Microfluidic chips, their usage methods, and microfluidic systems

Abstract

The microfluidic chip, its usage method, and microfluidic system disclosed herein include a substrate layer, which includes a substrate substrate and a driving electrode layer located on the substrate substrate; a cover layer, which is disposed opposite to the substrate layer, and the space between the cover layer and the substrate layer constitutes a solution containment space; the cover layer includes an inlet hole, an outlet hole, and a plurality of limiting grooves arranged in an array on the side of the cover layer facing the substrate layer, the inlet hole, the outlet hole, and each limiting groove are all in communication with the solution containment space, and the end face of the inlet hole adjacent to the substrate layer, the end face of the outlet hole adjacent to the substrate layer, and the opening faces of the plurality of limiting grooves are substantially flush.

Description

Technical Field

[0001] This disclosure relates to the field of microfluidics, and in particular to a microfluidic chip, its usage method, and a microfluidic system. Background Technology

[0002] Microfluidic chip technology is based on micron-level fluid manipulation, enabling complex biochemical reaction processes to be realized on small-sized chips. This allows large analytical instruments to continuously iterate and upgrade towards miniaturization, integration, automation, and high throughput, promoting the development of fields such as real-time detection and on-site analysis with rapid quantification as the core. Summary of the Invention

[0003] This disclosure provides a microfluidic chip, its usage method, and a microfluidic system, the specific solutions of which are as follows:

[0004] On one hand, embodiments of this disclosure provide a microfluidic chip, including:

[0005] A substrate layer, the substrate layer including a substrate substrate and a driving electrode layer located on the substrate substrate;

[0006] A cover plate layer is placed opposite the substrate layer, and the space between the cover plate layer and the substrate layer constitutes a solution containing space. The cover plate layer includes an inlet hole and an outlet hole that penetrate the thickness direction of the cover plate layer, and a plurality of limiting grooves arranged in an array on the side of the cover plate layer facing the substrate layer. The inlet hole, the outlet hole and the plurality of limiting grooves are all in communication with the solution containing space, and the opening surfaces of the inlet hole adjacent to the end face of the substrate layer, the outlet hole adjacent to the end face of the substrate layer and the plurality of limiting grooves are substantially flush.

[0007] In some embodiments, in the microfluidic chip provided in the present disclosure, a reaction groove is provided on the side of the cover plate facing the substrate layer, and the reaction groove and the substrate layer form the solution accommodating space;

[0008] The bottom surface of the reaction groove is approximately flush with the end face of the liquid inlet near the substrate layer, the end face of the liquid outlet near the substrate layer, and the opening surfaces of the plurality of limiting grooves.

[0009] In some embodiments, in the microfluidic chip provided in the present disclosure, the reaction groove and the plurality of limiting grooves are integrally injection molded.

[0010] In some embodiments, in the microfluidic chip provided in the present disclosure, the cover plate layer further includes an air valve cavity independent of the plurality of limiting grooves, and an air inlet channel and an air outlet channel connected through the air valve cavity;

[0011] The valve cavity is located on the side of the plurality of limiting grooves away from the substrate layer, and the orthogonal projection of the valve cavity on the substrate covers the orthogonal projection of the plurality of limiting grooves on the substrate.

[0012] In some embodiments, in the microfluidic chip provided in the present disclosure, the air valve cavity and the plurality of limiting grooves are integrally injection molded, or the portion where the air valve cavity is located and the portion where the plurality of limiting grooves are located are fixedly connected by a colloid.

[0013] In some embodiments, the volume of each of the limiting grooves in the microfluidic chip provided in the present disclosure is approximately the same.

[0014] In some embodiments, in the microfluidic chip provided in the present disclosure, the driving electrode layer includes a first electrode, a second electrode, and a plurality of third electrodes arranged in an array. The orthographic projection of the first electrode on the substrate covers the orthographic projection of the liquid inlet on the substrate, the orthographic projection of the second electrode on the substrate covers the orthographic projection of the liquid outlet on the substrate, and the orthographic projections of the plurality of third electrodes on the substrate overlap with the orthographic projections of the plurality of limiting grooves on the substrate.

[0015] In some embodiments, in the microfluidic chip provided in the present disclosure, the orthogonal projection of one of the limiting grooves on the substrate covers the orthogonal projection of at least one of the third electrodes on the substrate.

[0016] In some embodiments, in the microfluidic chip provided in the present disclosure, a plurality of transistors are located between the substrate and the driving electrode layer, and the transistors are electrically connected to the third electrode.

[0017] In some embodiments, in the microfluidic chip provided in the present disclosure, the driving electrode layer further includes a plurality of first connecting electrodes, the plurality of first connecting electrodes being located between the first electrode and the plurality of third electrodes, and between the second electrode and the plurality of third electrodes.

