High-performance droplet microfluidic chip based on three-dimensional superlubricity structure and magnetic control assistance

Abstract

The application discloses a high-performance droplet microfluidic chip based on a three-dimensional super-lubricating structure and magnetic control assistance, which comprises a three-dimensional super-lubricating structure substrate, two hydrophilic magnetic beads and a hydrophobic cover plate. A group of groove structures are arranged on the three-dimensional super-lubricating substrate according to experimental requirements, the groove structures comprise a plurality of grooves and micro flow channels for groove connection. The two hydrophilic magnetic beads comprise two hydrophilic magnetic beads. The hydrophilic magnetic beads enter the droplet to be tested through sample injection holes of the hydrophobic cover plate, and the droplet is pulled for merging, mixing and segmentation operation by adhesion between the magnetic beads and the droplet. The hydrophobic cover plate is arranged on the three-dimensional super-lubricating structure substrate in cooperation, the hydrophobic cover plate is provided with holes corresponding to positions of the grooves, and the operation of sample injection, detection and magnetic bead release of experimenters is facilitated. The three-dimensional super-lubricating surface is used as the substrate material of the microfluidic chip, so that the droplet to be tested has smaller loss in the transportation process and stronger anti-external interference capability.

Description

Technical Field

[0001] This invention relates to the field of microfluidic chip technology, specifically to a microfluidic chip that uses a magnetic field to control droplet transport on a superlubricated surface and mixes and separates droplets at specific sites. Background Technology

[0002] With the increasing aging of my country's population, the incidence of various diseases is constantly rising, putting significant pressure on the existing medical system. Microfluidic chips, with their significant advantages of speed, sensitivity, miniaturization, and low cost, have shown great potential in disease diagnosis and pollutant detection, attracting widespread attention. However, developing microfluidic chips that encompass sample processing, reaction, and real-time intelligent result analysis still presents considerable technical challenges. Magnetically controlled droplet microfluidic chips can leverage the non-contact nature of magnetic fields, rich operational functions, and ease of integration to achieve diversified reagent manipulation. After years of development, magnetically controlled droplet microfluidic chips have accumulated considerable expertise in analytical functional units, and currently can achieve functions such as droplet directional movement, mixing, and separation, providing technical support for diversified reagent processing.

[0003] However, current development of magneto-controlled droplet microfluidic chips suffers from limitations such as functional singularity. Researchers typically focus on a single function of these chips, resulting in limited performance and difficulty in device integration. Furthermore, traditional magneto-controlled droplet microfluidic chips require a magnetic field throughout the entire process, increasing the complexity and expertise required for manipulation, thus severely restricting the system's convenience, efficiency, and applicability. Therefore, the development of an integrated, high-performance magneto-controlled droplet microfluidic chip with low reagent consumption is urgently needed.

[0004] This invention proposes a high-performance microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance. The device consists of a hydrophobic cover plate, a three-dimensional superlubricated substrate, and hydrophilic-oleophobic magnetic beads. The hydrophobic cover plate provides a closed environment for droplet transport and incubation mixing processes, effectively suppressing droplet evaporation and improving detection accuracy. On the three-dimensional superlubricated structure layer, sample inlet grooves, incubation mixing grooves, detection grooves, fluid channels connecting the various functional areas, and a tip structure for synergistically cutting droplets with the dual magnetic beads are laser-etched. Compared to ordinary surfaces, the superlubricated surface effectively prevents reagent adhesion, improving the chip's anti-contamination properties. Simultaneously, the low adhesion resistance when droplets move on the superlubricated surface significantly reduces reagent loss due to adhesion during transport. The superlubricated substrate also possesses significant advantages such as structural stability and high mechanical strength, making the chip's stability and reusability higher than microfluidic chips with ordinary hydrophobic substrates. This invention controls the movement of two magnetic beads within a test droplet using dual magnets under a substrate, and relies on the adhesion between the hydrophilic magnetic beads and the droplet to pull the droplet for directional transport, achieving high response speed and high precision droplet manipulation. Simultaneously, a three-dimensional channel enables the droplet to move along a fixed trajectory between different functional areas. Furthermore, through the synergistic effect of the hydrophilic magnetic beads and the tip flow channel structure, the two magnetic beads pull the two ends of the droplet towards the flow channels on either side of the tip, thus completing the segmentation of a large droplet.

