CN113318799A

CN113318799A - Microfluidic device, manufacturing method thereof and microbead screening method

Info

Publication number: CN113318799A
Application number: CN202110739783.5A
Authority: CN
Inventors: 白云飞; 席克瑞; 贾振宇; 雷登明; 林柏全; 秦锋
Original assignee: Shanghai Tianma Microelectronics Co Ltd
Current assignee: Shanghai Tianma Microelectronics Co Ltd
Priority date: 2021-06-30
Filing date: 2021-06-30
Publication date: 2021-08-31
Anticipated expiration: 2041-06-30
Also published as: CN113318799B

Abstract

The application provides a micro-fluidic device, a manufacturing method thereof and a bead screening method, wherein the micro-fluidic device comprises a first substrate and a second substrate which are arranged in a stacked mode, the first substrate comprises a first input flow channel, a first flow channel and a first output flow channel which are sequentially communicated, the second substrate comprises a second input flow channel, a second flow channel and a second output flow channel which are sequentially communicated, the first flow channel and the second flow channel comprise a first overlapping portion, the first overlapping portion is communicated with the first flow channel and the second flow channel, and the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the first flow channel on the plane where the first substrate is located and is also located in the projection of the second flow channel on the plane where the first substrate is located. The microfluidic device is formed by etching and bonding, and the structure is simple and easy to manufacture. When the microbead samples with different densities enter the first flow channel, part of microbeads float or sink, enter the second flow channel through the first overlapping part and are extracted, the microbead screening and extracting process is simple and easy to operate, and the microbead pollution risk can be reduced.

Description

Microfluidic device, manufacturing method thereof and microbead screening method

Technical Field

The application relates to the technical field of microfluidics, in particular to a microfluidic device, a manufacturing method thereof and a microbead screening method.

Background

Microfluidics refers to systems that process or manipulate minute fluids of nanoliter to attoliter volumes using microchannels of tens to hundreds of microns in size, an emerging interdiscipline that involves chemistry, fluid physics, microelectronics, and biology. In the fields of biology and chemistry, target microbeads generally need to be screened and extracted from different types of microbeads, so that subsequent target microbeads can be subjected to chemical reaction, detection and other work. The existing microsphere screening method comprises a displacement reaction, and then the microsphere is extracted by using the steps of centrifugation, precipitation and the like according to the conditions, so that the microsphere is easily damaged and broken, and the physicochemical state of the microsphere is inevitably influenced.

Disclosure of Invention

In view of the above, the invention provides a microfluidic device, a manufacturing method thereof and a bead screening method, so as to solve the problems of complicated steps, high bead pollution risk and the like in bead screening and extraction in the prior art.

The invention provides a microfluidic device, which comprises at least one first substrate and at least one second substrate, wherein the first substrate comprises at least one first flow channel, the second substrate comprises at least one second flow channel, and the first substrate and the second substrate are arranged in a stacked manner; the first substrate further comprises at least one first input flow channel and at least one first output flow channel, the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel; the second substrate further comprises at least one second input flow channel and at least one second output flow channel, the second input flow channel and the second output flow channel are positioned at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel; the first flow channel and the second flow channel comprise at least one first overlapping part, the first overlapping part is communicated with the first flow channel and the second flow channel, the projection of the first overlapping part on the plane of the first substrate is located in the projection of the first flow channel on the plane of the first substrate, and the projection of the first overlapping part on the plane of the first substrate is located in the projection of the second flow channel on the plane of the first substrate.

Based on the same inventive concept, the invention also provides a manufacturing method of the microfluidic device, which comprises the following steps:

providing at least one first substrate and at least one second substrate; etching the first substrate to form at least one first flow channel, at least one first input flow channel and at least one first output flow channel, wherein the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel; etching the second substrate to form at least one second flow channel, at least one second input flow channel and at least one second output flow channel, wherein the second input flow channel and the second output flow channel are positioned at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel; bonding a first substrate and a second substrate, wherein the first substrate and the second substrate are arranged in a stacked mode, the first flow channel and the second flow channel comprise at least one first overlapping portion, the first overlapping portion is communicated with the first flow channel and the second flow channel, the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the first flow channel on the plane where the first substrate is located, and the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the second flow channel on the plane where the first substrate is located.

Based on the same inventive concept, the invention also provides a microbead screening method based on the microfluidic device, which comprises the following steps:

preparing a sample, wherein the sample comprises liquid and first microbeads and second microbeads with different densities, so that the first microbeads sink in the liquid and the second microbeads float upwards in the liquid; the liquid injection stage is that a sample is injected into the first input flow channel and flows into the first flow channel; in the screening stage, when a first substrate and a second substrate are sequentially arranged in the gravity direction, the first microbeads enter the second flow channel through the first overlapping part; or when the second substrate and the first substrate are arranged in sequence in the gravity direction, the second microbeads enter the second flow channel through the overlapping part; and in the extraction stage, liquid is injected into the second input flow channel, so that the microbeads in the second flow channel are discharged through the second output flow channel.

Compared with the prior art, the microfluidic device, the manufacturing method thereof and the bead screening method provided by the invention at least realize the following beneficial effects:

the invention provides a microfluidic device, which comprises at least one first substrate and at least one second substrate, wherein the first substrate comprises at least one first flow channel, the second substrate comprises at least one second flow channel, and the first substrate and the second substrate are arranged in a stacking manner; the first substrate further comprises at least one first input flow channel and at least one first output flow channel, the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel; the second substrate further comprises at least one second input flow channel and at least one second output flow channel, the second input flow channel and the second output flow channel are positioned at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel; the first flow channel and the second flow channel comprise at least one first overlapping part, the first overlapping part is communicated with the first flow channel and the second flow channel, the projection of the first overlapping part on the plane of the first substrate is located in the projection of the first flow channel on the plane of the first substrate, and the projection of the first overlapping part on the plane of the first substrate is located in the projection of the second flow channel on the plane of the first substrate. The microfluidic device is formed by etching and bonding, and the structure is simple and easy to manufacture. After a sample containing at least two microbeads with different densities enters the first flow channel from the first input flow channel, part of the microbeads float or sink due to different densities, enter the second flow channel through the first overlapping part and are extracted through the second output flow channel, and the microbead screening and extracting process is simple and easy to operate, so that the risk of microbead pollution is reduced.

Of course, it is not necessary for any product in which the present invention is practiced to specifically achieve all of the above-described technical effects simultaneously.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the provided drawings without creative efforts.

