阅读说明：本技术 一种交流电渗驱动乙醇行波型微泵及工作方法 (Alternating current electroosmosis driven ethanol traveling wave type micropump and working method ) 是由 于泳 李凯 林海 于 2019-09-05 设计创作，主要内容包括：本发明实施例公开了一种交流电渗驱动乙醇行波型微泵,包括微电极板上设置的电极阵列和微通道,电极阵列包括对称设置在微通道两侧的微电极接触点,微电极接触点上等间距阵列有若干个电极组,且位于微通道两侧的微电极接触点上的电极交错排列置于微通道中,其工作方法,包括步骤：在硅、玻璃或聚甲基丙烯酸甲酯上加工具有四个微电极接触点的微电极阵列,并将微电极阵列的电极阵列置于微通道内；向微通道内注入加了乙酸铵电解质的乙醇溶液；向微电极阵列的四个微电极接触点施加相同电压、相同频率、不同相位的交流电,驱动乙醇溶液流动,本发明采用的交流电渗驱动行波型微泵,克服了上述注入型电液动力泵的缺点,具有电压低,寿命长等优点,可以对乙醇长时间驱动。(The embodiment of the invention discloses an alternating current electroosmosis driven ethanol traveling wave type micropump, which comprises an electrode array and a microchannel, wherein the electrode array and the microchannel are arranged on a microelectrode plate, the electrode array comprises microelectrode contact points which are symmetrically arranged at two sides of the microchannel, a plurality of electrode groups are arranged on the microelectrode contact points at equal intervals, and electrodes positioned on the microelectrode contact points at two sides of the microchannel are arranged in the microchannel in a staggered way, and the working method comprises the following steps: processing a microelectrode array with four microelectrode contact points on silicon, glass or polymethyl methacrylate, and placing the electrode array of the microelectrode array in a microchannel; injecting an ethanol solution added with an ammonium acetate electrolyte into the microchannel; the alternating current electroosmosis driving travelling wave type micropump overcomes the defects of the injection type electro-hydraulic power pump, has the advantages of low voltage, long service life and the like, and can drive ethanol for a long time.)

1. An alternating current electroosmosis driving ethanol traveling wave type micropump is characterized by comprising an electrode array and a microchannel, wherein the electrode array and the microchannel are arranged on a microelectrode plate, the electrode array comprises microelectrode contact points which are symmetrically arranged on two sides of the microchannel, a plurality of electrode groups are arranged on the microelectrode contact points at equal intervals, and the electrodes positioned on the microelectrode contact points on the two sides of the microchannel are arranged in the microchannel in a staggered mode.

2. An AC electroosmosis driven alcohol traveling wave type micropump according to claim 1, wherein at least two microelectrode contact points are provided at one side of the microchannel.

3. An AC electroosmosis driven alcohol traveling wave type micropump according to claim 2, wherein the width and pitch of electrodes on the contact points of the microelectrodes on both sides of the microchannel are the same and 10 to 50 μm.

4. An AC electroosmosis driven alcohol traveling wave type micropump according to claim 2, wherein an insulating layer is provided between electrodes on at least two microelectrode contact points on one side of the microchannel.

5. An AC electroosmosis driven alcohol traveling wave type micro-pump according to claim 1, wherein the material of said micro-electrode contact point and electrode is the same, and is any one metal of gold, platinum or copper.

6. An alternating current electroosmosis driving ethanol traveling wave type micropump working method is characterized by comprising the following steps:

s100, processing a micro-channel and a micro-electrode array with four micro-electrode contact points on silicon, glass, Polydimethylsiloxane (PDMS) or polymethyl methacrylate, placing the electrode array of the micro-electrode array in the micro-channel for groove packaging, and processing into a traveling wave micro-pump;

s200, injecting an ethanol solution added with ammonium acetate electrolyte into the micro-channel; or adding ammonium acetate electrolyte into other alcohol solutions such as propanol and butanol, and driving by the same method;

s300, applying alternating current signals with the same voltage and frequency and different phases to four microelectrode contact points of the microelectrode array to drive the ethanol solution to flow.

7. The method according to claim 6, wherein ammonium acetate (CH) is added to the ethanol solution₃COONH₄) Electrolyte, regulating the conductivity of ethanol solution to 5-100 uS/cm; the method may be the same as that of adding an ammonium acetate electrolyte to a solution of other alcohols such as propanol and butanol.

8. The method according to claim 6, wherein the phase angles of the alternating current applied to the four microelectrode contact points of the microelectrode array are 0 °, 90 °, 180 ° and 270 °, and the frequency of the alternating current is in the range of 5 to-500 Hz.