[0018] In some embodiments, in the microfluidic chip provided in the present disclosure, a main channel region, a connecting channel region, and at least one branch channel region are respectively disposed between the first electrode and the plurality of third electrodes, and between the second electrode and the plurality of third electrodes. The at least one branch channel region is connected to the main channel region through the connecting channel region. The main channel region is disposed adjacent to the first electrode and the second electrode, and the branch channel region is disposed adjacent to the plurality of third electrodes. The main channel region, the connecting channel region, and each of the branch channel regions are respectively disposed with a plurality of first connecting electrodes.

[0019] In some embodiments, in the microfluidic chip provided in the present disclosure, the cover layer further includes: a first connection channel and at least one liquid storage groove, wherein the orthographic projection of the first connection channel on the substrate and the orthographic projection of the at least one liquid storage groove on the substrate do not overlap with the orthographic projection of the solution accommodating space on the substrate.

[0020] The liquid storage groove is recessed from the surface of the cover plate layer away from the substrate layer toward the cover plate layer, the first connecting channel is located inside the cover plate layer, and the liquid storage groove is connected to the liquid inlet hole through the first connecting channel.

[0021] In some embodiments, in the microfluidic chip provided in the present disclosure, there are multiple liquid storage grooves; the cover layer further includes a second connecting channel that connects each of the liquid storage grooves, the second connecting channel is located inside the cover layer, and the orthographic projection of the second connecting channel on the substrate does not overlap with the orthographic projection of the solution accommodating space on the substrate.

[0022] In some embodiments, in the microfluidic chip provided in the present disclosure, the driving electrode layer further includes: a fourth electrode corresponding to each of the liquid storage grooves, a plurality of second connecting electrodes corresponding to the first connecting channels and arranged in an array, and a plurality of third connecting electrodes corresponding to the second connecting channels and arranged in an array.

[0023] In some embodiments, in the microfluidic chip provided in the present disclosure, the liquid storage groove includes at least one of a sample storage groove, a magnetic bead and lysis buffer storage groove, a washing buffer storage groove, an elution buffer storage groove, a lysis waste liquid storage groove, a washing waste liquid storage groove, a magnetic bead waste liquid storage groove, and a product storage groove.

[0024] In some embodiments, in the microfluidic chip provided in the present disclosure, the substrate layer further includes a hydrophobic layer disposed on the side of the driving electrode layer away from the substrate.

[0025] On the other hand, this disclosure provides a microfluidic system, including the microfluidic chip described above.

[0026] On the other hand, this disclosure provides a method for using the above-mentioned microfluidic chip, including:

[0027] The reaction solution is injected into the solution holding space through the inlet hole;

[0028] An electrical signal is applied to the driving electrode layer, causing the reaction liquid to disperse into multiple droplets under the drive of the driving electrode layer;

[0029] Pressure is applied to the cover plate layer so that each droplet enters the space enclosed by each limiting groove and the substrate layer and is isolated from each other;

[0030] After the reaction is complete, the solution in the solution container is discharged through the liquid outlet.

[0031] In some embodiments, in the above-described method of use provided in this disclosure, applying pressure to the cover plate layer causes each droplet to enter the space enclosed by each limiting groove and the substrate layer and thus isolate themselves from each other, specifically including:

[0032] The air valve cavity is pressurized by inflating it, causing the air valve cavity to move the plurality of limiting grooves toward the substrate layer until the opening surface of each limiting groove contacts the substrate layer, so that each droplet enters the space enclosed by each limiting groove and the substrate layer and is isolated from each other.

[0033] In some embodiments, in the above-described method of use provided in this disclosure, applying pressure to the cover plate layer causes each droplet to enter the space enclosed by each limiting groove and the substrate layer and thus isolate themselves from each other, specifically including:

[0034] A weight is applied to the cover plate layer on the side away from the substrate layer until the opening surface of each of the limiting grooves contacts the substrate layer, so that each droplet enters the space enclosed by each of the limiting grooves and the substrate layer and is isolated from each other. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the structure of the substrate layer provided in an embodiment of the present disclosure;

[0036] Figure 2 This is a schematic diagram of the structure of the cover plate layer provided in an embodiment of this disclosure;

[0037] Figure 3 for Figure 1 The substrate layer shown is Figure 2 The diagram shows the structure after the cover plates are aligned.

[0038] Figure 4 For along Figure 3 Cross-sectional view of line I-I' in the middle;

[0039] Figure 5 for Figure 4 The diagram shows the Z1 region after compression.

