the flexible layer covers the fluid channel, openings are respectively formed in the inlet and the outlet of the fluid channel, the first polar plate and the second polar plate are fixed at the top of the fluid channel on the flexible layer, the first polar plate and the second polar plate are separated, the first polar plate is fixedly connected with one end of the first conductive part, the other end of the first conductive part is fixedly connected with the first electrode, the second polar plate is fixedly connected with one end of the second conductive part, and the other end of the second conductive part is fixedly. The invention has the advantage of high flow velocity detection precision.
Description
Technical Field
The invention relates to the field of micro-fluidic flow velocity detection, in particular to a micro-fluidic flow velocity detection device based on micro-capacitors.
Background
The microfluidic technology is an important platform for scientific research in the fields of fluid physics, biological laser technology, microreactors and the like. Microfluidic flow rate detection is an important link of microfluidic technology. The traditional flow velocity detection technology based on heat transfer and cantilever beam deformation has low precision.
Disclosure of Invention
In order to solve the above problems, the present invention provides a micro-fluidic flow velocity detection device based on micro-capacitors, comprising: the micro-fluidic chip comprises a micro-fluidic chip, a flexible layer, a first conductive part, a second conductive part, a first polar plate, a second polar plate, a first electrode and a second electrode, wherein a fluid channel is arranged on the surface of the micro-fluidic chip, the flexible layer covers the fluid channel, openings are respectively formed in the inlet and the outlet of the fluid channel, the first polar plate and the second polar plate are fixed at the top of the fluid channel on the flexible layer, the first polar plate and the second polar plate are separated, the first polar plate is fixedly connected with one end of the first conductive part, the other end of the first conductive part is fixedly connected with the first electrode, the second polar plate is fixedly connected with one end of the second conductive part, and the other end of the second conductive part is fixedly.
Further, the first plate and the second plate are disposed on both sides of a central position of the fluid passage.
Further, the first conductive portion and the second conductive portion extend to the outside of the fluid passage, respectively.
Further, the first electrode and the second electrode are disposed on the first conductive portion and the second conductive portion outside the fluid passage, respectively.
Further, the material of the first electrode and the second electrode is gold.
Still further, the material of the flexible layer is polydimethylsiloxane.
Still further, the flexible layer has a thickness of less than 50 microns.
Further, on top of the fluid channel, the flexible layer is thin; on top of the microfluidic chip, the flexible layer is thick.
Further, the first and second plates have heights greater than the heights of the first and second conductive portions, respectively.
Further, the widths of the first and second plates are greater than the widths of the first and second conductive portions, respectively.
The invention has the beneficial effects that: the invention provides a micro-fluidic flow velocity detection device based on a micro-capacitor, which comprises: the micro-fluidic chip comprises a micro-fluidic chip, a flexible layer, a first conductive part, a second conductive part, a first polar plate, a second polar plate, a first electrode and a second electrode, wherein a fluid channel is arranged on the surface of the micro-fluidic chip, the flexible layer covers the fluid channel, openings are respectively formed in the inlet and the outlet of the fluid channel, the first polar plate and the second polar plate are fixed at the top of the fluid channel on the flexible layer, the first polar plate and the second polar plate are separated, the first polar plate is fixedly connected with one end of the first conductive part, the other end of the first conductive part is fixedly connected with the first electrode, the second polar plate is fixedly connected with one end of the second conductive part, and the other end of the second conductive part is fixedly. When the flow velocity detector is applied, fluid flows in the fluid channel, the flexible layer is bent outwards under the action of pressure, the distance between the first polar plate and the second polar plate is changed, accordingly, the capacitance between the first polar plate and the second polar plate is changed, and flow velocity detection is achieved by detecting the change of the capacitance between the first polar plate and the second polar plate. The present invention has the advantage of high accuracy in detecting the flow velocity because the capacitance between the first and second plates is very sensitive to the distance therebetween. In addition, the invention is based on the traditional electrical quantity measurement, and the detection cost is low.
The present invention will be described in further detail below with reference to the accompanying drawings.
Drawings
Fig. 1 is a schematic diagram of a micro-fluidic flow rate detection device based on micro-capacitors.
Fig. 2 is a schematic diagram of another micro-capacitance based micro-fluidic flow rate detection device.
In the figure: 1. a microfluidic chip; 2. a fluid channel; 3. a flexible layer; 4. a first conductive portion; 5. a second conductive portion; 6. a first electrode plate; 7. a second polar plate; 8. a first electrode; 9. a second electrode.
