Multi-channel electroosmosis micropump based on liquid metal electrode process

Abstract

The invention relates to the technical field of microfluidics, and discloses a multi-channel electroosmosis micropump based on a liquid metal electrode technology, the multi-channel electroosmosis micropump based on the liquid metal electrode technology comprises a flexible base, the flexible base is provided with two groups of electrode channels, the two groups of electrode channels are both internally provided with liquid metal, and the flexible base is provided with a flexible electrode. A liquid metal positive electrode and a liquid metal negative electrode are formed, the flexible base is provided with a fluid inlet, a fluid outlet and a plurality of first fluid channels, the first fluid channels are communicated with the fluid inlet in parallel, and the first fluid channels are communicated with the fluid outlet in parallel. According to the invention, the problem that the size of the electro-osmosis micropump integrated by multiple fluid channels is relatively large in the prior art can be solved.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and in particular to a multi-channel electroosmotic micropump based on liquid metal electrode technology. Background Art

[0002] Micropumps are essential core components for precise microfluidic drive in microfluidic systems. They are the specific implementation of microfluidic drive technology in micro or even smaller volumes. They are widely used in biochemical analysis, microfluid (buffer, drug, etc.) transport, microelectronic chip cooling, etc. Electroosmotic micropumps have the characteristics of no moving parts, no mechanical wear, no pulsation, and continuous infusion, making them very popular in the fields of biochemical synthesis analysis and implantable drug delivery.

[0003] Direct current electroosmotic micropumps can be roughly divided into several types, such as fluid channel type, porous material type, and filler type, according to the structure and material properties. The production method of fluid channel type electroosmotic micropumps is relatively simple and convenient, and it is also convenient to be integrated with microfluidic chips for use, and is widely used. In the related art, fluid channel type electroosmotic micropumps usually use open fluid channels, such as capillary fluid channels, glass fluid channels, etc., and electrodes are placed on both sides of the open fluid channels to apply high voltage electricity to provide a strong electric field to induce electroosmotic flow. However, when the electroosmotic micropump of this structure is integrated with multiple fluid channels, the multiple fluid channels are usually integrated on a mounting plate, and the size of the electroosmotic micropump after the integration of multiple fluid channels will be larger, which is not conducive to the small size design of the electroosmotic micropump. Summary of the invention

[0004] The present invention provides a multi-channel electroosmotic micropump based on liquid metal electrode technology, which is used to solve the problem of large size of the electroosmotic micropump after integrating multiple fluid channels in the related art.

[0005] The present invention provides a multi-channel electroosmotic micropump based on liquid metal electrode technology, comprising a flexible base, wherein the flexible base is provided with two groups of electrode channels, liquid metal is provided in both groups of electrode channels to form a liquid metal positive electrode and a liquid metal negative electrode, and the flexible base is provided with a fluid inlet, a fluid outlet and a plurality of first fluid channels, wherein the plurality of first fluid channels are connected in parallel with the fluid inlet, and the plurality of first fluid channels are connected in parallel with the fluid outlet.

[0006] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the flexible base includes a flexible branch layer and a flexible connection layer which are stacked and connected, wherein:

[0007] The liquid metal positive electrode comprises a first positive electrode, the liquid metal negative electrode comprises a first negative electrode, the first positive electrode, the first negative electrode and the first fluid channels are all arranged on the end surface of the flexible branch layer facing the flexible connection layer;

[0008] The fluid inlet and the fluid outlet are provided in the flexible connection layer, and the flexible connection layer is provided with a positive electrode connection hole and a negative electrode connection hole, and the positive electrode connection hole and the negative electrode connection hole are used to install external electrical connectors.

[0009] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the first positive electrode includes a plurality of positive electrode branches distributed at intervals, and the plurality of positive electrode branches are electrically connected; the first negative electrode includes a plurality of negative electrode branches distributed at intervals, and the plurality of negative electrode branches are electrically connected; the positive electrode branches and the negative electrode branches are arranged opposite to each other in a one-to-one correspondence; there is a gap between two adjacent groups of the oppositely arranged positive electrode branches and the negative electrode branches; and the plurality of the first fluid channels are located in the plurality of the gaps in a one-to-one correspondence.

[0010] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the extension direction of the first fluid channel is consistent with the direction from the positive electrode branch to the negative electrode branch in a group of relatively arranged positive electrode branches and negative electrode branches.

[0011] According to the multi-channel electroosmotic micropump based on the liquid metal electrode process provided by the present invention, the liquid metal positive electrode further includes a second positive electrode, the liquid metal negative electrode further includes a second negative electrode, the second positive electrode and the second negative electrode are both arranged on the end surface of the flexible connection layer facing the flexible branch layer, the positive electrode connection hole is connected to the corresponding area of ​​the electrode channel that assists in forming the second positive electrode, and the negative electrode connection hole is connected to the corresponding area of ​​the electrode channel that assists in forming the second negative electrode;

[0012] The first positive electrode and the first negative electrode are at room temperature, the second positive electrode is in contact and electrically connected with the first positive electrode, and the second negative electrode is in contact and electrically connected with the first negative electrode;

[0013] The end surface of the flexible connection layer facing the flexible branch layer is provided with two second fluid channels, the two second fluid channels are respectively connected to the fluid inlet and the fluid outlet, one end of each of the first fluid channels is connected to one of the second fluid channels, and the other end of each of the first fluid channels is connected to another of the second fluid channels.