[0040] Figure 6 A schematic diagram of active driving of multiple third electrodes provided in an embodiment of this disclosure;

[0041] Figure 7 For along Figure 6 Cross-sectional view of line II-II' in the middle;

[0042] Figure 8 for Figure 7 A magnified structural diagram of the Z2 region;

[0043] Figure 9 This is a schematic diagram of the structure of the microfluidic chip provided in the embodiments of this disclosure;

[0044] Figure 10 For along Figure 9 Cross-sectional view of line III-III';

[0045] Figure 11 For along Figure 9 Cross-sectional view of line IV-IV' in the middle;

[0046] Figure 12 A flowchart illustrating the method of using the microfluidic chip provided in this embodiment of the disclosure;

[0047] Figure 13 A schematic diagram illustrating the physical isolation of droplets by a microfluidic chip provided in this embodiment of the present disclosure;

[0048] Figure 14 This is a schematic diagram illustrating the physical isolation of droplets by a microfluidic chip provided in an embodiment of this disclosure. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the dimensions and shapes of the figures in the drawings do not reflect actual proportions and are only intended to illustrate the content of this disclosure. Furthermore, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout the drawings.

[0050] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure and the claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “inner,” “outer,” “upper,” and “lower” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described object changes.

[0051] Currently, there are many types of biochemical reactions that can be integrated on microfluidic chips, one of which is polymerase chain reaction (PCR). It is a classic molecular biology experimental technique that synthesizes large quantities of target DNA fragments in vitro through enzymatic reactions. It has the characteristics of high specificity, high sensitivity, and simple operation, and has wide applications in gene cloning, sequence analysis, disease diagnosis, pathogen detection and other fields.

[0052] Digital PCR is a rapidly developing third-generation nucleic acid molecule quantitative analysis technology in recent years. Its principle involves uniformly distributing a sample into tens of thousands of different reaction units, each containing at least one copy of the target DNA template. PCR amplification is then performed separately in each reaction unit, and the fluorescence signals from each unit are statistically analyzed after amplification. This technology is independent of standard curves, less affected by amplification efficiency, and boasts excellent accuracy and reproducibility, enabling absolute quantitative analysis. It has demonstrated significant technological advantages in nucleic acid detection and identification research. Currently, digital PCR is mainly implemented in array-based chips and droplet-based chips. For array-based chips, two liquid phases need to be added sequentially. The later-added oil phase can easily wash out the previously added aqueous reaction solution, and air bubbles are easily introduced during sample addition, leading to aerosol contamination or crosstalk between reaction units during PCR. For droplet-based chips, the lack of physical separation between droplets makes them prone to crosstalk, and their dispersion stability in the oil phase is poor. These disadvantages, to varying degrees, limit the practical application of digital PCR technology.

[0053] To address the aforementioned technical problems in related technologies, this disclosure provides a microfluidic chip, such as... Figures 1 to 5 As shown, it includes:

[0054] The substrate layer 001 includes a substrate 101 and a driving electrode layer 102 located on the substrate 101; optionally, the substrate 101 may be made of glass or other rigid materials.

[0055] The cover plate layer 002 is placed opposite the substrate layer 001, and the space between the cover plate layer 002 and the substrate layer 001 constitutes the solution containing space S. The cover plate layer 002 includes an inlet hole 201 and an outlet hole 202 that penetrate through the thickness direction of the cover plate layer, and a plurality of limiting grooves 203 arranged in an array on the side of the cover plate layer 002 facing the substrate layer 001. The inlet hole 201, the outlet hole 202 and the plurality of limiting grooves 203 are all connected to the solution containing space S, and the end face of the inlet hole 201 adjacent to the substrate layer 001, the end face of the outlet hole 202 adjacent to the substrate layer 001 and the opening faces of the plurality of limiting grooves 203 are roughly flush (i.e., exactly flush or within the error range caused by manufacturing, measurement and other factors). Under pressure, within the solution containing space S, the opening surfaces of each limiting groove 203 contact the substrate layer 001, thus isolating the space (which can be used to contain droplets) enclosed by each limiting groove 203 and the substrate layer 001. Optionally, the cover layer 002 can be made of polydimethylsiloxane (PDMS) or other elastic plastics, so that minimal pressure can be applied to deform and move the cover layer 002 down to contact the substrate layer 001. In some embodiments, the area where the inlet hole 201 is located can be marked as the inlet area A, the area where the multiple limiting grooves 203 are located can be marked as the reaction area B, and the area where the outlet hole 202 is located can be marked as the outlet area C. The solution containing space S covers the inlet area A, the reaction area B, and the outlet area C.

[0056] In the microfluidic chip provided in this embodiment, the driving electrode layer 102 is used to drive the droplets, which can achieve uniform and rapid dispersion. This avoids problems such as bubbles, dead volume, or insufficient reaction liquid injection that are common in micro-trap array chips, thus improving the accuracy of the detection results. At the same time, the limiting groove 203 cooperates with the substrate layer 001 to achieve physical separation between the droplets, avoiding the phenomenon that droplet chips in related technologies cannot achieve physical isolation. This ensures the stability of the reaction system, prevents crosstalk between droplets, and improves the stability and reliability of the detection results.

