Micro-fluidic chip based on droplet splitting and fusion and manufacturing method thereof

Abstract

The invention discloses a micro-fluidic chip based on droplet splitting and fusion, through the design of an input end T-shaped structure and an output end multi-stage Y-shaped structure, the liquid concentration can be well and accurately controlled in space and time dimensions, a sample and a diluent are mixed by using the droplet splitting and fusion principle, the droplet size is controllable, and the detection accuracy is high. The concentration of the generated solution is easy to calculate and controllable, and a multiphase trace fluid with controllable concentration gradient is formed at the tail end to generate tiny liquid drops. The input end of the micro-fluidic chip does not need an accurate micro-flow pump to control the flow speed, and a specific concentration gradient can be realized only by using a common injector, so that the system cost is greatly reduced. The invention further provides a manufacturing method of the micro-fluidic chip.

Description

Technical Field

[0001] The present invention relates to the technical field of microfluidic devices, and in particular to a microfluidic chip based on droplet splitting and fusion and a manufacturing method thereof. Background Art

[0002] Microfluidics is an effective technology platform to generate stable gradients for cell behavior studies. Recent evidence suggests that recently, a universal gradient generation device has been proposed to generate gradients with only two starting solutions. A multi-stage solution divider is provided within the microchannel to limit diffusion mixing, so that gradients of arbitrary shapes can be generated. However, complex calculations are involved to determine the relative positions of the solution dividers for the gradient distribution. In addition, all the above-mentioned gradient generation devices are designed to generate gradients transverse to the mainstream. Chemical gradients can also be generated along the mainstream in microfluidic devices. Chemical gradients are generated by the diffusion of sample molecules. However, such gradient distributions have limited controllability.

[0003] In the research and application of microfluidic systems, an essential key link is the production of microfluidic molds. At present, the commonly used mold production methods at home and abroad are based on traditional photolithography technology. "Photolithography" refers to the process of transferring the pattern on the mask plate to a silicon wafer coated with photoresist with the help of light, and then undergoing post-baking, development, hard baking, etching, and other processes to successfully produce a microchannel structure on a silicon or glass substrate. The entire photolithography process must be completed in a standard clean laboratory environment by specially trained staff in strict accordance with the production process, and the quality and precision of the mask required in the photolithography are required to be high (usually a standard chrome plate is required).

[0004] At present, although the existing technology can generate concentration gradients at the microscale, it also has limitations. Most concentration gradient generation technologies cannot accurately control the distribution of concentration gradients as required. They only rely on changing the concentration of the injected fluid to change the concentration gradient, and the generated gradient is single. In addition, many concentration gradient generation devices have complex structures and place great demands on the manufacturing process of the device. At the same time, after the liquid enters the channel network from the concentration gradient generation device, part of the liquid may be retained in the corners of the channel, thereby interfering with the normal flow of the fluid, such as the most commonly used Christmas tree structure. And if you want to use the Christmas tree structure to generate an ultra-long concentration gradient, you need to add a large number of microchannel structures to form a large, complex and intertwined microchannel network.

[0005] The photolithography process has strict requirements on the surface quality of the substrate. The process is complex and requires expensive exposure and etching equipment. The cost is high, about one million yuan. The yield rate of the mask plate is low, and the entire photolithography process needs to be completed in a standard clean laboratory environment by specially trained staff in strict accordance with the production process. The photolithography process is complex, costly, and has a long cycle, which is the main bottleneck restricting the research and development of microfluidic technology in a non-clean environment. Traditional microfluidic chip processing technology hinders the rapid processing and preparation of microstructures of microfluidic chips. Summary of the invention

[0006] In order to solve the technical problems existing in the background technology, the present invention proposes a microfluidic chip based on droplet splitting and fusion and a manufacturing method thereof.