[0014] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the first positive electrode and the first negative electrode include bismuth-based alloy liquid metal electrodes; the second positive electrode and the second negative electrode include gallium-based alloy liquid metal electrodes or bismuth-based alloy liquid metal electrodes.

[0015] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the multi-channel electroosmotic micropump based on liquid metal electrode technology also includes a flexible membrane, and the flexible membrane is stacked between the flexible branch layer and the flexible connection layer.

[0016] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the flexible branch layer is provided with a first main channel and a second main channel, and both ends of each of the first fluid channels are respectively connected to the first main channel and the second main channel, and the flexible membrane is provided with two first connecting holes, the first main channel is connected to the fluid inlet through one of the first connecting holes, and the second main channel is connected to the fluid outlet through the other first connecting hole;

[0017] The liquid metal positive electrode also includes a second positive electrode, and the liquid metal negative electrode also includes a second negative electrode. The second positive electrode and the second negative electrode are both arranged on the end surface of the flexible connection layer facing the flexible branch layer. The flexible membrane is provided with a plurality of second connecting holes. The second positive electrode is electrically connected to the first positive electrode through the liquid metal in the second connecting hole opposite to it, and the second negative electrode is electrically connected to the first negative electrode through the liquid metal in the second connecting hole opposite to it.

[0018] According to the multi-channel electroosmotic micropump based on the liquid metal electrode process provided by the present invention, the surface of the flexible connection layer facing the flexible branch layer is provided with two second fluid channels, the two second fluid channels are respectively connected to the fluid inlet and the fluid outlet, the flexible membrane is provided with a plurality of third connecting holes, one end of each of the first fluid channels is connected to one of the second fluid channels through the third connecting hole opposite thereto, and the other end of each of the first fluid channels is connected to another of the second fluid channels through the third connecting hole opposite thereto;

[0019] The flexible film is provided with a plurality of fourth communication holes, some of the fourth communication holes are opposite to the positive electrode connection hole and the first positive electrode, and some of the fourth communication holes are opposite to the negative electrode connection hole and the first negative electrode.

[0020] According to the multi-channel electroosmotic micropump based on liquid metal electrode technology provided by the present invention, the material of the flexible membrane is polydimethylsiloxane or Ecoflex or silicone; the material of the flexible branch layer is polydimethylsiloxane or Ecoflex or silicone; the material of the flexible connecting layer is polydimethylsiloxane or Ecoflex or silicone.

[0021] Compared with the technical solution of using an open capillary or glass tube as a fluid channel in the related art, multiple fluid channels are integrated on a flexible base, and an inserted external electrode is used, in the embodiment of the present invention, an electrode channel is opened in the flexible base, and liquid metal is filled in the electrode channel to form a liquid metal positive electrode and a liquid metal negative electrode, and multiple first fluid channels are opened in the flexible base. The technical solution makes the liquid metal positive electrode, the liquid metal negative electrode and the multiple first fluid channels built into the flexible base, which is helpful for the small size design of the multi-channel electroosmotic micropump based on the liquid metal electrode process, and can improve the structural compactness of the multi-channel electroosmotic micropump based on the liquid metal electrode process. It can be seen that the embodiment of the present invention can solve the problem of the large size of the electroosmotic micropump after the integration of multiple fluid channels in the related art. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a structural schematic diagram of a multi-channel electroosmotic micropump based on liquid metal electrode technology according to a first embodiment of the present invention;

[0024] Figure 2 is a schematic structural diagram of a flexible branch circuit layer of a first embodiment provided by the present invention;

[0025] Figure 3 is a schematic structural diagram of a flexible connection layer of a first embodiment provided by the present invention;

[0026] Figure 4 is an exploded view of a multi-channel electroosmotic micropump based on a liquid metal electrode process according to a second embodiment of the present invention;

[0027] Figure 5 is a schematic structural diagram of a flexible branch circuit layer of a second embodiment provided by the present invention;

[0028] Figure 6 is a schematic structural diagram of a flexible connection layer of a second embodiment provided by the present invention;

[0029] Figure 7 is a schematic structural diagram of a flexible membrane according to a second embodiment of the present invention;

[0030] Figure 8 is an exploded view of a multi-channel electroosmotic micropump based on a liquid metal electrode process according to a third embodiment of the present invention;

[0031] Fig. 9 is a schematic structural diagram of a flexible branch circuit layer of a third embodiment provided by the present invention;

[0032] Fig.10 is a schematic structural diagram of a flexible connection layer of a third embodiment provided by the present invention;

[0033] Fig.11 It is a schematic structural diagram of a flexible membrane according to a third embodiment of the present invention.

[0034] Reference numerals:

[0035] 100, flexible branch layer; 110, first fluid channel; 120, first positive electrode; 121, positive electrode branch; 130, first negative electrode; 131, negative electrode branch; 140, first main channel; 150, second main channel;

[0036] 200, flexible connection layer; 210, second fluid channel; 220, second positive electrode; 230, second negative electrode; 240, positive electrode connection hole; 250, negative electrode connection hole; 260, fluid inlet; 270, fluid outlet;

[0037] 300, flexible membrane; 310, first connecting hole; 320, second connecting hole; 330, third connecting hole; 340, fourth connecting hole. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Please refer to Figures 1 to 11 The present invention discloses a multi-channel electroosmotic micropump based on liquid metal electrode technology. The disclosed multi-channel electroosmotic micropump based on liquid metal electrode technology includes a flexible base, and the flexible base is provided with two groups of electrode channels. Liquid metal is provided in both groups of electrode channels to form a liquid metal positive electrode and a liquid metal negative electrode, respectively.

