A microfluidic chip

Abstract

The embodiment of the present invention discloses a microfluidic chip. The microfluidic chip includes a first substrate and a second substrate arranged relatively to each other, a microfluidic channel is formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet; a plurality of driving electrodes, a plurality of first sensing electrodes and a plurality of second sensing electrodes are located on one side of the first substrate, and adjacent driving electrodes are loaded with different driving voltage signals to drive the droplet to move; the first sensing electrode and the second sensing electrode are loaded with detection signals, and the position of the droplet is determined according to the capacitance change formed by the first sensing electrode and a certain electrode and the capacitance change formed by the second sensing electrode and a certain electrode when the droplet flows through. The microfluidic chip provided by the embodiment of the present invention can obtain the position of the droplet while driving the droplet to move, solving the problem of low reliability of the device due to the inability to detect the position of the droplet in the prior art.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of microcontroller technology, and in particular to a microfluidic chip. Background Art

[0002] Microfluidics technology refers to a technology that uses microchannels (with a size of tens to hundreds of microns) to process or manipulate tiny fluids (volumes of nanoliters to attoliters). Microfluidic chips are the main platform for the implementation of microfluidic technology. Microfluidic chips have the characteristics of parallel collection and processing of samples, high integration, high throughput, fast analysis speed, low power consumption, low material consumption, and low pollution. Microfluidic chip technology can be applied to biological genetic engineering, disease diagnosis and drug research, cell analysis, environmental monitoring and protection, health quarantine, forensic identification and other fields.

[0003] When the surface of the driving unit that drives the droplet movement is uneven or has impurities due to raw materials, processes or environmental problems, it will affect the movement of the droplet. Since the driving timing has been determined in advance, if there is no droplet position feedback mechanism, it will affect the subsequent process, reduce experimental efficiency or even cause experimental failure. Especially in experiments with complex droplet movement paths, real-time feedback of droplet position will be more important.

[0004] In existing microfluidics technology, it is usually difficult to provide real-time feedback on the position of droplets. Some literature mentions that optical detection can be used to obtain the position of droplets, but this method usually requires external laser equipment, has a cumbersome structure, is not easy to diagnose on site, and is costly. Summary of the invention

[0005] An embodiment of the present invention provides a microfluidic chip, which can obtain the position of a droplet while driving the droplet to move, thereby solving the problem of low reliability of the device in the prior art due to the inability to detect the position of the droplet.

[0006] In a first aspect, an embodiment of the present invention provides a microfluidic chip, comprising a first substrate and a second substrate arranged opposite to each other, wherein a microfluidic channel is formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet;

[0007] a plurality of driving electrodes, a plurality of first sensing electrodes, and a plurality of second sensing electrodes located on one side of the first substrate, the driving electrodes being arranged in an array, the first sensing electrodes extending along a first direction and being arranged along a second direction, the second sensing electrodes extending along the second direction and being arranged along the first direction, the first direction being parallel to a row direction of the array formed by the driving electrodes, the second direction being parallel to a column direction of the array formed by the driving electrodes, the projection of the first sensing electrodes on the plane where the first substrate is located at least partially overlaps with the projection of the gaps between the driving electrodes in two adjacent rows on the plane where the first substrate is located, and the projection of the second sensing electrodes on the plane where the first substrate is located at least partially overlaps with the projection of the gaps between the driving electrodes in two adjacent columns on the plane where the first substrate is located;

[0008] Adjacent driving electrodes are loaded with different driving voltage signals to drive the droplet to move;

[0009] The first sensing electrode and the second sensing electrode are loaded with detection signals, and the position of the droplet is determined according to the capacitance change formed between the first sensing electrode and a certain electrode and the capacitance change formed between the second sensing electrode and a certain electrode when the droplet flows by.

[0010] In a second aspect, an embodiment of the present invention further provides a microfluidic chip, comprising a first substrate and a second substrate arranged opposite to each other, wherein a microfluidic channel is formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet;

[0011] A plurality of driving electrodes located on one side of the first substrate, the driving electrodes are arranged in an array, and adjacent driving electrodes are loaded with different driving voltage signals to drive the droplets to move;

[0012] At least one edge of the driving electrode extends in a curved shape.

[0013] In a third aspect, an embodiment of the present invention further provides a microfluidic chip, comprising a first substrate and a second substrate arranged opposite to each other, wherein a microfluidic channel is formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet;

[0014] A plurality of driving electrodes located on one side of the first substrate, the driving electrodes are arranged in an array, and adjacent driving electrodes are loaded with different driving voltage signals to drive the droplets to move;

[0015] It also includes a plurality of scanning signal lines extending along the first direction, a plurality of data signal lines extending along the second direction, and transistors corresponding to the driving electrodes one by one, wherein the gate of each transistor is connected to one of the scanning signal lines, the first electrode is connected to one of the data signal lines, and the second electrode is connected to the corresponding driving electrode;

[0016] The scanning signal line, the data signal line and the transistor are all located on a side of the driving electrode away from the second substrate;

[0017] At least one of the scanning signal line, the data signal line and the transistor overlaps with the driving electrode. The microfluidic chip provided by the embodiment of the present invention comprises a first substrate and a second substrate arranged opposite to each other, and a microfluidic channel is formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet; a plurality of array-arranged driving electrodes are arranged on one side of the first substrate, and adjacent driving electrodes are loaded with different driving voltage signals to drive the droplet to move; a plurality of first sensing electrodes and a plurality of second sensing electrodes are arranged on one side of the first substrate, and the first sensing electrodes and the second sensing electrodes are loaded with detection signals, and the position of the droplet is determined according to the capacitance change formed between the first sensing electrode and a certain electrode and the capacitance change formed between the second sensing electrode and a certain electrode when the droplet flows through, wherein the first sensing electrode The second sensing electrodes extend along the first direction and are arranged along the second direction. The first direction is parallel to the row direction of the array formed by the driving electrodes, and the second direction is parallel to the column direction of the array formed by the driving electrodes. The projection of the first sensing electrode on the plane where the first substrate is located at least partially overlaps with the projection of the gap between two adjacent rows of driving electrodes on the plane where the first substrate is located, and the projection of the second sensing electrode on the plane where the first substrate is located at least partially overlaps with the projection of the gap between two adjacent columns of driving electrodes on the plane where the first substrate is located; thereby, the position of the droplet can be obtained while the droplet is driven to move, thereby solving the problem of low reliability of the device due to the inability to detect the position of the droplet in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a microfluidic chip in the related art;

[0019] Figure 2 It is a schematic diagram of the structure of another microfluidic chip in the related art;