[0007] The present invention provides a microfluidic chip based on droplet splitting and fusion, comprising: two input parts and one output part;

[0008] The input part comprises a first input end, a second input end, a dispersed phase input end and two T-shaped input structures, the longitudinal ends of the two T-shaped structures are connected to the dispersed phase input end, and the first input end and the second input end are respectively connected to the first transverse ends of the two T-shaped input structures;

[0009] The output part includes a primary output structure and at least one secondary output structure, the primary output structure includes two Y-shaped structures, the two Y-shaped structures are arranged in parallel and the main road ends of the two Y-shaped structures are respectively connected to the second lateral ends of the two T-shaped input structures, and the adjacent branch ends of the two Y-shaped structures form a primary mixing chamber that is connected to each other, and the primary mixing chamber has a mixing output port;

[0010] The secondary output structure includes two end Y-shaped structures and at least one middle Y-shaped structure located between the two end Y-shaped structures, the end Y-shaped structures and the middle Y-shaped structure are arranged in parallel, the main road end of the end Y-shaped structure is connected to the outer branch end of the upper Y-shaped structure, the main road end of the middle Y-shaped structure is connected to the mixing output port of the primary mixing chamber, and the branch ends of adjacent Y-shaped structures form secondary mixing chambers that are connected to each other, and the secondary mixing chambers have mixing output ports;

[0011] The mixing output port of the terminal secondary output structure and the outer branch end of the end Y-shaped structure serve as the droplet output end.

[0012] Preferably, the output part includes multiple secondary output structures, and the number of middle Y-shaped structures of the multiple secondary output structures gradually increases in the direction away from the primary output structure. The main road end of each end Y-shaped structure is connected to the outer branch end of the previous end Y-shaped structure, and the main road end of the middle Y-shaped structure is connected to the mixing output port of the previous mixing chamber.

[0013] Preferably, the Y-shaped structures of the output parts have the same dimensions.

[0014] In the present invention, the proposed microfluidic chip based on droplet splitting and fusion can well control the liquid concentration in the dimensions of space and time through the T-shaped structure of the input end and the multi-stage Y-shaped structure design of the output end. The sample and the diluent are mixed by using the principle of droplet splitting and fusion. The droplet size is controllable, and the concentration calculation of the generated solution is simple and controllable. A multiphase microfluid with a controllable concentration gradient is formed at the end to generate tiny droplets. The input end of the microfluidic chip of the present invention does not need a precise microfluidic pump to control the flow rate, and only an ordinary syringe can be used to achieve a specific concentration gradient, which greatly reduces the system cost.

[0015] In addition, multi-component concentration gradients can be achieved simultaneously, allowing biological and chemical reactions to be carried out simultaneously at different drug concentrations. The concentration gradient fluid is divided into droplets, and each droplet can serve as a separate microreactor, which not only reduces cross contamination but also reduces the volume of the chip.

[0016] The present invention also proposes a method for manufacturing the above-mentioned microfluidic chip based on droplet splitting and fusion, comprising the following steps:

[0017] S1: Mask production; create chip mask pattern and print transparent mask sheet according to chip mask pattern;

[0018] S2: Making a positive mold; covering the surface of a glass slide with two layers of photosensitive dry film to form a glass slide with a photosensitive dry film layer, using a UV lamp to expose the glass slide using a transparent mask, so that the chip pattern on the mask is transferred to the photosensitive dry film layer through the principle of exposure imaging, and then the exposed glass slide is baked and developed with a developer, and finally heated and cured to obtain a photosensitive dry film with a chip mask pattern as a positive mold;

[0019] S3: Fabrication of microfluidic chips: Stir the PDMS prepolymer and curing agent to ensure uniform distribution of bubbles in the mixed liquid, and evacuate the mixed liquid through a vacuum dryer until the bubbles disappear; then pour the mixed liquid into a positive mold and put it into an oven for curing; cut and demold the chip mask pattern, and punch holes at the inlet and outlet to form a chip embryo; finally, treat the chip embryo with oxygen plasma, cover the photosensitive dry film side of the slide with a cover slip, and bond the two through a locking reaction to obtain a microfluidic chip.

[0020] Preferably, in S3, the ratio of the prepolymer to the curing agent is 10:1.

[0021] Preferably, in S3, pouring the mixed solution into the male mold is specifically, firstly wrapping the edge of the male mold with tin foil, then placing it in a culture dish, and then slowly pouring the prepared mixed solution into it to ensure that the PDMS is evenly distributed in the male mold and the liquid level is level;

[0022] Preferably, in S3, the mixed liquid is poured into the male mold and then vacuumed again.

