Microfluidic Chip

Abstract

The present invention provides a microfluidic chip, which belongs to the field of biological detection technology. The microfluidic chip is divided into a central region having a liquid storage zone and a detection zone, and a peripheral region, and comprises first and second substrates, the first substrate including a first base and a first electrode layer, and the second substrate including a second base and a second electrode layer. A liquid storage tank located in the liquid storage zone and a liquid inlet hole are formed on the first base side of the second substrate. The liquid storage tank has a first side edge that is parallel to a cross section of the liquid storage zone facing the detection zone along the thickness direction of the first substrate and approaches the detection zone. The first side edge has first and second endpoints, the first endpoint being farther from the second substrate than the second endpoint. A line connecting these endpoints extends in an inclined direction to the axial direction of the liquid inlet hole, and the distance from the first endpoint to the axis of the liquid inlet hole is shorter than the distance from the second endpoint to the axis of the liquid inlet hole.

Description

[Technical Field]

[0001] The present invention is in the field of biodetection technology, and more particularly relates to microfluidic chips. [Background technology]

[0002] Microfluidic control technology can realize precise control and manipulation of microdroplets. Digital microfluidic control based on dielectric wetting technology is driven by electrical signals and has advantages such as strong driving force, simple operation, simple chip structure, and high degree of automation, making it an important component of lab-on-a-chip systems.

[0003] Digital microfluidics (DMF) utilizes the principle of electrowetting of droplets on a hydrophobic surface. By applying a control signal to an electrode array, the contact angle of the droplets can be changed, allowing for precise control of the droplets. Compared to traditional channel-based microfluidic chips, digital microfluidic chips are powered by electrical signals and do not require micropumps, microvalves, or other moving parts. This simplifies the chip structure and control, eliminates complex microchannels, and enables the timing control of droplet movement paths, allowing for the parallel manipulation of multiple droplets to improve throughput. Furthermore, it consumes less reagents. Due to their significant advantages in analytical scale, response speed, and high throughput, digital microfluidic chips have been widely studied and applied in fields such as biology, chemistry, and medicine. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a microfluidic chip that solves at least one of the technical problems existing in the prior art. [Means for solving the problem]

[0005] An embodiment of the present disclosure provides a microfluidic chip comprising a first substrate and a second substrate disposed opposite each other, the first substrate being divided into an intermediate region having a liquid storage zone and a detection zone, and a peripheral region surrounding the intermediate region, the first substrate including a first base, a first electrode layer disposed on one side of the first base facing the second substrate, and a first lyophobic layer, the second substrate including a second base, a second electrode layer disposed on one side of the second base facing the first substrate, and a second lyophobic layer, a liquid storage tank and a liquid inlet hole penetrating a bottom surface of the liquid storage tank are formed on one side of the first base facing the second substrate, the liquid storage tank and the liquid inlet hole both being located in the liquid storage zone; a microfluidic chip is provided in which the liquid storage tank has a first side edge that approaches the detection zone along a thickness direction of the first substrate and is parallel to a cross section of the liquid storage zone in a direction facing the detection zone, the first side edge has a first endpoint and a second endpoint, the first endpoint is farther from the second substrate than the second endpoint, an extension direction of a line connecting the first endpoint and the second endpoint is inclined with respect to an axial direction of the liquid inlet hole, and the distance from the first endpoint to an axis line of the liquid inlet hole is shorter than the distance from the second endpoint to the axis line of the liquid inlet hole;

[0006] The first side is a straight side.

[0007] The angle formed by the direction of extension of the line connecting the first end point and the second end point and the axial direction of the liquid inlet hole is θ, and the value that θ can take is 30° to 60°.

[0008] an interlayer dielectric layer is provided on a layer of the second electrode layer away from the second base, and an included angle formed by an extension direction of a line connecting the first end point and the second end point and an axial direction of the liquid inlet hole is θ; tanθ>2d(FG) / ε0·ε r ·V 2 where ε0 represents the vacuum permittivity and ε r represents the relative permittivity of the interlayer dielectric layer, d is the thickness of the interlayer dielectric layer, F represents the support force that the interlayer dielectric layer provides to the droplet to be detected, G represents the gravity of the droplet to be detected, and V represents the voltage value applied by the second electrode layer.

[0009] Wherein, the liquid inlet hole includes a first port and a second port, and the liquid inlet hole communicates with the liquid storage tank through the first port, and the orthogonal projection of the first port on the second base and the orthogonal projection of the second electrode layer on the second base at least partially overlap.

[0010] wherein an orthogonal projection of an edge of the second electrode layer on the second base passes through a center of an orthogonal projection of the first port on the second base; or An orthogonal projection of an edge of the second electrode layer on the second base and an orthogonal projection of an edge of the first port on the second base contact each other.

