Microfluidic chip and application method

Abstract

The present invention relates to the field of microbial detection technology, and provides a microfluidic chip and an application method. The above-mentioned microfluidic chip includes a first main body layer, a flexible film, and a second main body layer that are stacked and bonded. The first main body layer is provided with a first sample cavity and a first liquid inlet structure, and the first liquid inlet structure is connected to the first sample cavity; the second main body layer is provided with a driving mechanism and a plurality of liquid inlets, and the flexible film is provided with a through groove to connect the first liquid inlet structure with the liquid inlet; the driving mechanism is used to drive the flexible film to lift up, and when the flexible film is in a falling state, the sample enters the first liquid inlet structure; when the flexible film is in a lifted state, the sample enters the liquid inlet from the first liquid inlet structure. The above-mentioned microfluidic chip can utilize the deformation of the flexible film to drive the first liquid inlet structure to inflate and discharge liquid, so that the multiple liquid inlets are filled with samples, and the discrete differentiation of the sample is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of microorganism detection, and in particular to a microfluidic chip and an application method thereof. Background Art

[0002] Existing analytical detection technologies can only achieve qualitative analysis in scientific research and industrial applications, with insufficient quantitative capabilities and low sensitivity. In social life and production, qualitative analysis alone is far from meeting current needs, especially in situations involving fluid property analysis, component detection and process control. Quantitative analysis is of great significance. In recent years, microfluidic technology has made great progress due to its advantages such as simple operation, low cost and small sample size. How to achieve qualitative analysis to quantitative analysis of samples through microfluidic technology has become an urgent problem to be solved in the industry. Summary of the invention

[0003] The present invention provides a microfluidic chip and an application method for realizing qualitative analysis to quantitative analysis of samples through microfluidic technology.

[0004] The present invention provides a microfluidic chip, comprising a first main body layer, a flexible film and a second main body layer which are stacked and bonded, wherein the first main body layer is a flexible main body layer; the first main body layer is provided with a first sample cavity and a first liquid inlet structure, the first liquid inlet structure is communicated with the first sample cavity, the first liquid inlet structure is arranged inside the first main body layer, and the first sample cavity is used to accommodate a sample; the second main body layer is provided with a driving mechanism and a plurality of liquid inlet parts, the plurality of liquid inlet parts are communicated in sequence, the flexible film is provided with a through groove so that the first liquid inlet structure is communicated with the liquid inlet part; the driving mechanism is used to drive the flexible film to lift up so that the first liquid inlet structure is blocked, when the flexible film is in a falling state, the first liquid inlet structure is turned on, and the sample enters the first liquid inlet structure; when the flexible film is in a lifting state, the first liquid inlet structure is blocked, and the sample enters the liquid inlet part from the first liquid inlet structure.

[0005] According to a microfluidic chip provided by the present invention, the first liquid inlet structure includes: a first flow channel, a liquid storage cavity and a second flow channel, the liquid storage cavity is connected to the first sample cavity through the first flow channel, the second flow channel is connected to the liquid storage cavity, and the second flow channel is connected to the through groove; when the flexible film is in a raised state, the first flow channel is blocked, and the sample in the liquid storage cavity enters the liquid inlet portion; when the flexible film is in a dropped state, the first flow channel is connected, and the sample in the first sample cavity enters the liquid storage cavity.

[0006] According to a microfluidic chip provided by the present invention, the driving mechanism includes: an air chamber and a driving component, a first groove is provided on the surface of the second main layer facing the flexible film, and the first groove forms the air chamber; the air chamber is connected to the driving component, and the driving component can be lifted up when the air chamber is pressed, and when the driving component is lifted up, the flexible film is lifted up.

[0007] According to a microfluidic chip provided by the present invention, the driving component includes: an inflation cavity and an air valve, a second groove is further provided on the surface of the second main layer facing the flexible film, the second groove is communicated with the first groove, the second groove forms the inflation cavity, and the inflation cavity is opposite to the liquid storage cavity; a third flow channel is further provided on the surface of the second main layer facing the flexible film, the third flow channel is communicated with the air chamber, an air bag is provided at the end of the third flow channel, the air bag forms the air valve, and the air valve is opposite to part of the first flow channel; when the air chamber is pressed, the inflation cavity and the air valve can be lifted up.