[0023] Preferably, in S3, the chip embryo is subjected to oxygen plasma treatment, specifically, the cover sheet and the glass slide are placed in a plasma cleaning machine, the radio frequency power is 45W, and the oxygen plasma treatment time is 3 minutes.

[0024] The present invention provides a method for manufacturing a microfluidic chip based on droplet splitting and fusion, which is simple to prepare and low in cost, and can provide an economical scientific research experimental platform for the application of microfluidic chips. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic structural diagram of an implementation of a microfluidic chip based on droplet splitting and fusion proposed by the present invention.

[0026] Figure 2 This is a schematic structural diagram of the input portion of an implementation of a microfluidic chip based on droplet splitting and fusion proposed by the present invention.

[0027] Figure 3 The schematic diagram of the structure of the first-stage output structure of an implementation mode of a microfluidic chip based on droplet splitting and fusion proposed by the present invention.

[0028] Figure 4 This is a schematic structural diagram of the output end of an implementation mode of a microfluidic chip based on droplet splitting and fusion proposed by the present invention.

[0029] Figure 5 The present invention is a flowchart of an implementation method of a method for manufacturing a microfluidic chip based on droplet splitting and fusion.

[0030] Figure 6 This is a sample diagram of an implementation of a microfluidic chip based on droplet splitting and fusion proposed by the present invention. DETAILED DESCRIPTION

[0031] like Figures 1 to 6 As shown, Figure 1 This is a schematic diagram of the structure of an embodiment of a microfluidic chip based on droplet splitting and fusion proposed by the present invention. Figure 2 This is a schematic diagram of the structure of the input part of an embodiment of a microfluidic chip based on droplet splitting and fusion proposed by the present invention. Figure 3 This is a schematic diagram of the structure of the first-stage output structure of an embodiment of a microfluidic chip based on droplet splitting and fusion proposed by the present invention. Figure 4This is a schematic diagram of the structure of the output end of an embodiment of a microfluidic chip based on droplet splitting and fusion proposed by the present invention. Figure 5 This is a flow chart of an implementation method of a method for manufacturing a microfluidic chip based on droplet splitting and fusion proposed by the present invention. Figure 6 This is a sample diagram of an implementation of a microfluidic chip based on droplet splitting and fusion proposed by the present invention.

[0032] Reference Figures 1 to 4 , a microfluidic chip based on droplet splitting and fusion proposed by the present invention comprises: an input part and an output part;

[0033] The input part comprises a first input end 1, a second input end 2, a dispersed phase input end 3 and two T-shaped input structures, the longitudinal ends of the two T-shaped structures are connected to the dispersed phase input end 3, and the first input end 1 and the second input end 2 are respectively connected to the first transverse ends of the two T-shaped input structures;

[0034] The output part includes a primary output structure and at least one secondary output structure, the primary output structure includes two Y-shaped structures, the two Y-shaped structures are arranged in parallel and the main road ends of the two Y-shaped structures are respectively connected to the second lateral ends of the two T-shaped input structures, and the adjacent branch ends of the two Y-shaped structures form a primary mixing chamber 4 that is connected to each other, and the primary mixing chamber 4 has a mixing output port;

[0035] The secondary output structure includes two end Y-shaped structures and at least one middle Y-shaped structure located between the two end Y-shaped structures. The end Y-shaped structures and the middle Y-shaped structure are arranged in parallel. The main road end of the end Y-shaped structure is connected to the outer branch end of the upper Y-shaped structure. The main road end of the middle Y-shaped structure is connected to the mixing output port of the primary mixing chamber 4. The branch ends of adjacent Y-shaped structures form secondary mixing chambers 5 that are connected to each other. The secondary mixing chamber 5 has a mixing output port.

[0036] The mixing output port of the terminal secondary output structure and the outer branch end of the end Y-shaped structure serve as the droplet output end 6 .

[0037] An auxiliary channel is provided between the two main channels, and the main channel entrance is used to input drug reagents and auxiliary functional reagents or diluents of the drug reagents, and the middle auxiliary channel entrance is used to input silicone oil. The auxiliary channel outlets are respectively connected to the two main channels laterally to form two T-shaped structures. The two groups of droplets generated by the T-shaped structure are split into two groups of small droplets through the inverted Y-shaped structure, and then merged into the diffusion channel through the Y-shaped structure for fusion. Multiphase microfluids are used to generate tiny droplets, and the droplet size is controlled by adjusting the flow rate of the injection pump, and each droplet generated at the end is regarded as a microreactor.