[0011] The liquid inlet includes a first port and a second port arranged opposite each other, and the liquid inlet communicates with the liquid storage tank through the first port, and the orthogonal projection of the second port on the second base covers the orthogonal projection of the first port on the second base.

[0012] The liquid inlet hole further includes a liquid inlet pillar arranged coaxially with the liquid inlet hole, the liquid inlet hole including a first port and a second port arranged opposite to each other, and the liquid inlet hole communicates with the liquid storage tank through the first port, the liquid inlet pillar including a third port and a fourth port arranged opposite to each other, and the third port of the liquid inlet pillar is connected to the second port of the liquid inlet hole.

[0013] The liquid inlet hole further includes a liquid inlet pillar arranged coaxially with the liquid inlet hole, the liquid inlet hole including a first port and a second port arranged opposite each other, and the liquid inlet hole communicates with the liquid storage tank through the first port, the liquid inlet pillar including a third port and a fourth port arranged opposite each other, and the orthogonal projection of the third port of the liquid inlet pillar on the second base is located within the orthogonal projection of the fourth port on the second base.

[0014] The first and second liquid inlet ports have the same diameter.

[0015] Between the first substrate and the second substrate, a sealant is provided, the sealant being located in the peripheral region and surrounding the intermediate region.

[0016] A first receiving groove is formed on one side of the first base that is close to the second substrate, and the sealant is formed in the first receiving groove.

[0017] Among these, a conductive member is provided between the first substrate and the second substrate, located in the peripheral region, for electrically connecting the first electrode layer to the connection pad on the second substrate.

[0018] A second receiving groove is formed on one side of the first base that is close to the second substrate, and the conductive member is disposed in the second receiving groove.

[0019] Between the first and second substrates, a support structure is provided to maintain the box thickness between the first and second substrates.

[0020] An exhaust port is provided on the first base, penetrating the first base along the thickness direction.

[0021] A first lyophobic layer is provided on one side of the first electrode layer that is close to the second substrate, and a second lyophobic layer is provided on one side of the second electrode layer that is close to the second substrate. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a plan view of a microfluidic chip according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a cross-sectional view of a microfluidic chip according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a cross-sectional view of another microfluidic chip according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a cross-sectional view of another microfluidic chip according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a plan view of another microfluidic chip according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is a cross-sectional view of another microfluidic chip according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is a diagram showing the positional relationship between the second electrode layer and the liquid inlet hole in the microfluidic chip according to the embodiment of the present disclosure. [Figure 8] FIG. 8 is a diagram showing the positional relationship between the second electrode layer and the liquid inlet holes in another microfluidic chip according to an embodiment of the present disclosure. [Figure 9] FIG. 9 is a diagram illustrating the positional relationship between the second electrode layer and the liquid inlet holes in another microfluidic chip according to an embodiment of the present disclosure. [Figure 10] FIG. 10 is a schematic diagram illustrating a microfluidic chip according to an embodiment of the present disclosure splitting a droplet. [Figure 11] FIG. 11 is a schematic diagram illustrating a microfluidic chip according to an embodiment of the present disclosure splitting a droplet. [Figure 12] FIG. 12 is a schematic diagram illustrating a microfluidic chip according to an embodiment of the present disclosure splitting a droplet. [Figure 13] FIG. 13 is a schematic diagram illustrating a microfluidic chip according to an embodiment of the present disclosure splitting a droplet. [Figure 14] FIG. 14 is a schematic diagram illustrating a microfluidic chip according to an embodiment of the present disclosure splitting a droplet. [Figure 15] FIG. 15 is a schematic diagram illustrating a microfluidic chip according to an embodiment of the present disclosure splitting a droplet. DETAILED DESCRIPTION OF THE INVENTION

[0023] In order for those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below in combination with drawings and specific embodiments.

[0024] Unless otherwise defined, technical or scientific terms used in this disclosure should have the ordinary meaning that can be understood by those skilled in the art. As used in this disclosure, the terms "first," "second," and similar terms do not denote any order, quantity, or importance, but are used only to distinguish between different components. Similarly, similar terms such as "one," "one," or "the" do not denote a limitation of quantity, but rather denote the presence of at least one. Similar terms such as "comprise" or "include" mean that the element or component before the term encompasses the element or component after the term and its equivalents, without excluding other elements or components. Terms such as "connected" or "communicating" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "top," "bottom," "left," "right," and the like are used only to indicate relative positions, and the relative positions may change accordingly after the absolute positions of the objects being described are changed.

