A microfluidic chip

Abstract

The present invention discloses a microfluidic chip, comprising a substrate and a cover plate arranged at the top of the substrate; a dispersed phase injection area, a continuous phase injection area, a first microfluidic channel, a second microfluidic channel, a mixing buffer zone, a third microfluidic channel and a reaction recovery zone are provided on the substrate; the dispersed phase injection area, the second microfluidic channel, the mixing buffer zone, the third microfluidic channel and the reaction recovery zone are connected in sequence; one end of the first microfluidic channel is connected to the continuous phase injection area; the other end of the first microfluidic channel is connected to the fourth microfluidic channel; the fourth microfluidic channel is connected to the second microfluidic channel through the fifth microfluidic channel and the sixth microfluidic channel in sequence; the sixth microfluidic channel is arranged perpendicular to the second microfluidic channel near one end of the second microfluidic channel; the third microfluidic channel and the fifth microfluidic channel are both arranged in a serpentine structure. The present invention can improve the mixing and dispersion effect and slow down the flow rate of droplets by arranging a mixing buffer zone and setting the third microfluidic channel in a serpentine structure, so that the droplets can be mixed more evenly.

Description

Technical Field

[0001] The present invention relates to the field of microfluidic technology, and more particularly to a microfluidic chip. Background Art

[0002] Microfluidic chips are the primary platform for implementing microfluidic technology. They can integrate essential analytical processes such as sample preparation, reaction, separation, and detection into a single, compact chip. Microchannels automate the entire analytical process, enabling the functionality of conventional chemical or biological laboratories. Microfluidic chips offer advantages such as compact size, minimal sample and reagent usage, rapid reaction speed, massive parallel processing capabilities, and disposable design. They hold enormous potential in fields such as biology, chemistry, and medicine. In recent years, they have developed into a new research field at the intersection of biology, chemistry, medicine, fluidics, electronics, materials, and mechanics. Droplet microfluidics, a key branch of microfluidic chip research, has recently evolved from traditional continuous-flow microfluidic systems and has found widespread application in biomedicine. Microdroplets often serve as microreactors, enabling biochemical reactions, rapid reagent mixing, and microparticle synthesis, significantly enhancing the inherent advantages of microfluidic chips, including low consumption, automation, and high throughput.

[0003] Chinese invention patent publication number CN109351369A discloses a microfluidic droplet generation chip, comprising a chip body, a sealing layer, a sample phase injection hole and a continuous phase injection hole extending through the upper and lower surfaces of the chip body, a droplet storage reservoir, and a continuous phase channel, a sample phase channel, a sample phase branch channel, a continuous phase filtration zone, and a sample phase filtration zone disposed on the lower surface of the chip body. The microfluidic droplet generation chip provided by the present invention generates droplets by varying the size and relative height of the flare connecting the sample phase channel and the continuous phase channel. This allows for rapid droplet generation without adjusting the pressure balance between the mobile phase and the continuous phase, with minimal dependence on the droplet flowability and the continuous phase flow rate ratio, resulting in no sample loss. The generation method is simple, easy to operate, and the generated droplets exhibit good uniformity and stability, offering significant advantages in practical applications, being simple and reliable.

[0004] However, although the microfluidic droplet generation chip in the above patent can make the generated droplets have good uniformity and stability, the problem of uneven mixing of droplets still exists.

[0005] Therefore, how to provide a microfluidic chip that can make liquid mixing more uniform is one of the technical problems that urgently need to be solved in this field. Summary of the Invention

[0006] In view of this, the present invention provides a microfluidic chip, the purpose of which is to solve the problems existing in the prior art.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A microfluidic chip comprises: a substrate and a cover plate arranged on the top of the substrate; the substrate is provided with a dispersed phase injection area, a continuous phase injection area, a first microfluidic channel, a second microfluidic channel, a mixing buffer area, a third microfluidic channel and a reaction recovery area; the dispersed phase injection area, the second microfluidic channel, the mixing buffer area, the third microfluidic channel and the reaction recovery area are connected in sequence; one end of the first microfluidic channel is connected to the continuous phase injection area; the other end of the first microfluidic channel is connected to the fourth microfluidic channel; the fourth microfluidic channel is connected to the second microfluidic channel in sequence through a fifth microfluidic channel and a sixth microfluidic channel; the sixth microfluidic channel is arranged perpendicular to the second microfluidic channel near one end of the second microfluidic channel; the third microfluidic channel and the fifth microfluidic channel are both configured as serpentine structures.