[0040] The flexible base is provided with a fluid inlet 260, a fluid outlet 270 and a plurality of first fluid channels 110. The plurality of first fluid channels 110 can be arranged in parallel. The plurality of first fluid channels 110 are connected in parallel with the fluid inlet 260 so that the fluid can enter the plurality of first fluid channels 110 through the fluid inlet 260. The plurality of first fluid channels 110 are connected in parallel with the fluid outlet 270 so that the fluid in the plurality of first fluid channels 110 can be discharged from the multi-channel electroosmotic micropump based on liquid metal electrode technology through the fluid outlet 270. Optionally, the fluid can be deionized water.

[0041] The liquid metal positive electrode and the liquid metal negative electrode are used to connect to external electrical connectors, such as wires or flexible circuit boards. Voltage is applied to the liquid metal positive electrode and the liquid metal negative electrode to form an electric field. The first fluid channel 110 is located in the electric field to form an electroosmotic flow, so that the fluid in the first fluid channel 110 flows in a directional manner. In the present invention, the fluid flows in the first fluid channel 110 in the direction from the fluid inlet 260 to the fluid outlet 270.

[0042] Compared with the technical solution of using an open capillary or glass tube as a fluid channel in the related art, multiple fluid channels are integrated on the mounting base, and an inserted external electrode is used, in the embodiment of the present invention, an electrode channel is opened in the flexible base, and liquid metal is filled in the electrode channel to form a liquid metal positive electrode and a liquid metal negative electrode, and multiple first fluid channels are opened in the flexible base. The technical solution makes the liquid metal positive electrode, the liquid metal negative electrode and the multiple first fluid channels built into the flexible base, which is helpful for the small size design of the multi-channel electroosmotic micropump based on the liquid metal electrode process, and can improve the structural compactness of the multi-channel electroosmotic micropump based on the liquid metal electrode process. It can be seen that the embodiment of the present invention can solve the problem of the large size of the electroosmotic micropump after the integration of multiple fluid channels in the related art.

[0043] In addition, the embodiments of the present invention contribute to the small-size design of a multi-channel electroosmotic micropump based on the liquid metal electrode process. In the small-size multi-channel electroosmotic micropump based on the liquid metal electrode process, the distance between the liquid metal positive electrode and the liquid metal negative electrode is correspondingly small. In this way, the required electric field strength can be met by a smaller voltage, and multiple first fluid channels 110 are integrated in the flexible base. Compared with the single first fluid channel 110, the total flow rate of the multi-channel electroosmotic micropump based on the liquid metal electrode process can be improved. Therefore, the multi-channel electroosmotic micropump based on the liquid metal electrode process provided by the present invention can realize multi-channel integration in a small volume, thereby reducing the driving voltage of the multi-channel electroosmotic micropump based on the liquid metal electrode process and improving the overall flow rate of the multi-channel electroosmotic micropump based on the liquid metal electrode process.

[0044] In the structure of the multi-channel electroosmotic micropump based on the liquid metal electrode process, in order to prevent the leakage of liquid metal in the electrode channel and to prevent the fluid from leaking from a position other than the fluid inlet 260 and the fluid outlet 270 of the flexible base when there is fluid in the first fluid channel 110, the electrode channel and the first fluid channel 110 are located inside the flexible base. However, this makes the processing of the electrode channel and the first fluid channel 110 more difficult. To this end, in an embodiment of the present invention, the flexible base may include a flexible branch layer 100 and a flexible connection layer 200 that are stacked and connected. The flexible branch layer 100 and the flexible connection layer 200 may be connected by oxygen plasma bonding.

[0045] The liquid metal positive electrode may include a first positive electrode 120, a group of electrode channels for assisting in forming the liquid metal positive electrode may include a first positive electrode channel, the first positive electrode channel is filled with liquid metal to form the first positive electrode 120, the liquid metal negative electrode may include a first negative electrode 130, a group of electrode channels for assisting in forming the liquid metal negative electrode may include a first negative electrode channel, the first negative electrode channel is filled with liquid metal to form the first negative electrode 130. Optionally, the first positive electrode 120 and the first negative electrode 130 may be symmetrically distributed.

[0046] The first positive electrode 120, the first negative electrode 130 and the plurality of first fluid channels 110 can all be arranged on the end surface of the flexible branch layer 100 facing the flexible connection layer 200, that is, the plurality of first fluid channels 110, the first positive electrode channel for filling liquid metal to form the first positive electrode 120, and the first negative electrode channel for filling liquid metal to form the first negative electrode 130 are opened on the end surface of the flexible branch layer 100 facing the flexible connection layer 200.

[0047] In this case, before the flexible branch layer 100 and the flexible connection layer 200 are stacked and connected, the first positive electrode channel, the first negative electrode channel and the first fluid channel 110 can be processed on the end surface of the flexible branch layer 100, and the flexible branch layer 100 and the flexible connection layer 200 are stacked and connected after processing, so as to open the above-mentioned channels in layers inside the flexible base. Compared with the technical solution of directly opening the above-mentioned channels inside the flexible base, in this embodiment, the method of opening the above-mentioned channels on the end surface of the flexible branch layer can undoubtedly reduce the difficulty of processing the first positive electrode channel, the first negative electrode channel and the first fluid channel 110.