[0025] Fig. 1 is a plan view of a microfluidic chip according to an embodiment of the present disclosure, and Fig. 2 is a schematic diagram of a microfluidic chip according to an embodiment of the present disclosure. As shown in Figs. 1 and 2, an embodiment of the present disclosure provides a microfluidic chip that is divided into a middle region Q1 and a peripheral region Q2 surrounding the middle region Q1, the middle region Q1 includes a plurality of test units 10, and each test unit 10 includes a liquid storage zone Q11 and a detection zone Q12, where the plurality of test units 10 in the microfluidic chip may be arranged in an array, but is not limited to this. A microfluidic chip according to an embodiment of the present disclosure includes a first substrate and a second substrate arranged opposite each other, wherein the first substrate includes a first base 11, a first electrode layer 12 arranged on one side of the first base 11 facing the second substrate, and a first lyophobic layer, the first electrode layer 12 and the first lyophobic layer covering the intermediate region Q1 and the peripheral region Q2, and the second substrate includes a second base 21, a second electrode layer 22 arranged on one side of the second base 21 facing the first substrate, and a second lyophobic layer.

[0026] FIG. 2 is a cross-section of the microfluidic chip shown in FIG. 1 taken along its thickness direction and parallel to the direction of the liquid storage zone Q11 and the detection zone Q12. Referring to FIG. 2, the first base 11 includes a liquid storage tank 112 facing the second substrate and a liquid inlet 111 communicating with the liquid storage tank 112, both of which are located in the liquid storage zone Q11. As shown in FIG. 2, the cross-section of the liquid storage tank 112 has a first side L1, a second side L2, and a bottom L3, which are opposite each other. The first side L1 is closer to the detection zone Q12 than the second side L2, and is inclined relative to the bottom L3. Specifically, the first side L1 has a first end point and a second end point opposite each other, and the first end point is farther from the second substrate than the second end point. For example, the first endpoint is a node connecting the first side L1 and the bottom side, and the second endpoint is another endpoint of the first side. The distance from the first endpoint to the axis of the liquid inlet hole 111 is shorter than the distance from the second endpoint to the axis of the liquid inlet hole 111. In other words, the extension direction of the line connecting the first endpoint and the second endpoint of the first side L1 (the orientation of the first side L1) transitions at an angle from the liquid storage zone Q11 to the detection zone Q12.

[0027] 2, the orientation of the first side edge L1 of the cross section of the liquid storage tank 112 transitions from the liquid storage zone Q11 to the detection zone Q12, that is, the routing on one side of the side wall of the liquid storage tank 112 approaching the detection zone Q12 is inclined and not perpendicular to the bottom surface of the liquid storage tank 112. This reduces the movement resistance of the droplets as they move to the detection zone Q12 after the reaction liquid flows into the liquid storage zone Q11 through the liquid inlet hole 111.

[0028] In some examples, the angle formed by the direction of the first side edge L1 of the cross section of the liquid storage tank 112 shown in Figure 2 (i.e., the line connecting the first endpoint and the second endpoint) and the axial direction of the liquid inlet hole 111 is θ, which is 30° to 60°, preferably 45°. By rationally setting the side wall inclination angle of the liquid storage tank 112, the movement resistance of the droplets when they move can be effectively reduced.

[0029] In some examples, the microfluidic chip further includes an interlayer dielectric layer 23 provided on one side of the second electrode layer 22 away from the second base 21, and the included angle formed by the extension direction of a line connecting the first end point and the second end point of the first side edge L1 and the axial direction of the liquid inlet hole 111 is θ, and tan θ>2d(FG) / ε0·ε r ·V 2 Among them, ε0 represents the vacuum permittivity, and ε r where F is the dielectric constant of the interlayer dielectric layer, d is the thickness of the interlayer dielectric layer 23, F is the supporting force provided by the interlayer dielectric layer 23 to the droplet to be detected, G is the gravity of the droplet to be detected, and V is the voltage value applied by the second electrode layer. The interlayer dielectric layer may be a single film layer, such as a polyimide film layer. Of course, the interlayer dielectric layer may also be a composite film layer of a polyimide film layer and a lyophobic layer.

[0030] In some examples, the liquid storage tank 112 on the first base 11 may resemble a rectangular groove having four side walls and a bottom wall, or a cylindrical groove having only one side wall and a bottom wall. In this embodiment, the liquid storage tank 112 has four side walls and a bottom wall. For example, two side walls of the liquid storage zone Q11 facing each other in the direction toward the detection zone Q12 are designated as the first and second side walls, respectively, and another pair of side walls facing each other are designated as the third and fourth side walls. The dihedral angles between the second, third, and fourth side walls and the bottom wall are all 90° or approximately 90°. The dihedral angle between the first side wall and the bottom wall is an obtuse angle, preferably in the range of 120° to 150°. For example, the dihedral angle between the first side wall and the bottom wall is 135°. Note that the dihedral angles refer to the interior angles of the liquid storage tank 112. Of course, in the embodiments of the present disclosure, the second side wall, the third side wall, and the fourth side wall may all be inclined relative to the bottom wall, and in some embodiments, the dihedral angles between the second side wall, the third side wall, and the fourth side wall and the bottom wall may all be equal to the dihedral angle between the first side wall and the bottom wall.