[0057] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 2 and Figure 4As shown, a reaction groove 204 is provided on the side of the cover plate layer 002 facing the substrate layer 001. The reaction groove 204 and the substrate layer 001 form a solution containing space S. This eliminates the need for grooves in the substrate layer 001, ensuring the surface flatness of the substrate layer 001 and facilitating droplet movement. Optionally, the bottom surface of the reaction groove 204 can be approximately flush with (i.e., exactly flush or within the error range caused by manufacturing, measurement, or other factors) the end face of the liquid inlet 201 adjacent to the substrate layer 001, the end face of the liquid outlet 202 adjacent to the substrate layer 001, and the opening surfaces of the multiple limiting grooves 203.

[0058] In some embodiments, in the microfluidic chip provided in the present disclosure, the reaction groove 204 can be integrally injection molded with multiple limiting grooves 203 to save processes and reduce costs.

[0059] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 2 and Figure 4 As shown, the cover layer 002 may further include a valve cavity 205 independent of the multiple limiting grooves 203, and an air inlet channel 206 and an air outlet channel 207 connected through the valve cavity 205. The valve cavity 205 is located on the side of the multiple limiting grooves 203 away from the substrate layer 001, and the orthographic projection of the valve cavity 205 on the substrate 101 covers (i.e., is greater than or equal to) the orthographic projection of all the limiting grooves 203 on the substrate 101. In practical applications, the air outlet channel 207 can be closed, and the valve cavity 205 can be pressurized by the air inlet channel 206, causing the limiting grooves 203 below the valve cavity 205 to move down to contact the substrate layer 001. This allows the limiting grooves 203 to collect the droplets within them, achieving physical separation. After the deformation of the cover layer 002 stabilizes, the air inlet channel 206 is closed. In this way, the cover plate layer 002 is pressurized by the air valve cavity 205, causing the limiting groove 203 below the air valve cavity 205 to move down and contact the substrate layer 001. Of course, in some embodiments, a heavy object can also be used to press down on the cover plate layer 002 to move the limiting groove 203 below the air valve cavity 205 down and contact the substrate layer 001.

[0060] In some embodiments, in the microfluidic chip provided in this disclosure, the valve cavity 205 can be integrally injection molded with all the limiting grooves 203; or, the portion containing the valve cavity 205 and the portion containing all the limiting grooves 203 can be fixedly connected by an adhesive. In this case, the valve cavity 205 can be formed by a single injection molding process, and the limiting grooves 203 and the reaction grooves 204 can be formed by another injection molding process. Using a mature injection molding process can effectively reduce costs and improve production efficiency. Optionally, to improve the fixed connection effect between the portion containing the valve cavity 205 and the portion containing all the limiting grooves 203, the adhesive can be applied as a whole layer between the portion containing the valve cavity 205 and the portion containing all the limiting grooves 203, and hollowed out at the liquid inlet 201 and the liquid outlet 202.

[0061] Optionally, such as Figure 4 As shown, the cover layer 002 provided in this disclosure has a thickness of 7 mm. The vertical distance between the valve cavity 205 and the surface of the cover layer 002 away from the substrate layer 001 is 2 mm. The dimensions of the valve cavity 205 can be 47 mm × 47 mm × 2 mm. An air inlet channel 206 and an air outlet channel 207 communicating with the valve cavity 205 are provided on both sides. The air inlet channel 206 and the air outlet channel 207 can both have a diameter of 1.5 mm and a depth of 2 mm. At a vertical distance of 1 mm from the bottom of the valve cavity 205, there are multiple limiting grooves 203 arranged in an array. The diameter of a single limiting groove 203 is 1.4 mm and the depth is 1 mm. The width of the protrusion between the limiting grooves 203 is 0.14 mm. The surface of the cover plate layer 001 adjacent to the substrate layer 001 has an elliptical reaction groove 204 with a depth of 1 mm. The two ends of the reaction groove 204 are provided with an inlet hole 201 with a diameter of 2 mm and a outlet hole 202 with a depth of 6 mm.

[0062] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 5 As shown, the volumes of each limiting groove 203 are approximately the same, which helps to ensure good uniformity of droplet volume within each limiting groove 203. In this disclosure, due to limitations in process conditions or the influence of other factors such as measurement, "approximately the same" may be completely equivalent or may have some deviation (e.g., ±5% deviation). Therefore, the "approximately the same" relationship between related features is within the protection scope of this disclosure as long as the error is permissible.

[0063] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 1 and Figure 4As shown, the driving electrode layer 102 may include a first electrode 1021, a second electrode 1022, and a plurality of third electrodes 1023 arranged in an array. The orthogonal projection of the first electrode 1021 on the substrate 100 may be located in the liquid inlet area A and cover (i.e., greater than or equal to) the orthogonal projection of the liquid inlet hole 201 on the substrate 101. The orthogonal projection of the second electrode 1022 on the substrate 101 may be located in the liquid outlet area C and cover (i.e., greater than or equal to) the orthogonal projection of the liquid outlet hole 202 on the substrate 101. The orthogonal projections of the plurality of third electrodes 1023 on the substrate 101 may be located in the reaction area B and overlap with the orthogonal projections of the plurality of limiting grooves 203 on the substrate 101. In this case, the reaction liquid injected into the first electrode 1021 through the liquid inlet 201 can move to the third electrode 1023 under the drive of the first electrode 1021 and the third electrode 1023, and disperse into droplets at each third electrode 1023 under the drive of multiple third electrodes 1023. Finally, all droplets move to the second electrode 1022 under the drive of the third electrode 1023 and the second electrode 1022, and are discharged through the liquid outlet 202 above the second electrode 1022.