[0005] In summary, this invention presents a high-performance, full-function microfluidic chip based on a three-dimensional superlubricated structure, which enables droplet manipulation with low loss, strong resistance to external interference, and a simple and efficient process. Furthermore, by utilizing the synergistic effect of bihydrophilic magnetic beads and the special flow channel structure in the three-dimensional superlubricated layer to achieve droplet directional movement, merging, mixing, and separation, this droplet manipulation device exhibits significant advantages in high integration and high performance. Summary of the Invention

[0006] This invention proposes a high-performance, multifunctional droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance. The invention utilizes a three-dimensional superlubricated surface to reduce droplet resistance and adhesion loss during transport. Simultaneously, two hydrophilic magnetic beads are flexibly controlled by dual magnets at the bottom to achieve directional droplet movement. This invention achieves rapid and efficient manipulation of droplet movement, aggregation, and splitting through the synergistic effect between the magnetic beads and the inherent three-dimensional superlubricated structure, greatly simplifying the droplet manipulation process and resulting in a simple, versatile, widely applicable, high-performance, and multifunctional droplet microfluidic chip reactor.

[0007] The technical solution of the present invention is as follows:

[0008] A high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance is characterized by comprising a three-dimensional superlubricated structure substrate, dual hydrophilic magnetic beads, and a hydrophobic cap.

[0009] A set of groove structures is set on the three-dimensional superlubricated substrate according to experimental requirements. The groove structure includes multiple grooves, microchannels for groove connection, and a tip structure for working in conjunction with dual magnetic beads to complete droplet cutting.

[0010] The bihydrophilic magnetic beads include two hydrophilic magnetic beads. The bihydrophilic magnetic beads enter the droplet to be tested through the sample inlet of the hydrophobic cover plate. The droplet merging, mixing and splitting operations are achieved through the synergistic effect of the hydrophilic magnetic beads and the three-dimensional superlubricating structure.

[0011] The hydrophobic cover plate is fitted onto the three-dimensional superlubricated structure substrate. The cover plate has holes corresponding to the groove positions, facilitating sample introduction, testing, and magnetic bead placement by experimental personnel. Furthermore, the hydrophobic cover plate provides a sealed environment for the transport, incubation, and mixing of the test droplets, effectively suppressing droplet evaporation and improving anti-interference capabilities.

[0012] Furthermore, the three-dimensional superlubricated structure substrate has a length of 40-60 mm, a width of 20-40 mm, and a thickness of 3-8 mm. An injection groove for droplet introduction, an exit groove for droplet exit, a detection groove for droplet detection, a mixing groove for droplet mixing, a merging groove for droplet merging, a tip cutting structure for droplet segmentation, a waste liquid groove for waste liquid collection, a recovery groove for magnetic bead recovery, and microchannels connecting the various grooves are etched onto the superlubricated surface.

[0013] Furthermore, the surface of the amphiphilic magnetic beads is hydrophilic-oleophobic, the size of the amphiphilic magnetic beads is 0.5-1.5mm, and the amphiphilic magnetic beads are controlled and driven by two magnets at the bottom to directionally transport droplets.

[0014] Furthermore, the hydrophobic cover plate is 40-60mm long, 20-40mm wide, and 3-8mm thick. The hydrophobic cover plate has multiple holes with a diameter of 3-5mm. The hole positions correspond to the sample injection, sample removal, and detection grooves on the three-dimensional superlubricated substrate, making it more convenient for researchers to perform sample injection, sample removal, and detection operations through the holes.