[0020] Figure 3 A schematic diagram of the structure of a microfluidic chip provided by an embodiment of the present invention;

[0021] Figure 4 For along Figure 3 A schematic diagram of a cross-sectional structure of the middle section line AA';

[0022] Figure 5 A schematic diagram of the circuit structure of a microfluidic chip provided in an embodiment of the present invention;

[0023] Figure 6 A schematic cross-sectional structure diagram of a microfluidic chip provided in an embodiment of the present invention;

[0024] Figure 7 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention;

[0025] Figure 8 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention;

[0026] Fig. 9 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention;

[0027] Fig.10 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention;

[0028] Fig.11 A schematic diagram of the structure of another microfluidic chip provided by an embodiment of the present invention;

[0029] Fig.12 For along Fig.11 A schematic diagram of a cross-sectional structure along the middle section line BB';

[0030] Fig.13 A schematic diagram of a partial structure of a microfluidic chip provided in an embodiment of the present invention;

[0031] Fig.14 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0032] Fig.15 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0033] Fig.16 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0034] Fig.17 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0035] Fig.18 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0036] Fig.19 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0037] Fig. 20 A schematic top view of a common electrode in a microfluidic chip provided by an embodiment of the present invention;

[0038] Fig.21 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention;

[0039] Fig. 22 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0040] Fig.23 For along Fig. 22 A schematic diagram of a cross-sectional structure along the center section line CC';

[0041] Fig.24 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention;

[0042] Fig.25 for Fig.24 A schematic diagram of a cross-sectional structure. DETAILED DESCRIPTION

[0043] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0044] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. It should be noted that the directional words such as "upper", "lower", "left", "right" and the like described in the embodiments of the present invention are described at the angles shown in the accompanying drawings and should not be understood as limitations on the embodiments of the present invention. In addition, in the context, it is also necessary to understand that when it is mentioned that an element is formed "on" or "under" another element, it can not only be directly formed "on" or "under" another element, but also indirectly formed "on" or "under" another element through an intermediate element. The terms "first", "second" and the like are only used for descriptive purposes and do not indicate any order, quantity or importance, but are only used to distinguish different components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0045] The research on microfluidic chips began in the early 1990s. It is a potential technology for realizing lab-on-a-chip. It can integrate basic operation units such as sample preparation, reaction, separation, and detection in biological, chemical, and medical analysis processes into a micrometer-scale chip. The microchannels form a network, and the controllable fluid runs through the entire system to replace the various functions of conventional biological or chemical laboratories and automatically complete the entire analysis process. Due to its great potential in integration, automation, portability, and efficiency, microfluidic chip technology has become a current research hotspot and one of the world's cutting-edge technologies. In the past two decades, digital microfluidic chips have shown a booming trend in laboratory research and industrial applications, especially digital microfluidic chips based on microdroplet manipulation have made great progress. At present, the volume of the manipulated droplets can reach the microliter or even nanoliter level. In this way, at the microscale, microliter and nanoliter droplets can be mixed more accurately, and the chemical reaction inside the droplets is more sufficient. In addition, different biochemical reaction processes inside the droplets can be monitored, and the microdroplets can contain cells and biomolecules, such as proteins and DNA, thus achieving higher throughput monitoring. Among the many methods of driving microdroplets, the traditional method is to generate and control microdroplets in microchannels, but the manufacturing process of microchannels is very complicated, and microchannels are easily blocked, with low reusability, and require complex peripheral equipment for driving.

[0046] Since the dielectric wetting effect has many advantages, it is increasingly used to manipulate microdroplets in digital microfluidic chips. Because microfluidic chips based on dielectric wetting do not require complex equipment such as micropipes, micropumps, and microvalves, their manufacturing process is simple, heat generation is low, response is fast, power consumption is low, and packaging is simple. Microfluidic cores based on the dielectric wetting effect can achieve the distribution, separation, transportation, and merging of microdroplets. Digital microfluidic chips based on electrowetting on dielectrics use electrodes as control units to manipulate droplets, so a large number of electrode units are required. For example, Figure 1 is a schematic diagram of the structure of a microfluidic chip in the related art, refer to Figure 1 The microfluidic chip includes a control circuit 01 and multiple driving units 02. Each driving unit 02 is electrically connected to the control circuit 01 and is used to drive the droplets 03 to flow along a preset motion path. This microfluidic chip has the advantages of simple structure and low cost, but it cannot provide real-time feedback on the position of the droplets, and its application scenarios are limited. Figure 2 is a schematic diagram of the structure of another microfluidic chip in the related art, refer to Figure 2The microfluidic chip includes a control circuit 01, multiple drive units 02 and a laser head 04. The drive unit 02 and the laser head 04 are electrically connected to the control circuit 01. The drive unit 02 is used to drive the movement of the droplets. The laser head 04 emits a laser beam for detecting the position of the droplets. The droplet positioning is achieved by optical detection method. The structure is complicated, it is not easy to make instant diagnosis on site, and the cost is relatively high.

[0047] In view of this, an embodiment of the present invention provides a microfluidic chip, comprising a first substrate and a second substrate arranged opposite to each other, a microfluidic channel formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet; a plurality of driving electrodes, a plurality of first sensing electrodes and a plurality of second sensing electrodes located on one side of the first substrate, the driving electrodes are arranged in an array, the first sensing electrodes extend along a first direction and are arranged along a second direction, the second sensing electrodes extend along the second direction and are arranged along the first direction, the first direction is parallel to the row direction of the array formed by the driving electrodes, and the second direction is parallel to the column direction of the array formed by the driving electrodes, the projection of the first sensing electrode on the plane where the first substrate is located and the projection of the gap between two adjacent rows of driving electrodes on the plane where the first substrate is located at least partially overlap, and the projection of the second sensing electrode on the plane where the first substrate is located and the projection of the gap between two adjacent columns of driving electrodes on the plane where the first substrate is located at least partially overlap; different driving voltage signals are loaded on adjacent driving electrodes to drive the droplet to move; the first sensing electrode and the second sensing electrode are loaded with detection signals, and the position of the droplet is determined according to the capacitance change formed between the first sensing electrode and a certain electrode and the capacitance change formed between the second sensing electrode and a certain electrode when the droplet flows through.