[0031] 2, in some examples, the sidewall of the liquid storage tank 112 has a smooth surface, and the first side edge L1 of the cross section of the liquid storage tank 112 is a straight side edge. Of course, the surface of the sidewall of the liquid storage tank 112 does not have to be smoothly formed, for example, by having a step structure on the sidewall, as long as it is ensured that the orientation of the first side edge L1 of the cross section of the liquid storage tank 112 transitions from the liquid storage zone Q11 to the detection zone Q12.

[0032] In some examples, the depth of the liquid storage tank 112 is approximately 200 μm to 500 μm, and the volume is 5 μl to 1000 μl. By rationally designing the depth of the liquid storage tank 112, the amount of accumulated reaction liquid can be increased, the amount of reagent absorbed into the detection zone Q12 can be increased, and the number of manual sample injections can be effectively reduced.

[0033] In the embodiment of the present disclosure, the liquid inlet hole 111 penetrates the bottom wall of the liquid storage tank 112, and the liquid inlet hole 111 may be cylindrical, conical, or a combination of cylindrical and conical shapes. Of course, the shape of the liquid inlet hole 111 should be further adapted to the shape of the gun head of the reactant liquid so that the reactant liquid can be easily dripped into the liquid storage tank 112. The liquid inlet hole 111 in the embodiment of the present disclosure will be described in detail below.

[0034] In one example, as shown in FIG. 2, the microfluidic chip not only has the above-mentioned structure but also includes a liquid inlet column 100. As shown in FIG. 7, the liquid inlet hole 111 includes a first port 1111 and a second port 1112 arranged opposite each other, and the liquid inlet column 100 includes a third port 1001 and a fourth port 1002 arranged opposite each other. The liquid inlet hole 111 communicates with the liquid storage tank 112 through its first port 1111 and with the liquid inlet column 100 through its second port 1112, and the second port 1112 of the liquid inlet hole 111 and the third port 1001 of the liquid inlet column 100 share a port. For example, the liquid inlet hole 111 and the liquid inlet column 100 are integrally structured. The further integral structure of the liquid inlet hole 111 and the liquid inlet column 100 is compatible with a gun head for a reaction liquid. Specifically, the liquid inlet hole 111 fits into the drip end of the gun head, and the liquid inlet post 100 fits into the main body of the gun head. For example, the liquid inlet hole 111 is cylindrical, and the liquid inlet post 100 is inverted conical, i.e., the orthogonal projection of the fourth port 1002 of the liquid inlet hole 111 on the second base 21 covers the orthogonal projection of its third port 1001 on the second base 21. In some examples, the diameter of the liquid inlet hole 111 is approximately 0.9 mm to align with the drip end of the gun head. In some examples, the liquid inlet post 100 can be integral with the first base 11, for example, by forming the first base 11 and the liquid inlet post 100 by injection molding.

[0035] 3 is a cross-sectional view of another microfluidic chip according to an embodiment of the present disclosure. As shown in FIG. 3, the microfluidic chip further includes a liquid inlet column 100 including a third port 1001 and a fourth port 1002 disposed opposite each other, and a liquid inlet hole 111 including a first port 1111 and a second port 1112 disposed opposite each other. The liquid inlet hole 111 communicates with a liquid storage tank 112 via the first port 1111 and with the liquid inlet column 100 via the second port 1112. For example, the liquid inlet hole 111 and the liquid inlet column 100 are both cylindrical, and the hole diameter of the liquid inlet hole 111 is smaller than that of the liquid inlet column 100, i.e., the orthogonal projection of the third port 1001 of the liquid inlet column 100 on the second base 21 covers the orthogonal projection of the second port 1112 of the liquid inlet hole 111 on the second base 21, so that the reaction liquid flows through the large-pore liquid inlet column 100 into the small-pore liquid inlet hole 111 and then into the liquid storage tank 112. The reaction liquid passes through the small-pore liquid inlet hole 111, which can slow down the dripping speed of the reaction liquid and prevent the reaction liquid from accumulating in the liquid storage tank 112 and causing inefficient movement. In some examples, the liquid inlet column 100 may be integral with the first base 11, for example, the first base 11 and the liquid inlet column 100 are formed by injection molding.