[0048] In a specific structure, the first fluid channel 110 , the first positive electrode channel and the first negative electrode channel may all include groove structures opened on the end surface of the flexible branch layer 100 facing the flexible connection layer 200 , and the notches of the groove structures all face the flexible connection layer 200 .

[0049] The fluid inlet 260 and the fluid outlet 270 may be provided in the flexible connection layer 200, and the flexible connection layer 200 may be provided with a positive electrode connection hole 240 and a negative electrode connection hole 250, and the positive electrode connection hole 240 and the negative electrode connection hole 250 are used to install external electrical connectors so as to apply voltage to the first positive electrode 120 and the first negative electrode 130 through the external electrical connectors. The positive electrode connection hole 240 and the negative electrode connection hole 250 may also be used to inject liquid metal into the corresponding electrode channels to prepare a liquid metal positive electrode and a liquid metal negative electrode.

[0050] The size of the positive electrode connection hole 240 and the negative electrode connection hole 250 is adapted to the size of the external electrical connection. The diameter and other sizes of the positive electrode connection hole 240, the negative electrode connection hole 250, the fluid inlet 260, and the fluid outlet 270 are not limited herein. The positive electrode connection hole 240, the negative electrode connection hole 250, the fluid inlet 260, and the fluid outlet 270 can all be punched with a punch, and the punch size of the punch can be selected according to the size actually required.

[0051] The first positive electrode 120 may include a plurality of positive electrode branches 121 that are spaced apart, and after a voltage is applied to the liquid metal positive electrode, the plurality of positive electrode branches 121 are electrically connected. The first negative electrode 130 may include a plurality of negative electrode branches 131 that are spaced apart, and after a voltage is applied to the liquid metal negative electrode, the plurality of negative electrode branches 131 are electrically connected. The positive electrode branches 121 and the negative electrode branches 131 are arranged opposite to each other in a one-to-one correspondence, and there is a gap between two adjacent groups of oppositely arranged positive electrode branches 121 and negative electrode branches 131, so that a plurality of gaps are formed in the area where the liquid metal positive electrode and the liquid metal negative electrode are located, and the plurality of first fluid channels 110 are located in the plurality of gaps in a one-to-one correspondence.

[0052] In this case, the multiple first fluid channels 110 can be more evenly distributed in the area where the first positive electrode 120 and the first negative electrode 130 are located, preventing the problem of a large difference in the distance between each first fluid channel 110 and the first positive electrode 120 and the first negative electrode 130, which would lead to a large difference in the electric field strength in the areas where different first fluid channels 110 are located, thereby making the fluid flow in the multiple first fluid channels 110 more stable.

[0053] In a further technical solution, the extension direction of the first fluid channel 110 may be consistent with the direction from the positive electrode branch 121 to the negative electrode branch 131 in a group of positive electrode branches 121 and negative electrode branches 131 arranged opposite to each other. In this case, after the liquid metal positive electrode and the liquid metal negative electrode are applied with voltage, the direction of the electric field formed is parallel to the extension direction of the first fluid channel 110, so that the fluid flow in the first fluid channel 110 is more stable.

[0054] Of course, in order to ease the contact between the liquid first positive electrode 120, the first negative electrode 130 and the fluid in the first fluid channel 110, the first fluid channel 110 and the first positive electrode 120 and the first negative electrode 130 are also spaced apart, which can be understood as the first fluid channel 110 and a group (or two groups) of positive electrode branches 121 and negative electrode branches 131 adjacent thereto that are arranged oppositely are spaced apart. In this case, the problems of electrode damage, gas generation, heat generation and fluid contamination caused by the contact of the fluid with the liquid metal positive electrode and the liquid metal negative electrode during the operation of the multi-channel electroosmotic micropump based on the liquid metal electrode process can be alleviated.

[0055] In a first optional embodiment, the liquid metal positive electrode may further include a second positive electrode 220, a group of electrode channels for assisting in forming the liquid metal positive electrode may include a second positive electrode channel, the second positive electrode channel is filled with liquid metal to form the second positive electrode 220, the liquid metal negative electrode may further include a second negative electrode 230, a group of electrode channels for assisting in forming the liquid metal negative electrode may include a second negative electrode channel, the second negative electrode channel is filled with liquid metal to form the second negative electrode 230, the second positive electrode 220 and the second negative electrode 230 are both arranged on the end surface of the flexible connection layer 200 facing the flexible branch layer 100, that is, the second positive electrode channel and the second negative electrode channel for filling liquid metal to form the second positive electrode 220 and the second positive electrode 220 are arranged on the end surface of the flexible connection layer 200 facing the flexible branch layer 100.

[0056] The positive electrode connection hole 240 is connected to the corresponding area of ​​the electrode channel that assists in forming the second positive electrode 220 (which can be understood as the second positive electrode channel in this embodiment), that is, the port of the positive electrode connection hole 240 located inside the flexible base is opposite to the second positive electrode 220, so that when an electrical connector is installed in the positive electrode connection hole 240, the electrical connector can be in contact with and electrically connected to the second positive electrode 220. The negative electrode connection hole 250 is connected to the corresponding area of ​​the electrode channel that assists in forming the second negative electrode 230 (which can be understood as the second negative electrode channel in this embodiment), that is, the port of the negative electrode connection hole 250 located inside the flexible base is opposite to the second negative electrode 230, so that when an electrical connector is installed in the negative electrode connection hole 250, the electrical connector can be in contact with and electrically connected to the second negative electrode 230, thereby applying voltage to the second positive electrode 220 and the second negative electrode 230 through the electrical connector.