Fig. 1 is a schematic disassembled three-dimensional structure of a microfluidic device provided by the present invention;

FIG. 2 is a schematic diagram of a microfluidic device according to the present invention;

FIG. 3 is a cross-sectional view taken along A-A' of FIG. 2;

FIG. 4 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 5 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 6 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 7 is another cross-sectional view taken along A-A' of FIG. 2;

FIG. 8 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 9 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 10 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 11 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 12 is a cross-sectional view taken along line B-B' of FIG. 11;

FIG. 13 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 14 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 15 is a schematic view of another configuration of a microfluidic device provided by the present invention;

FIG. 16 is a schematic view of another configuration of a microfluidic device provided by the present invention;

fig. 17 is a schematic view of a method of making a microfluidic device provided by the present invention;

fig. 18 is a schematic view of a method of making a microfluidic device provided by the present invention;

FIG. 19 is a bead screening method using a microfluidic device according to the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The embodiments in the present description are described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other. The device disclosed by the embodiment corresponds to the method disclosed by the embodiment, so that the description is simple, and the relevant points can be referred to the method part for description.

Fig. 1 is a schematic diagram of a three-dimensional structure of a microfluidic device according to the present invention, fig. 2 is a schematic diagram of a structure of the microfluidic device according to the present invention, fig. 3 is a cross-sectional view taken along a-a' of fig. 2, and referring to fig. 1 to 3, the microfluidic device according to the present invention includes: the structure comprises at least one first substrate 1 and at least one second substrate 2, wherein the first substrate 1 comprises at least one first flow channel 11, the second substrate 2 comprises at least one second flow channel 21, and the first substrate 1 and the second substrate 2 are arranged in a stacked mode; the first substrate 1 further comprises at least one first input flow channel 12 and at least one first output flow channel 13, the first input flow channel 12 and the first output flow channel 13 are located at two ends of the first flow channel 11, and the first flow channel 11 is communicated with the first input flow channel 12 and the first output flow channel 13; the second substrate 2 further comprises at least one second input flow channel 22 and at least one second output flow channel 23, the second input flow channel 22 and the second output flow channel 23 are located at two ends of the second flow channel 21, and the second flow channel 21 is communicated with the second input flow channel 22 and the second output flow channel 23; the first flow channel 11 and the second flow channel 21 comprise at least one first overlapping part 50, the first overlapping part 50 is communicated with the first flow channel 11 and the second flow channel 21, the projection of the first overlapping part 50 on the plane of the first substrate 1 is positioned in the projection of the first flow channel 11 on the plane of the first substrate 1, and the projection of the first overlapping part 50 on the plane of the first substrate 1 is positioned in the projection of the second flow channel 21 on the plane of the first substrate 1.

Specifically, with continuing reference to fig. 1 to fig. 3, the microfluidic device provided by the present invention includes at least one first substrate 1 and at least one second substrate 2, where the first substrate 1 and the second substrate 2 are stacked, and fig. 1 illustrates a structure of the first substrate 1 and the second substrate 2 after being separated, and the stacked first substrate 1 and the stacked second substrate 2 are obtained after bonding the first substrate 1 and the second substrate 2. The first substrate 1 comprises at least one first flow channel 11, at least one first input flow channel 12 and at least one first output flow channel 13, the first input flow channel 12 and the first output flow channel 13 are positioned at two ends of the first flow channel 11, the first flow channel 11 is communicated with the first input flow channel 12 and the first output flow channel 13, and the first flow channel 11, the first input flow channel 12 and the first output flow channel 13 can be manufactured on the first surface 71 of the first substrate 1 through etching; the second substrate 2 includes at least one second flow channel 21, at least one second input flow channel 22 and at least one second output flow channel 23, the second input flow channel 22 and the second output flow channel 23 are located at two ends of the second flow channel 21, the second flow channel 21 is communicated with the second input flow channel 22 and the second output flow channel 23, and the second flow channel 21, the second input flow channel 22 and the second output flow channel 23 can be formed on the second surface 72 of the second substrate 2 by etching.

It is understood that, as shown in fig. 1, the first surface 71 and the second surface 72 are oppositely arranged, and the first surface 71 of the first substrate 1 and the second surface 72 of the second substrate 2 are bonded to each other in a face-to-face manner, so that the first substrate 1 and the second substrate 2 are arranged in a stacked manner, fig. 2 is a schematic diagram after the first surface 71 and the second surface 72 are bonded, the first flow channel 11 and the second flow channel 21 include at least one first overlapping portion 50, a projection of the first overlapping portion 50 on a plane where the first substrate 1 is located in a projection of the first flow channel 11 on a plane where the first substrate 1 is located, a projection of the first overlapping portion 50 on a plane where the first substrate 1 is located in a projection of the second flow channel 21 on a plane where the first substrate 1 is located, and the first overlapping portion 50 can communicate the first flow channel 11 with the second flow channel 21. The microfluidic device is formed by etching and bonding, and the structure is simple and easy to manufacture. After a sample containing at least two microbeads with different densities enters the first flow channel 11 from the first input flow channel 12, part of the microbeads float or sink due to different densities of the microbeads, enter the second flow channel 21 through the first overlapping part 50, are extracted through the second output flow channel 23, and are screened and extracted according to density differences among the microbeads and between the microbeads and sample liquid, the screening and extraction process is simple and easy to operate, other substances are not introduced, and the risk of microbead pollution is reduced; secondly, the sample liquid not containing the microbeads is introduced into the second input flow channel 22, so that the microbeads in the second flow channel 21 can be accelerated to flow out; optionally, in another embodiment, a gas is introduced into the second input flow channel 22, which can accelerate the outflow of the microbeads in the second flow channel 21, and the gas may be an inert gas; optionally, in another embodiment, a sample liquid containing the microbeads to be extracted is introduced into the second input flow channel 22, a part of the microbeads float or sink when the second flow channel 21 reaches the first overlapping portion 50, and the samples of the microbeads to be extracted are introduced into the first input flow channel 12 and the second input flow channel 22, so that the screening and extraction efficiency of the microbeads can be improved.

Alternatively, the material of the first substrate 1 and the second substrate 2 may be glass, quartz, PDMS (polydimethylsiloxane), PMMA (polymethyl methacrylate).

It should be noted that the widths of the first flow channel 11, the first input flow channel 12, the first output flow channel 13, the second flow channel 21, the second input flow channel 22, and the second output flow channel 23 in fig. 1 to 3 are only used for illustration, and cannot be used for comparing the widths of the flow channels.