[0048] Wherein, the first substrate and the second substrate can both be glass substrates, and a sealant is arranged between the first substrate and the second substrate to form one or more microfluidic channels for accommodating the movement of droplets. The driving electrodes can be block electrodes arranged in an array on the first substrate, and can be formed using metal oxides (for example, indium tin oxide ITO). The area of ​​a driving electrode is smaller than the projection area of ​​the droplet on the first substrate. When driving the droplet to move, adjacent driving electrodes are loaded with different driving voltages, and the droplet is driven by the differential voltage between the adjacent driving electrodes, and the droplet is controlled to move along a preset path. Since the driving electrodes are arranged in an array and separately, electrodes can be arranged between the driving electrodes to form a capacitor. When the droplet flows through, the capacitance of the capacitor will change, thereby obtaining the position of the droplet. In the technical solution of the embodiment of the present invention, a first sensing electrode and a second sensing electrode extending in a first direction (row direction of the driving electrode array) and a second direction (column direction of the driving electrode array) are arranged on the first substrate, wherein at least a part of the area of ​​the first sensing electrode is located in the gap between two adjacent rows of driving electrodes, and at least a part of the area of ​​the second sensing electrode is located in the gap between two adjacent columns of driving electrodes, but cannot be completely located below the driving electrode, thereby avoiding the driving electrode shielding the signal of the sensing electrode. When detecting the position of the droplet, the first sensing electrode and the second sensing electrode are both loaded with corresponding voltages, the first sensing electrode and an electrode in the microfluidic chip form a first capacitor, and the second sensing electrode and an electrode in the microfluidic chip form a second capacitor, wherein a certain electrode can be a common electrode arranged on the second substrate, a certain line in the first substrate or a certain pole of other capacitors, or the first sensing electrode and the second sensing electrode can be the other pole of each other's capacitor, and only need to form a capacitor with the corresponding sensing electrode. When the droplet flows through a certain position, due to the influence of the droplet, the size of the first capacitor and the second capacitor at the position will change, and the position of the droplet can be obtained by detecting the change of the capacitance.

[0049] The technical solution of the embodiment of the present invention is to form a microfluidic channel between a first substrate and a second substrate, the microfluidic channel is used to accommodate at least one droplet; a plurality of array-arranged drive electrodes are provided on one side of the first substrate, and adjacent drive electrodes are loaded with different drive voltage signals to drive the droplet to move; a plurality of first sensing electrodes and a plurality of second sensing electrodes are provided on one side of the first substrate, and the first sensing electrodes and the second sensing electrodes are loaded with detection signals, and the position of the droplet is determined according to the capacitance change formed between the first sensing electrode and a certain electrode and the capacitance change formed between the second sensing electrode and a certain electrode when the droplet flows through, so that the position of the droplet can be obtained while driving the droplet to move, thereby solving the problem of low reliability of the device due to the inability to detect the position of the droplet in the prior art.

[0050] The above is the core idea of ​​the embodiment of the present invention. The technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention.

[0051] For example, Figure 3 A schematic diagram of the structure of a microfluidic chip provided by an embodiment of the present invention, Figure 4 For along Figure 3 A schematic diagram of a cross-section structure along the center section line AA'. Figure 3 The schematic diagram of the top view of the microfluidic chip is shown, and the microfluidic chip includes a plurality of driving electrodes 11, a plurality of first sensing electrodes 12, and a plurality of second sensing electrodes 13, wherein the driving electrodes 11 are arranged in an array, and adjacent driving electrodes 11 are loaded with different driving voltages, and the droplets are driven by the differential voltage between adjacent driving electrodes 11, and the droplets are controlled to move along a preset path. The first sensing electrodes 12 extend along the first direction x and are arranged along the second direction y, and the second sensing electrodes 13 extend along the second direction y and are arranged along the first direction x, and the first direction x is parallel to the row direction of the array formed by the driving electrodes 11, and the second direction y is parallel to the column direction of the array formed by the driving electrodes 11. Figure 3 The shapes of the driving electrode 11, the first sensing electrode 12 and the second sensing electrode 13 are all rectangular, which is only for reference. They can be set according to actual conditions during implementation. Figure 4 , the microfluidic chip comprises a first substrate 10 and a second substrate 20 arranged opposite to each other, a microfluidic channel 30 is formed between the first substrate 10 and the second substrate 20, and the microfluidic channel 30 is used to accommodate at least one droplet 31; illustratively, in this embodiment, the driving electrode 11, the first sensing electrode 12 and the second sensing electrode 13 are all located on the side of the first substrate 10 close to the second substrate 20, and an insulating layer 14 is arranged between different electrode layers. Along the direction z from the first substrate 10 to the second substrate 20, the first sensing electrode 12 covers the gap between two adjacent rows of driving electrodes 11, and the second sensing electrode 13 covers the gap between two adjacent columns of driving electrodes 11, that is, Figure 4 In the embodiment of the present invention, the width d1 of the first sensing electrode 12 is greater than the width d2 of the gap between two adjacent rows of driving electrodes 11, and the width d3 of the second sensing electrode 13 is greater than the width d4 of the gap between two adjacent columns of driving electrodes 11. By setting the widths of the first sensing electrode 12 and the second sensing electrode 13 to be wider, it is beneficial to reduce the resistance of the first sensing electrode 12 and the second sensing electrode 13, and reduce the voltage drop when the detection signal is loaded; in other embodiments, the width of the first sensing electrode 12 can also be set to be less than or equal to the gap between two adjacent rows of driving electrodes 11, and the width of the second sensing electrode 13 can be less than or equal to the gap between two adjacent columns of driving electrodes 11. The specific implementation can be designed according to actual conditions. The embodiment of the present invention does not limit the width of the gap between the sensing electrode and the driving electrode. Figure 4In the example, a common electrode 21 is also provided on one side of the second substrate 20. The common electrode 21 can be formed by ITO. When the detection signal is applied to the first sensing electrode 12 and the second sensing electrode 13, the first sensing electrode 12 and the common electrode 21 form a first capacitor C1, and the second sensing electrode 13 and the common electrode 21 form a second capacitor C2. When the droplet flows through, the dielectric constant between the sensing electrode and the common electrode changes, and the capacitance between the first sensing electrode 12 and the common electrode 21 becomes C1', and the capacitance between the second sensing electrode 13 and the common electrode 21 becomes C2', thereby determining the position of the droplet. In other embodiments, the other electrode that forms a capacitor with the sensing electrode can also be a certain line in the microfluidic chip or a certain pole of other capacitors, etc., which can be designed according to actual conditions during specific implementation.

[0052] Based on the above embodiments, Figure 5 A schematic diagram of the circuit structure of a microfluidic chip provided in an embodiment of the present invention, referring to Figure 5 Optionally, the microfluidic chip provided in this embodiment also includes a plurality of scanning signal lines 15 extending along the first direction x, a plurality of data signal lines 16 extending along the second direction y, and transistors 17 corresponding one to one with the driving electrodes 11, wherein the gate of each transistor 17 is connected to a scanning signal line 15, the first electrode is connected to a data signal line, and the second electrode is connected to the corresponding driving electrode 11.