[0008] According to a microfluidic chip provided by the present invention, the volume of the air chamber is greater than the volume of the air-filled cavity.

[0009] According to a microfluidic chip provided by the present invention, a fourth flow channel is provided on the surface of the second main layer facing the flexible film, the fourth flow channel is connected to the liquid inlet, and the second flow channel, the through groove and the fourth flow channel are connected.

[0010] According to a microfluidic chip provided by the present invention, each of the liquid inlet parts includes a plurality of second liquid inlet structures, the plurality of second liquid inlet structures are connected in sequence, and one of the second liquid inlet structures is connected to the fourth flow channel.

[0011] According to a microfluidic chip provided by the present invention, each of the second liquid inlet structures includes: a fifth flow channel and a second sample chamber, along the flow direction of the sample, the end of the fifth flow channel is connected to the second sample chamber, the fifth flow channels of multiple second liquid inlet structures are connected in sequence, and one fifth flow channel is connected to the fourth flow channel.

[0012] According to a microfluidic chip provided by the present invention, each of the second liquid inlet structures further includes a sixth flow channel, and both ends of the sixth flow channel are respectively connected to the second sample chamber and the fifth flow channel of the next second liquid inlet structure; the connection point of the two fifth flow channels is located downstream of the sixth flow channel.

[0013] The present invention also provides an application method of the microfluidic chip as described above, comprising: driving the driving mechanism to lift up the flexible film, closing the first flow channel, and generating negative pressure in the liquid storage chamber; stopping driving the driving mechanism, causing the flexible film to fall, and the liquid storage chamber to absorb the sample into the liquid storage chamber using the negative pressure; driving the driving mechanism again to lift up the flexible film again, closing the first flow channel, generating negative pressure in the liquid storage chamber, and at the same time, the flexible film squeezes the liquid storage chamber to squeeze the sample into the liquid inlet.

[0014] The microfluidic chip provided by the present invention, by providing a driving mechanism and a flexible film, can utilize the deformation of the flexible film to drive the first liquid inlet structure to inlet and discharge liquid, so that multiple liquid inlet parts are filled with samples, achieving discrete differentiation of the samples, and facilitating quantitative analysis of the samples. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is an exploded view of the microfluidic chip provided by the present invention.

[0017] Figure 2 This is a front view of the microfluidic chip provided by the present invention.

[0018] Figure 3 It is a structural schematic diagram of the driving mechanism and the liquid inlet part.

[0019] Figure 4 Schematic diagram of the structure of each second liquid inlet structure.

[0020] Reference numerals:

[0021] 10. first main body layer; 11. first sample chamber; 12. first flow channel; 13. liquid storage chamber; 14. second flow channel;

[0022] 20. Flexible film;

[0023] 30. Second main body layer; 31. Liquid inlet; 32. Air chamber; 33. Inflatable cavity; 34. Third flow channel; 35. Air valve; 36. Fourth flow channel; 311. Second liquid inlet structure; 3111. Fifth flow channel; 3112. Second sample cavity; 3113. Sixth flow channel. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] Combine the following Figure 1-Figure 4 The microfluidic chip and application method of the present invention are described.

[0026] like Figure 1 As shown, the microfluidic chip includes: a first main body layer 10, a flexible film 20 and a second main body layer 30 which are stacked and bonded. The first main body layer 10 is a flexible main body layer. The first main body layer 10 is provided with a first sample cavity 11 and a first liquid inlet structure. The first liquid inlet structure is connected to the first sample cavity 11. The first liquid inlet structure is arranged inside the first main body layer 10. The first sample cavity 11 is used to accommodate the sample. The second main body layer 30 is provided with a driving mechanism and a plurality of liquid inlet parts 31. The plurality of liquid inlet parts 31 are connected in sequence. The flexible film 20 is provided with a through groove so that the first liquid inlet structure is connected to the liquid inlet part 31. The driving mechanism is used to drive the flexible film 20 to lift up so that the first liquid inlet structure is blocked. When the flexible film 20 is in a falling state, the first liquid inlet structure is turned on and the sample enters the first liquid inlet structure. When the flexible film 20 is in a lifted state, the first liquid inlet structure is blocked and the sample enters the liquid inlet part 31 from the first liquid inlet structure.