[0015] Furthermore, under the control of the two magnets at the bottom, the bihydrophilic magnetic beads pull the droplets toward both sides of the tip structure to achieve the purpose of droplet cutting.

[0016] Furthermore, a magnetic stirring device is installed on the three-dimensional superlubricated structure substrate below the mixing groove. Through the rapid change of the magnetic poles, the two magnetic beads in the droplet rotate at high speed, so as to achieve full mixing of the reagent and the solution.

[0017] Furthermore, in the waste liquid groove on the three-dimensional superlubricated structure substrate, the bihydrophilic magnetic beads are simultaneously detached from the left and right sides of the droplet by the bottom magnetic field control, and the magnetic beads enter the recycling groove for reuse.

[0018] Furthermore, the preparation process of the superlubricating surface of the three-dimensional superlubricating structure substrate is as follows:

[0019] Use sandpaper to sand away the original oxide layer from an aluminum plate that is 20–40 mm wide, 60–100 mm long, and 3–8 mm thick.

[0020] The polished aluminum plate is then soaked in deionized water at 95°C for 1 hour to form a layer of nanostructured Al3O2.

[0021] The aluminum plate surface was hydrophobically treated with perfluorodecyltriethoxysilane using vapor deposition. The fluorosilane was deposited on the aluminum in a vacuum chamber and dried at 80°C for 12 hours.

[0022] The structure of the superhydrophobic matrix was examined using a scanning electron microscope. The contact angle between the substrate and the silicone oil was 3°, and the contact angle with water was 161°. By injecting a silicone oil-based ferrofluid into the superhydrophobic substrate, a superlubricated surface can be obtained.

[0023] Furthermore, the preparation process of the hydrophilic magnetic beads is as follows:

[0024] First, the magnetic beads are etched using a mixed solution of hydrochloric acid, hydrofluoric acid, and deionized water. Then, the magnetic beads are washed with ethanol, acetone, and deionized water and dried with nitrogen.

[0025] The operation process of a high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance includes the following steps:

[0026] Directional transport of droplets:

[0027] 1) Drop the test solution into the injection groove;

[0028] 2) Then, two hydrophilic magnetic beads are added into the droplet;

[0029] 3) Apply two magnets to the bottom to attract the corresponding hydrophilic magnetic beads;

[0030] 4) By controlling the magnet, the hydrophilic magnetic beads can drive the droplets for directional transport;

[0031] Droplet splitting operation:

[0032] 4) Introduce all the droplets to be split into the groove;

[0033] 5) Control the movement of the two magnetic beads into the flow channels on both sides of the tip-cutting structure respectively;

[0034] 6) After the droplet has completely passed through the tip-cutting structure, the large droplet is divided into two smaller droplets;

[0035] Droplet mixing operation:

[0036] 7) Introduce the droplets to be mixed into the mixing groove;

[0037] 8) Remove the magnet that originally controlled the magnetic bead;

[0038] 9) Replace with a magnetic stirrer;

[0039] 10) Turn on the magnetic stirrer; the two magnetic beads will rotate at high speed.

[0040] 11) Once the droplets are fully mixed, turn off the stirrer.

[0041] Compared with existing technologies, the beneficial effects of this invention are mainly reflected in:

[0042] This invention uses a super-lubricated surface as the substrate material for the microfluidic chip, which reduces the loss of the droplet during transportation and enhances its resistance to external interference.

[0043] This invention utilizes the synergistic effect of amphiphilic-oleophobic magnetic beads and a special flow channel structure to achieve droplet directional transport, merging, mixing, and cutting operations. This gives the chip the advantages of high integration and high performance, overcoming the pain point of the single function of past magnetically controlled microfluidic chips.

[0044] This invention differs from the traditional single-magnetic-bead mode that controls droplets with magnetic beads; the dual-magnetic-bead mode can improve the stability of droplet transport.