[0053] It can be understood that for a microfluidic chip with a large number of driving electrodes and a relatively complex structure, an active driving method including a scanning signal line 15, a data signal line 16 and a transistor 17 can be set. Similar to a display panel, each driving electrode 11 is similar to a sub-pixel in the display panel, and scanning is achieved by using the scanning signal line 15 and the data signal line 16, and the active driving of the driving electrode 11 is achieved by turning the transistor 17 on and off, wherein the first electrode of the transistor 17 can be a source electrode, and the second electrode can be a drain electrode. The transistor 17 can be a thin film transistor, and specifically a thin film transistor formed by an active layer made of amorphous silicon material, polycrystalline silicon material or metal oxide material.

[0054] Optionally, the scan signal line, the data signal line and the transistor are all located on a side of the driving electrode away from the second substrate; and at least one of the scan signal line, the data signal line and the transistor overlaps with the driving electrode.

[0055] For example, Figure 6 A schematic cross-sectional structure diagram of a microfluidic chip provided in an embodiment of the present invention, referring to Figure 6, the transistor 17 includes a gate 171, an active layer 172, a source 173 (first electrode) and a drain 174 (second electrode), and the scanning signal line 15, the data signal line 16 and the transistor 17 are all located on the side of the driving electrode 11 away from the second substrate 20; in this embodiment, since the first sensing electrode 12 and the second sensing electrode 13 need to be at least partially located in the gap of the driving electrode 11, in order to increase the strength of the positioning signal and reduce signal interference, the scanning signal line 15 and / or the data signal line 16 are not routed between the gaps of the driving electrode 11 as much as possible, and are all located below the driving electrode 11. Correspondingly, the transistor 17 is also arranged below the driving electrode 11, not in the gap, so that the driving electrode 11 can shield the parasitic capacitance caused by the scanning signal line 15, the data signal line 16 or the transistor 17, thereby improving the droplet positioning accuracy.

[0056] Understandably, Figure 6 In the cross-sectional structure shown, the shape of the section line is similar to Figure 3 The broken line AA' in the figure, wherein the section line of the left part of the dotted line extends along the first direction x (the row direction of the driving electrode array), and the section line of the right part of the dotted line extends along the second direction y (the column direction of the driving electrode array), wherein the scanning signal line 15 is connected to the gate 171 of the transistor 17, Figure 6 The structure of the connection position between the scanning signal line 15 and the gate 171 is not shown. Figure 6 The scanning signal line 15 and the gate 171 are separated, and the data signal line 16 is connected to the source 173 of the transistor 17. Figure 6 1 shows a structure in which the data signal line 16 and the source electrode 173 are connected as one.

[0057] Figure 6 In the embodiment shown, a common electrode 21 is provided on one side of the second substrate 20. When a detection signal is applied to the first sensing electrode 12 and the second sensing electrode 13, the first sensing electrode 12 and the common electrode 21 form a first capacitor C1, and the second sensing electrode 13 and the common electrode 21 form a second capacitor C2. When a droplet flows through, the dielectric constant between the sensing electrode and the common electrode changes, and the capacitance between the first sensing electrode 12 and the common electrode 21 becomes C1', and the capacitance between the second sensing electrode 13 and the common electrode 21 becomes C2', thereby determining the position of the droplet. In other embodiments, a common electrode may not be provided, and the sensing electrode forms a capacitor with a certain wiring or other electrode in the microfluidic chip. For example, Figure 7A schematic diagram of the cross-sectional structure of another microfluidic chip provided in an embodiment of the present invention. It can be understood that driving the droplet to move and detecting the position of the droplet are generally performed in a time-sharing manner. In this embodiment, when the detection signal is loaded to the first sensing electrode 12 and the second sensing electrode 13, the first sensing electrode 12 can form a third capacitor C3 with the scanning signal line 15 (in other embodiments, it can also be other signal lines or electrodes, which are not limited in the embodiment of the present invention), and the second sensing electrode 13 and the data signal line 16 (in other embodiments, it can also be other signal lines or electrodes, which are not limited in the embodiment of the present invention) form a fourth capacitor C4. When the droplet flows through, the distribution of the induced charge in the droplet changes due to the influence of the sensing electrode, thereby causing the capacitance between the first sensing electrode 12 and the scanning signal line 15 to become C3', and the capacitance between the second sensing electrode 13 and the data signal line 16 to become C4', thereby determining the position of the droplet according to the change in capacitance. The principle and embodiment of the common electrode are not shown below. Figure 7 similar.

[0058] Figure 8 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention is shown in FIG. Figure 8 Optionally, the first sensing electrodes 12 are disposed on the same layer as the scanning signal lines 15 , and the second sensing electrodes 13 are disposed on the same layer as the data signal lines 16 .

[0059] Since the extension direction of the first sensing electrode 12 is the same as that of the scanning signal line 15, and the extension direction of the second sensing electrode 13 is the same as that of the data signal line 16, in order to reduce the film layer of the microfluidic chip, the first sensing electrode 12 and the scanning signal line 15 can be arranged in the same layer, and the second sensing electrode 13 and the data signal line 16 can be arranged in the same layer. During preparation, the first sensing electrode 12 and the scanning signal line 15 can be formed at one time using the same process, and the second sensing electrode 13 and the data signal line 16 can be formed at one time using the same process, thereby reducing the thickness and preparation cost of the microfluidic chip.

[0060] Optionally, the first sensing electrode or the second sensing electrode is disposed in the same layer as the driving electrode. Fig. 9 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention, wherein the cross-sectional line is parallel to the column direction of the driving electrode array, Fig. 9 , the first sensing electrodes 12 are in the same layer as the driving electrodes 11, that is, the first sensing electrodes 12 are arranged in the gap between two adjacent rows of driving electrodes 11; Fig.10 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention, wherein the cross section is parallel to the row direction of the driving electrode array, with reference to Fig.10The second sensing electrode 13 is in the same layer as the driving electrode 11, that is, the second sensing electrode 13 is arranged in the gap between two adjacent columns of driving electrodes 11. In a specific implementation, the sensing electrode arranged in the same layer as the driving electrode and the driving electrode are optionally formed of the same material. Fig. 9 In the embodiment shown, the first sensing electrode 12 and the driving electrode 11 are made of the same material. Fig.10 In the embodiment shown, the second sensing electrode 13 and the driving electrode 11 are made of the same material, for example, the material of the driving electrode 11 may be ITO, which may be selected according to actual conditions during implementation. In other embodiments, the first sensing electrode and the second sensing electrode may be arranged in the same layer as the driving electrode, and a bridge may be arranged at the intersection of the first sensing electrode and the second sensing electrode to prevent a short circuit between the first sensing electrode and the second sensing electrode, which is similar to the structure of a touch electrode in a display panel.