[0009] Preferably, the interior of the third microfluidic channel is divided into a left half area and a right half area relative to each other along its axial direction; the inner wall of the left half area is provided with a first contact area and a second contact area alternately distributed in sequence along the axial direction of the third microfluidic channel; the inner wall of the right half area is provided with a third contact area and a fourth contact area alternately distributed in sequence along the axial direction of the third microfluidic channel; the first contact area is arranged corresponding to the third contact area; the second contact area is arranged corresponding to the fourth contact area; the surface energy of the first contact area is different from the surface energy of the third contact area; the surface energy of the second contact area is different from the surface energy of the fourth contact area.

[0010] Preferably, the surface energy of the first contact area is greater than the surface energy of the third contact area; and the surface energy of the second contact area is less than the surface energy of the fourth contact area.

[0011] Preferably, the number of the fourth microchannels is two; the two fourth microchannels are arranged on the left and right sides of the end of the first microchannel away from the continuous phase injection region.

[0012] Preferably, the number of the sixth microfluidic channels is two; and the connections between the two sixth microfluidic channels and the second microfluidic channel are arranged opposite to each other.

[0013] Preferably, the reaction recovery zone includes a seventh microchannel, multiple reaction zones and multiple recovery zones; the seventh microchannel is connected to the end of the third microchannel away from the mixing buffer zone; each of the reaction zones is connected to the seventh microchannel; the number of the recovery zones is the same as that of the reaction zones, and they are arranged in a one-to-one correspondence; each of the recovery zones is connected to the corresponding reaction zone.

[0014] Preferably, the cover plate is provided with a recovery hole corresponding to the recovery area.

[0015] Preferably, a dispersed phase injection hole and a continuous phase injection hole are provided on the cover plate; the dispersed phase injection hole is arranged corresponding to the dispersed phase injection area; the continuous phase injection hole is arranged corresponding to the continuous phase injection area.

[0016] Compared with the prior art, the present invention has achieved the following technical effects:

[0017] 1) The present invention provides a mixing buffer zone and a serpentine structure for the third microchannel, which can improve the mixing and dispersion effect of the droplets and slow down the flow rate, thereby making the droplets more evenly mixed and dispersed, and thus enabling more reliable reaction data to be obtained after the droplets enter the reaction recovery zone;

[0018] 2) The present invention arranges a first contact area, a second contact area, a third contact area and a fourth contact area with different surface energies inside the third microchannel, so that the contact angles between the droplets and the inner walls of the different contact areas are different, thereby making the surface tensions generated between the liquid and the inner walls of the different contact areas different, and further making the droplets continuously deflected during the flow inside the third microchannel 8, thereby improving the mixing effect inside the droplets. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic structural diagram of a microfluidic chip of the present invention;

[0020] Figure 2 is a structural diagram of the substrate;

[0021] Figure 3 is a schematic diagram of the interior of the third microfluidic channel;

[0022] Figure 4 is a schematic diagram of the longitudinal section of the mixed buffer zone;

[0023] In the figure: 1. substrate; 2. cover plate; 3. dispersed phase injection area; 4. continuous phase injection area; 5. first microfluidic channel; 6. second microfluidic channel; 7. mixing buffer zone; 8. third microfluidic channel; 9. reaction recovery area; 901. seventh microfluidic channel; 902. reaction area; 903. recovery area; 10. fourth microfluidic channel; 11. fifth microfluidic channel; 12. sixth microfluidic channel; 13. first contact area; 14. second contact area; 15. third contact area; 16. fourth contact area; 17. recovery hole; 18. dispersed phase injection hole; 19. continuous phase injection hole; 20. eighth microfluidic channel. DETAILED DESCRIPTION

[0024] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 making creative efforts are within the scope of protection of the present invention.