It should be noted that, only 3 first flow channels 11 and 3 second flow channels 21 are illustrated in fig. 1 to fig. 3, and relevant practitioners may reasonably set the number of the first flow channels 11 and the second flow channels 21 according to actual needs, and 10 or even more than hundred may be set to improve the efficiency of bead screening and extraction; secondly, the number of the first flow channels 11 and the second flow channels 21 does not need to be correspondingly set, and the number of the same or different first flow channels 11 and second flow channels 21 can be reasonably set according to the actual width of the first substrate 1 and the second substrate 2.

In fig. 1 to 3, the first substrate 1 has only one first input flow channel 12 and one first output flow channel 13, three first flow channels 11 are arranged between the first input flow channel 12 and the first output flow channel 13 in parallel, the first input flow channel 12 communicates with the three first flow channels 11, the three first flow channels 11 communicate with the first output flow channel 13, the second substrate 2 has only one second input flow channel 22 and one second output flow channel 23, three parallel second flow channels 21 are arranged between the second input flow channel 22 and the second output flow channel 23, the second input flow channel 22 is divided into three portions to communicate with the three second flow channels 21, and the three second flow channels 21 and three portions are communicated with the second output flow channel 23.

Alternatively, as shown in fig. 4, fig. 4 is another schematic structural diagram of the microfluidic device provided by the present invention, in which the first flow channel 11 is disposed in one-to-one correspondence with the first input flow channel 12 and the first output flow channel 13, and the second flow channel 21 is disposed in one-to-one correspondence with the second input flow channel 22 and the second output flow channel 23. Fig. 4 shows three first runners 11 and three second runners 21, one end of each of the three first runners 11 is respectively connected to three first input runners 12, and the other end thereof is respectively connected to three first output runners 13, one end of each of the three second runners 21 is respectively connected to three second input runners 22, and the other end thereof is respectively connected to three second output runners 23, in other words, one end of each of the three first runners 11 is multiplexed as three first input runners 12, and the other end thereof is multiplexed as three first output runners 13, and one end of each of the three second runners 21 is multiplexed as three second input runners 22, and the other end thereof is multiplexed as three second output runners 23. When the microfluidic device of the present embodiment is used for screening and extracting microbeads, a sample containing at least two microbeads with different densities can enter the first flow channel 11 from the three first input flow channels 12, respectively, and then, after a part of the microbeads float or sink due to different densities of the microbeads, enter the second flow channel 21 through the first overlapping portion 50, and are extracted through the second output flow channel 23. It should be noted that, the relevant practitioner can reasonably set the number of the first flow passage 11, the first input flow passage 12, the first output flow passage 13, the second flow passage 21, the second input flow passage 22 and the second output flow passage 23 according to actual needs.

In one embodiment, referring to fig. 2, the first channel 11 extends along the Y direction; and/or the second flow channel 21 extends in the X direction, the Y direction intersecting the X direction.

Specifically, with continued reference to fig. 2, in the present embodiment, the first flow channel 11 extends along the Y direction, the second flow channel 21 extends along the X direction, the Y direction intersects the X direction, the first flow channel 11 and the second flow channel 21 extend in different directions, the first flow channel 11 and the second flow channel 21 may form a first overlapping portion 50, a projection of the first overlapping portion 50 on a plane where the first substrate 1 is located in a projection of the first flow channel 11 on a plane where the first substrate 1 is located, a projection of the first overlapping portion 50 on a plane where the first substrate 1 is located in a projection of the second flow channel 21 on a plane where the first substrate 1 is located, the first overlapping portion 50 communicates the first flow channel 11 with the second flow channel 21, and during the bead screening and extracting process, beads may only enter the first flow channel 11 or the second flow channel 21 from the first overlapping portion 50. As shown in fig. 2, the Y direction and the X direction may intersect in a mutually perpendicular manner; optionally, fig. 5 is another schematic structural diagram of the microfluidic device provided by the present invention, please refer to fig. 5, the Y direction and the X direction may intersect in an acute angle or an obtuse angle, and an included angle between the direction in which the first flow channel 11 extends and the direction in which the second flow channel 21 extends is an acute angle or an obtuse angle.

Optionally, fig. 6 is another schematic structural diagram of the microfluidic device provided by the present invention, please refer to fig. 6, the first flow channel 11 is arranged in an arc shape, the second flow channel 21 extends along the X direction, the overall extending direction of the first flow channel 11 is along the Y direction, a first overlapping portion 50 may be formed between the first flow channel 11 and the second flow channel 21, the first overlapping portion 50 communicates the first flow channel 11 and the second flow channel 21, and during the bead screening and extracting process, the beads may enter the first flow channel 11 or the second flow channel 21 only from the first overlapping portion 50. Optionally, the first flow channel 11 extends along the Y direction, the second flow channel 21 is disposed in an arc shape, the extending direction of the whole second flow channel 21 is along the X direction, the first flow channel 11 and the second flow channel 21 may form a first overlapping portion 50, and the first overlapping portion 50 communicates the first flow channel 11 and the second flow channel 21, which is not described in detail in this embodiment.

In an embodiment, referring to fig. 3 and 7, fig. 7 is another cross-sectional view taken along a-a' of fig. 2, a dimension H of the first overlapping portion 50 in a direction perpendicular to the first substrate 1 is greater than or equal to a sum of dimensions (H1+ H2) of the first flow channel 11 and the second flow channel 21 in the direction perpendicular to the first substrate 1.

Specifically, referring to fig. 3, the present embodiment provides that the dimension H of the first overlapping portion 50 in the direction perpendicular to the first substrate 1 is equal to the sum (H1+ H2) of the dimensions of the first flow channel 11 and the second flow channel 21 in the direction perpendicular to the first substrate 1, the dimension of the first flow channel 11 in the direction perpendicular to the first substrate 1 is H1, and the dimension of the second flow channel 21 in the direction perpendicular to the first substrate 1 is H2. It can be understood that the dimension H of the first overlapping portion 50 in the direction perpendicular to the first substrate 1 is equal to the sum (H1+ H2) of the dimensions of the first flow channel 11 and the second flow channel 21 in the direction perpendicular to the first substrate 1, the first surface 71 of the first substrate 1 and the second surface 72 of the second substrate 2 are oppositely bonded only by overlapping the first flow channel 11 and the second flow channel 21, the first overlapping portion 50 can be obtained at a position where the first flow channel 11 and the second flow channel 21 are communicated, and the first overlapping portion 50 is communicated with the first flow channel 11 and the second flow channel 21, and the manufacturing process of the microfluidic device of the present embodiment is simple.