[0061] In another embodiment, for example, when the number of driving electrodes of the microfluidic chip is small and the structure is relatively simple, a passive driving method can be adopted, that is, no transistor is provided. Optionally, the microfluidic chip provided in this embodiment further includes a plurality of data signal lines extending along the first direction or the second direction, and each data signal line is connected to a corresponding driving electrode.

[0062] For example, taking the case where the data signal line extends along the first direction, Fig.11 A schematic diagram of another microfluidic chip provided in an embodiment of the present invention, referring to Fig.11 The microfluidic chip further includes a plurality of data signal lines 16 extending along the first direction x, each data signal line 16 is connected to a corresponding driving electrode 11. In specific implementation, the electrical connection can be achieved by providing a via hole in the film layer between the data signal line 16 and the driving electrode 11. In other embodiments, the data signal line can also extend along the second direction, and its structure is similar to Fig.11 Similarly, the difference is that when the data signal line extends along the second direction, the data signal line extends along the column direction of the driving electrode array.

[0063] Fig.12 For along Fig.11 A schematic diagram of a cross-section structure of the middle section line BB', reference Fig.12 Optionally, the data signal line 16 is located on a side of the driving electrode 11 away from the second substrate 20; the data signal line 16 is insulated and overlapped with the driving electrode 11'.

[0064] It can be understood that the data signal line 16 is electrically connected to the corresponding driving electrode 11, and is insulated and overlapped with other driving electrodes 11' in the same row. This arrangement can prevent the data signal line 16 from occupying the gap between the driving electrodes 11, and reduce the influence of the parasitic capacitance generated by the data signal line 16 on the signal of the first sensing electrode 12 or the second sensing electrode 13.

[0065] Continue to refer Fig.11 and Fig.12 Optionally, the data signal line 16 extends along the first direction x, the first sensing electrode 12 is arranged on the same layer as the data signal line 16, and the second sensing electrode 13 is arranged on the same layer as the driving electrode 11. Optionally, the sensing electrode arranged on the same layer as the driving electrode and the driving electrode are formed of the same material. In specific implementation, the first sensing electrode 12 and the data signal line 16 can be formed at one time using the same process and material, and the second sensing electrode 13 and the driving electrode 11 can be formed at one time using the same process and material; or in another embodiment, the data signal line extends along the second direction, the second sensing electrode and the data signal line are arranged on the same layer, the first sensing electrode and the driving electrode are arranged on the same layer, and the second sensing electrode and the data signal line are formed at one time using the same process and material. The implementation method is the same as Fig.11 and Fig.12 Similar, no further details will be given here.

[0066] Optionally, the first sensing electrode extends in a curved shape along the first direction, and / or the second sensing electrode extends in a curved shape along the second direction.

[0067] For example, Fig.13 A schematic diagram of a local structure of a microfluidic chip provided in an embodiment of the present invention, referring to Fig.13 In this embodiment, the first sensing electrode 12 extends in a curved shape along the first direction x, and the second sensing electrode 13 extends in a curved shape along the second direction y. This arrangement is conducive to increasing the area of ​​the sensing capacitor formed by the first sensing electrode 12 and the second sensing electrode 13, thereby increasing the signal strength. Accordingly, the edge of the driving electrode 11 needs to match the shape of the sensing electrode. It can be understood that Fig.13 In the embodiment, the width of the first sensing electrode 12 and the second sensing electrode 13 is the same as the gap width of the driving electrode 11, so their boundaries overlap. In other embodiments, the width of the first sensing electrode 12 and the second sensing electrode 13 may be smaller than the gap of the driving electrode 11, or may be larger than the gap of the driving electrode 11. In a specific implementation, it is necessary to make partial areas of the first sensing electrode 12 and the second sensing electrode 13 located in the gap of the driving electrode 11 to ensure the signal strength when detecting the position of the droplet.

[0068] Optionally, the curved shape includes a sawtooth shape or a wave shape.

[0069] Continue to refer Fig.13 The first sensing electrode 12 and the second sensing electrode 13 both extend in a wave shape. In other embodiments, the shape of the sensing electrode may also be a sawtooth shape. For example, Fig.14 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, referring to Fig.14The first sensing electrode 12 and the second sensing electrode 13 both extend in a sawtooth shape. In other embodiments, the first sensing electrode 12 and the second sensing electrode 13 may also be designed to be other curved shapes, which is not limited in the embodiment of the present invention.

[0070] It should be noted that Fig.13 and Fig.14 The curved shapes of the first sensing electrode 12 and the second sensing electrode 13 are shown in the figure for exemplary purposes only. In other embodiments, only the first sensing electrode or the second sensing electrode may be curved, and the edge shape of the corresponding driving electrode corresponds to the edge shape of the sensing electrode. The design may be based on actual conditions during implementation.

[0071] Optional, continue to refer to Fig.13 or Fig.14 , the edge of the driving electrode 11 has the same shape as the edge of the adjacent first sensing electrode 12 or second sensing electrode 13 near the driving electrode, that is, the edge shape of the driving electrode 11 and the adjacent first sensing electrode 12 or second sensing electrode 13 mesh with each other. The projection of the first sensing electrode 12 on the plane where the first substrate is located is between the projection of the gap between two adjacent rows of driving electrodes 11 on the plane where the first substrate is located, that is, the first sensing electrode 12 is located in the gap between two adjacent rows of driving electrodes 11, and the two can be in the same layer or in different layers, and the projection of the second sensing electrode 13 on the plane where the first substrate is located is between the projection of the gap between two adjacent columns of driving electrodes 11 on the plane where the first substrate is located, that is, the second sensing electrode 13 is located in the gap between two adjacent columns of driving electrodes 11, and the two can be in the same layer or in different layers. Fig.13 and Fig.14 What is shown are all schematic top views of the microfluidic chip, and the structure of the first substrate is not shown.

[0072] Since an electric field needs to be formed between adjacent driving electrodes 11 in this embodiment to drive the droplets to move, the edges of the driving electrodes 11 are also designed to be curved, which can increase the overlapping length between adjacent driving electrodes 11 and effectively increase the facing area between adjacent driving electrodes 11, thereby increasing the electric field strength formed between the two driving electrodes 11, which is more conducive to driving the movement of the droplets.