[0064] In some embodiments, in the microfluidic chip provided in the present disclosure, to facilitate the placement of droplets at the third electrode 1023 by the limiting groove 203, the orthogonal projection of the limiting groove 203 on the substrate 101 can cover (i.e., be greater than or equal to) the orthogonal projection of at least one third electrode 1023 on the substrate 101. For example, in Figure 5 In this case, the orthographic projection of a limiting groove 203 on the substrate 101 roughly coincides with the orthographic projection of a third electrode 1023 on the substrate 101 (i.e., exactly coincides or within the error range caused by measurement, manufacturing, etc.). At this time, the gap width between two adjacent third electrodes 1023 can be approximately equal to (i.e., exactly equal to or within the error range caused by measurement, manufacturing, etc.) the protrusion width between two adjacent limiting grooves 203. For example, the orthographic projection of a limiting groove 203 on the substrate 101 corresponds to (i.e., greater than or equal to) the orthographic projection of two or more third electrodes 1023 on the substrate 101, and the two or more third electrodes 1023 corresponding to a limiting groove 203 are grouped together. In this case, in order to facilitate the limiting groove 203 to receive the droplets at the third electrode 1023, the gap width between adjacent third electrodes 1023 in the same group can be less than or equal to half of the protrusion width between two adjacent limiting grooves 203, while the gap width between two adjacent groups can be approximately equal to (i.e. exactly equal or within the error range caused by measurement, manufacturing, etc.) the protrusion width between two adjacent limiting grooves 203.

[0065] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figures 6 to 8As shown, it may further include a plurality of transistor TFTs located between the driving electrode layer 102 and the substrate 101. The transistor TFTs are electrically connected to the third electrode 1023. Optionally, in this disclosure, each third electrode 1023 may be electrically connected to a corresponding transistor TFT. The third electrodes 1023 in the same row are electrically connected to a scan line GL through their respective corresponding transistor TFTs, and the third electrodes 1023 in the same column are electrically connected to a data line DL through their respective corresponding transistor TFTs, so as to realize active driving of each third electrode 1023. Optionally, the transistor TFT can be a top-gate transistor or a bottom-gate transistor (e.g., Figure 8 (As shown) or a dual-gate transistor, the active layer material of the transistor TFT can be amorphous silicon, low-temperature polycrystalline silicon, oxide (e.g., indium gallium zinc oxide), etc. The scan line GL can be set in the same layer as the gate of the transistor TFT, and the data line DL can be set in the same layer as the source and drain of the transistor TFT.

[0066] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 1 and Figure 4 As shown, the driving electrode layer 102 may further include a plurality of first connecting electrodes 1024, which are located between the first electrode 1021 and all the third electrodes 1023, and between the second electrode 1022 and all the third electrodes 1023. Optionally, the area where the plurality of first connecting electrodes 1024 are located may be labeled as a connecting region D, and the first connecting electrodes 1024 may form at least one row within the connecting region D. Driven by the first connecting electrodes 1024, the reaction liquid is rapidly dispersed into multiple droplets and moves to the plurality of third electrodes 1023, so that the reaction liquid is dispersed into multiple droplets before moving to the plurality of third electrodes 1023, which facilitates the subsequent process of droplet distribution to each third electrode 1023. Optionally, the first connecting electrode 1021 in this disclosure also adopts Figure 6 The electrical signal is applied using an active drive method, as shown.

[0067] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 1As shown, to accelerate the dispersion and transfer speed of droplets, the regions between the first electrode 1021 and all the third electrodes 1023 (i.e., the connection region D) and the regions between the second electrode 1022 and all the third electrodes 1023 (i.e., the connection region D) can be divided into a main channel region D1, a connection channel region D2, and at least one branch channel region D3, respectively. All branch channel regions D3 are directly connected to the main channel region D1 through the connection channel region D2. The main channel region D1 is located adjacent to the first electrode 1021 and the second electrode 1022, and the branch channel regions D3 are located adjacent to multiple third electrodes 1023. Multiple first connection electrodes 1024 are respectively provided in the main channel region D1, the connection channel region D2, and each branch channel region D3. Optionally, the first connection electrodes 1024 form at least one row in the main channel region D1, the connection channel region D2, and each branch channel region D2.