[0036] 4 is a cross-sectional view of another microfluidic chip according to an embodiment of the present disclosure. As shown in FIG. 4, the liquid inlet hole 111 on the first base 11 has a first port 1111 and a second port 1112 arranged opposite to each other, where the first port 1111 of the liquid inlet hole 111 is connected to the liquid storage tank 112, and the diameter of the second port 1112 approaching the first port 1111 is equal to or smaller than the diameter of the second port 1112 approaching the first port 1111. For example, the liquid inlet hole 111 includes a first cylindrical sub-through hole and a second inverted cone-shaped sub-through hole arranged coaxially, where one end of the first sub-through hole is connected to the liquid storage tank 112 and the other end is connected to the second sub-through hole. In addition, the first sub-through hole and the second sub-through hole have an integral structure and fit into the drip end of the gun head.

[0037] In some examples, FIG. 5 is a plan view of another microfluidic chip according to an embodiment of the present disclosure, and FIG. 6 is a cross-sectional view of another microfluidic chip according to an embodiment of the present disclosure. As shown in FIGS. 5 and 6, the only difference from the microfluidic chips shown in FIGS. 1 and 2 is that a support structure 40 is further provided between the first and second substrates of the microfluidic chip to maintain the thickness of the box between the first and second substrates. The remaining structure is substantially identical to the microfluidic chip structure shown in FIGS. 1 and 2, and therefore will not be described in detail here. The number of support structures 40 may be multiple, and the multiple support structures 40 may be spaced apart. For example, the multiple support structures 40 may be arranged in an array to maintain the thickness of the box between the first and second substrates. The thickness of the support structure 40 may be approximately 100 μm to 500 μm, and may be specifically determined based on the required thickness of the box between the first and second substrates. The shape of the support structure 40 may be cylindrical, elliptical, or the like. The embodiments of the present disclosure are not limited to the shape of the support structure 40 .

[0038] In some examples, regardless of which of the above structures is adopted for the liquid inlet hole 111 on the first base 11, the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21 and the orthogonal projection of the second electrode layer 22 on the second base 21 at least partially overlap. In other words, to ensure that the reaction liquid can be driven to move after a voltage is applied to the second electrode layer 22, the reaction liquid that flows into the liquid storage tank 112 through the liquid inlet hole 111 can contact the second electrode layer 22. For example, the orthogonal projection of the edge of the second electrode layer 22 on the second base 21 passes through the center of the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21, or the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21 contacts the edge of the orthogonal projection of the second electrode layer 22 on the second base 21.

[0039] Below are shown three exemplary schematic diagrams of the positional relationship between the liquid inlet hole 111 and the second electrode layer 22. In the drawings, only the first port 1111 of the liquid inlet hole 111 is illustrated as a circular port, and it should be understood that the first port 1111 of the liquid inlet hole 111 may have other shapes, such as a rectangle or an oval.

[0040] 7 is a diagram illustrating the positional relationship between the second electrode layer 22 and the liquid inlet hole 111 in a microfluidic chip according to an embodiment of the present disclosure. As shown in FIG. 7, the second electrode layer 22 may include a first electrode group located in the liquid storage zone Q11 and a second electrode group located in the detection zone Q12. The first electrode group includes a plurality of first sub-electrodes 221, and the second electrode group includes a plurality of second sub-electrodes 222 and a plurality of third sub-electrodes 223. The first sub-electrodes 221 are aligned in a direction toward the detection zone Q12 of the liquid storage zone Q11 and spaced apart from each other. The first sub-electrodes 221 may include, but are not limited to, stripe-shaped (rectangular) electrodes. The second sub-electrodes 222 are aligned in a direction toward the detection zone Q12 of the liquid storage zone Q11 and spaced apart from each other. The second sub-electrodes 222 may include, but are not limited to, block-shaped (square) electrodes. The plurality of third sub-electrodes 223 are spaced apart from the second sub-electrodes 222 in a direction perpendicular to the direction of the liquid storage zone Q11 toward the detection zone Q12, and the third sub-electrodes 223 are located on one side of the detection zone Q12 closer to the liquid storage zone Q11. The third sub-electrodes 223 may include, but are not limited to, striped (rectangular) electrodes. Note that while Figure 6 illustrates the shape and arrangement of each sub-electrode in the second electrode layer 22, the shape of each sub-electrode in an actual product is not limited to this and any other shape may be adopted. 7 , the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21 is inscribed in the orthogonal projection of the first sub-electrode 221 of the first electrode group that is farthest from the second electrode group on the second base 21. In this case, the reaction liquid dripped from the liquid inlet hole 111 can be dripped directly onto the second electrode layer 22, thereby effectively attracting the movement of the reaction liquid when a voltage is applied to the first sub-electrode 221. In some examples, the second endpoint of the first side edge L1 of the liquid storage tank 112 is located between the first electrode group in the liquid storage zone Q11 and the second electrode group located in the detection zone Q12, and an extension line of the side edge opposite to the first side edge L1 penetrates the hole wall of the liquid inlet hole 111.