[0045] Instruction manual illustrations

[0046] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0047] Figure 2 This is a schematic diagram of an embodiment of the present invention;

[0048] Figure 3 This is a top view of the cover plate according to an embodiment of the present invention;

[0049] Figure 4 This is a top view of the three-dimensional superlubricating structure layer of the present invention as an embodiment;

[0050] In the diagram: A. Hydrophobic cover plate; B. Three-dimensional super-lubricated substrate; C. Groove structure; D. Tip-cut structure; E. Hole;

[0051] 1. Sample inlet; 2. Positive control solution inlet; 3. Negative control solution inlet; 4. Blank control group inlet; 5. Inlet; 6. Washing port; 7. Detection port; 8. Sample inlet groove; 9. Positive control solution inlet groove; 10. Negative control solution inlet groove; 11. Blank control group inlet groove; 12. Inlet groove; 13. Incubation and mixing groove; 14. Washing groove; 15. Color development groove; 16. Detection groove. Detailed Implementation

[0052] The present invention will be further described below with reference to the accompanying drawings.

[0053] As shown in the figure, a high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance includes a three-dimensional superlubricated structure substrate, hydrophilic magnetic beads, and a hydrophobic cover plate.

[0054] The three-dimensional superlubricated substrate features sample introduction grooves, mixing grooves, detection grooves, a tip cutting structure, waste liquid grooves, recovery grooves, merging grooves, and microchannels connecting the various functional areas. The three-dimensional superlubricated substrate, with a length of 40–60 mm, a width of 20–40 mm, and a thickness of 3–8 mm, has a superlubricated surface etched with microstructures for droplet introduction, effluent extraction, detection, merging, thorough mixing, and cutting, as well as microchannels connecting the grooves, according to experimental requirements. Researchers can control the magnets at the bottom to pull the test droplets between the grooves using bihydrophilic-oleophobic magnetic beads. Furthermore, the lubricating layer makes the magnetically controlled droplet transport more stable, reducing losses due to adhesion during transport.

[0055] The amphiphilic magnetic beads consist of two hydrophilic-oleophobic magnetic beads that enter the test droplet through the sample inlet groove to achieve multiple complex operations such as droplet merging, mixing, and splitting. The hydrophobic cover plate has corresponding holes on the base plate for the detection groove and sample inlet groove, facilitating sample introduction, detection, and bead placement by the experimenter. In this embodiment: the test sample inlet 1, positive control solution inlet 2, negative control solution inlet 3, blank control solution inlet 4, inlet 5, washing port 6, and detection port 7 correspond to the test sample inlet groove 8, positive control solution inlet groove 9, negative control solution inlet groove 10, blank control solution inlet groove 11, inlet groove 12, washing groove 14, and detection groove 16, respectively.

[0056] Hydrophilic magnetic beads are created by specially modifying the surface of ordinary magnetic beads to achieve a hydrophilic-oleophobic surface. These beads, ranging in size from 0.5 to 1.5 mm, move parallel to each other within a droplet, stabilizing its transport. The synergistic effect of the dual hydrophilic beads and a pointed cutting structure achieves droplet cutting. A magnetic stirring device is installed on a mixing groove substrate. Rapid changes in magnetic poles cause the dual magnetic beads within the droplet to rotate at high speed, ensuring thorough mixing of the reagent and solution. In a waste liquid groove, a bottom magnetic field controls the simultaneous detachment of the dual hydrophilic magnetic beads from the left and right sides of the droplet. The beads then enter a recycling groove for reuse by researchers.

[0057] The hydrophobic cover plate has multiple holes with a diameter of 3-5 mm drilled into it. The cover plate is 40-60 mm long, 20-40 mm wide, and 3-8 mm thick. The holes are located at the center of the superlubricated surface, corresponding to the sample injection groove, thorough mixing groove, detection groove, and magnetic bead recovery groove. The holes allow researchers to more conveniently perform multiple operations such as sample injection, sample removal, washing, and detection.