[0068] Optionally, in this disclosure, the thickness of the substrate layer 001 can be 2 mm, the size of a single third electrode 1023 can be 1 mm × 1 mm × 0.1 mm, and the number of third electrodes 1023 can be 40 × 40; the first electrode 1021 and the second electrode 1022 can be located on both sides of the third electrode 1023, and the size of the first electrode 1021 and the second electrode 1022 can both be 5 mm × 5 mm × 0.1 mm, so that the first electrode 1021 and the second electrode 1022 can function as a liquid reservoir. The size of the first connecting electrode 1024 can also be 1 mm × 1 mm × 0.1 mm.

[0069] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figures 9 to 11 As shown, the cover layer 002 may further include: a first connecting channel 208 and at least one liquid storage groove 209. The orthographic projection of the first connecting channel 208 on the substrate 101 and the orthographic projection of all the liquid storage grooves 209 on the substrate 101 can both be non-overlapping with the orthographic projection of the solution accommodating space S on the substrate 101. The liquid storage grooves 209 are recessed from the surface of the cover layer 002 away from the substrate layer 001 toward the cover layer 002. The first connecting channel 208 is located inside the cover layer 002, and the liquid storage grooves 209 are connected to the liquid inlet 201 through the first connecting channel 208. Optionally, the area where the first connecting channel 208 and all the liquid storage grooves 209 are located can be the extraction area E, thus enabling co-use with an extraction chip, allowing extraction and amplification operations to be completed on a single microfluidic chip.

[0070] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figures 9 to 11As shown, the liquid storage recess 209 may include at least one of the following: sample storage recess 2091, magnetic bead and lysis buffer storage recess 2092, washing buffer storage recess 2093, eluent storage recess 2094, lysis waste liquid storage recess 2095, washing waste liquid storage recess 2096, magnetic bead waste liquid storage recess 2097, and product storage recess 2098. Optionally, when there are multiple liquid storage recesses 209, such as... Figures 9 to 11 As shown, the cover layer 002 may also include a second connecting channel 210 that connects each liquid storage groove 209. The second connecting channel 210 is located inside the cover layer 002. The orthographic projection of the second connecting channel 210 on the substrate 101 does not overlap with the orthographic projection of the solution containing channel S on the substrate 101. Optionally, the second connecting channel 210 is also located in the extraction area E.

[0071] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figures 9 to 11 As shown, the driving electrode layer 102 further includes: a fourth electrode 1025 corresponding one-to-one with the liquid storage groove 209 in the extraction zone E; a plurality of second connecting electrodes 1026 corresponding to the first connecting channel 208 and arranged in an array; and a plurality of third connecting electrodes 1027 corresponding to the second connecting channel 210 and arranged in an array. Optionally, the second connecting electrodes 1026 and the third connecting electrodes 1027 are both actively driven. The fourth electrode 1025, the second connecting electrodes 1026, and the third connecting electrodes 1027 can provide driving force for the flow of liquid in the extraction zone E, improving the smoothness of liquid flow in the extraction zone E.

[0072] In some embodiments, in the microfluidic chip provided in the present disclosure, such as Figure 4 , Figure 5 , Figure 7 , Figure 10 and Figure 11 As shown, the substrate layer 001 may further include a hydrophobic layer 103 disposed on the side of the driving electrode layer 102 away from the substrate 101. Since the reaction solution for PCR amplification is usually an aqueous solution, by providing a flat hydrophobic layer 103 on the side of the substrate layer 001 adjacent to the cover plate layer 002, the contact angle of the droplets on the hydrophobic layer 103 can be flexibly controlled by the driving electrode layer 102 based on electrowetting technology, forcing the droplets to deform and displace.

[0073] Based on the same inventive concept, this disclosure provides a method for using the microfluidic chip described above. Since the principle of this method for solving the problem is similar to that of the microfluidic chip, the implementation of the method provided in this disclosure can refer to the implementation of the microfluidic chip provided in this disclosure. Repeated details will not be repeated.

[0074] Specifically, this disclosure provides a method for using the above-mentioned microfluidic chip, such as... Figure 12 As shown, it includes the following steps:

[0075] S1201. Inject the reaction solution into the solution holding space through the inlet hole;

[0076] S1202. Apply an electrical signal to the driving electrode layer, causing the reaction liquid to disperse into multiple droplets under the drive of the driving electrode layer;

[0077] S1203. Apply pressure to the cover plate layer so that each droplet enters the space enclosed by each limiting groove and the substrate layer and is isolated from each other.

[0078] S1204. After the reaction is complete, the solution in the solution container is discharged through the liquid outlet.

[0079] In some embodiments, in the above-described usage method provided in this disclosure, pressure is applied to the cover plate layer so that each droplet enters the space enclosed by the limiting grooves and the substrate layer and is isolated from each other. This can be achieved in the following two ways:

[0080] One implementation method is to pressurize the air valve cavity, causing the air valve cavity to move multiple limiting grooves toward the substrate layer until the opening surface of each limiting groove contacts the substrate layer, so that each droplet enters the space enclosed by each limiting groove and the substrate layer and is isolated from each other.