[0073] Fig.15 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, optionally, refer to Fig.15 The microfluidic chip provided in this embodiment further includes a plurality of scanning signal lines 15, a plurality of data signal lines 16, first electrodes 18 corresponding to the driving electrodes 11 one by one, and transistors 17 corresponding to the driving electrodes 11 one by one. Fig.15What is shown in the figure is a circuit schematic diagram of the transistor 17, and the specific structure of the transistor 17 is not shown). The gate of each transistor 17 is connected to a scanning signal line 15, the first electrode is connected to a data signal line 16, and the second electrode is connected to the corresponding driving electrode 11 through a through hole. The first electrode 18 and the driving electrode 11 form a storage capacitor; the scanning signal line 15, the data signal line 16, the first electrode 18 and the transistor 17 are located in the projection of the driving electrode 11 on the plane where the first substrate is located, and the edges of the scanning signal line 15, the data signal line 16 and the driving electrode 11 bypass the edge of the transistor 17.

[0074] It is understandable that when the driving voltage is applied to the driving electrode 11, it is often necessary to maintain it for a certain period of time. In order to maintain the voltage stability of the driving electrode 11, the first electrode 18 and the driving electrode 11 may be provided to form a storage capacitor. Since the first sensing electrode 12 and the second sensing electrode 13 are located in the gap between the driving electrode 11, the scanning signal line 15, the data signal line 16, the first electrode 18 and the transistor 17 are designed to be located below the driving electrode 11. The scanning signal line 15, the area of ​​the data signal line 16 close to the transistor 17, and the edges of the first sensing electrode 12 and the second sensing electrode 13 all bypass the area where the transistor 17 is located to leave enough space for setting the transistor 17. The specific routing method may be designed according to actual conditions.

[0075] Fig.15 In the structure shown, each first electrode 18 is a discrete electrode. Since the function of the first electrode 18 is to form a storage capacitor with the driving electrode 11, in other embodiments, multiple first electrodes 18 can be electrically connected and loaded with the same voltage signal. Optionally, at least two adjacent first electrodes are electrically connected, and the connecting portion of the two first electrodes electrically connected to each other includes a hollow area, and the hollow area overlaps with the first sensing electrode and / or the second sensing electrode.

[0076] For example, Fig.16 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, referring to Fig.16 Two adjacent first electrodes 18 are electrically connected through a connecting wire 191 of an inter-electrode connecting portion 19 . The connecting portion 19 includes a hollow region 192 . The hollow region 192 overlaps with the first sensing electrode 12 or the second sensing electrode 13 .

[0077] It is understandable that by setting at least two first electrodes 18 to be electrically connected, multiple first electrodes 18 can be loaded with signals at the same time, reducing wiring difficulty and driving cost. By setting a hollow area 192 in the connecting portion 19, the signal interference of the connecting portion 19 on the sensing electrode can be reduced, thereby improving detection accuracy. Fig.16The arrangement of four connecting wires 192 and three hollow areas 192 between the two first electrodes 18 shown in the figure is only for illustration, and the number of connecting wires and hollow areas is not limited in specific implementation.

[0078] Fig.16 In the embodiment shown, the first electrode 18 and the first sensing electrode 12 and the second sensing electrode 13 are all arranged in different layers, for example, corresponding to Figure 6 In the structure, in other embodiments, in order to reduce the number of film layers, optionally, the first sensing electrode is arranged in the same layer as the scanning signal line, and the second sensing electrode is arranged in the same layer as the data signal line; exemplarily, Fig.17 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, referring to Fig.17 The first electrode 18 and the first sensing electrode 12 are disposed in the same layer, and the connecting trace 191 of the connecting portions 19 of the two first electrodes 18 electrically connected to each other extends along the first direction x. Fig.18 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, referring to Fig.18 The first electrode 18 and the second sensing electrode 13 are arranged in the same layer, and the connecting wire 191 of the connecting portion 19 of the two first electrodes 18 electrically connected to each other extends along the second direction y. Fig.17 and Fig.18 All show a top view of the microfluidic chip, with the same filling indicating the same layer setting, e.g. Fig.17 The first electrode 18 and the first sensing electrode 12 are filled with the same shape.

[0079] Optionally, the first sensing electrode and the second sensing electrode both include a first region and a second region, and the first region of the first sensing electrode and the first region of the second sensing electrode are insulated and overlapped; a width of the first region of the first sensing electrode is smaller than a width of the second region of the first sensing electrode, and / or a width of the first region of the second sensing electrode is smaller than a width of the second region of the second sensing electrode.

[0080] For example, Fig.19 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, referring to Fig.19 First sensing electrode 12 includes first region 121 and second region 122, second sensing electrode 13 includes first region 131 and second region 132, first region 121 of first sensing electrode 12 and first region 131 of second sensing electrode 13 intersect, and by setting width d5 ​​of first region 121 of first sensing electrode 12 to be smaller than width d6 of second region 122, and width d7 of first region 131 of second sensing electrode 13 to be smaller than width d8 of second region 132, the overlapping area of ​​the two sensing electrodes can be reduced, thereby reducing parasitic capacitance.

[0081] When the first sensing electrode 12 and the second sensing electrode 13 extend in a curved shape, the width of the crossing region may also be designed to be narrower, which may be designed according to actual conditions during implementation.

[0082] In other embodiments, only the first sensing electrode or the second sensing electrode may be designed to have a narrow line width at the intersection, so as to reduce the parasitic capacitance.

[0083] In some embodiments, for example, in a microfluidic chip with a small number of driving electrodes, a simple structure, and only one droplet, in order to simplify the circuit structure, detection signals can be loaded to all first sensing electrodes and second sensing electrodes at the same time, and the position of the droplet is determined based on the change in capacitance. However, when there are two or more droplets, in order to avoid the generation of ghost points, a scanning method can be used to load signals to the sensing electrodes in one direction. Optionally, detection signals can be loaded to the first sensing electrodes in turn along the second direction in a time-sharing manner, or detection signals can be loaded to the second sensing electrodes in turn along the first direction in a time-sharing manner, and the position of the droplet is determined based on the change in capacitance formed between the first sensing electrode and a certain electrode and the change in capacitance formed between the second sensing electrode and a certain electrode when the droplet flows over.

[0084] Since the first sensing electrode and the second sensing electrode are cross-arranged, a capacitor can be formed at their intersection, so the position of the droplet can be determined by using the change in capacitance formed between the first sensing electrode and the second sensing electrode. In a certain embodiment, optionally, one of the first sensing electrode and the second sensing electrode is a transmitting electrode and the other is a receiving electrode, and the position of the droplet is determined according to the change in capacitance between the first sensing electrode and the second sensing electrode when the droplet flows past.