[0027] Specifically, a groove is provided on the surface of the first main body layer 10 away from the flexible film 20 to form a first sample cavity 11, and the first sample cavity 11 is used to accommodate the sample. The first liquid inlet structure is formed inside the first main body layer 10. When the driving mechanism is driven, the pressure inside the driving mechanism increases, thereby lifting the flexible film 20, and the flexible film 20 squeezes the first liquid inlet structure, so that the first liquid inlet structure is blocked from the first sample cavity 11, and the pressure inside the first liquid inlet structure increases. When the driving mechanism is released, the flexible film 20 falls, and the pressure inside the first liquid inlet structure decreases instantly to generate negative pressure, so that the sample in the first sample cavity 11 is sucked into the first liquid inlet structure.

[0028] The driving mechanism is driven again, and the pressure inside the driving mechanism increases again, thereby lifting the flexible film 20 again, and the flexible film 20 squeezes the first liquid inlet structure again. The first liquid inlet structure is squeezed, and the sample inside it is squeezed out, and the sample falls into the liquid inlet portion 31 in the second main body layer 30 through the through groove on the flexible film 20. When the driving mechanism is released, the flexible film 20 falls again, and the pressure inside the first liquid inlet structure decreases again instantly to generate negative pressure, and the sample in the first sample cavity 11 is sucked into the first liquid inlet structure again.

[0029] By repeating the above operation, the sample in the first sample chamber 11 can be continuously distributed to the multiple liquid inlets 31 until each liquid inlet 31 is filled with the sample, thereby achieving discrete differentiation of the sample. Since each liquid inlet 31 has an equal volume, quantitative analysis of the sample can be achieved.

[0030] In the embodiment of the present invention, the first main body layer 10 and the flexible film 20 are both made of flexible materials, so that when the flexible film 20 is lifted up, the first main body layer 10 can be driven to deform.

[0031] Optionally, in an embodiment of the present invention, the material of the flexible film 20 may be polydimethylsiloxane.

[0032] In an embodiment of the present invention, there are multiple liquid inlet parts 31 , which are arranged in parallel on the second main body layer 30 , and the multiple liquid inlet parts 31 are connected in sequence so that each liquid inlet part 31 is filled with the sample.

[0033] The microfluidic chip provided in the embodiment of the present invention, by providing a driving mechanism and a flexible film, can utilize the deformation of the flexible film to drive the first liquid inlet structure to inlet and discharge liquid, so that multiple liquid inlet parts are filled with samples, realizing discrete differentiation of the samples, and facilitating quantitative analysis of the samples.

[0034] like Figure 1 and Figure 2 As shown, in the embodiment of the present invention, the first liquid inlet structure includes: a first flow channel 12, a liquid storage cavity 13 and a second flow channel 14. The liquid storage cavity 13 is connected to the first sample cavity 11 through the first flow channel 12, the second flow channel 14 is connected to the liquid storage cavity 13, and the second flow channel 14 is connected to the through groove. When the flexible film 20 is in the lifted state, the first flow channel 12 is blocked, and the sample in the liquid storage cavity 13 enters the liquid inlet portion 31; when the flexible film 20 is in the dropped state, the first flow channel 12 is connected, and the sample in the first sample cavity 11 enters the liquid storage cavity 13.

[0035] Specifically, the first flow channel 12, the liquid storage cavity 13 and the second flow channel 14 are all formed inside the first main layer 10, the two ends of the first flow channel 12 are respectively connected to the first sample cavity 11 and the liquid storage cavity 13, and the second flow channel 14 runs through the surface where the first main layer 10 and the flexible film 20 are stacked.