[0038] The input part of this embodiment is provided with two T-shaped structures, and two groups of droplets are generated at the same time. The droplets are split by the inverted Y-shaped structure design, and the droplet fusion is realized by using the Y-shaped structure and the expansion structure. In this embodiment, the concentration gradient does not rely on diffusion mixing, but divides the diluent and the sample into two groups of droplets A and B. When the droplets flow through the differential structure, they are split into two groups, namely A11, A22 and B11, B12. A11 and B11 meet in the Y-shaped structure and mix in the expansion structure, and the generated droplet string is a first concentration droplet. The first concentration droplet flows through the bifurcated structure again and splits into two groups. After one group meets and mixes with A22 in the Y-shaped structure, it is diluted into a second concentration droplet with a concentration less than the first concentration, and after the other group meets and mixes with B12 in the Y-shaped structure, it is diluted into a third concentration droplet with a concentration greater than the first concentration. The chemical gradient distribution along the mainstream can control the sample solution distributed step by step and convection. The key component microchannel for stepwise distribution is to the Y-shaped structure. By increasing the number of stages of the split mixing structure, a complex and controllable gradient distribution can be generated.

[0039] In this embodiment, the proposed microfluidic chip based on droplet splitting and fusion can well control the liquid concentration in the dimensions of space and time through the T-shaped structure of the input end and the multi-stage Y-shaped structure design of the output end. The sample and the diluent are mixed by using the principle of droplet splitting and fusion. The droplet size is controllable, and the concentration calculation of the generated solution is simple and controllable. A multiphase microfluid with a controllable concentration gradient is formed at the end to produce tiny droplets. The input end of the microfluidic chip of the present invention does not require a precise microfluidic pump to control the flow rate, and only an ordinary syringe can be used to achieve a specific concentration gradient, which greatly reduces the system cost.

[0040] In the specific design of the output part, the output part includes multiple secondary output structures, the number of the middle Y-shaped structures of the multiple secondary output structures gradually increases in the direction away from the primary output structure, the main road end of each end Y-shaped structure is connected to the outer branch end of the upper end Y-shaped structure, and the main road end of the middle Y-shaped structure is connected to the mixing output port of the upper mixing chamber 4. A multi-stage output structure can be set as needed, so that the sample and the diluent are mixed in a gradient distribution, and finally at the end, droplets with a concentration that increases or decreases step by step from one end Y-shaped branch to the other end are obtained. With a multi-stage structure setting, the concentration gradient required by increasing or decreasing the number of stages is configured according to the detection requirements.

[0041] In actual design, the Y-shaped structures of the output parts have the same dimensions.

[0042] This embodiment also proposes a method for manufacturing the above-mentioned microfluidic chip based on droplet splitting and fusion, comprising the following steps:

[0043] S1: Mask production; create chip mask pattern and print transparent mask sheet according to chip mask pattern;

[0044] S2: Making a positive mold; covering the surface of a glass slide with two layers of photosensitive dry film to form a glass slide with a photosensitive dry film layer, using a UV lamp to expose the glass slide using a transparent mask, so that the chip pattern on the mask is transferred to the photosensitive dry film layer through the principle of exposure imaging, and then the exposed glass slide is baked and developed with a developer, and finally heated and cured to obtain a photosensitive dry film with a chip mask pattern as a positive mold;

[0045] S3: Fabrication of microfluidic chips: Stir the PDMS prepolymer and curing agent to ensure uniform distribution of bubbles in the mixed liquid, and evacuate the mixed liquid through a vacuum dryer until the bubbles disappear; then pour the mixed liquid into a positive mold and put it into an oven for curing; cut and demold the chip mask pattern, and punch holes at the inlet and outlet to form a chip embryo; finally, treat the chip embryo with oxygen plasma, cover the photosensitive dry film side of the slide with a cover slip, and bond the two through a locking reaction to obtain a microfluidic chip.

[0046] Specifically, the ratio of prepolymer to curing agent is 10:1.