Alternatively, referring to fig. 7, the present embodiment provides that the size H of the first overlapping portion 50 in the direction perpendicular to the first substrate 1 is greater than the sum of the sizes of the first flow channel 11 and the second flow channel 21 in the direction perpendicular to the first substrate 1 (H1+ H2). It is understood that the fifth substrate 5 is disposed between the first substrate 1 and the second substrate 2, the first surface 71 of the first substrate 1 provided with the first flow channel 11 is disposed opposite to the second surface 72 of the second substrate 2 provided with the second flow channel 21, the fifth channel 55 is disposed at the fifth substrate corresponding to the overlapping of the first flow channel 11 and the second flow channel 21 in the direction perpendicular to the first substrate 1, the fifth channel 55 can communicate the first flow channel 11 and the second flow channel 21, so that the fifth channel 55 and the first flow channel 11 and the second flow channel 21 at the overlapping constitute the first overlapping portion 50, and the dimension H of the first overlapping portion 50 in the direction perpendicular to the first substrate 1 is greater than the sum (H1+ H2) of the dimensions of the first flow channel 11 and the second flow channel 21 in the direction perpendicular to the first substrate 1. The size H of the first overlapped part 50 in the direction perpendicular to the first substrate 1 is prolonged, in the screening and extracting process of the microbeads, the retention time of the microbeads at the first overlapped part 50 can be increased, the situation that the microbeads enter wrong flow channels due to flowing of sample liquid is avoided, for example, the microbeads with high density float upwards to enter an upper flow channel, or the microbeads with low density sink to enter a lower flow channel is avoided, and the accuracy of microbead screening is effectively improved.

In an embodiment, referring to fig. 2 and 8, fig. 8 is another schematic structural diagram of the microfluidic device provided in the present invention, the second flow channel 21 includes a second main flow channel 212 and a second sub-flow channel 213, the second sub-flow channel 213 is located at an end of the second main flow channel 212 close to the second input flow channel 22, a width of the second sub-flow channel 213 is smaller than or equal to a width of the second main flow channel 212, and the width is a dimension of the flow channel perpendicular to an extending direction of the flow channel in a plane of the second substrate 2.

Specifically, with reference to fig. 8, the second flow channel 21 of the present embodiment includes a second main flow channel 212 and a second sub-flow channel 213, the second sub-flow channel 213 is located at an end of the second main flow channel 212 close to the second input flow channel 22, a width of the second sub-flow channel 213 is smaller than a width of the second main flow channel 212, and the width is a dimension of the flow channel perpendicular to the flow channel extending direction in a plane where the second substrate 2 is located. In the bead screening and extracting process, when the second input flow channel 22 is not filled with the sample liquid, the second sub-flow channel 213 with a smaller width can intercept the beads in the second flow channel 21, so as to prevent the beads entering the second flow channel 21 from the first flow channel 11 through the first overlapping portion 50 from flowing back to the second input flow channel 22, and the microfluidic device of the embodiment is used for screening and extracting the beads, so that the efficiency of the beads flowing out from the second output flow channel 23 can be effectively improved.

It should be noted that, when the microfluidic device of this embodiment is used to screen and extract microbeads, a sample liquid containing microbeads to be extracted is introduced from the first input flow channel 12, a part of the microbeads float or sink when the first flow channel 11 reaches the first overlapping portion 50, and a sample liquid containing no microbeads is introduced into the second input flow channel 22 to drive the microbeads in the second flow channel 21 to flow toward the second output flow channel 23 and flow out from the second output flow channel 23.

Please refer to fig. 8, one end of the second sub-flow channel 213 in the extending direction is connected to the second input flow channel 22, and the other end of the second sub-flow channel 213 in the extending direction is located between the first overlapping portion 50 and the second input flow channel 22. The second sub flow passage 213 and the second main flow passage 212 are collinear at the center line of their flow passage widths.

Alternatively, the other end of the second sub flow passage 213 in the extending direction may be connected to the first overlapping portion 50 (not shown in fig. 8), alternatively, both ends of the second sub flow channel 213 in the extending direction are not connected to the first overlapping portion 50 and the second input flow channel 22, the second sub flow channel 213 is located at one end of the second main flow channel 212 close to the second input flow channel 22, and the second sub flow channel 213 is ensured to be located between the first overlapping portion 50 and the second input flow channel 22, in the bead screening and extracting process, when the second input flow channel 22 is not filled with the sample liquid, the second sub-flow channel 213 with a smaller width can intercept the beads in the second flow channel 21, so as to prevent the beads entering the second flow channel 21 from the first flow channel 11 through the first overlapping portion 50 from flowing back to the second input flow channel 22, and the microfluidic device of the embodiment is used for screening and extracting the beads, so that the efficiency of the beads flowing out from the second output flow channel 23 can be effectively improved.

In one embodiment, referring to fig. 2, the first substrate 1 includes at least two first runners 11 arranged in parallel, the first input runner 12 includes a first input runner subsection 122 and a first input runner main body portion 121, the first input runner subsection 122 connects the two first runners 11 and the first input runner main body portion 121, and the first input runner subsection 122 intersects with the extending direction of the first input runner main body portion 121;

and/or the first outlet flow channel 13 comprises a first outlet flow channel subsection 132 and a first outlet flow channel main body part 131, the first outlet flow channel subsection 132 communicates the two first flow channels 11 and the first outlet flow channel main body part 131, and the first outlet flow channel subsection 132 intersects with the extending direction of the first outlet flow channel main body part 131;

and/or the second substrate 2 comprises at least two second runners 21 arranged in parallel, the second inlet runner 22 comprises a second inlet runner subsection 222 and a second inlet runner body part 221, the second inlet runner subsection 222 communicates the two second runners 21 and the second inlet runner body part 221, and the second inlet runner subsection 222 intersects with the extension direction of the second inlet runner body part 221;

and/or the second output flow channel 23 includes a second output flow channel subsection 232 and a second output flow channel main body portion 231, the second output flow channel subsection 232 communicates with the two second flow channels 21 and the second output flow channel main body portion 231, and the second output flow channel subsection 232 intersects with the extending direction of the second output flow channel main body portion 231.