[0036] When the driving mechanism is driven, the pressure inside the driving mechanism increases, and then the flexible film 20 is lifted up, and the flexible film 20 squeezes the first flow channel 12, so that the first flow channel 12 is blocked. At the same time, the flexible film 20 also squeezes the liquid storage chamber 13, and the pressure inside the liquid storage chamber 13 increases. When the driving mechanism is released, the flexible film 20 falls, the first flow channel 12 is connected, and the pressure inside the liquid storage chamber 13 is instantly reduced to generate negative pressure, so that the sample in the first sample chamber 11 is sucked into the liquid storage chamber 13.

[0037] The driving mechanism is driven again, and the pressure inside the driving mechanism increases again, thereby lifting the flexible film 20 again, and the flexible film 20 squeezes the first flow channel 12 and the liquid storage chamber 13 again. The liquid storage chamber 13 is squeezed, and the sample inside it is squeezed into the second flow channel 14. The sample passes through the through groove and enters the liquid inlet portion 31 of the second main body layer 30. When the driving mechanism is released, the flexible film 20 falls again, the first flow channel 12 is connected, and the pressure inside the liquid storage chamber 13 decreases again instantly to generate negative pressure, and the sample in the first sample chamber 11 is sucked into the liquid storage chamber 13 again.

[0038] like Figure 1 and Figure 3 As shown, the driving mechanism includes: an air chamber 32 and a driving component. A first groove is provided on the surface of the second main layer 30 facing the flexible film 20. The first groove forms the air chamber 32. The air chamber 32 is connected to the driving component. When the air chamber 32 is pressed, the driving component can be lifted up. When the driving component is lifted up, the flexible film 20 is lifted up.

[0039] Specifically, the flexible film 20 covers the second main body layer 30, so that the first groove forms a closed space, which is the air chamber 32. When the air chamber 32 is pressed, the gas in the air chamber 32 flows to the driving component, causing the pressure in the driving component to increase, and the driving component is lifted to lift the flexible film 20. When the air chamber 32 is released, the gas in the driving component flows into the air chamber 32, the driving component falls, and the flexible film 20 also falls.

[0040] Furthermore, if Figure 1 As shown, the driving assembly includes: an air filling cavity 33 and an air valve 35. A second groove is provided on the surface of the second main body layer 30 facing the flexible film 20, and the second groove is connected to the first groove. The first groove forms an air chamber 32, and the second groove forms an air filling cavity 33. The air filling cavity 33 is opposite to the liquid storage cavity 13. A third flow channel 34 is also provided on the surface of the second main body layer 30 facing the flexible film 20. The third flow channel 34 is connected to the air chamber 32. An air bag is provided at the end of the third flow channel 34. The air bag forms an air valve 35. The air valve 35 is opposite to a part of the first flow channel 12. When the air chamber 32 is pressed, the air filling cavity 33 and the air valve 35 can be lifted up.

[0041] Specifically, the second main body layer 30 is further provided with a second groove and a third flow channel 34 on the surface facing the flexible film 20, and the flexible film 20 covers the second groove and the third flow channel 34, and the second groove forms a closed cavity, thereby forming an inflation cavity 33. An air bag is provided at the end of the third flow channel 34 to form an air valve 35. When the air chamber 32 is pressed, the gas in the air chamber 32 flows into the inflation cavity 33 and the air valve 35, so that the inflation cavity 33 and the air valve 35 are lifted up. When the inflation cavity 33 is lifted up, the flexible film 20 is lifted up, and the flexible film 20 squeezes the liquid storage cavity 13; when the air valve 35 is lifted up, the flexible film 20 is lifted up, and the flexible film 20 squeezes the first flow channel 12. When the air chamber 32 is released, the gas in the inflation cavity 33 and the air valve 35 enters the air chamber 32, and the inflation cavity 33 and the air valve 35 fall down, and the flexible film 20 also falls down.

[0042] The microfluidic chip provided in the embodiment of the present invention can drive the flexible film to lift up or drop down by setting an air chamber, an inflation cavity and an air valve, thereby dispersing the sample in the first sample cavity to the liquid inlet part, realizing discrete differentiation of the sample. The operation process only requires pressing the air chamber, and no pumping mechanism is required for transportation. The operation is simple and convenient, and is suitable for use at the detection site.