[0085] In another embodiment, the position of the droplet can be determined according to the capacitance change formed by the sensing electrode and the common electrode located on the second substrate. Optionally, the common electrode includes a plurality of branch electrodes extending along the first direction or the second direction, and the number of the branch electrodes is the same as the number of the first sensing electrodes or the second sensing electrodes.

[0086] For example, Fig. 20 A schematic top view of a common electrode in a microfluidic chip provided in an embodiment of the present invention, Fig.21 A schematic cross-sectional structure diagram of another microfluidic chip provided in an embodiment of the present invention, Fig. 20 and Fig.21 Taking the example that the common electrode includes a plurality of branch electrodes extending along the first direction, Fig.21 What is shown is a schematic diagram of a cross-sectional structure along a section line parallel to the second direction. In this embodiment, the branch electrode can also be driven separately to form a capacitor in cooperation with the first sensing electrode or the second sensing electrode to realize the positioning of the droplet.

[0087] In a microfluidic chip, the size of the driving electrode is generally in the order of millimeters, and the spacing between the driving electrodes can be tens of microns. Optionally, along the first direction, the distance between two adjacent driving electrodes is 10μm to 40μm; along the second direction, the distance between two adjacent driving electrodes is 10μm to 40μm, which can ensure that the area of ​​the first sensing electrode and the second sensing electrode is large, and the signal strength when detecting the position of the droplet can be ensured. In other embodiments, optionally, the first substrate and the second substrate are both provided with an insulating hydrophobic layer on one side adjacent to the microfluidic channel to play a role in insulation and reducing the resistance to the movement of the droplet.

[0088] An embodiment of the present invention also provides a microfluidic chip, comprising a first substrate and a second substrate arranged opposite to each other, a microfluidic channel formed between the first substrate and the second substrate, the microfluidic channel being used to accommodate at least one droplet; a plurality of driving electrodes located on one side of the first substrate, the driving electrodes being arranged in an array, adjacent driving electrodes being loaded with different driving voltage signals to drive the droplet to move; at least one edge of the driving electrode extending in a curved shape.

[0089] For example, Fig. 22 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, Fig.23 For along Fig. 22 A schematic diagram of a cross-section structure of the center section line CC', reference Fig. 22 The microfluidic chip includes a plurality of driving electrodes 11 arranged in an array, and adjacent driving electrodes 11 are loaded with different driving voltages. The droplets are driven by the differential voltage between the adjacent driving electrodes 11, and the droplets are controlled to move along a preset path. The edge of the driving electrode 11 extends in a curved shape, wherein Fig. 22 The wave shape shown in the figure is only for reference. In practice, it can be a sawtooth shape or other curved shape. Fig.23 The microfluidic chip includes a first substrate 10 and a second substrate 20 arranged opposite to each other, and a microfluidic channel 30 is formed between the first substrate 10 and the second substrate 20, and the microfluidic channel 30 is used to accommodate at least one droplet 31. In other embodiments, a common electrode can be set on the second substrate 20, and structures such as scanning signal lines, data signal lines and transistors can be included. A first sensing electrode and a second sensing electrode can be set in the gap of the driving electrode to obtain the position of the droplet. The specific implementation can be designed according to actual needs.

[0090] An embodiment of the present invention also provides a microfluidic chip, comprising a first substrate and a second substrate arranged opposite to each other, a microfluidic channel formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet; a plurality of driving electrodes are located on one side of the first substrate, the driving electrodes are arranged in an array, and adjacent driving electrodes are loaded with different driving voltage signals to drive the droplet to move; it also includes a plurality of scanning signal lines extending along a first direction, a plurality of data signal lines extending along a second direction, and transistors corresponding to the driving electrodes one by one, the gate of each transistor is connected to a scanning signal line, the first electrode is connected to a data signal line, and the second electrode is connected to the corresponding driving electrode; the scanning signal line, the data signal line and the transistor are all located on the side of the driving electrode away from the second substrate; at least one of the scanning signal line, the data signal line and the transistor overlaps with the driving electrode.

[0091] For example, Fig.24 A schematic diagram of a partial structure of another microfluidic chip provided in an embodiment of the present invention, Fig.25 for Fig.24 A cross-sectional structural diagram of Fig.24 The microfluidic chip includes a plurality of drive electrodes 11 arranged in an array, and adjacent drive electrodes 11 are loaded with different drive voltages. The droplets are driven by the differential voltage between the adjacent drive electrodes 11, and the droplets are controlled to move along a preset path; it also includes a plurality of scanning signal lines 15 extending along a first direction x, a plurality of data signal lines 16 extending along a second direction y, and transistors 17 corresponding to the drive electrodes 11 one by one, and the gate of each transistor 17 is connected to a scanning signal line 15, the first electrode is connected to a data signal line 16, and the second electrode is connected to the corresponding drive electrode 11; refer to Fig.25 , the transistor 17 includes a gate 171, an active layer 172, a source 173 (first electrode) and a drain 174 (second electrode), the scanning signal line 15, the data signal line 16 and the transistor 17 are all located on the side of the driving electrode 11 away from the second substrate 20; the scanning signal line 15 and / or the data signal line 16 are not routed between the gaps of the driving electrode 11 as much as possible, and are all located below the driving electrode 11. Correspondingly, the transistor 17 is also arranged below the driving electrode 11, not in the gap, so that the driving electrode 11 can shield the parasitic capacitance caused by the scanning signal line 15, the data signal line 16 or the transistor 17, improve the droplet driving accuracy and speed, and avoid the electric field generated between the scanning signal line 15 / data signal line 16 and the driving electrode to form a reaction force on the droplet movement. In other embodiments, at least one of the scanning signal line, the data signal line and the transistor overlaps the driving electrode and extends in a curved shape at the edge of the driving electrode 11, similar to Fig. 22In other embodiments, a first sensing electrode and a second sensing electrode may be provided in the gap between the driving electrodes to obtain the position of the droplet, and in combination with the embodiment having the droplet positioning function, the structure of the microfluidic chip provided in the above embodiment may be specifically referred to.