Specifically, with continued reference to fig. 2, the first substrate 1 of the present embodiment includes at least two first runners 11 arranged in parallel, the first input runner 12 includes a first input runner subsection 122 and a first input runner main body portion 121, the first input runner subsection 122 connects the two first runners 11 and the first input runner main body portion 121, the number of the first runners 11 is not limited in the present embodiment, the number of the first runners 11 that can be arranged in parallel can be reasonably set according to the length of the first input runner subsection 122 in the extending direction, and the first input runner subsection 122 connects one end of the first runners 11 arranged in parallel, that is, during the bead screening and extracting process, the bead sample enters the first input runner subsection 122 at the first input runner main body portion 121, and then is distributed into each of the connected first runners 11; the first input flow-channel subsection 122 intersects with the extending direction of the first input flow-channel main body part 121, the first input flow-channel main body part 121 is arranged at the midpoint position of the first input flow-channel subsection 122 in the extending direction, in the bead screening and extracting process, when the bead sample flows into the first input flow-channel subsection 122, the bead sample is divided into two parts, then the bead sample is divided into two parts, the bead sample enters the first flow channel 11, and the bead screening and extracting efficiency can be improved after the bead screening and extracting process is carried out for a plurality of times.

Alternatively, the first inlet flow channel main body portion 121 may be provided at any position of the first inlet flow channel subsection 122 in the extending direction.

Referring to fig. 2, the extending direction of the first input flow channel main body portion 121 is the same as the extending direction of the first flow channel 11; optionally, the extending direction of the first input flow channel main body part 121 is not consistent with the extending direction of the first flow channel 11, and a relevant practitioner may reasonably set the extending direction of the first input flow channel main body part 121 and the extending direction of the first flow channel 11 according to actual needs.

It should be noted that the second substrate 2 includes at least two second runners 21 arranged in parallel, the second inlet runner 22 includes a second inlet runner subsection 222 and a second inlet runner main body portion 221, the second inlet runner subsection 222 communicates the two second runners 21 and the second inlet runner main body portion 221, the second inlet runner subsection 222 intersects with the extending direction of the second inlet runner main body portion 221, the second inlet runner main body portion 221 can be arranged at any position of the second inlet runner subsection 222 in the extending direction, whether the extending direction of the second inlet runner main body portion 221 is the same as the extending direction of the second runner 21 is not limited, and related workers can reasonably set the number of the second runners 21 arranged in parallel according to the length of the second inlet runner subsection 222 in the extending direction.

The first output flow path 13 includes a first output flow path branch 132 and a first output flow path main body portion 131, the first output flow path branch 132 communicates between the two first flow paths 11 and the first output flow path main body portion 131, the first output flow path branch 132 intersects with the extending direction of the first output flow path main body portion 131, the first output flow path main body portion 131 may be provided at any position of the first output flow path branch 132 in the extending direction, and whether the extending direction of the first output flow path main body portion 131 is the same as the extending direction of the first flow path 11 is not limited. The second output flow path 23 includes a second output flow path branch 232 and a second output flow path main body portion 231, the second output flow path branch 232 communicates with the two second flow paths 21 and the second output flow path main body portion 231, the second output flow path branch 232 intersects with the extending direction of the second output flow path main body portion 231, and the second output flow path main body portion 231 may be disposed at any position of the second output flow path branch 232 in the extending direction, without limiting whether the extending direction of the second output flow path main body portion 231 is the same as the extending direction of the second flow path 21.

In an embodiment, referring to fig. 9, fig. 9 is another schematic structural diagram of the microfluidic device provided in the present invention, the first output channel 13 further includes a first sub-portion 133, the first output channel sub-portion 132 connects the first sub-portion 133 and the first output channel main portion 131, and the first sub-portion 133 and the first output channel sub-portion 132 extend in the same direction; and/or the second outlet flow channel 23 further includes a second sub-portion 233, the second outlet flow channel subsection 232 communicates the second sub-portion 233 with the second outlet flow channel main portion 231, and the second sub-portion 233 extends in the same direction as the second outlet flow channel subsection 232.

Specifically, with continued reference to fig. 9, the first output flow channel 13 further includes a first sub-portion 133, the first output flow channel sub-portion 132 communicates with the first sub-portion 133 and the first output flow channel main body portion 131, the first sub-portion 133 communicates with one end of the first output flow channel sub-portion 132, and during the bead screening and extracting process, when the beads to be extracted enter the first output flow channel 13 from the first flow channel 11, the sample liquid containing no beads is input from the first sub-portion 133, so that the flow of the beads out of the first output flow channel 13 can be accelerated, and the bead screening and extracting efficiency can be improved; the first sub-section 133 and the first output flow-path subsection 132 extend in the same direction, and the beads flow from the first sub-section 133 into the first output flow-path subsection 132 along a straight line without passing through a flow-path having corners or turns, so that the possibility of breakage of the beads due to collision with the corners or turns of the flow-path can be reduced, and the bead screening and extraction efficiency can be improved in terms of ensuring the integrity of the beads.

Optionally, the embodiment further provides that the second output flow channel 23 further includes a second sub-portion 233, the second output flow channel sub-portion 232 communicates with the second sub-portion 233 and the second output flow channel main body portion 231, the second sub-portion 233 communicates with one end of the second output flow channel sub-portion 232, and in the bead screening and extracting process, when the beads to be extracted enter the second output flow channel 23 from the second flow channel 21, the sample liquid not containing the beads is input from the second sub-portion 233, so that the flow of the beads out of the second output flow channel 23 can be accelerated, and the bead screening and extracting efficiency can be improved; the second sub-section 233 and the second output flow-channel subsection 232 extend in the same direction, and the beads flow from the second sub-section 233 into the second output flow-channel subsection 232 along a straight line without passing through a flow-channel having a corner or turn, so that the possibility of breakage of the beads due to collision with the corner or turn of the flow-channel can be reduced, and the bead screening and extraction efficiency can be improved in terms of ensuring the integrity of the beads.

It should be noted that fig. 9 shows that the first output flow channel main body 131 is located at one end of the first output flow channel subsection 132, the first sub-section 133 is located at the other end of the first output flow channel subsection 132, optionally, the first output flow channel main body 131 is located at any position in the middle of the first output flow channel subsection 132, one first sub-section 133 may be respectively disposed at two ends of the first output flow channel subsection 132, the sample liquid not containing the microbeads is introduced into the two first sub-sections 133, and the microbeads in the first output flow channel subsection 132 are driven to flow into the first output flow channel main body 131 from two ends of the first output flow channel subsection 132, so that the efficiency of the bead screening and extraction can be improved.