[0043] like Figure 3 As shown, in the embodiment of the present invention, the surface of the second main layer 30 facing the flexible film 20 is provided with a fourth flow channel 36, the fourth flow channel 36 is connected to the liquid inlet 31, and the second flow channel 14, the through groove and the fourth flow channel 36 are connected.

[0044] Specifically, in this embodiment, the second flow channel 14, the through groove and the fourth flow channel 36 are aligned, wherein the second flow channel 14 penetrates the surface where the first main body layer 10 and the flexible film 20 are stacked. When the air chamber 32 is pressed again, the inflation cavity 33 and the air valve 35 are lifted up, and the flexible film 20 squeezes the liquid storage cavity 13 and the first flow channel 12. Since the first flow channel 12 is in a blocked state at this time, the sample in the liquid storage cavity 13 is squeezed to the second flow channel 14, and then falls into the fourth flow channel 36 through the through groove from the second flow channel 14, and then flows into the liquid inlet 31.

[0045] like Figure 3 As shown, in an embodiment of the present invention, each liquid inlet portion 31 includes a plurality of second liquid inlet structures 311 , and the plurality of second liquid inlet structures 311 are connected in sequence, wherein one second liquid inlet structure 311 is connected to the fourth flow channel 36 to distribute the sample into each second liquid inlet structure 311 .

[0046] like Figure 4As shown, each second liquid inlet structure 311 includes: a fifth flow channel 3111 and a second sample chamber 3112. Along the flow direction of the sample, the end of the fifth flow channel 3111 is connected to the second sample chamber 3112, and the fifth flow channels 3111 of the plurality of second liquid inlet structures 311 are connected in sequence, and one fifth flow channel 3111 is connected to the fourth flow channel 36.

[0047] Specifically, the end of each fifth flow channel 3111 is connected to a second sample chamber 3112 , and the fifth flow channels 3111 of the plurality of second liquid inlet structures 311 are sequentially connected so that the sample entering the fourth flow channel 36 can be gradually distributed into each second sample chamber 3112 .

[0048] Furthermore, each second liquid inlet structure 311 also includes a sixth flow channel 3113 , both ends of which are respectively connected to the second sample chamber 3112 and the fifth flow channel 3111 of the next second liquid inlet structure 311 , and the connection between the two fifth flow channels 3111 is located downstream of the sixth flow channel 3113 .

[0049] Specifically, when the sample flows along the fourth flow channel 36, it will not only enter the first fifth flow channel 3111, and then enter the first second sample cavity 3112 from the first fifth flow channel 3111, but also enter the second fifth flow channel 3111, and then enter the second second sample cavity 3112. In this embodiment, by providing the sixth flow channel 3113, when the first second sample cavity 3112 is full of sample, the excess sample can flow from the sixth flow channel 3113 to the second fifth flow channel 3111, and this can be repeated to ensure that the amount of sample in each second sample cavity 3112 is equal, thereby achieving quantitative distribution of the sample after discrete differentiation, so as to facilitate quantitative analysis of the sample.

[0050] Furthermore, after the air chamber 32 is pressed and then released, the sample will enter the liquid storage chamber 13 from the first sample chamber 11, and correspondingly, the sample will also flow back into the liquid storage chamber 13 from the fourth flow channel 36. Figure 4 For example, when liquid returns, the sample in the fifth flow channel 3111 of the first second liquid inlet structure 311 and the sample in the sixth flow channel 3113 both flow into the fifth flow channel 3111 of the second second liquid inlet structure 311, and the liquid in the second sample chamber 3112 of the first second liquid inlet structure 311 is pulled on both sides. The liquid in the fifth flow channel 3111 of the first second liquid inlet structure 311 is subjected to a first component force (return force) toward the fourth flow channel 36, a second component force toward the second sample chamber 3112, and a third component force toward the second fifth flow channel 3111, and the three forces cancel each other out, resulting in no impulse when the sample returns, so that the sample in the second sample chamber 3112 will not return.