[0058] Preparation of superlubricated surfaces:

[0059] An aluminum plate with a width of 20–40 mm, a length of 60–100 mm, and a thickness of 3–8 mm was sanded to remove the original oxide layer. The sanded aluminum plate was then immersed in deionized water at 95°C for 1 hour to form a nanostructured Al3O2 layer. The aluminum plate surface was then hydrophobically treated with perfluorodecyltriethoxysilane using vapor deposition. This fluorosilane was deposited on the aluminum in a vacuum chamber and dried at 80°C for 12 hours. The structure of the superhydrophobic matrix was examined using a scanning electron microscope. The substrate showed a low contact angle with silicone oil (approximately 3°) and a high contact angle with water (161°). Injecting a silicone oil-based ferrofluid into this superhydrophobic substrate yielded a superlubricated surface.

[0060] Preparation of superhydrophilic-oleophobic magnetic beads:

[0061] First, etch the beads using a mixed solution of hydrochloric acid (40 ml), hydrofluoric acid (2.5 ml), and deionized water (12.5 ml); then, wash the beads with ethanol, acetone, and deionized water and dry them with nitrogen.

[0062] The specific operation of the directional transport of droplets in this invention is as follows:

[0063] 1) The experimenter drops the test liquid into the sample inlet groove;

[0064] 2) Then, two hydrophilic-oleophobic magnetic beads were added into the droplet;

[0065] 3) Apply two tiny magnets to the bottom to attract the corresponding magnetic beads;

[0066] 4) Researchers controlled magnets to make magnetic beads carry droplets in a directional manner.

[0067] The specific operation of droplet splitting in this invention is as follows:

[0068] 1) Introduce all the droplets to be split into the splitting groove;

[0069] 2) Control the movement of the two magnetic beads into the flow channels on both sides of the tip structure respectively;

[0070] 3) After the droplet has completely passed through the tip structure, the large droplet is divided into two smaller droplets.

[0071] The specific steps for ensuring thorough mixing of droplets in this invention are as follows:

[0072] 1) Introduce the droplets to be mixed into the mixing groove;

[0073] 2) Remove the tiny magnet that originally controlled the magnetic bead;

[0074] 3) Replace with a magnetic stirrer;

[0075] 4) Turn on the magnetic stirrer switch; the two magnetic beads will rotate at high speed.

[0076] 5) Once the droplets are fully mixed, turn off the stirrer.

[0077] Example

[0078] The detection of hepatitis B virus surface antigen (ELISA) was performed using a microfluidic chip.

[0079] The specific steps are as follows:

[0080] Add 200 μl of the sample to be tested to sample injection tank 8 and blank control injection tank 11 respectively. Add 200 μl of positive control solution to positive control injection tank 9 and 200 μl of negative control solution to negative control injection tank 10.

[0081] Two hydrophilic-oleophobic magnetic beads are placed in the sample injection tank 8, blank control injection tank 11, positive control solution injection tank 9, and negative control injection tank 10. The magnetic beads are controlled by a magnet at the bottom of the injection tank.

[0082] The spacing between the two magnetic beads is 5 mm, and the distance between the apex of the tip-cutting structure and the two magnetic beads is 2.5 mm. The two magnetic beads move towards the flow channels on both sides of the tip structure at a speed of 2 mm / s. The large droplet is cut into 100 μl droplets to be diluted and enters the dilution groove 12.

[0083] Add 20 μl of sample diluent to each of the six sample inlets 12 through the inlet 5.

[0084] After the diluent is added, a hydrophilic-oleophobic magnetic bead coated with HBsAb antibody is added to each of the six injection grooves 12 through injection port 5.

[0085] The two magnetic beads inside the droplet are controlled by the two magnets at the bottom of the chip, which pull the droplet in the six sample inlet grooves 12 to the closed incubation and mixing groove 13.

[0086] Turn on the heating magnetic stirring mechanism under the mixing groove 13, set the temperature to 37±5℃, and stir for 60±10min to ensure that the diluent is fully mixed with the test sample and the positive and negative control solutions.