Optionally, during the bead screening and extracting process, the first sub-section 133 and the first output flow channel main body 131 may be used to output the screened beads in the first output flow channel 13 at the same time; alternatively, the second sub-section 233 may be used to output the beads screened in the second output flow channel 23 simultaneously with the second output flow channel main body section 231.

In an embodiment, please refer to fig. 10, fig. 10 is another schematic structural diagram of a microfluidic device provided in the present invention, and the present embodiment provides that the first substrate 1 includes at least two first flow channels 11 arranged in parallel, the first input flow channel 12 includes a first input flow channel subsection 122 and a first input flow channel main body portion 121, the first input flow channel subsection 122 connects the two first flow channels 12 and the first input flow channel main body portion 121, and the first input flow channel subsection 122 and the first input flow channel main body portion 121 extend in the same direction; and/or the first outlet flow duct 13 comprises a first outlet flow duct subsection 132 and a first outlet flow duct main body part 131, the first outlet flow duct subsection 132 connects the two first flow ducts 11 and the first outlet flow duct main body part 131, and the first outlet flow duct subsection 132 extends in the same direction as the first outlet flow duct main body part 131; and/or the second substrate 2 comprises at least two second runners 21 arranged in parallel, the second inlet runner 22 comprises a second inlet runner subsection 222 and a second inlet runner body section 221, the second inlet runner subsection 222 communicates the two second runners 21 with the second inlet runner body section 221, and the second inlet runner subsection 222 extends in the same direction as the second inlet runner body section 221; and/or the second output flow channel 23 includes a second output flow channel subsection 232 and a second output flow channel main body portion 231, the second output flow channel subsection 232 communicates with the two second flow channels 21 and the second output flow channel main body portion 231, and the second output flow channel subsection 232 and the second output flow channel main body portion 231 extend in the same direction.

Specifically, with continued reference to fig. 10, the first substrate 1 of the present embodiment includes at least two first runners 11 arranged in parallel, the first input runner 12 includes a first input runner subsection 122 and a first input runner main body portion 121, the first input runner subsection 122 connects the two first runners 12 and the first input runner main body portion 121, the number of the first runners 11 in the embodiment is not limited, the number of the first runners 11 that can be arranged in parallel can be reasonably set according to the length of the first input runner subsection 122 in the extending direction, and the first input runner subsection 122 connects one end of the first runners 11 arranged in parallel, that is, during the bead screening and extracting process, the bead sample enters the first input runner subsection 122 at the first input runner main body portion 121 and then is distributed into each of the connected first runners 11; the first inlet flow-channel subsection 122 extends in the same direction as the first inlet flow-channel main body part 121, and during the bead screening and extraction process, the beads flow from the first inlet flow-channel main body part 121 into the first inlet flow-channel subsection 122 along the straight direction without passing through the flow channel having corners or turns, so that the possibility of bead breakage due to collision with the corners or turns of the flow channel can be reduced, and the bead screening and extraction efficiency can be improved in terms of ensuring the bead integrity.

Optionally, the first output flow channel 13 includes a first output flow channel subsection 132 and a first output flow channel main body part 131, the first output flow channel subsection 132 connects the two first flow channels 11 and the first output flow channel main body part 131, and the first output flow channel subsection 132 and the first output flow channel main body part 131 extend in the same direction; optionally, the second substrate 2 includes at least two second runners 21 arranged in parallel, the second inlet runner 22 includes a second inlet runner subsection 222 and a second inlet runner main body portion 221, the second inlet runner subsection 222 communicates the two second runners 21 and the second inlet runner main body portion 221, and the second inlet runner subsection 222 and the second inlet runner main body portion 221 extend in the same direction; optionally, the second output flow channel 23 includes a second output flow channel subsection 232 and a second output flow channel main body portion 231, the second output flow channel subsection 232 communicates with the two second flow channels 21 and the second output flow channel main body portion 231, the second output flow channel subsection 232 and the second output flow channel main body portion 231 extend in the same direction, in bead sorting and extraction, beads flow from the first outlet flow channel subsection 132 into the first outlet flow channel body section 131 in a linear direction, beads flow from the second inlet flow channel body section 221 into the second inlet flow channel subsection 222 in a linear direction, beads flow from the second outlet flow channel subsection 232 into the second outlet flow channel body section 231 in a linear direction without passing through a flow channel having corners or turns, the probability of breakage of the microbeads caused by collision or turning of the beads on the corners of the flow channel can be reduced, and the bead screening and extracting efficiency can be improved in the aspect of ensuring the completeness of the beads.

In an embodiment, referring to fig. 11 and 12, fig. 11 is another schematic structural diagram of a microfluidic device provided by the present invention, fig. 12 is a cross-sectional view taken along B-B' of fig. 11, and this embodiment provides that the width a2 of the second flow channel 21 is smaller than or equal to the width a1 of the first flow channel 11, and the width is the dimension of the flow channel in the plane of the second substrate 2 perpendicular to the extending direction of the flow channel.

With continuing reference to fig. 11 and 12, fig. 11 and 12 show that the width a2 of the second flow channel 21 is smaller than the width a1 of the first flow channel 11, in this embodiment, at the first overlapping portion 50, the first flow channel 11 points to the second flow channel 21 and is the same as the direction of gravity, when a sample containing microbeads with different sizes and different densities is introduced into the first flow channel 11 during the screening and extracting process of the microbeads, due to the density difference of the microbeads, a part of the microbeads float up or sink, and due to the size difference of the microbeads, at the first overlapping portion 50, the microbeads with larger density and smaller size enter the second flow channel 21 through the first overlapping portion 50 and are extracted through the second output flow channel 23, in this embodiment, the microbeads are screened and extracted according to the density between the microbeads, between the microbeads and the sample liquid, and the size difference between the microbeads and the first flow channel 11 and the second flow channel 21, the screening and extracting process is simple and easy to operate, no other substances are introduced, so that the risk of bead pollution is reduced; or, at the first overlapping portion 50, the first flow channel 11 is directed to the second flow channel 21 in the opposite direction to the gravity direction (not shown in fig. 12), in the bead screening and extracting process, a sample containing beads with different sizes and different densities is introduced into the first flow channel 11, and the beads with smaller densities and smaller sizes enter the second flow channel 21 through the first overlapping portion 50 and are extracted through the second output flow channel 23.

Optionally, the microfluidic device provided in this embodiment may be used to screen and extract microbeads with different sizes and the same density, in the process of screening and extracting the microbeads, a sample containing microbeads with different sizes and the same density is introduced from the first input flow channel 12 with a larger width, and the microbeads with a smaller size float or sink upward through the first overlapping portion 50 and enter the second flow channel 21, and are extracted through the second output flow channel 23.