[0081] For specific implementation, see Figure 4 and Figure 13 Mineral oil or electronic fluorinated liquid, etc., can be added through the inlet 201 to seal the oil phase O until the entire solution container space S is filled; then, an appropriate amount of aqueous PCR reaction solution is added again through the inlet 201 to the position of the first electrode 1021, and the excess oil phase O is discharged through the outlet 202; at this time, driven by the first electrode 1021, the first connecting electrode 1024 and the third electrode 1023, the PCR reaction solution at the first electrode 1021 forms droplets W and disperses to each of the third electrodes 1023; after the droplets W are completely dispersed and on each of the third electrodes... After the liquid droplets are stably arranged at electrode 1023, the liquid inlet 201 is sealed, and the gas valve cavity 205 at reaction zone B is pressurized with gas so that the opening surfaces of each limiting groove 203 in the solution containing space S move down to contact the substrate layer 001. Thus, the limiting grooves 203 physically separate the arranged liquid droplets W and the surrounding oil phase O. Excess oil phase O flows out through the liquid outlet 202. After the deformation of the cover plate layer 002 stabilizes, the liquid inlet 201 and the liquid outlet 202 are sealed to complete the distribution of the reaction unit, so as to carry out subsequent temperature control cycle operation.

[0082] Another implementation involves applying pressure to the cover plate layer on the side away from the substrate layer using a heavy object until the opening surfaces of each limiting groove contact the substrate layer, allowing each droplet to enter the space enclosed by the limiting grooves and the substrate layer and thus isolate itself from the others. This implementation is similar to the one described above, except that a heavy object H is used to press down on the cover plate layer 002. See details... Figure 14 A weight H, with an area equal to that of all the limiting grooves 1023 and the protrusions therebetween, can be pressed down on the cover layer 002, causing the openings of the multiple limiting grooves 203 to move down to contact the substrate layer 001. This collects the droplets W within the space enclosed by the limiting grooves 203 and the substrate layer 001, completing the physical separation of the droplets W. Furthermore, the weight H can be integrated into the subsequent heating and temperature control device, for example, by placing it on the cover of a heating instrument. In this way, covering the instrument is equivalent to applying the weight H, allowing for immediate commencement of subsequent experimental procedures.

[0083] Based on the same inventive concept, this disclosure provides a microfluidic system as described above. Since the principle of solving the problem by this microfluidic system is similar to that of solving the problem by the microfluidic chip described above, the implementation of the microfluidic system provided in this disclosure can refer to the implementation of the microfluidic chip provided in this disclosure, and the repeated parts will not be described again.

[0084] Obviously, those skilled in the art can make various modifications and variations to the embodiments of this disclosure without departing from the spirit and scope of the embodiments of this disclosure. Therefore, if these modifications and variations to the embodiments of this disclosure fall within the scope of the claims of this disclosure and their equivalents, this disclosure is also intended to include these modifications and variations.

Claims

1. A microfluidic chip, wherein, include: A substrate layer, the substrate layer including a substrate substrate and a driving electrode layer located on the substrate substrate; A cover plate layer is placed opposite the substrate layer, and the space between the cover plate layer and the substrate layer constitutes a solution containing space; The cover plate layer includes an inlet hole and an outlet hole that penetrate the thickness direction of the cover plate layer, and a plurality of limiting grooves arranged in an array on the side of the cover plate layer facing the substrate layer. The inlet hole, the outlet hole and the plurality of limiting grooves are all in communication with the solution accommodating space, and the opening surfaces of the inlet hole adjacent to the end face of the substrate layer, the outlet hole adjacent to the end face of the substrate layer and the plurality of limiting grooves are substantially flush. The cover plate layer also includes a valve cavity that is independent of the plurality of limiting grooves, and an air inlet channel and an air outlet channel that are connected through the valve cavity. The valve cavity is located on the side of the plurality of limiting grooves away from the substrate layer, and the orthographic projection of the valve cavity on the substrate layer covers the orthographic projection of the plurality of limiting grooves on the substrate layer; wherein, the limiting groove is used to move to contact the substrate layer under pressure and collect each droplet into the limiting groove.

2. The microfluidic chip as described in claim 1, wherein, A reaction groove is provided on the side of the cover plate facing the substrate layer, and the reaction groove and the substrate layer form the solution accommodating space; The bottom surface of the reaction groove is approximately flush with the end face of the liquid inlet near the substrate layer, the end face of the liquid outlet near the substrate layer, and the opening surfaces of the plurality of limiting grooves.

3. The microfluidic chip as described in claim 2, wherein, The reaction groove and the plurality of limiting grooves are integrally injection molded.

4. The microfluidic chip as described in claim 3, wherein, The air valve cavity and the plurality of limiting grooves are integrally injection molded, or the part where the air valve cavity is located and the part where the plurality of limiting grooves are located are fixedly connected by a glue.

5. The microfluidic chip according to any one of claims 1 to 4, wherein, The volumes of the limiting grooves are approximately the same.