[0025] Example

[0026] Reference Figure 1-4 As shown, the present invention discloses a microfluidic chip, comprising: a substrate 1 and a cover plate 2 arranged on the top of the substrate 1; a dispersed phase injection area 3, a continuous phase injection area 4, a first microfluidic channel 5, a second microfluidic channel 6, a mixing buffer area 7, a third microfluidic channel 8 and a reaction recovery area 9 are provided on the substrate 1; the dispersed phase injection area 3, the second microfluidic channel 6, the mixing buffer area 7, the third microfluidic channel 8 and the reaction recovery area 9 are connected in sequence; one end of the first microfluidic channel 5 is connected to the continuous phase injection area 4; the other end of the first microfluidic channel 5 is connected to the fourth microfluidic channel 10; the fourth microfluidic channel 10 is connected to the second microfluidic channel 6 in sequence through the fifth microfluidic channel 11 and the sixth microfluidic channel 12; the sixth microfluidic channel 12 is arranged perpendicular to the second microfluidic channel 6 near one end of the second microfluidic channel 6; the third microfluidic channel 8 and the fifth microfluidic channel 11 are both arranged in a serpentine structure; when in use, the continuous phase fluid enters the continuous phase injection area 4, the first microfluidic channel 5, In the fourth microchannel 10, the fifth microchannel 11 and the sixth microchannel 12, the dispersed phase fluid enters the dispersed phase injection area 3 and the second microchannel 6 in turn, and the dispersed phase fluid and the continuous phase fluid meet at the connection between the second microchannel 6 and the sixth microchannel 12. The dispersed phase fluid forms droplets under the action of the continuous phase fluid, and the formed liquid enters the reaction recovery area through the mixing buffer zone 7 and the third microchannel 8 in turn. In this process, by setting the fifth microchannel 11 to a serpentine structure, a buffering effect can be played on the continuous phase fluid, so that the continuous phase fluid reaches equilibrium and stability during its flow. At the same time, by setting the mixing buffer zone 7 and setting the third microchannel 8 to a serpentine structure, the mixing and dispersion effect of the droplets can be improved and the flow rate can be slowed down, so that the droplets can be mixed and dispersed more evenly, and more reliable reaction data can be obtained after the droplets enter the reaction recovery area 9.

[0027] In this embodiment, the interior of the third microfluidic channel 8 is divided into a left half area and a right half area relative to each other along its axial direction; the inner wall of the left half area is alternately distributed with the first contact area 13 and the second contact area 14 along the axial direction of the third microfluidic channel 8; the inner wall of the right half area is alternately distributed with the third contact area 15 and the fourth contact area 16 along the axial direction of the third microfluidic channel 8; the first contact area 13 is arranged corresponding to the third contact area 15; the second contact area 14 is arranged corresponding to the fourth contact area 16; the surface energy of the first contact area 13 is different from the surface energy of the third contact area 15; the surface energy of the second contact area 14 is different from the surface energy of the fourth contact area 16; by arranging the first contact areas with different surface energies inside the third microfluidic channel 8 Zone 13, the second contact zone 14, the third contact zone 15 and the fourth contact zone 16 make the contact angles between the droplet and the inner walls of different contact zones different, thereby making the surface tension generated between the liquid and the inner walls of different contact zones different (specifically, when the droplet is placed on a solid surface, if the solid surface energy is relatively high, the droplet is more likely to spread on the solid surface, showing good wettability, a smaller contact angle, and a smaller surface tension. On the contrary, if the solid surface energy is low, the droplet may be difficult to spread, showing poor wettability, a larger contact angle, and a larger surface tension), thereby causing the droplet to continuously deflect during the flow inside the third microfluidic channel 8, thereby improving the internal mixing effect of the droplet.

[0028] In this embodiment, the surface energy of the first contact region 13 is greater than the surface energy of the third contact region 15 ; and the surface energy of the second contact region 14 is less than the surface energy of the fourth contact region 16 .

[0029] In this embodiment, there are two fourth microchannels 10 ; the two fourth microchannels 10 are disposed on the left and right sides of the end of the first microchannel 5 away from the continuous phase injection region 4 .

[0030] In this embodiment, there are two sixth micro-channels 12 ; the two sixth micro-channels 12 are disposed opposite to the connection points with the second micro-channel 6 .

[0031] In this embodiment, the reaction recovery zone 9 includes a seventh microchannel 901, multiple reaction zones 902 and multiple recovery zones 903; the seventh microchannel 901 is connected to the end of the third microchannel 8 away from the mixing buffer zone 7; each reaction zone 902 is connected to the seventh microchannel 901; the number of recovery zones 903 is the same as that of the reaction zones 902, and they are arranged in one-to-one correspondence; each recovery zone 903 is connected to the corresponding reaction zone 902.

[0032] In this embodiment, a recovery hole 17 corresponding to the recovery area 903 is provided on the cover plate 2 .

[0033] In this embodiment, the cover plate 2 is provided with a dispersed phase injection hole 18 and a continuous phase injection hole 19 ; the dispersed phase injection hole 18 is arranged corresponding to the dispersed phase injection area 3 ; the continuous phase injection hole 19 is arranged corresponding to the continuous phase injection area 4 .