[0041] 8 is a diagram illustrating the positional relationship between the second electrode layer 22 and the liquid inlet hole 111 in another microfluidic chip according to an embodiment of the present disclosure. As shown in FIG. 8, the structure of the second electrode layer 22 in this microfluidic chip is the same as that in FIG. 5, except that the center of the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21 is located at the edge of the orthogonal projection of the first sub-electrode 221, which is the farthest from the second electrode group among the first electrode group, on the second base 21. In this case, at least a portion of the reaction liquid dripped from the liquid inlet hole 111 can be dripped directly onto the second electrode layer 22, and thus, application of a voltage to the first sub-electrode 221 can effectively drive the movement of the reaction liquid.

[0042] 9 is a diagram illustrating the positional relationship between the second electrode layer 22 and the liquid inlet hole 111 in another microfluidic chip according to an embodiment of the present disclosure. As shown in FIG. 9, the structure of the second electrode layer 22 in this microfluidic chip is the same as that in FIG. 5, except that the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21 is circumscribed by the orthogonal projection of the first sub-electrode 221, which is the farthest from the second electrode group among the first electrode group, on the second base 21. In this case, the reaction liquid dripped from the liquid inlet hole 111 contacts the edge of the second electrode layer 22, and therefore, applying a voltage to the first sub-electrode 221 can effectively attract the movement of the reaction liquid.

[0043] Although only three exemplary schematic diagrams of the positional relationship between the liquid inlet hole 111 and the second electrode layer 22 are shown above, in actual applications, there may be a certain distance between the orthogonal projection of the first port 1111 of the liquid inlet hole 111 on the second base 21 and the edge of the second electrode layer 22, but this distance must be such that the electric field force generated by applying a voltage to the second electrode layer 22 can move the reaction liquid dropped through the liquid inlet hole 111 toward the detection zone Q12.

[0044] In some examples, a sealant 200 is provided between the first and second substrates of the microfluidic chip and is located in the peripheral region Q2. The sealant 200 is used to seal the microfluidic chip. Examples of the sealant 200 include, but are not limited to, UV adhesive or double-sided tape. The first and second substrates have a certain thickness relative to the box to provide space for the generation and splitting of microdroplets of the reaction liquid. Silicone oil and fluorinated liquid are typically filled between the first and second substrates to prevent the reaction liquid from volatilizing and reduce the driving voltage. In some examples, to prevent the sealant 200 from reacting with the silicone oil and fluorinated liquid, a first receiving groove 20 is formed in the peripheral region Q2 of the first base 11, surrounding the middle region Q1. The sealant 200 is formed in the first receiving groove 20. For example, the first receiving groove 20 and the first base 11 are integrally molded, and both may be formed by injection molding. In some examples, the depth of the first accommodating groove 20 is approximately 50 μm to 2 mm, and of course, the depth of the first accommodating groove 20 must be set according to the thickness of the sealant 200 and also taking into account the thickness requirements of the box between the first substrate and the second substrate.

[0045] In some embodiments, a conductive member 300 is provided in the peripheral region Q2 between the first and second substrates of the microfluidic chip to connect the first electrode layer 12 to a conductive pad on the second substrate and provide an electrical signal to the first electrode layer 12. For example, the first electrode layer 12 may be a ground electrode. In this case, the ground electrode extends to the peripheral region Q2 and is connected to the conductive member 300, which is then connected to a ground pad on the second substrate, thereby realizing a connection between the ground electrode and the ground pad. In some examples, the conductive member 300 includes, but is not limited to, a conductive silver paste or a conductive foam. In some examples, the conductive member 300 may be located on one side of the sealant 200 away from the middle region Q1. For example, the microfluidic chip may be rectangular, and the conductive members 300 are located at the four corners of the first base 11, i.e., one conductive member 300 is provided at each corner. In some examples, a second receiving groove 30 having a conductive member 300 is further provided on one side of the first base 11 that is adjacent to the second substrate. For example, the second receiving groove 30 and the first base 11 may be integrally formed by injection molding. In some examples, the depth of the second receiving groove 30 is approximately 50 μm to 2 mm. Naturally, the depth of the second receiving groove 30 must be determined according to the thickness of the conductive member 300 and the thickness of the box between the first substrate and the second substrate. In some examples, the shape of the second receiving groove 30 includes, but is not limited to, a rectangle, a square, a circle, and a polygon, and the number of the second receiving grooves 30 is approximately 1 to 4.