Technical Field

The embodiment of the invention relates to the technical field of driving an ethanol micropump in a microfluidic system, in particular to an alternating current electroosmosis driving ethanol traveling wave type micropump and a working method.

Background

With the development of the performance and miniaturization of electronic components, the requirement for heat dissipation is higher and higher. The reliability of microelectronic devices is very sensitive to temperature, and the temperature rise of electronic devices can greatly reduce their reliability. The reliability of the device is reduced by 5% when the temperature of the device is increased by 1 ℃ at the level of 70-80 ℃. The development of future intellectualization requires that the CPU speed is increased by 2-3 orders of magnitude, and the existing air cooling technology cannot meet the heat dissipation requirement, so that a new liquid cooling technology needs to be developed. With the development of microfluidic systems, micropumps have become a key technology in microfluidic control and microelectronic cooling systems.

In a microfluidic system, a micro-flow driving and controlling technology of liquid is always a more critical technical problem. Control of microfluidics refers to control of fluids in systems or devices with feature sizes smaller than 1mm, and a driving technology for precise control of microfluidics is an inevitable requirement for the development of microfluidic systems. Therefore, microfluidic systems require the integration of controllable micropumps for pumping small volumes of microfluid, and the research of micropumps has become an important marker in the development of microfluidic systems.

The micropumps are structurally divided into mechanical micropumps and non-mechanical micropumps according to the operating principle, and the main difference between the mechanical micropumps and the non-mechanical micropumps is the presence or absence of moving parts. At present, mechanical micropumps mainly comprise: piezoelectric micropumps, electromagnetic micropumps, electrostatic micropumps, shape memory alloy micropumps, thermally driven micropumps and the like. The mechanical micropump has a long development history and a mature theory, can drive almost any type of liquid, and has the defects of easy friction generation, unstable pumping speed, micro leakage, short service life, difficult integration with a chip and the like in the micropump because of containing a moving part, and the reliability of the pump is greatly reduced. The non-mechanical micropump is a new direction for the research of the micropump.

The micropumps are structurally divided into mechanical micropumps and non-mechanical micropumps according to the operating principle, and the main difference between the mechanical micropumps and the non-mechanical micropumps is the presence or absence of moving parts. At present, mechanical micropumps mainly comprise: piezoelectric micropumps, electromagnetic micropumps, electrostatic micropumps, shape memory alloy micropumps, thermally driven micropumps and the like. The mechanical micropump has a long development history and a mature theory, can drive almost any type of liquid [3], and has the defects of easy friction generation, unstable pumping speed, micro leakage, short service life, difficult integration with a chip and the like in the micropump because of the moving part, and the reliability of the pump is greatly reduced. The non-mechanical micropump is a new direction for the research of the micropump.

The electroosmotic micro pump is the most important non-mechanical micro pump at present, and has the advantages of easiness in processing and control, no need of moving parts, high repeatability and reliability and the like. And can be classified into a direct current electroosmotic driving and an alternating current electroosmotic driving according to the type of applied voltage. The direct current electroosmosis micropump has the advantages of adjustable flow, wide range, no piston, no valve, no dynamic seal, low manufacturing cost, simple design and the like, and is an effective liquid driving mode. The disadvantages are that high voltage and high direct current voltage (up to thousands of volts) are needed for the direct current electroosmosis fluid driving technology, potential safety hazards exist, electrolysis reaction is easy to occur to generate bubbles, a large amount of electric heat is generated, and the flowing stability of microfluid is further influenced. Because the voltage is very large and has certain harmfulness, the application range of the direct current electroosmosis pump is limited to a certain extent.

The driving liquid is mainly divided into aqueous solution and non-aqueous solution, the aqueous solution is widely applied in the biological field, and the liquid with the most extensive driving requirements in other fields is the non-aqueous solution, such as methanol, ethanol and the like, and is widely applied to systems such as micro fuel cells, chips, integrated circuits, electric appliance heat dissipation and the like. The current method for driving the non-aqueous solution mainly adopts an injection type electro-hydraulic power pump, such as an ion drag pump, and the main principle is that direct current voltage is applied to an anode electrode to generate electrochemical reaction on the surface of the anode. The anode metal electrode material generates cations under the action of high voltage or the liquid generates ions through electrochemical reaction, and the ions are then injected into the liquid. The injected cations are driven under the influence of the electric field to the other, more proximal electrode, the collector, thereby creating a net charge flow. Due to viscous drag, the energy of the cations is transferred into the fluid, causing the fluid to flow from the anode to the cathode. This method has the advantage of being able to drive substantially all solutions, including organic solutions that do not contain a charge, and has the disadvantage of consuming anode material at higher voltages, and the micropump made by this method will quickly fail.