It should be noted that the second input flow channel 22 may also be used as a sample into which microbeads with different sizes and different densities are introduced, and then the microbeads with different sizes and densities are screened and extracted according to the stacking direction of the first flow channel 11 and the second flow channel 21, and related technical personnel may reasonably set according to actual needs, which is not described in detail in this embodiment.

Optionally, with continuing reference to fig. 12, the present embodiment does not limit whether the depth b2 of the second flow channel 21 in the direction perpendicular to the plane of the first substrate 1 is the same as the width a2 of the second flow channel 21.

In an embodiment, fig. 13 is another schematic structural diagram of a microfluidic device provided by the present invention, fig. 14 is another schematic structural diagram of a microfluidic device provided by the present invention, please refer to fig. 13 and fig. 14, a first flow channel 11, a first input flow channel 12, a first output flow channel 13, a second flow channel 21, a second input flow channel 22, a second output flow channel 23 and a first overlapping portion 50 form a flow channel array layer, the microfluidic device includes a plurality of cascaded flow channel array layers, the first output flow channel 13 of an upper flow channel array layer 1A communicates with the first input flow channel 12 of a lower flow channel array layer 2A, the second output flow channel 23 of the upper flow channel array layer 1A does not communicate with the second input flow channel 22 of the lower flow channel array layer 2A; or, the second output runner 23 of the upper runner array layer 1A is communicated with the second input runner 22 of the lower runner array layer 2A, and the first output runner 13 of the upper runner array layer 1A is not communicated with the first input runner 12 of the lower runner array layer 2A.

With reference to fig. 13 and 14, the first flow channel 11, the first input flow channel 12, the first output flow channel 13, the second flow channel 21, the second input flow channel 22, the second output flow channel 23 and the first overlapping portion 50 form a flow channel array layer, the microfluidic device includes a plurality of cascaded flow channel array layers, fig. 13 shows that the first output flow channel 13 of the upper flow channel array layer 1A is communicated with the first input flow channel 12 of the lower flow channel array layer 2A, the second output flow channel 23 of the upper flow channel array layer 1A is not communicated with the second input flow channel 22 of the lower flow channel array layer 2A, and by connecting at least two flow channel array layers 1A and 2A in series, during the bead screening and extraction process, beads that are not completely separated in the upper flow channel array layer 1A can enter the first input flow channel 12 of the lower flow channel array layer 2A through the first output flow channel 13, and continue to be screened and extracted in the lower flow channel array layer 2A, through at least two-stage screening and extraction, the screening and extraction efficiency of the microbeads can be effectively improved. Fig. 14 shows that the second output flow channel 23 of the upper flow channel array layer 1A is communicated with the second input flow channel 22 of the lower flow channel array layer 2A, the first output flow channel 13 of the upper flow channel array layer 1A is not communicated with the first input flow channel 12 of the lower flow channel array layer 2A, and the microsphere screening and extraction efficiency can be effectively improved by at least two-stage screening and extraction.

It should be noted that the first output flow channel 13 of the upper flow channel array layer 1A is communicated with the first input flow channel 12 of the lower flow channel array layer 2A, a part of the microbeads are screened by the first flow channel 11 through the first overlapping portion 50 and enter the second flow channel 22, and can flow out and be collected through the second output flow channel 23, the second output flow channel 23 of the upper flow channel array layer 1A is not communicated with the second input flow channel 22 of the lower flow channel array layer 2A, so that the screened and extracted part of the microbeads can be prevented from flowing into the lower flow channel array layer 2A.

Optionally, referring to fig. 15, fig. 15 is another schematic structural diagram of the microfluidic device provided in the present invention, a first output flow channel 13 and a second output flow channel 23 of an upper flow channel array layer 1A may be respectively cascaded to a flow channel array layer, a same kind of sample with microbeads having different densities may be simultaneously introduced into a first input flow channel 12 and a second input flow channel 22 of the upper flow channel array layer 1A, the first output flow channel 13 of the upper flow channel array layer 1A is communicated with the first input flow channel 12 of the first lower flow channel array layer 2A-1, and the second output flow channel 23 of the upper flow channel array layer 1A is communicated with the second input flow channel 22 of the second lower flow channel array layer 2A-2.

In an embodiment, fig. 16 is another schematic structural diagram of a microfluidic device provided in the present invention, please refer to fig. 16, the microfluidic device further includes at least one third substrate 3, the third substrate 3 includes at least one third flow channel 31, and the third substrate 3, the first substrate 1, and the second substrate 2 are sequentially stacked; the first flow channel 11 penetrates the first substrate 1; the third substrate 3 further includes at least one third input flow channel 32 and at least one third output flow channel 33, the third input flow channel 32 and the third output flow channel 33 are located at two ends of the third flow channel 31, and the third flow channel 31 communicates the third input flow channel 32 and the third output flow channel 33; the first flow channel 11 and the third flow channel 31 comprise at least one second overlapping part 51, the second overlapping part 51 is communicated with the first flow channel 11 and the third flow channel 31, the projection of the second overlapping part 51 on the plane of the first substrate 1 is positioned in the projection of the first flow channel 11 on the plane of the first substrate 1, and the projection of the second overlapping part 51 on the plane of the first substrate 1 is positioned in the projection of the third flow channel 31 on the plane of the first substrate 1.

Specifically, with continuing reference to fig. 16, the microfluidic device provided in this embodiment further includes at least one third substrate 3, where the third substrate 3, the first substrate 1, and the second substrate 2 are sequentially stacked, and fig. 16 illustrates a structure of the first substrate 1, the second substrate 2, and the third substrate 3 after being separated, and the stacked third substrate 3, the first substrate 1, and the second substrate 2 are obtained after sequentially bonding the third substrate 3, the first substrate 1, and the second substrate 2; the first flow channel 11 penetrates through the first substrate 1 in a direction perpendicular to the plane of the first substrate 1, the first flow channel 11 can be obtained by etching the first surface 71 of the first substrate 1, and the first flow channel 11 penetrates to the other surface 73 of the first substrate 1; the third substrate 3 comprises at least one third flow channel 31, at least one third input flow channel 32 and at least one third output flow channel 33 which are positioned at two ends of the third flow channel 31, the third flow channel 31 is communicated with the third input flow channel 32 and the third output flow channel 33, and the third flow channel 31, the third input flow channel 32 and the third output flow channel 33 are obtained by etching on the surface 74 of the third substrate 3; the first flow channel 11 and the third flow channel 31 comprise at least one second overlapping part 51, the second overlapping part 51 is communicated with the first flow channel 11 and the third flow channel 31, the projection of the second overlapping part 51 on the plane of the first substrate 1 is positioned in the projection of the first flow channel 11 on the plane of the first substrate 1, and the projection of the second overlapping part 51 on the plane of the first substrate 1 is positioned in the projection of the third flow channel 31 on the plane of the first substrate 1.