[0087] After mixing is complete, the double magnetic beads inside the droplets are controlled by the magnet at the bottom of the chip, which pulls the droplets in the 6 mixing grooves back to the injection groove 12.

[0088] Add 50 μl of enzyme conjugate to each of the six injection grooves 12 through injection port 5.

[0089] The dual magnetic beads inside the droplet are controlled by the magnet at the bottom of the chip, which pull the droplet in the six sample inlet grooves 12 to the closed incubation and mixing groove 13.

[0090] Turn on the heating magnetic stirring mechanism under the incubation mixing groove 13, set the temperature to 37±5℃, and stir for 30±10min to ensure that the diluent is fully mixed with the test sample and the positive and negative control solutions.

[0091] The magnet at the bottom of the chip controls the dual magnetic beads inside the droplets, pulling the droplets in the six mixing grooves 13 to their corresponding washing tanks 14. At the same time, the magnet at the bottom of the chip controls the dual magnetic beads inside the droplets to pull the droplets in the blank control tank 4 into their corresponding washing tanks 14.

[0092] Use a magnet to firmly attach the magnetic beads to the bottom of the washing tank, pour out the liquid in the tank, clean the washing groove 5 times with washing liquid, and then pour out the washing liquid.

[0093] After washing, add 50 μl each of color developer A and B to the seven washing grooves 14 through washing hole 6.

[0094] The magnet at the bottom of the chip controls the two magnetic beads inside the droplet to pull the droplet in the washing groove 14 into the corresponding color developing groove 15.

[0095] Turn on the heating magnetic stirring mechanism under the color development groove 15, set the temperature to 37±5℃, and stir for 30±10 minutes to allow the proteins bound on the magnetic beads to fully react with the color developer.

[0096] After the color development is complete, the dual magnetic beads inside the droplet are controlled by the magnet at the bottom of the chip to pull the droplet in the color development groove 14 into the corresponding detection groove 16.

[0097] The measurement was performed using an ELISA reader at a wavelength of 450–650 nm. After zeroing the detection well 16 corresponding to the blank control well 11, the A value of each well was measured.

[0098] Interpretation of test results:

[0099] The average A value in the two detection grooves 16 corresponding to the positive control groove 9 must be ≥0.8, and the average A value in the two detection grooves 16 corresponding to the negative control groove 10 must be ≤0.1; otherwise, the experiment is invalid.

[0100] Negative determination: The average A value in the two detection grooves 16 corresponding to sample groove 8 is less than the critical value for HbsAg negative.

[0101] Positive determination: The average value of A in the two detection grooves 16 corresponding to sample groove 8 is greater than or equal to the critical value, indicating a positive result for HbsAg.

Claims

1. A high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance, characterized in that, Includes a three-dimensional super-lubricated substrate, dual hydrophilic magnetic beads, and a hydrophobic cover plate; A set of groove structures is provided on the three-dimensional super-lubricating structure substrate, and the groove structure includes multiple grooves and microchannels for groove connection. The amphiphilic magnetic beads include two hydrophilic magnetic beads; the amphiphilic magnetic beads can enter the droplet to be tested, and droplet merging, mixing and splitting operations are achieved through the synergistic effect of the amphiphilic magnetic beads and the three-dimensional superlubricated structure substrate. The hydrophobic cover plate is fitted onto the three-dimensional super-lubricated structure substrate. The hydrophobic cover plate has holes corresponding to the groove positions to facilitate the operation of sample injection, detection, and magnetic bead placement by experimental personnel. The three-dimensional superlubricated structure substrate is 40-60 mm long, 20-40 mm wide, and 3-8 mm thick. Its superlubricated surface can be etched with sample inlet grooves for droplet injection, sample outlet grooves for droplet ejection, detection grooves for droplet detection, mixing grooves for droplet mixing, merging grooves for droplet merging, tip cutting structures for droplet segmentation, waste liquid grooves for waste liquid collection, recovery grooves for magnetic bead recovery, and microchannels connecting the various grooves. The surface of the bihydrophilic magnetic beads is hydrophilic-oleophobic, and the size of the bihydrophilic magnetic beads is 0.5-1.5 mm. The bihydrophilic magnetic beads are controlled and driven by two magnets at the bottom of the three-dimensional superlubricated structure substrate to directionally transport droplets. The bihydrophilic magnetic beads, under the control of the two magnets at the bottom, pull the droplets toward both sides of the tip structure to achieve the purpose of droplet cutting.