[0057] The first positive electrode 120 and the first negative electrode 130 solidify at room temperature, the second positive electrode 220 and the second negative electrode 230 can be liquid or solid at room temperature, the second positive electrode 220 is in contact and electrically connected with the first positive electrode 120, and the second negative electrode 230 is in contact and electrically connected with the first negative electrode 130, so that when a voltage is loaded on the second positive electrode 220 and the second negative electrode 230, the first positive electrode 120 and the first negative electrode 130 can also be loaded with a voltage.

[0058] The surface of the flexible connection layer 200 facing the flexible branch layer 100 is provided with two second fluid channels 210, and the two second fluid channels 210 are respectively connected to the fluid inlet 260 and the fluid outlet 270, one end of each first fluid channel 110 is connected to one of the second fluid channels 210, and the other end of each first fluid channel 110 is connected to another second fluid channel 210. Optionally, the fluid inlet 260 and the fluid outlet 270 can be respectively connected to the middle of the two second fluid channels 210, and of course, can also be connected to other parts of the second fluid channels 210, which is not limited herein.

[0059] In a specific structure, the second positive electrode channel, the second negative electrode channel, and the second fluid channel 210 may all be groove structures, and the groove openings of the groove structures all face the flexible branch layer 100 .

[0060] The notch of the second positive electrode channel is opposite to the notch of the first positive electrode channel, so that the first positive electrode 120 formed in the first positive electrode channel and the second positive electrode 220 formed in the second positive electrode channel are in contact and electrically connected; the notch of the second negative electrode channel is opposite to the notch of the first negative electrode channel, so that the first negative electrode 130 formed in the first negative electrode channel and the second negative electrode 230 formed in the second negative electrode channel are in contact and electrically connected; the extension direction of the second fluid channel 210 can be perpendicular to the extension direction of the first fluid channel 110, and span multiple first fluid channels 110, so that a partial area of ​​the first fluid channel 110 and a partial area of ​​the second fluid channel 210 are opposite, so that the first fluid channel 110 is connected to the second fluid channel 210.

[0061] In this embodiment, the first positive electrode 120 and the first negative electrode 130 may include bismuth-based alloy liquid metal electrodes, so that the first positive electrode 120 and the first negative electrode 130 are solidified at room temperature. The second positive electrode 220 and the second negative electrode 230 may include gallium-based alloy liquid metal electrodes or bismuth-based alloy liquid metal electrodes.

[0062] According to the flow deformation properties of liquid metal, in the specific process of preparing the first positive electrode 120 and the first negative electrode 130, a reversible bonding process can be used to bond a layer of flexible PC (polycarbonate) film on the surface of the flexible branch layer 100 provided with the first positive electrode channel and the first negative electrode channel to block the notches of the first positive electrode channel and the first negative electrode channel, and then a manual injection method can be used to inject liquid metal into the first positive electrode channel and the first negative electrode channel on a hot plate with a temperature higher than the melting point of the liquid metal (bismuth-based alloy liquid metal) to form the first positive electrode 120 and the first negative electrode 130. The injection device for injecting liquid metal can be used but is not limited to an ordinary micro-syringe. This method of injecting liquid metal is simple to operate, has good repeatability, is formed in one time, and the electrode structure formed is stable.

[0063] After the first positive electrode 120 and the first negative electrode 130 are prepared, the PC film on the flexible branch layer 100 can be peeled off, and then the flexible connection layer 200 can be superimposed and connected on the flexible branch layer 100, and then the corresponding liquid metal is poured into the second positive electrode channel and the second negative electrode channel through the positive electrode connection hole 240 and the negative electrode connection hole 250 to form the second positive electrode 220 and the second negative electrode 230.

[0064] Optionally, the flexible branch circuit layer 100 and the PC film may be subjected to plasma treatment to achieve encapsulation (connection) and peeling of the two.

[0065] In the above solution, the first positive electrode 120 may include a plurality of positive electrode branches 121, and the first negative electrode 130 may include a plurality of negative electrode branches 131. In the first optional embodiment, please refer to Figure 2 The first positive electrode 120 and the first negative electrode 130 may be a comb-shaped structure. The first positive electrode 120 may include a main body and a plurality of positive electrode branches 121 connected in parallel to the main body, and the positive electrode branches 121 form the teeth of the comb-shaped structure. The first negative electrode 130 may include a main body and a plurality of negative electrode branches 131 connected in parallel to the main body, and the negative electrode branches 131 form the teeth of the comb-shaped structure. Optionally, the main body of the first positive electrode 120 and the main body of the first negative electrode 130 may both be U-shaped.

[0066] The multi-channel electroosmotic micropump based on the liquid metal electrode process may further include a flexible membrane 300, which may be stacked between the flexible branch layer 100 and the flexible connection layer 200. In this case, the first fluid channel 110 on the flexible branch layer 100 is easily encapsulated, the contact between the fluid and the first positive electrode 120 and the first negative electrode 130 is reduced, and the problems of electrode damage, gas and heat generation, and fluid contamination of the first positive electrode 120 and the first negative electrode 130 of the multi-channel electroosmotic micropump based on the liquid metal electrode process during operation are alleviated.