[0034] In this embodiment, both ends of the mixing buffer zone 7 are trumpet-shaped structures.

[0035] In this embodiment, the number of reaction zones 902 , recovery zones 903 and recovery holes 17 are all six.

[0036] In this embodiment, the dispersed phase injection zone 3 is connected to the second microchannel 6 through the eighth microchannel 20; the eighth microchannel 20 is composed of a gradually enlarging section and a gradually contracting section alternately arranged in sequence; by setting the eighth microchannel 20 as a structure in which the gradually enlarging section and the gradually contracting section are alternately connected, the dispersed phase can be continuously accelerated and decelerated alternately in the eighth microchannel 20, so that the dispersed phase can be mixed more evenly.

[0037] In this embodiment, the longitudinal section of the mixing buffer zone 7 is trapezoidal in shape, which can further improve the deceleration and mixing effect on the droplets.

[0038] In some other embodiments, the number of reaction zones 902, recovery zones 903 and recovery holes 17 can be designed according to actual conditions.

[0039] The above description is merely a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A microfluidic chip, characterized in that: include: A substrate (1) and a cover plate (2) arranged on the top of the substrate (1); a dispersed phase injection area (3), a continuous phase injection area (4), a first microfluidic channel (5), a second microfluidic channel (6), a mixing buffer area (7), a third microfluidic channel (8) and a reaction recovery area (9) are provided on the substrate (1); the dispersed phase injection area (3), the second microfluidic channel (6), the mixing buffer area (7), the third microfluidic channel (8) and the reaction recovery area (9) are connected in sequence; one end of the first microfluidic channel (5) is connected to the continuous phase injection area (4); the other end of the first microfluidic channel (5) is connected to the fourth microfluidic channel (10); the fourth microfluidic channel (10) is connected to the second microfluidic channel (6) in sequence through the fifth microfluidic channel (11) and the sixth microfluidic channel (12); the sixth microfluidic channel (12) is arranged perpendicular to the second microfluidic channel (6) near one end of the second microfluidic channel (6); the third microfluidic channel (8) and the fifth microfluidic channel (11) are both arranged in a serpentine structure; The interior of the third microfluidic channel (8) is divided into a left half region and a right half region relative to each other along its axial direction; the inner wall of the left half region is alternately distributed with a first contact area (13) and a second contact area (14) along the axial direction of the third microfluidic channel (8); the inner wall of the right half region is alternately distributed with a third contact area (15) and a fourth contact area (16) along the axial direction of the third microfluidic channel (8); the first contact area (13) is arranged corresponding to the third contact area (15); the second contact area (14) is arranged corresponding to the fourth contact area (16); the surface energy of the first contact area (13) is different from the surface energy of the third contact area (15); the surface energy of the second contact area (14) is different from the surface energy of the fourth contact area (16).

2. A microfluidic chip according to claim 1, characterized in that: The surface energy of the first contact area (13) is greater than the surface energy of the third contact area (15); and the surface energy of the second contact area (14) is less than the surface energy of the fourth contact area (16).

3. The microfluidic chip according to claim 1, characterized in that: The number of the fourth microchannels (10) is two; the two fourth microchannels (10) are arranged on the left and right sides of the first microchannel (5) away from one end of the continuous phase injection zone (4).

4. A microfluidic chip according to claim 3, characterized in that: The number of the sixth microchannels (12) is two; the two sixth microchannels (12) are arranged opposite to each other at the connection points with the second microchannel (6).

5. The microfluidic chip according to claim 1, characterized in that: The reaction recovery zone (9) includes a seventh microchannel (901), multiple reaction zones (902) and multiple recovery zones (903); the seventh microchannel (901) is connected to the end of the third microchannel (8) away from the mixing buffer zone (7); each of the reaction zones (902) is connected to the seventh microchannel (901); the number of the recovery zones (903) is the same as that of the reaction zones (902), and they are arranged in a one-to-one correspondence; each of the recovery zones (903) is connected to the corresponding reaction zone (902).

6. The microfluidic chip according to claim 5, characterized in that: The cover plate (2) is provided with a recovery hole (17) corresponding to the recovery area (903).

7. The microfluidic chip according to claim 1, characterized in that: The cover plate (2) is provided with a dispersed phase injection hole (18) and a continuous phase injection hole (19); the dispersed phase injection hole (18) is arranged corresponding to the dispersed phase injection area (3); and the continuous phase injection hole (19) is arranged corresponding to the continuous phase injection area (4).

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