Detailed Description
To further explain the technical means and effects of the present invention adopted to achieve the intended purpose, the following detailed description of the embodiments, structural features and effects of the present invention will be made with reference to the accompanying drawings and examples.
Example 1
The invention provides a micro-fluidic flow velocity detection device based on a micro-capacitor. As shown in fig. 1, the micro-fluidic flow velocity detection device based on micro-capacitance comprises a micro-fluidic chip 1, a flexible layer 3, a first conductive part 4, a second conductive part 5, a first electrode plate 6, a second electrode plate 7, a first electrode 8 and a second electrode 9. The surface of the microfluidic chip 1 is provided with a fluid channel 2, a flexible layer 3 coats the fluid channel 2, and the flexible layer 3 is provided with openings at an inlet and an outlet of the fluid channel 2 respectively. That is, only the inlet and outlet of the fluid channel 2 are open, and the other parts of the fluid channel 2 are closed. The material of the flexible layer 3 is an insulating flexible material. Preferably, the material of the flexible layer 3 is polydimethylsiloxane. The surface tension of the polydimethylsiloxane is small, and the polydimethylsiloxane can be bent outwards more under the action of the fluid. In addition, polydimethylsiloxane has good chemical stability and is suitable for a wider variety of fluids. The thickness of the flexible layer 3 is less than 50 microns so that the flexible layer 3 is bent outwardly to a greater extent under the influence of the fluid. A first plate 6 and a second plate 7 are fixed on top of the fluid channel 2 on the flexible layer 3, the first plate 6 and the second plate 7 being separated. The first electrode plate 6 is fixedly connected to one end of the first conductive part 4, and the other end of the first conductive part 4 is fixedly connected to the first electrode 8. The second plate 7 is fixedly connected to one end of the second conductive part 5, and the other end of the second conductive part 5 is fixedly connected to the second electrode 9. The material of the first electrode 8 and the second electrode 9 is gold. The material of the first conductive part 4 and the second conductive part 5 is gold. The material of the first polar plate 6 and the second polar plate 7 is gold, silver or copper.
In application, fluid flows in the fluid channel 2, the flexible layer 3 is pressed to bend outwards, the distance between the first polar plate 6 and the second polar plate 7 is changed, the capacitance between the first polar plate 6 and the second polar plate 7 is changed, and flow speed detection is achieved by detecting the change of the capacitance between the first polar plate 6 and the second polar plate 7. The present invention has an advantage of high accuracy in detecting a flow velocity because the capacitance between the first plate 6 and the second plate 7 is very sensitive to the distance therebetween. In addition, the invention is based on the traditional electrical quantity measurement, and the detection cost is low.
Example 2
On the basis of embodiment 1, the first plate 6 and the second plate 7 are disposed on both sides of the center position of the fluid passage 2. Thus, when the flexible layer 3 is bent outward, the first plate 6 and the second plate 7 are positionally changed with the flexible layer 3. Specifically, the distance between the first plate 6 and the second plate 7 not only increases, but also changes the relative angle between the first plate 6 and the second plate 7, that is, the first plate 6 and the second plate 7 gradually change from being relatively parallel to being relatively inclined, which reduces the relative area of the first plate 6 and the second plate 7. Both effects reduce the capacitance between the first and second plates 6, 7, i.e. make the capacitance decrease more, thereby improving the accuracy of the flow rate detection. The first and second conductive parts 4 and 5 extend to the outside of the fluid channel 2, respectively, and the first and second electrodes 8 and 9 are placed on the first and second conductive parts 4 and 5 outside the fluid channel 2, respectively. That is, the first and second electrode plates 6 and 7 are respectively disposed at the top of the fluid channel 2, but the first and second electrodes 8 and 9 are not disposed at the top of the fluid channel 2. The first conductive part 4 is fixedly connected with the first polar plate 6 and the first electrode 8; the second conductive part 5 fixedly connects the second plate 7 and the second electrode 9. Thus, on the one hand, the structure of the detection device is stable; on the other hand, the mass attached to the flexible layer 3 at the top of the fluid channel 2 is small, so that the flexible layer 3 can be bent outwards to a greater extent, and the accuracy of flow velocity detection is improved.
Example 3
On the basis of example 2, the flexible layer 3 is thin on top of the fluid channel 2; on top of the microfluidic chip 1, the flexible layer 3 is thick. In particular, in the middle of the cross-section of the fluid channel 2, the flexible layer 3 is thin; the flexible layer 3 becomes thicker gradually in a direction away from the middle of the cross section of the fluid channel 2. Thus, under the action of the fluid, the middle part of the flexible layer 3 protrudes outwards more, and the distance between the first polar plate 6 and the second polar plate 7 and the relative angle between the first polar plate 6 and the second polar plate 7 are changed more, so that the capacitance between the first polar plate 6 and the second polar plate 7 is changed more, and the accuracy of flow velocity detection is improved.