[0067] The flexible branch layer 100 and the flexible film 300 may be connected by oxygen plasma bonding, and the flexible film 300 and the flexible connection layer 200 may be connected by oxygen plasma bonding.

[0068] In a second optional embodiment, the flexible branch layer 100 may be provided with a first main channel 140 and a second main channel 150, and both ends of each first fluid channel 110 are respectively connected to the first main channel 140 and the second main channel 150, and the flexible membrane 300 may be provided with two first connecting holes 310, and the first main channel 140 is connected to the fluid inlet 260 through one of the first connecting holes 310, and the second main channel 150 is connected to the fluid outlet 270 through the other first connecting hole 310, so that each first fluid channel 110 is connected in parallel with the fluid inlet 260 and in parallel with the fluid outlet 270.

[0069] The liquid metal positive electrode may also include a second positive electrode 220, and a group of electrode channels used to assist in forming the liquid metal positive electrode may include a second positive electrode channel, and the second positive electrode channel is filled with liquid metal to form the second positive electrode 220. The liquid metal negative electrode also includes a second negative electrode 230, and a group of electrode channels used to assist in forming the liquid metal negative electrode may include a second negative electrode channel, and the second negative electrode channel is filled with liquid metal to form the second negative electrode 230.

[0070] The second positive electrode 220 and the second negative electrode 230 can be arranged on the end surface of the flexible connection layer 200 facing the flexible branch layer 100, a partial area of ​​the second positive electrode 220 is opposite to the positive electrode connection hole 240, and a partial area of ​​the second negative electrode 230 is opposite to the negative electrode connection hole 250. When the positive electrode connection hole 240 and the negative electrode connection hole 250 are installed with electrical connectors, voltage can be applied to the second positive electrode 220 and the second negative electrode 230 through the electrical connectors.

[0071] The flexible membrane 300 may be provided with a plurality of second connecting holes 320, and the second positive electrode 220 is electrically connected to the first positive electrode 120 through the liquid metal in the second connecting hole 320 opposite thereto, so that a voltage is applied to the first positive electrode 120 through the second positive electrode 220, and the second negative electrode 230 is electrically connected to the first negative electrode 130 through the liquid metal in the second connecting hole 320 opposite thereto, so that a voltage is applied to the first negative electrode 130 through the second negative electrode 230.

[0072] In a specific structure, both the second positive electrode channel and the second negative electrode channel may be groove structures provided on the end surface of the flexible connection layer 200 facing the flexible branch layer 100 , and the groove openings face the flexible film 300 .

[0073] The first positive electrode 120 may include a plurality of positive electrode branches 121 arranged at intervals. Figure 6 The second positive electrode 220 may include a main segment and multiple branch segments, a partial area of ​​the main segment is opposite to the positive electrode connecting hole 240, the main segment is opposite to one of the positive electrode branches 121 through the second connecting hole 320, and is in contact and electrically connected with the positive electrode branch 121 through the liquid metal in the second connecting hole 320, and the two ends of the branch segment are respectively opposite to the two adjacent positive electrode branches 121 through the second connecting hole 320, and the two adjacent positive electrode branches 121 are electrically connected through the liquid metal in the second connecting hole 320 and the second positive electrode in the branch segment opposite to it, thereby realizing the contact and electrical connection between the second positive electrode 220 and the first positive electrode 120.

[0074] The structure of the second negative electrode 230 is the same as that of the second positive electrode 220 , and also includes a main segment and a plurality of branch segments.

[0075] In this embodiment, the flexible membrane 300 can also play a role in blocking the contact between the second positive electrode 220 and the second negative electrode 230 on the flexible connection layer 200 and the first fluid channel 110 on the flexible branch layer 100, thereby avoiding problems such as damage to the second positive electrode 220 and the second negative electrode 230, gas and heat generation, and fluid contamination during the operation of the multi-channel electroosmotic micropump based on liquid metal electrode technology.

[0076] According to the flow deformation properties of liquid metal, in the specific process of preparing liquid metal positive electrode and liquid metal negative electrode, the liquid metal is injected into the electrode channel by manual injection method. In this case, the method of injecting liquid metal is simple to operate, has good repeatability, is formed in one time, and the formed electrode structure is stable.

[0077] Optionally, a femtosecond laser method may be used to open the first communication hole 310 and the second communication hole 320 on the flexible film 300 .

[0078] In a third optional embodiment, the surface of the flexible connection layer 200 facing the flexible branch layer 100 may be provided with two second fluid channels 210, and the two second fluid channels 210 may be connected to the fluid inlet 260 and the fluid outlet 270 respectively. The flexible membrane 300 may be provided with a plurality of third connecting holes 330, and one end of each first fluid channel 110 is connected to one of the second fluid channels 210 via the third connecting hole 330 opposite thereto, and the other end of each first fluid channel 110 is connected to another second fluid channel 210 via the third connecting hole 330 opposite thereto.

[0079] In a specific structure, the second fluid channel 210 may be a groove structure provided on the end surface of the flexible connection layer 200 facing the flexible branch layer 100, with the groove opening facing the flexible branch layer 100. The second fluid channel 210 may be perpendicular to the first fluid channel 110, and the second fluid channel 210 may span across a plurality of first fluid channels 110, so that the plurality of first fluid channels 110 are opposite to the second fluid channel 210 through the corresponding third communication holes 330 so as to be connected.