[0051] After all the second sample chambers 3112 are filled with samples, the samples are left to stand for color development. After the samples are colored, photos are taken with a smart phone and uploaded to the developed APP for analysis of the test results to obtain quantitative analysis data.

[0052] The microfluidic chip provided in the embodiment of the present invention realizes sample differentiation through droplet discretization, and avoids sample backflow in the second sample chamber by combining the setting characteristics of the fifth flow channel and the sixth flow channel, thereby realizing quantitative distribution and quantitative detection after sample differentiation, reducing the skill requirements for operators, eliminating the need for complex pumping systems, facilitating on-site detection at the grassroots level, and saving detection costs.

[0053] The following examples illustrate the method of using the microfluidic chip provided in the embodiments of the present invention.

[0054] When the microfluidic chip provided in the embodiment of the present invention is used in the quantitative detection of influenza A virus nucleic acid in combination with influenza A virus recombinase-mediated isothermal nucleic acid amplification technology (Recombinase Aided Amplification, RAA):

[0055] Insert a disposable sterile sampling swab into the nasal cavity 1.5 cm away, rotate it right four times, rotate it left four times, and then soak it in buffer for 30 seconds. During this period, squeeze it four times and break the swab to obtain the liquid to be tested.

[0056] The test liquid and the prepared test liquid are dripped into the first sample cavity 11. Specifically, 4 drops of the test liquid are dripped, the freeze-dried powder reaction components are added, and the test liquid is dripped to the fixed scale line to ensure that the volume of the mixed liquid can fill the second sample cavity 3112.

[0057] The air chamber 32 is squeezed to push up the air valve 35, which pushes up the flexible film 20, thereby blocking the first flow channel 12. The pressure in the inflation cavity 33 increases to push up the flexible film 20, and the flexible film 20 squeezes the liquid storage cavity 13, increasing its pressure synchronously.

[0058] The air chamber 32 is released, and the air chamber 32 returns to its original state, the air valve 35 rebounds, the first flow channel 12 is connected, the pressure in the inflation cavity 33 decreases, the flexible film 20 falls, and the pressure in the liquid storage cavity 13 decreases instantly to generate negative pressure, and the negative pressure is used to suck the mixed liquid in the first sample cavity 11 into the liquid storage cavity 13.

[0059] The air chamber 32 is squeezed again, and the air valve 35 is lifted up by the pressure, blocking the first flow channel 12. The pressure in the inflation cavity 33 increases to lift the flexible film 20, and the flexible film 20 squeezes the liquid storage cavity 13, squeezing the mixed liquid to the fourth flow channel 36, and then flows from the fourth flow channel 36 to the second sample cavity 3112.

[0060] Repeat the above operation until each second sample cavity 3112 is filled with the mixed solution, and then let it stand until the mixed solution displays a fluorescent color.

[0061] After color development, photos are taken with a smartphone, and the results are analyzed using a self-developed app to provide quantitative data.

[0062] The microfluidic chip provided in the embodiment of the present invention can also be used in the quantitative detection of aflatoxin in Chinese medicine Ziziphus jujuba seeds in combination with aflatoxin total residue detection kit:

[0063] Weigh 2g of crushed spinach kernel sample into a 50ml centrifuge tube, add 5ml sample extract, oscillate for 5 minutes, and centrifuge at 4000 rpm at room temperature for 10 minutes; take 0.5ml of supernatant, add 0.5ml of deionized water, and mix well; take 200μl and add it to the first sample chamber 11, add 50µl of enzyme marker, add 50µl of antibody working solution, and then add working solution to the fixed scale line to ensure that the volume of the mixed solution can just fill the second sample chamber 3112.

[0064] The operation process of transferring the sample from the first sample chamber 11 to each second sample chamber 3112 is the same as that of the previous embodiment, so it will not be repeated. Correspondingly, the method of quantitative detection of the sample is also the same as that of the previous embodiment, so it will not be repeated.