[0047] Specifically, the mixed solution is poured into the male mold by first wrapping the edge of the male mold with tin foil, then placing it in a culture dish, and then slowly pouring the prepared mixed solution to ensure that the PDMS is evenly distributed in the male mold and the liquid level is level.

[0048] Specifically, the mixed liquid is poured into the male mold and then vacuumed again.

[0049] Specifically, the chip embryo is subjected to oxygen plasma treatment, specifically, the cover sheet and the glass slide are placed in a plasma cleaning machine, the radio frequency power is 45W, and the oxygen plasma treatment time is 3 minutes.

[0050] The mold is prepared by dry film method, and the channel size within 100 microns can be manufactured. The micro-machining technology that can be quickly carried out in ordinary laboratories can produce efficient and low-cost microfluidic chips, which can serve as a beneficial supplement to traditional classical microfluidic processing technology and provide an economical scientific research experimental platform for the application of microfluidic chips.

[0051] The microfluidic chip based on droplet splitting and fusion and the method for manufacturing the same are described in detail below through specific examples.

[0052] The technical solution adopted in this embodiment is as follows: a split-mixing microfluidic concentration gradient droplet chip, comprising a glass bottom plate, a PDMS substrate is arranged inside the glass bottom plate, two continuous phase inlets and one dispersed phase inlet are arranged on one side of the top of the PDMS substrate, and the two continuous phase channels and the dispersed phase channel form a T-shaped structure to generate two groups of droplets. An inverted Y-shaped structure is arranged at the output end of the T-shaped structure. A Y-shaped structure and a droplet fusion region are arranged at the output end of the inverted Y-shaped structure.

[0053] It is further defined that the output end of the continuous phase inlet is arranged in a horizontal direction, and the output end of the discrete phase inlet is arranged in a vertical direction.

[0054] It is further defined that the droplet fusion structure adopts an expansion channel structure.

[0055] It is further defined that the Y-shaped structure, the inverted Y-shaped structure and the droplet fusion structure are increased and expanded downward in sequence.

[0056] The beneficial effects of this embodiment are as follows: this embodiment generates two groups of droplets at the same time by setting two T-shaped structures, splits the droplets by an inverted Y-shaped structure design, and realizes droplet fusion by using a Y-shaped structure and an expansion structure. In this embodiment, the concentration gradient does not rely on diffusion mixing, but divides the diluent and the sample into two groups of droplets A and B. When the droplets flow through the differential structure, they split into two groups, namely A11, A22 and B11, B12. A11 and B11 meet in the Y-shaped structure and mix in the expansion structure, and the generated droplet string is a first concentration droplet. The first concentration droplets flow through the bifurcated structure again and split into two groups. One group meets and mixes with A22 in the Y-shaped structure, and is diluted into a second concentration droplet with a concentration less than the first concentration. The other group meets and mixes with B12 in the Y-shaped structure, and is diluted into a third concentration droplet with a concentration greater than the first concentration. The chemical gradient distribution along the mainstream can control the sample solution distributed stepwise and convectively. The key component microchannel for stepwise distribution is the Y-shaped structure. By increasing the number of stages of the split-mixing structure, complex and controllable gradient profiles can be generated.

[0057] Reference Figure 5 , a method for preparing a split-mixing microfluidic concentration gradient droplet chip, comprising the following steps:

[0058] S1: Mask production: Use AutoCAD program to create masks and use film printer to print high-resolution transparent film masks;

[0059] S2: preparation of positive mold; the glass slide is cleaned with anhydrous ethanol and deionized water and then dried, and then two layers of photosensitive dry film are covered on the surface of the glass slide to prepare a dry film layer with a thickness of 60 μm. The glass slide with the photosensitive dry film layer is placed at a temperature of 55°C and a pressure of 40 kPa and pressed for 1 min to complete the operation of removing bubbles and solidifying the film. Then, the drawn microfluidic chip design drawing is printed on a high-resolution transparent film as a mask, and then the glass slide is exposed with a UV lamp, so that the microfluidic chip design pattern on the mask is transferred to the photosensitive dry film layer through the principle of exposure imaging, so as to achieve the effect of solidifying the channel shape. Then, the exposed glass slide is baked at a high temperature of 95°C for 4 minutes, and then developed with a developer, and finally heated and cured with a heating plate, and the remaining photosensitive dry film pattern is the positive mold;