2. The high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance according to claim 1, characterized in that, The hydrophobic cover plate is 40-60 mm long, 20-40 mm wide, and 3-8 mm thick. Multiple holes with a diameter of 3-5 mm are opened on the hydrophobic cover plate. The hole positions correspond to the grooves on the three-dimensional superlubricated substrate. Through the holes, researchers can more clearly observe the state of the droplet to be tested and recover the magnetic beads.

3. The high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance according to claim 1, characterized in that, A magnetic stirring device is installed on the three-dimensional superlubricated substrate below the mixing groove. Through the rapid change of the magnetic poles, the two magnetic beads in the droplet rotate at high speed, so as to achieve full mixing of reagent and solution.

4. The high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance according to claim 1, characterized in that, In the waste liquid groove on the three-dimensional super-lubricated structure substrate, the bihydrophilic magnetic beads are simultaneously detached from the left and right sides of the droplet by the bottom magnetic field control, and the magnetic beads enter the recycling groove for reuse.

5. A high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance as described in claim 1, characterized in that, The preparation process of the superlubricating surface of the three-dimensional superlubricating structure substrate is as follows: Remove the original oxide layer from an aluminum plate that is 20-40 mm wide, 60-100 mm long, and 3-8 mm thick using sandpaper. The polished aluminum plate is then soaked in deionized water at 90-100 ℃ for 1 hour to form a nanostructure layer. ; The aluminum plate surface was hydrophobically treated with perfluorodecyltriethoxysilane by vapor deposition. The fluorosilane was deposited on the aluminum in a vacuum chamber and dried at 80-90 °C for 12 hours. The structure of the superhydrophobic substrate was examined using a scanning electron microscope. The contact angle between the substrate and silicone oil was 2°-10°, and the contact angle with water was 150°-170°. By injecting a silicone oil-based ferrofluid into the superhydrophobic substrate, a superlubricated surface can be obtained.

6. The high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance according to claim 1, characterized in that, The preparation process of the hydrophilic magnetic beads is as follows: First, the magnetic beads are etched using a mixed solution of hydrochloric acid, hydrofluoric acid, and deionized water. Then, the magnetic beads are washed with ethanol, acetone, and deionized water and dried with nitrogen.

7. The application of the high-performance droplet microfluidic chip based on a three-dimensional superlubricated structure and magnetic control assistance as described in claim 1, characterized in that, Includes the following steps: Directional transport of droplets: 1) Drop the test solution into the injection groove; 2) Then, two hydrophilic magnetic beads are added into the droplet; 3) Apply two magnets to the bottom to attract the corresponding hydrophilic magnetic beads; 4) By controlling the magnet, the hydrophilic magnetic beads can drive the droplets for directional transport; Droplet splitting operation: 4) Introduce all the droplets to be split into the groove; 5) Control the movement of the two magnetic beads into the flow channels on both sides of the tip-cutting structure respectively; 6) After the droplet has completely passed through the tip-cutting structure, the large droplet is divided into two smaller droplets; Droplet mixing operation: 7) Introduce the droplets to be mixed into the mixing groove; 8) Remove the magnet that originally controlled the magnetic bead; 9) Replace with a magnetic stirrer; 10) Turn on the magnetic stirrer; the two magnetic beads will rotate at high speed. 11) Once the droplets are fully mixed, turn off the stirrer.

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