[0065] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microfluidic chip, characterized in that: It comprises a first main body layer, a flexible film and a second main body layer which are stacked and bonded, wherein the first main body layer is a flexible main body layer; The first main body layer is provided with a first sample cavity and a first liquid inlet structure, the first liquid inlet structure is communicated with the first sample cavity, the first liquid inlet structure is arranged inside the first main body layer, and the first sample cavity is used to accommodate a sample; The second main body layer is provided with a driving mechanism and a plurality of liquid inlet parts, the plurality of liquid inlet parts are connected in sequence, and the flexible film is provided with a through groove so that the first liquid inlet structure is connected with the liquid inlet parts; The driving mechanism is used to drive the flexible film to lift up so that the first liquid inlet structure is blocked. When the flexible film is in a falling state, the first liquid inlet structure is turned on and the sample enters the first liquid inlet structure. When the flexible film is in a lifted state, the first liquid inlet structure is blocked, and the sample enters the liquid inlet portion through the first liquid inlet structure; A fourth flow channel is provided on the surface of the second main body layer facing the flexible film, the fourth flow channel is communicated with the liquid inlet portion, and the through groove is communicated with the fourth flow channel; Each of the liquid inlet parts includes a plurality of second liquid inlet structures, which are connected in sequence, and one of the second liquid inlet structures is connected to the fourth flow channel. Each of the second liquid inlet structures includes: a fifth flow channel and a second sample cavity. Along the flow direction of the sample, the end of the fifth flow channel is connected to the second sample cavity. The fifth flow channels of the plurality of second liquid inlet structures are connected in sequence, and one of the fifth flow channels is connected to the fourth flow channel. Each of the second liquid inlet structures also includes a sixth flow channel, and both ends of the sixth flow channel are respectively connected to the second sample cavity and the fifth flow channel of the next second liquid inlet structure; the connection point of the two fifth flow channels is located downstream of the sixth flow channel.

2. The microfluidic chip according to claim 1, characterized in that: The first liquid inlet structure comprises: a first flow channel, a liquid storage cavity and a second flow channel, the liquid storage cavity is connected with the first sample cavity through the first flow channel, the second flow channel is connected with the liquid storage cavity, and the second flow channel is connected with the through groove; When the flexible film is in a lifted state, the first flow channel is blocked, and the sample in the liquid storage cavity enters the liquid inlet portion; When the flexible film is in a falling state, the first flow channel is connected, and the sample in the first sample cavity enters the liquid storage cavity.

3. The microfluidic chip according to claim 2, characterized in that: The driving mechanism comprises: an air chamber and a driving assembly, a first groove is provided on the surface of the second main body layer facing the flexible film, and the first groove forms the air chamber; The air chamber is communicated with the driving assembly. When the air chamber is pressed, the driving assembly can be lifted up. When the driving assembly is lifted up, the flexible film is lifted up.

4. The microfluidic chip according to claim 3, characterized in that: The driving assembly comprises: an air-filling cavity and an air valve, and a second groove is further provided on the surface of the second main body layer facing the flexible film, the second groove is communicated with the first groove, the second groove forms the air-filling cavity, and the air-filling cavity is opposite to the liquid storage cavity; The surface of the second main body layer facing the flexible film is further provided with a third flow channel, the third flow channel is communicated with the air chamber, an air bag is provided at the end of the third flow channel, the air bag forms the air valve, and the air valve is opposite to a part of the first flow channel; When the air chamber is pressed, the inflation cavity and the air valve can be lifted up.

5. The microfluidic chip according to claim 4, characterized in that: The volume of the air chamber is greater than the volume of the air-filled cavity.

6. An application method of the microfluidic chip according to any one of claims 2 to 5, characterized in that: include: The driving mechanism is driven to lift the flexible film, the first flow channel is closed, and negative pressure is generated in the liquid storage chamber; The driving mechanism is stopped, the flexible film falls, and the liquid storage chamber uses negative pressure to suck the sample into the liquid storage chamber; The driving mechanism is driven again to lift up the flexible film again, the first flow channel is closed, negative pressure is generated in the liquid storage cavity, and at the same time, the flexible film squeezes the liquid storage cavity to squeeze the sample into the liquid inlet portion.

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