[0060] S3: Microfluidic chip fabrication: Weighing PDMS prepolymer and curing agent: Place weighing paper on the electronic balance, put the plastic cup in, then reset the balance, pour PDMS prepolymer into the plastic cup, pouring at a speed from fast to slow until 18g of PDMS prepolymer is obtained, then reset the balance, and use a plastic dropper to drop PDMS curing agent into the plastic cup until 1.8g of PDMS curing agent is obtained. The required ratio of prepolymer to curing agent is 10:1;

[0061] Stir until the mixture is evenly mixed: Use a rubber-tipped dropper or a glass rod to stir the PDMS prepolymer and curing agent until the bubbles in the mixture are evenly distributed;

[0062] Vacuuming: Place the plastic cup in a vacuum dryer for vacuuming. As bubbles will affect the observation of the situation in the microfluidic chip pipeline, all bubbles in the mixed liquid must disappear before proceeding to the next step.

[0063] Pour PDMS into the positive mold: First, wrap the edge of the positive mold silicon wafer with microchannel structure with tin foil, and then put it into the culture dish to prevent PDMS from overflowing during subsequent operations, and then slowly pour the configured PDMS to ensure that the PDMS on the positive mold is evenly distributed and the liquid level is good, with a thickness of about 1 mm;

[0064] Vacuuming: Since bubbles will still be generated during the pouring process, it is necessary to vacuum again until there are no bubbles at all;

[0065] Baking: Place the culture dish in an oven and adjust the temperature to 70°C. The curing time is about 1.5 hours.

[0066] Cutting and demolding: Use a scalpel to cut the part of the microfluidic channel into a suitable size, then demold it and clamp it into a culture dish with tweezers;

[0067] Punching: Since holes need to be opened at the two-phase inlet and outlet of the microfluidic channel to facilitate the insertion of the hose, a PDMS manual puncher is needed to perform vertical punching operations on the chip;

[0068] Bonding: The PDMS cover and glass slide with microfluidic channels are cleaned and dried with anhydrous ethanol and deionized water, and then placed in a plasma cleaner. The selected RF power is HIGH (about 45W), and the oxygen plasma treatment time is 3 minutes. After oxygen plasma treatment, take out the glass slide and PDMS cover from the plasma cleaner, and immediately use tweezers to fit the sides treated with oxygen plasma together. Since the silicon hydroxyl groups on the surfaces of the substrate and the cover can come into contact with each other, a condensation reaction can occur. The condensation reaction can cause irreversible and permanent bonding between the substrate and the cover, thus completing the production of the microfluidic chip.

[0069] In S2, the heat press machine was set to 55°C, 40 kPa, and the press was performed for 1 min at this setting.

[0070] In the S3, the required ratio of the prepolymer to the curing agent is 10:1.

[0071] During the punching process, all PDMS residues in the puncher and chip must be cleaned out.

[0072] The technical effects of this embodiment are as follows:

[0073] 1. A micro-fabrication technology that can be quickly carried out in ordinary laboratories to produce efficient and low-cost microfluidic chips. It can serve as a beneficial supplement to traditional classical microfluidic processing technology, provide an economical scientific research experimental platform for the application of microfluidic chips, and to a certain extent promote the promotion and rapid development of microfluidic technology.

[0074] 2. The feature of this embodiment is that it can generate tiny droplets using multiphase microfluids, and each droplet can be regarded as a microreactor. In addition, droplet microfluidics can perform operations such as droplet fusion, transportation, sorting and splitting, so it can be used in many research fields such as drug transportation, biochemical detection, cell culture, and screening of specific viruses.

[0075] 3. The preparation method mentioned in this embodiment is a beneficial supplement and attempt to the traditional photolithography and precision machining process, which can provide an economical scientific research experimental platform for more microfluidic chip applications and promote the application of microfluidic chips in various fields.

[0076] 4. This embodiment can accurately control the liquid concentration in the dimensions of space and time, thereby controlling the cell microenvironment, and has a very bright application prospect in cell research.