6. The microfluidic chip according to any one of claims 1 to 4, wherein, The driving electrode layer includes a first electrode, a second electrode, and a plurality of third electrodes arranged in an array. The orthographic projection of the first electrode on the substrate covers the orthographic projection of the liquid inlet hole on the substrate. The orthographic projection of the second electrode on the substrate covers the orthographic projection of the liquid outlet hole on the substrate. The orthographic projections of the plurality of third electrodes on the substrate overlap with the orthographic projections of the plurality of limiting grooves on the substrate.

7. The microfluidic chip as described in claim 6, wherein, The orthogonal projection of one of the limiting grooves on the substrate covers the orthogonal projection of at least one of the third electrodes on the substrate.

8. The microfluidic chip as described in claim 6, wherein, The substrate layer further includes a plurality of transistors located between the substrate and the driving electrode layer, the transistors being electrically connected to the third electrode.

9. The microfluidic chip as described in claim 6, wherein, The driving electrode layer further includes a plurality of first connecting electrodes, which are located between the first electrode and the plurality of third electrodes, and between the second electrode and the plurality of third electrodes.

10. The microfluidic chip as described in claim 9, wherein, A main channel region, a connecting channel region, and at least one branch channel region are respectively provided between the first electrode and the plurality of third electrodes, and between the second electrode and the plurality of third electrodes. The at least one branch channel region is connected to the main channel region through the connecting channel region. The main channel region is located adjacent to the first electrode and the second electrode, and the branch channel region is located adjacent to the plurality of third electrodes. A plurality of first connecting electrodes are respectively provided in the main channel region, the connecting channel region, and each of the branch channel regions.

11. The microfluidic chip according to any one of claims 1 to 4, wherein, The cover plate layer further includes: a first connecting channel and at least one liquid storage groove, wherein the orthographic projection of the first connecting channel on the substrate and the orthographic projection of the at least one liquid storage groove on the substrate do not overlap with the orthographic projection of the solution accommodating space on the substrate. The liquid storage groove is recessed from the surface of the cover plate layer away from the substrate layer toward the cover plate layer, the first connecting channel is located inside the cover plate layer, and the liquid storage groove is connected to the liquid inlet hole through the first connecting channel.

12. The microfluidic chip as described in claim 11, wherein, The liquid storage groove is multiple; the cover plate layer also includes a second connecting channel that connects each of the liquid storage grooves. The second connecting channel is located inside the cover plate layer, and the orthographic projection of the second connecting channel on the substrate does not overlap with the orthographic projection of the solution accommodating space on the substrate.

13. The microfluidic chip as described in claim 12, wherein, The driving electrode layer further includes: a fourth electrode corresponding to each of the liquid storage grooves, a plurality of second connecting electrodes corresponding to the first connecting channels and arranged in an array, and a plurality of third connecting electrodes corresponding to the second connecting channels and arranged in an array.

14. The microfluidic chip as described in claim 11, wherein, The liquid storage groove includes at least one of the following: sample storage groove, magnetic bead and lysis buffer storage groove, washing buffer storage groove, elution buffer storage groove, lysis waste liquid storage groove, washing waste liquid storage groove, magnetic bead waste liquid storage groove, and product storage groove.

15. The microfluidic chip as described in claim 1, wherein, The substrate layer further includes a hydrophobic layer disposed on the side of the driving electrode layer away from the substrate.

16. A microfluidic system, wherein, Including the microfluidic chip as described in any one of claims 1 to 15.

17. A method of using the microfluidic chip as described in any one of claims 1 to 15, wherein, include: The reaction solution is injected into the solution holding space through the inlet hole; An electrical signal is applied to the driving electrode layer, causing the reaction liquid to disperse into multiple droplets under the drive of the driving electrode layer; Pressure is applied to the cover plate layer so that each droplet enters the space enclosed by each limiting groove and the substrate layer and is isolated from each other; After the reaction is complete, the solution in the solution container is discharged through the liquid outlet.

18. The method of use as described in claim 17, wherein, Applying pressure to the cover plate layer causes each droplet to enter the space enclosed by the respective limiting grooves and the substrate layer, thereby isolating them from each other. Specifically, this includes: The air valve cavity is pressurized by inflating it, causing the air valve cavity to move the plurality of limiting grooves toward the substrate layer until the opening surface of each limiting groove contacts the substrate layer, so that each droplet enters the space enclosed by each limiting groove and the substrate layer and is isolated from each other.

19. The method of use as described in claim 17, wherein, Applying pressure to the cover plate layer causes each droplet to enter the space enclosed by the respective limiting grooves and the substrate layer, thereby isolating them from each other. Specifically, this includes: A weight is applied to the cover plate layer on the side away from the substrate layer until the opening surface of each of the limiting grooves contacts the substrate layer, so that each droplet enters the space enclosed by each of the limiting grooves and the substrate layer and is isolated from each other.

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