[0092] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments, combinations and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A microfluidic chip, characterized in that: It comprises a first substrate and a second substrate arranged opposite to each other, wherein a microfluidic channel is formed between the first substrate and the second substrate, and the microfluidic channel is used to accommodate at least one droplet; a plurality of driving electrodes, a plurality of first sensing electrodes, and a plurality of second sensing electrodes located on one side of the first substrate, the driving electrodes being arranged in an array, the first sensing electrodes extending along a first direction and being arranged along a second direction, the second sensing electrodes extending along the second direction and being arranged along the first direction, the first direction being parallel to a row direction of the array formed by the driving electrodes, the second direction being parallel to a column direction of the array formed by the driving electrodes, the projection of the first sensing electrodes on the plane where the first substrate is located at least partially overlaps with the projection of the gaps between the driving electrodes in two adjacent rows on the plane where the first substrate is located, and the projection of the second sensing electrodes on the plane where the first substrate is located at least partially overlaps with the projection of the gaps between the driving electrodes in two adjacent columns on the plane where the first substrate is located; Different driving voltage signals are loaded on adjacent driving electrodes, and the droplets are driven by the differential voltage between the adjacent driving electrodes, so as to control the droplets to move along a preset path; The first sensing electrode and the second sensing electrode are loaded with detection signals, and the position of the droplet is determined according to the capacitance change formed between the first sensing electrode and a certain electrode and the capacitance change formed between the second sensing electrode and a certain electrode when the droplet flows over; wherein the certain electrode is one of a common electrode arranged on the second substrate, a certain wiring in the first substrate, or a certain pole of other capacitors; A plurality of scanning signal lines extending along the first direction, a plurality of data signal lines extending along the second direction and transistors corresponding to the driving electrodes one by one, the gate of each transistor being connected to one of the scanning signal lines, the first electrode of the transistor being connected to one of the data signal lines, and the second electrode of the transistor being connected to the corresponding driving electrode; the scanning signal lines, the data signal lines and the transistors are all located on the side of the driving electrode away from the second substrate; the scanning signal lines and / or the data signal lines are not routed between the gaps of the driving electrodes, but are all located below the driving electrodes, and the transistors are arranged below the driving electrodes, but not in the gaps of the driving electrodes.

2. The microfluidic chip according to claim 1, characterized in that: At least one of the scan signal line, the data signal line, and the transistor overlaps the driving electrode.

3. The microfluidic chip according to claim 1, characterized in that: The first sensing electrodes are disposed in the same layer as the scanning signal lines, and the second sensing electrodes are disposed in the same layer as the data signal lines.

4. The microfluidic chip according to claim 1, characterized in that: The first sensing electrodes or the second sensing electrodes are arranged in the same layer as the driving electrodes.

5. The microfluidic chip according to claim 1, characterized in that: It also includes a plurality of data signal lines extending along the first direction or the second direction, and each of the data signal lines is connected to a corresponding driving electrode.

6. The microfluidic chip according to claim 5, characterized in that: The data signal line is located at a side of the driving electrode away from the second substrate; The data signal line is insulated and overlapped with the driving electrode.

7. The microfluidic chip according to claim 5, characterized in that: The data signal line extends along the first direction, the first sensing electrode and the data signal line are arranged in the same layer, and the second sensing electrode and the driving electrode are arranged in the same layer; or The data signal line extends along the second direction, the second sensing electrode and the data signal line are arranged in the same layer, and the first sensing electrode and the driving electrode are arranged in the same layer.

8. The microfluidic chip according to claim 4 or 7, characterized in that: The sensing electrodes disposed on the same layer as the driving electrodes are formed of the same material as the driving electrodes.

9. The microfluidic chip according to claim 1, characterized in that: The first sensing electrode extends in a bent shape along the first direction, and / or the second sensing electrode extends in a bent shape along the second direction.

10. The microfluidic chip according to claim 9, characterized in that: The curved shape includes a sawtooth shape or a wave shape.

11. The microfluidic chip according to claim 9, characterized in that: The edge of the driving electrode has the same shape as the edge of the adjacent first sensing electrode or the second sensing electrode close to the driving electrode; the projection of the first sensing electrode on the plane where the first substrate is located is between the projections of the gaps between two adjacent rows of the driving electrodes on the plane where the first substrate is located; and the projection of the second sensing electrode on the plane where the first substrate is located is between the projections of the gaps between two adjacent columns of the driving electrodes on the plane where the first substrate is located.

12. The microfluidic chip according to claim 11, characterized in that: It also includes a first electrode corresponding to the driving electrodes one by one, the second electrode of the transistor is connected to the corresponding driving electrode through a through hole, and the first electrode and the driving electrode form a storage capacitor; The scan signal line, the data signal line, the first electrode and the transistor are located within the projection of the drive electrode on the plane where the first substrate is located, and the edges of the scan signal line, the data signal line and the drive electrode bypass the edge of the transistor.

13. The microfluidic chip according to claim 12, characterized in that: At least two adjacent first electrodes are electrically connected, and a connecting portion of the two first electrodes electrically connected to each other comprises a hollow area, and the hollow area overlaps with the first sensing electrode and / or the second sensing electrode.

14. The microfluidic chip according to claim 13, characterized in that: The first sensing electrode is disposed in the same layer as the scanning signal line, and the second sensing electrode is disposed in the same layer as the data signal line; The first electrode and the first sensing electrode are arranged in the same layer, and a connection line of the connection parts of the two first electrodes electrically connected to each other extends along the first direction; or the first electrode and the second sensing electrode are arranged in the same layer, and a connection line of the connection parts of the two first electrodes electrically connected to each other extends along the second direction.

15. The microfluidic chip according to claim 1, characterized in that: The first sensing electrode and the second sensing electrode each include a first region and a second region, and the first region of the first sensing electrode and the first region of the second sensing electrode are insulated and overlapped; The width of the first region of the first sensing electrode is smaller than the width of the second region of the first sensing electrode, and / or the width of the first region of the second sensing electrode is smaller than the width of the second region of the second sensing electrode.

16. The microfluidic chip according to claim 1, characterized in that: The detection signals are sequentially applied to the first sensing electrodes along the second direction in a time-sharing manner, or the detection signals are sequentially applied to the second sensing electrodes along the first direction in a time-sharing manner.

17. The microfluidic chip according to claim 1, characterized in that: One of the first sensing electrode and the second sensing electrode is a transmitting electrode, and the other is a receiving electrode. The position of the droplet is determined according to a change in capacitance between the first sensing electrode and the second sensing electrode when the droplet flows past.

18. The microfluidic chip according to claim 1, characterized in that: The common electrode is located at one side of the second substrate.

19. The microfluidic chip according to claim 18, characterized in that: The common electrode includes a plurality of branch electrodes extending along a first direction or a second direction, and the number of the branch electrodes is the same as the number of the first sensing electrodes or the second sensing electrodes.

20. The microfluidic chip according to claim 1, characterized in that: Along the first direction, the distance between two adjacent driving electrodes is 10 μm to 40 μm; Along the second direction, a distance between two adjacent driving electrodes is 10 μm to 40 μm.

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