Disclosure of Invention

Therefore, the embodiment of the invention provides an alternating current electroosmosis driven ethanol traveling wave type micropump and a working method thereof.

In order to achieve the above object, an embodiment of the present invention provides the following:

an alternating current electroosmosis driving ethanol traveling wave type micropump comprises an electrode array and a microchannel, wherein the electrode array and the microchannel are arranged on a microelectrode plate, the electrode array comprises microelectrode contact points which are symmetrically arranged on two sides of the microchannel, a plurality of electrode groups are arranged on the microelectrode contact points at equal intervals, and the electrodes positioned on the microelectrode contact points on the two sides of the microchannel are arranged in the microchannel in a staggered mode.

In a preferred embodiment of the present invention, at least two microelectrode contact points are located on one side of the microchannel.

As a preferable scheme of the invention, the width and the distance of the electrodes on the contact points of the micro-electrode positioned at the two sides of the micro-channel are the same and are 10-50 mu m.

In a preferred embodiment of the present invention, an insulating layer is provided between the electrodes on at least two of the contact points of the micro-electrode on one side of the micro-channel.

In a preferred embodiment of the present invention, the material of the microelectrode contact point and the electrode is the same, and is any one of gold, platinum or copper.

An alternating current electroosmosis driving ethanol traveling wave type micro pump working method comprises the following steps:

s100, processing a micro-channel and a micro-electrode array with four micro-electrode contact points on silicon, glass, Polydimethylsiloxane (PDMS) or polymethyl methacrylate, placing the electrode array of the micro-electrode array in the micro-channel for groove packaging, and processing into a traveling wave micro-pump;

s200, injecting an ethanol solution added with ammonium acetate electrolyte into the micro-channel; or adding ammonium acetate electrolyte into other alcohol solutions such as propanol and butanol, and driving by the same method;

s300, applying alternating current signals with the same voltage and frequency and different phases to four microelectrode contact points of the microelectrode array to drive the ethanol solution to flow.

As a preferable embodiment of the present invention, ammonium acetate (CH) is added to an ethanol solution₃COONH₄) Electrolyte, regulating the conductivity of ethanol solution to 5-100 uS/cm; the method may be the same as that of adding an ammonium acetate electrolyte to a solution of other alcohols such as propanol and butanol.

As a preferable scheme of the invention, the phase angles of the alternating current applied to the four microelectrode contact points of the microelectrode array are respectively 0 degrees, 90 degrees, 180 degrees and 270 degrees, and the frequency of the alternating current is in the range of 5 to-500 Hz.

The embodiment of the invention has the following advantages:

the AC electroosmosis driving traveling wave type micropump overcomes the defects of an injection type electrohydraulic power pump, has the advantages of low voltage, long service life and the like, and can drive ethanol for a long time.

In the invention, a trace amount of ammonium acetate electrolyte is added into an ethanol solution to replace a method of generating cations by applying high voltage on an anode metal electrode material and then injecting the cations into liquid, thereby achieving the purpose of not damaging the electrode and prolonging the service life of the micropump.

The invention designs the microelectrodes into four groups, and applies alternating current with different phases to the four groups of microelectrodes, thereby obviously reducing the applied voltage and the power consumption of the micropump.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. It should be apparent that the drawings in the following description are merely exemplary, and that other embodiments can be derived from the drawings provided by those of ordinary skill in the art without inventive effort.

The structures, ratios, sizes, and the like shown in the present specification are only used for matching with the contents disclosed in the specification, so as to be understood and read by those skilled in the art, and are not used to limit the conditions that the present invention can be implemented, so that the present invention has no technical significance, and any structural modifications, changes in the ratio relationship, or adjustments of the sizes, without affecting the effects and the achievable by the present invention, should still fall within the range that the technical contents disclosed in the present invention can cover.

Fig. 1 is a schematic structural view of an ac electroosmosis driven ethanol traveling wave type micro pump according to embodiment 1 of the present invention;

FIG. 2 shows CH in embodiment 2 of the present invention₃COONH₄The traveling wave alternating current electroosmosis driving experiment result chart of the ethanol solution;

FIG. 3 is a schematic view of a traveling wave AC electroosmosis driving structure according to embodiment 3 of the present invention;

fig. 4 is a flow chart of a process for manufacturing an ac electroosmosis driven ethanol traveling wave type micropump in embodiment 2 of the present invention.

In the figure:

1. 2, 3, 4-microelectrode contact points; 5. 6-an insulating layer; 7-micro-channel.

Detailed Description

The present invention is described in terms of particular embodiments, other advantages and features of the invention will become apparent to those skilled in the art from the following disclosure, and it is to be understood that the described embodiments are merely exemplary of the invention and that it is not intended to limit the invention to the particular embodiments disclosed. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.