[0046] In some examples, the first substrate not only includes the first electrode layer 12, but also has a first lyophobic layer on one side of the first electrode layer 12 that is close to the second substrate, in which case a reaction liquid is added to the microfluidic chip through the liquid inlet hole 111, and after the reaction liquid flows into the liquid storage tank 112, the reaction liquid contacts the underside of the first substrate. Because the underside of the first substrate is the first lyophobic layer that exhibits lyophobic properties, the reaction liquid is less likely to remain on the underside of the first lyophobic layer and can more easily flow into the liquid storage tank 112. Similarly, the second substrate not only includes the second electrode layer 22, but also has a second lyophobic layer on one side of the second electrode layer 22 that is closest to the first substrate. In this case, when a voltage is applied between the first electrode layer 12 and the second electrode layer 22 to move the reactant liquid that has flowed into the liquid storage tank 112, the upper surface of the second substrate is the second lyophobic layer that exhibits lyophobic properties, which allows the reactant liquid to move more easily and effectively reduces the movement resistance of the reactant liquid. Both the first and second lyophobic layers include, but are not limited to, lyophobic layers, and the materials thereof may include various types of materials (e.g., fluoropolymers such as Teflon (registered trademark) and CYTOP), and are not limited thereto.

[0047] To facilitate the droplets entering the chamber, in some examples, an exhaust port 60 is provided on the first base 11, penetrating the first substrate 110 in the thickness direction, as shown in FIG.

[0048] In some examples, the liquid inlet hole 111, the liquid storage tank 112, the first accommodating groove 20, and the second accommodating groove 30 are formed on the first base 11 of the first substrate by micromachining (e.g., injection molding, laser engraving, sandblasting, etc.).

[0049] In the following, in order to clarify the operating principle of the microfluidic chip according to the embodiment of the present disclosure, the operating process of the microfluidic chip according to the embodiment of the present disclosure will be described using an example in which the second electrode layer 22 adopts the structure shown in Figure 7.

[0050] First, as shown in FIG. 10, the reaction liquid is added to the liquid storage tank 112 from the liquid inlet port 111 via the gun head. Next, a reference voltage, for example, a ground voltage, is applied to the first electrode layer 12, and voltages are sequentially applied to the first sub-electrodes 221 in the liquid storage zone Q11 in the direction from the liquid storage zone Q11 to the reaction zone Q12, thereby forming the reaction liquid in the liquid storage zone Q11 into a rectangular shape as shown in FIG. 11. Note that when a voltage is applied to the next first sub-electrode 221, the voltage on the previous first sub-electrode 221 is released. Then, voltages are sequentially applied to the second sub-electrodes 222 in the detection zone Q12, thereby elongating the reaction liquid into a columnar shape as shown in FIGS. 12 to 14. Finally, as shown in Figure 15, the voltage applied to the second sub-electrode 222 close to the liquid storage zone Q11 is released, and the voltage applied to the second sub-electrode 222 away from the liquid storage zone Q11 and the voltage applied to the first sub-electrode 221 remain unchanged, thereby forming a single droplet.

[0051] It should be noted that the above-described embodiments are merely examples for explaining the principles of the present invention, and the present invention is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention. [Explanation of symbols]

[0052] 10 Test Unit 11 First Base 12 First electrode layer 20 First Receiving Groove 21 Second Base 22 Second electrode layer 23 Interlayer dielectric layer 30 Second Receiving Groove 40 Support structure 60 exhaust port 100 Liquid inflow column 110 first substrate 111 Liquid inlet hole 112 Liquid storage tank 200 sealant 221 first sub-electrode 222 second sub-electrode 223 Third sub-electrode 300 Conductive materials 1001 Third Port 1002 Fourth Port 1111 First port 1112 Secondary port

Claims

1. A microfluidic chip comprising a first substrate and a second substrate disposed opposite each other, the first substrate being divided into an intermediate region having a liquid storage zone and a detection zone, and a peripheral region surrounding the intermediate region, the first substrate including a first base and a first electrode layer disposed on one side of the first base facing the second substrate, and the second substrate including a second base and a second electrode layer disposed on one side of the second base facing the first substrate, a liquid storage tank and a liquid inlet hole penetrating a bottom surface of the liquid storage tank are formed on one side of the first base facing the second substrate, the liquid storage tank and the liquid inlet hole both being located in the liquid storage zone; the liquid storage tank has a first side edge that approaches the detection zone along the thickness direction of the first substrate and is parallel to a cross section of the liquid storage zone in a direction facing the detection zone, the first side edge has a first endpoint and a second endpoint, the first endpoint is farther from the second substrate than the second endpoint, the extension direction of a line connecting the first endpoint and the second endpoint is inclined with respect to the axial direction of the liquid inlet hole, and the distance from the first endpoint to the axis of the liquid inlet hole is shorter than the distance from the second endpoint to the axis of the liquid inlet hole, The shape of the liquid inlet hole is adapted to the shape of the drip end of the gun head for adding the reaction liquid, and the liquid inlet hole is cylindrical; the microfluidic chip further comprises a liquid inlet column arranged coaxially with the liquid inlet hole, the shape of the liquid inlet column conforming to the shape of the main body of the gun head, and the liquid inlet column having an inverted cone shape; The liquid storage tank further has a second side edge opposite the first side edge, and another pair of third and fourth side edges arranged opposite each other, and a dihedral angle between the second side edge, the third side edge, and the fourth side edge and a bottom surface of the liquid storage tank is 90° or approximately 90°.