Example 4
In example 3, as shown in fig. 2, the heights of the first plate 6 and the second plate 7 are larger than the heights of the first conductive part 4 and the second conductive part 5, respectively. That is, the first plate 6 and the second plate 7 are vertically formed in a plate shape, and the relative area between the first plate 6 and the second plate 7 is larger. In this way, when the flexible layer 3 is bent outward, the capacitance between the first and second plates 6 and 7 is changed more, thereby achieving more accurate flow rate detection.
Example 5
In example 4, the widths of the first electrode plate 6 and the second electrode plate 7 are larger than the widths of the first conductive part 4 and the second conductive part 5, respectively. That is, the first plate 6 and the second plate 7 are wide to serve as both plates of a parallel plate capacitor; the first conductive portion 4 and the second conductive portion 5 are narrow to serve as connection wires. In this way, the first conductive part 4 and the second conductive part 5 attached to the flexible layer 3 less block the flexible layer 3 from bending outward, so that the flexible layer 3 is bent outward to a greater extent, and the capacitance between the first plate 6 and the second plate 7 is changed more, thereby achieving more accurate flow velocity detection.
The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.
Claims (10)
1. A micro-fluidic flow velocity detection device based on micro-capacitors is characterized by comprising: the micro-fluidic chip comprises a micro-fluidic chip, a flexible layer, a first conductive part, a second conductive part, a first polar plate, a second polar plate, a first electrode and a second electrode, wherein a fluid channel is arranged on the surface of the micro-fluidic chip, the flexible layer covers the fluid channel, openings are respectively arranged at an inlet and an outlet of the fluid channel, the first polar plate and the second polar plate are fixed on the flexible layer, the top of the fluid channel is separated from the first polar plate, the first polar plate is fixedly connected with one end of the first conductive part, the other end of the first conductive part is fixedly connected with the first electrode, the second polar plate is fixedly connected with one end of the second conductive part, and the other end of the second conductive part is fixedly connected with the second electrode.
2. The micro-capacitance based microfluidic flow velocity detection device of claim 1, wherein: the first and second plates are disposed on opposite sides of a central location of the fluid channel.
3. The micro-capacitance based microfluidic flow velocity detection device of claim 2, wherein: the first conductive portion and the second conductive portion extend to the outside of the fluid passage, respectively.
4. The micro-capacitance based microfluidic flow velocity detection device of claim 3, wherein: the first electrode and the second electrode are respectively arranged on the first conductive part and the second conductive part outside the fluid channel.
5. The micro-capacitance based microfluidic flow velocity detection device according to any one of claims 1-4, wherein: the material of the first electrode and the second electrode is gold.
6. The micro-capacitance based microfluidic flow velocity detection device of claim 5, wherein: the flexible layer is made of polydimethylsiloxane.
7. The micro-capacitance based microfluidic flow velocity detection device of claim 6, wherein: the flexible layer has a thickness of less than 50 microns.
8. The micro-capacitance based microfluidic flow velocity detection device of claim 7, wherein: the flexible layer is thin on top of the fluid channel and thick on top of the microfluidic chip.
9. The micro-capacitance based microfluidic flow velocity detection device of claim 8, wherein: the heights of the first polar plate and the second polar plate are respectively greater than the heights of the first conductive part and the second conductive part.
10. The micro-capacitance based microfluidic flow velocity detection device of claim 9, wherein: the widths of the first polar plate and the second polar plate are respectively larger than the widths of the first conductive part and the second conductive part.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011207244.9A CN112326996A (en) | 2020-11-03 | 2020-11-03 | Micro-fluidic flow velocity detection device based on micro-capacitor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011207244.9A CN112326996A (en) | 2020-11-03 | 2020-11-03 | Micro-fluidic flow velocity detection device based on micro-capacitor |
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| Publication Number | Publication Date |
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| CN112326996A true CN112326996A (en) | 2021-02-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011207244.9A Withdrawn CN112326996A (en) | 2020-11-03 | 2020-11-03 | Micro-fluidic flow velocity detection device based on micro-capacitor |
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| CN (1) | CN112326996A (en) |
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2020
- 2020-11-03 CN CN202011207244.9A patent/CN112326996A/en not_active Withdrawn
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