[0077] 5. This embodiment has low requirements for operators, high automation and stability, and increases the controllability of the concentration gradient, which is beneficial to generating multi-component controllable concentration gradients.

[0078] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A microfluidic chip based on droplet splitting and fusion, characterized in that: include: Two inputs and one output; The input portion comprises a first input end (1), a second input end (2), a dispersed phase input end (3) and two T-shaped input structures, wherein the longitudinal ends of the two T-shaped structures are connected to the dispersed phase input end (3), and the first input end (1) and the second input end (2) are respectively connected to the first transverse ends of the two T-shaped input structures; The output part comprises a primary output structure and at least one secondary output structure, the primary output structure comprises two Y-shaped structures, the two Y-shaped structures are arranged in parallel and the main road ends of the two Y-shaped structures are respectively connected to the second lateral ends of the two T-shaped input structures, and the adjacent branch road ends of the two Y-shaped structures form a primary mixing chamber (4) that is connected to each other, and the primary mixing chamber (4) has a mixing output port; The secondary output structure comprises two end Y-shaped structures and at least one middle Y-shaped structure located between the two end Y-shaped structures, the end Y-shaped structures and the middle Y-shaped structure are arranged in parallel, the main road end of the end Y-shaped structure is connected to the outer branch end of the upper Y-shaped structure, the main road end of the middle Y-shaped structure is connected to the mixing output port of the primary mixing chamber (4), and the branch ends of adjacent Y-shaped structures form secondary mixing chambers (5) that are connected to each other, and the secondary mixing chambers (5) have a mixing output port; The mixing output port of the terminal secondary output structure and the outer branch end of the end Y-shaped structure serve as the droplet output end (6).

2. The microfluidic chip based on droplet splitting and fusion according to claim 1, characterized in that: The output section comprises a plurality of secondary output structures, wherein the number of the middle Y-shaped structures of the plurality of secondary output structures gradually increases in the direction away from the primary output structure, the main path end of each end Y-shaped structure is connected to the outer branch end of the previous end Y-shaped structure, and the main path end of the middle Y-shaped structure is connected to the mixing output port of the previous mixing chamber (4).

3. The microfluidic chip based on droplet splitting and fusion according to claim 1, characterized in that: The Y-shaped structures of the output parts have the same dimensions.

4. A method for manufacturing a microfluidic chip based on droplet splitting and fusion according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: Mask production; create chip mask pattern and print transparent mask sheet according to chip mask pattern; S2: Making a positive mold; covering the surface of a glass slide with two layers of photosensitive dry film to form a glass slide with a photosensitive dry film layer, using a UV lamp to expose the glass slide using a transparent mask, so that the chip pattern on the mask is transferred to the photosensitive dry film layer through the principle of exposure imaging, and then the exposed glass slide is baked and developed with a developer, and finally heated and cured to obtain a photosensitive dry film with a chip mask pattern as a positive mold; S3: Fabrication of microfluidic chips: Stir the PDMS prepolymer and curing agent to ensure uniform distribution of bubbles in the mixed liquid, and evacuate the mixed liquid through a vacuum dryer until the bubbles disappear; then pour the mixed liquid into a positive mold and put it into an oven for curing; cut and demold the chip mask pattern, and punch holes at the inlet and outlet to form a chip embryo; finally, treat the chip embryo with oxygen plasma, cover the photosensitive dry film side of the slide with a cover slip, and bond the two through a locking reaction to obtain a microfluidic chip.

5. The method according to claim 4, characterized in that: In S3, the ratio of prepolymer to curing agent is 10:

1.

6. The method according to claim 4, characterized in that: In S3, the mixed liquid is poured into the positive mold, specifically, firstly wrapping the edge of the positive mold with tin foil, then putting it into a culture dish, and then slowly pouring the prepared mixed liquid into it to ensure that the PDMS is evenly distributed in the positive mold and the liquid level is level.

7. The manufacturing method according to claim 6, characterized in that: In S3, the mixed liquid is poured into the male mold and then vacuumed again.

8. The manufacturing method according to claim 4, characterized in that: In S3, the chip The embryos were treated with oxygen plasma, specifically, the coverslips and slides were placed in a plasma cleaner. The RF power was 45 W, and the oxygen plasma treatment time was 3 min.

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