2. The microfluidic chip of claim 1 , wherein the first side is a straight side.

3. 2. The microfluidic chip according to claim 1, wherein an included angle formed by an extension direction of a line connecting the first endpoint and the second endpoint and an axial direction of the liquid inlet hole is θ, and a value that θ can take is 30° to 60°.

4. an interlayer dielectric layer is provided on a layer of the second electrode layer away from the second base, and an included angle formed by an extension direction of a line connecting the first end point and the second end point and an axial direction of the liquid inlet hole is θ; tanθ>2d(FG) / ε 0 ・ε r ・V 2 Among them, ε 0 represents the vacuum permittivity, and ε r 2. The microfluidic chip of claim 1, wherein ℓ represents a dielectric constant of an interlayer dielectric layer, d is a thickness of the interlayer dielectric layer, F represents a support force provided by the interlayer dielectric layer to a droplet to be detected, G represents a gravity force of the droplet to be detected, and V represents a voltage value applied by the second electrode layer.

5. 2. The microfluidic chip of claim 1, wherein the liquid inlet hole includes a first port and a second port, and the liquid inlet hole communicates with the liquid storage tank via the first port, and an orthogonal projection of the first port on the second base and an orthogonal projection of the second electrode layer on the second base at least partially overlap.

6. an orthogonal projection of an edge of the second electrode layer on the second base passes through a center of an orthogonal projection of the first port on the second base; or The microfluidic chip of claim 4 , wherein an orthogonal projection of an edge of the second electrode layer on the second base and an orthogonal projection of the first port on the second base are contiguous.

7. 7. The microfluidic chip according to claim 1, wherein the liquid inlet hole includes a first port and a second port arranged opposite each other, the liquid inlet hole communicates with the liquid storage tank via the first port, and an orthogonal projection of the second port on the second base covers an orthogonal projection of the first port on the second base.

8. 7. The microfluidic chip according to claim 1, wherein the liquid inlet hole includes a first port and a second port provided opposite each other, and the liquid inlet hole communicates with the liquid storage tank via the first port, and the liquid inlet pillar includes a third port and a fourth port provided opposite each other, and the third port of the liquid inlet pillar is connected to the second port of the liquid inlet hole.

9. 7. The microfluidic chip according to claim 1, wherein the liquid inlet hole includes a first port and a second port provided opposite each other and communicates with the liquid storage tank via the first port, the liquid inlet pillar includes a third port and a fourth port provided opposite each other, and an orthogonal projection of the third port of the liquid inlet pillar on the second base is located within an orthogonal projection of the fourth port on the second base.

10. 10. The microfluidic chip according to claim 8, wherein the first port and the second port of the liquid inlet hole have the same hole diameter.

11. The microfluidic chip according to any one of claims 1 to 9, wherein a sealant is provided between the first substrate and the second substrate, the sealant being located in the peripheral region and surrounding the intermediate region.

12. 12. The microfluidic chip according to claim 11, wherein a first receiving groove is formed on one side of the first base that is close to the second substrate, and the sealant is formed in the first receiving groove.

13. The microfluidic chip according to any one of claims 1 to 9, wherein a conductive member is provided between the first substrate and the second substrate, the conductive member being located in a peripheral region and electrically connecting a first electrode layer to a connection pad on the second substrate.

14. 14. The microfluidic chip according to claim 13, wherein a second receiving groove is formed on one side of the first base that is close to the second substrate, and the conductive member is disposed in the second receiving groove.

15. A support structure for maintaining a box thickness between the first substrate and the second substrate is provided between the first substrate and the second substrate. The microfluidic chip according to any one of claims 1 to 9.

16. 10. The microfluidic chip according to claim 1, wherein an exhaust port is provided on the first base, penetrating the first base along a thickness direction.

17. a first lyophobic layer is provided on one side of the first electrode layer that is close to the second substrate; 10. The microfluidic chip according to claim 1, wherein a second lyophobic layer is provided on one side of the second electrode layer that is close to the first substrate.

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