[0080] The flexible membrane 300 may be provided with a plurality of fourth connecting holes 340, and some of the fourth connecting holes 340 are opposite to the positive electrode connecting hole 240 and the first positive electrode 120, so that when an electrical connector is installed in the positive electrode connecting hole 240, the electrical connector can be electrically connected to the first positive electrode 120 through the liquid metal in the fourth connecting hole 340, and when a voltage is applied to the liquid metal in the corresponding fourth connecting hole 340 through the electrical connector, a voltage can also be applied to the first positive electrode 120, and some of the fourth connecting holes 340 are opposite to the negative electrode connecting hole 250 and the first negative electrode 130, so that when an electrical connector is installed in the negative electrode connecting hole 250, the electrical connector can be electrically connected to the first negative electrode 130 through the liquid metal in the fourth connecting hole 340, and when a voltage is applied to the liquid metal in the corresponding fourth connecting hole 340 through the electrical connector, a voltage can also be applied to the first negative electrode 130.

[0081] In this embodiment, please refer again to Fig. 9 The first positive electrode 120 may include a connected main body and a serpentine portion, the serpentine portion may form the above-mentioned multiple positive electrode branches 121, and the first negative electrode 130 may include a connected main body and a serpentine portion, the serpentine portion may form the above-mentioned multiple negative electrode branches 131.

[0082] In this embodiment, the flexible membrane 300 can also serve to block the contact between the second fluid channel 210 and the first positive electrode 120 and the first negative electrode 130, thereby alleviating problems such as damage to the first positive electrode 120 and the first negative electrode 130, gas and heat production, and fluid contamination during the operation of the multi-channel electroosmotic micropump based on liquid metal electrode technology.

[0083] According to the flow deformation properties of liquid metal, in the specific process of preparing liquid metal positive electrode and liquid metal negative electrode, the liquid metal is injected into the electrode channel by manual injection method. In this case, the method of injecting liquid metal is simple to operate, has good repeatability, is formed in one time, and the formed electrode structure is stable.

[0084] The third communication hole 330 and the fourth communication hole 340 may be opened on the flexible film 300 by using a femtosecond laser method.

[0085] In the second optional embodiment and the third optional embodiment of the present invention, the first positive electrode 120 and the first negative electrode 130 may include bismuth-based alloy liquid metal electrodes, or gallium-based alloy liquid metal electrodes; the second positive electrode 220 and the second negative electrode 230 may include gallium-based alloy liquid metal electrodes or bismuth-based alloy liquid metal electrodes.

[0086] In the embodiment of the present invention, the material of the flexible film 300 may be polydimethylsiloxane (PDMS) or Ecoflex (aliphatic aromatic random copolyester) or silicone. The material of the flexible branch layer 100 may be polydimethylsiloxane or Ecoflex or silicone. The material of the flexible connection layer 200 may be polydimethylsiloxane or Ecoflex or silicone.

[0087] In any of the above embodiments of the present invention, the width of the first positive electrode 120, the first negative electrode 130, the first fluid channel 110, the second positive electrode 220, the second negative electrode 230, and the second fluid channel 210 may be 20-100 μm, the distance between the first fluid channel 110 and the adjacent first positive electrode 120 and the first negative electrode 130 may be 20-100 μm, and the thickness of the flexible film 300 may be 10-100 μm.

[0088] In the embodiment of the present invention, the liquid metal of the first positive electrode 120 and the second positive electrode 220 can be the same liquid metal or different types of liquid metals, and the liquid metal of the first negative electrode 130 and the second negative electrode 230 can be the same liquid metal or different types of liquid metals. The specific type of liquid metal can be selected according to specific needs.

[0089] The embodiment of the present invention takes advantage of micromachining to directly inject room temperature liquid metal into the electrode channel of the flexible base to form a liquid metal positive electrode and a liquid metal negative electrode, which greatly reduces the complexity of electrode production compared to traditional processes such as sputtering. Combined with the high flexibility, deformability, electrical conductivity, thermal conductivity and non-toxicity of liquid metal, it has made outstanding contributions to the improvement of the production process and performance of multi-channel electroosmotic micropumps based on liquid metal electrode technology. Liquid metal is poured into a flexible base as an electrode to manufacture a stable, soft, safe, small, biocompatible and implantable multi-channel electroosmotic micropump based on liquid metal electrode technology.

[0090] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A multi-channel electroosmotic micropump based on liquid metal electrode technology, characterized in that: The invention comprises a flexible base, wherein the flexible base is provided with two groups of electrode channels, liquid metal is provided in the two groups of electrode channels to form a liquid metal positive electrode and a liquid metal negative electrode, and the flexible base is provided with a fluid inlet (260), a fluid outlet (270) and a plurality of first fluid channels (110), wherein the plurality of first fluid channels (110) are connected in parallel with the fluid inlet (260), and the plurality of first fluid channels (110) are connected in parallel with the fluid outlet (270).

2. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 1, characterized in that: The flexible base comprises a flexible branch layer (100) and a flexible connection layer (200) which are stacked and connected, wherein: The liquid metal positive electrode comprises a first positive electrode (120), the liquid metal negative electrode comprises a first negative electrode (130), the first positive electrode (120), the first negative electrode (130) and the plurality of first fluid channels (110) are all arranged on the end surface of the flexible branch layer (100) facing the flexible connection layer (200); The fluid inlet (260) and the fluid outlet (270) are provided in the flexible connection layer (200), and the flexible connection layer (200) is provided with a positive electrode connection hole (240) and a negative electrode connection hole (250), and the positive electrode connection hole (240) and the negative electrode connection hole (250) are used to install external electrical connectors.

3. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 2, characterized in that: The first positive electrode (120) includes a plurality of positive electrode branches (121) distributed at intervals, and the plurality of positive electrode branches (121) are electrically connected. The first negative electrode (130) includes a plurality of negative electrode branches (131) distributed at intervals, and the plurality of negative electrode branches (131) are electrically connected. The positive electrode branches (121) and the negative electrode branches (131) are arranged opposite to each other in a one-to-one correspondence, and there is a gap between two adjacent groups of the positive electrode branches (121) and the negative electrode branches (131) arranged opposite to each other. The plurality of first fluid channels (110) are located in the plurality of gaps in a one-to-one correspondence.

4. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 3, characterized in that: The extension direction of the first fluid channel (110) is consistent with the direction from the positive electrode branch (121) to the negative electrode branch (131) in a group of the positive electrode branches (121) and the negative electrode branches (131) arranged opposite to each other.

5. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 2 or 3, characterized in that: The liquid metal positive electrode further comprises a second positive electrode (220), and the liquid metal negative electrode further comprises a second negative electrode (230), the second positive electrode (220) and the second negative electrode (230) are both arranged on the end surface of the flexible connection layer (200) facing the flexible branch layer (100), the positive electrode connection hole (240) is connected to a corresponding area of ​​the electrode channel that assists in forming the second positive electrode (220), and the negative electrode connection hole (250) is connected to a corresponding area of ​​the electrode channel that assists in forming the second negative electrode (230); The first positive electrode (120) and the first negative electrode (130) are solidified at room temperature, the second positive electrode (220) is in contact with and electrically connected to the first positive electrode (120), and the second negative electrode (230) is in contact with and electrically connected to the first negative electrode (130); The end surface of the flexible connection layer (200) facing the flexible branch layer (100) is provided with two second fluid channels (210), the two second fluid channels (210) are respectively connected to the fluid inlet (260) and the fluid outlet (270), one end of each of the first fluid channels (110) is connected to one of the second fluid channels (210), and the other end of each of the first fluid channels (110) is connected to another of the second fluid channels (210).

6. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 5, characterized in that: The first positive electrode (120) and the first negative electrode (130) include bismuth-based alloy liquid metal electrodes; the second positive electrode (220) and the second negative electrode (230) include gallium-based alloy liquid metal electrodes or bismuth-based alloy liquid metal electrodes.

7. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 2 or 3, characterized in that: The multi-channel electroosmotic micropump based on the liquid metal electrode process further comprises a flexible membrane (300), wherein the flexible membrane (300) is stacked between the flexible branch layer (100) and the flexible connection layer (200).

8. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 7, characterized in that: The flexible branch layer (100) is provided with a first main channel (140) and a second main channel (150), and both ends of each of the first fluid channels (110) are respectively connected to the first main channel (140) and the second main channel (150), and the flexible membrane (300) is provided with two first communication holes (310), the first main channel (140) is connected to the fluid inlet (260) through one of the first communication holes (310), and the second main channel (150) is connected to the fluid outlet (270) through the other of the first communication holes (310); The liquid metal positive electrode further comprises a second positive electrode (220), and the liquid metal negative electrode further comprises a second negative electrode (230). The second positive electrode (220) and the second negative electrode (230) are both arranged on the end surface of the flexible connection layer (200) facing the flexible branch layer (100). The flexible membrane (300) is provided with a plurality of second connecting holes (320). The second positive electrode (220) is in contact and electrically connected with the first positive electrode (120) through the liquid metal in the second connecting hole (320) opposite thereto, and the second negative electrode (230) is in contact and electrically connected with the first negative electrode (130) through the liquid metal in the second connecting hole (320) opposite thereto.

9. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 7, characterized in that: The surface of the flexible connection layer (200) facing the flexible branch layer (100) is provided with two second fluid channels (210), and the two second fluid channels (210) are respectively connected to the fluid inlet (260) and the fluid outlet (270); the flexible membrane (300) is provided with a plurality of third communication holes (330); one end of each first fluid channel (110) is connected to one of the second fluid channels (210) through the third communication hole (330) opposite thereto, and the other end of each first fluid channel (110) is connected to another second fluid channel (210) through the third communication hole (330) opposite thereto; The flexible film (300) is provided with a plurality of fourth connecting holes (340), some of the fourth connecting holes (340) are opposite to the positive electrode connecting hole (240) and the first positive electrode (120), and some of the fourth connecting holes (340) are opposite to the negative electrode connecting hole (250) and the first negative electrode (130).

10. The multi-channel electroosmotic micropump based on liquid metal electrode technology according to claim 7, characterized in that: The material of the flexible film (300) is polydimethylsiloxane, Ecoflex or silicone; the material of the flexible branch layer (100) is polydimethylsiloxane, Ecoflex or silicone; the material of the flexible connection layer (200) is polydimethylsiloxane, Ecoflex or silicone.

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