It should be noted that, in the bead screening and extracting process, after the sample liquid containing beads with different densities enters the first flow channel 11 from the first input flow channel 12, the first substrate 1 is located between the second substrate 2 and the third substrate 3, in one embodiment, as shown in fig. 16, the second substrate 2 is located above the first substrate 1 and the third substrate 3 is located below the first substrate 1 along the gravity direction, the beads with the smaller density float upward through the first overlapping portion 50 into the second flow channel 21, and extracted through the second output flow channel 23, the microbeads with higher density sink down to enter the third flow channel 31 through the second overlapping part 51 and are extracted through the third output flow channel 33, the microbeads are screened and extracted according to the density difference among the microbeads and between the microbeads and the sample liquid, the screening and extracting process is simple and easy to operate, and other substances are not introduced, so that the risk of pollution of the microbeads is reduced; in this embodiment, at least three kinds of microbeads with different densities can be screened and extracted, and the efficiency of microbead screening is further effectively improved.

Alternatively, the extending direction of the third flow channel 31 intersects with the direction of the first flow channel 11, and the extending direction of the third flow channel 31 may be the same as the direction of the second flow channel 21.

Optionally, in a direction perpendicular to the plane of the first substrate 1, the first overlapping portion 50 may overlap with the second overlapping portion 51, and in the bead screening and extracting process, beads with different densities may float or sink at the overlapping position of the first overlapping portion 50 and the second overlapping portion 51, so as to accelerate the bead screening speed and improve the bead screening efficiency.

Optionally, referring to fig. 16, in the gravity direction, the second substrate 2 is located above the first substrate 1, and the third substrate 3 is located below the first substrate 1, in the process of screening and extracting the microbeads, after the sample liquid containing the microbeads with different densities enters the third flow channel 31 from the third input flow channel 32, the microbeads with smaller densities float upward and first enter the first flow channel 11 through the second overlapping portion 51, and the liquid is introduced from the first input flow channel 12 to adjust the liquid density of the sample, so that the densities of the microbeads entering the first flow channel have a size difference, the microbeads with reduced densities continuously float upward and enter the second flow channel 21 through the first overlapping portion 50, and finally, the microbeads with different densities are extracted from the output flow channels of the three substrates. It should be noted that, the sample liquid containing microbeads with different densities is introduced from the second input flow channel 22, so that each of the microbeads with a higher density sequentially enters the first flow channel 11 through the first overlapping portion 50, and then enters the third flow channel 31 through the second overlapping portion 51, thereby screening and extracting three kinds of microbeads with different densities. The technicians in the field can choose to introduce the micro-bead samples to be extracted from the input flow channels at the upper layer, the middle layer and the lower layer according to the actual sample liquid and the density of the micro-beads.

Optionally, in an embodiment, X layers of substrates may be sequentially stacked, X is greater than or equal to 3, each layer of substrate has a flow channel array layer, the flow channel array layer includes an input flow channel, an output flow channel, and a flow channel for communicating the input flow channel and the output flow channel, the flow channel array layer of the X-2 layers of substrates in the middle layer penetrates through the substrate in the layer, during the bead screening and extraction process, by adjusting the density of the sample liquid in the middle layer, this embodiment can at least screen out X beads with different densities, and improve the bead screening efficiency.

Based on the same inventive concept, the embodiment of the invention also provides a manufacturing method of the microfluidic device, and the manufacturing method can be used for manufacturing the microfluidic device in any embodiment. Fig. 17 is a schematic view of a method for manufacturing a microfluidic device according to the present invention, and referring to fig. 17, the method for manufacturing a microfluidic device includes:

s1, providing at least one first substrate and at least one second substrate;

s2, etching the first substrate to form at least one first flow channel, at least one first input flow channel and at least one first output flow channel, wherein the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel;

s3, etching the second substrate to form at least one second flow channel, at least one second input flow channel and at least one second output flow channel, wherein the second input flow channel and the second output flow channel are located at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel;

s4, bonding the first substrate and the second substrate, wherein the first substrate and the second substrate are arranged in a stacked mode, the first flow channel and the second flow channel comprise at least one first overlapping portion, the first overlapping portion is communicated with the first flow channel and the second flow channel, the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the first flow channel on the plane where the first substrate is located, and the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the second flow channel on the plane where the first substrate is located.

In this embodiment, the flow channel etching may be performed by PVD (Physical Vapor Deposition), Photo (Photo), Etch (etching), or other processes.

Note that, in step S4, when the first substrate and the second substrate are bonded, the first flow channel on the first substrate and the second flow channel on the second substrate are arranged in a face-to-face bonding manner, so that the first overlapping portion communicates the first flow channel and the second flow channel.

It should be noted that the first flow channel, the first input flow channel, and the first output flow channel formed on the first substrate are not limited to the depth in the direction perpendicular to the plane of the first substrate, and the second flow channel, the second input flow channel, and the second output flow channel formed on the second substrate are not limited to the depth in the direction perpendicular to the plane of the first substrate, so that the flow channel structures can be formed by one-time etching, and then the microfluidic device can be obtained by bonding the first substrate and the second substrate, where the bonding can be by gluing, low-temperature melting, and the like.

Alternatively, step S2 and step S3 may be performed simultaneously.

In an embodiment, fig. 18 is another schematic view of a method for manufacturing a microfluidic device according to the present invention, and referring to fig. 18, the method for manufacturing a microfluidic device further includes:

s1, providing at least one third substrate;

s31, etching the third substrate to form at least one third flow channel, at least one third input flow channel and at least one third output flow channel, wherein the third input flow channel and the third output flow channel are located at two ends of the third flow channel, and the third flow channel is communicated with the third input flow channel and the third output flow channel;

s21, etching through the first substrate to form a first flow channel;

s4, sequentially bonding the third substrate, the first substrate and the second substrate, so that the third substrate, the first substrate and the second substrate are sequentially stacked, the first flow channel and the third flow channel comprise at least one second overlapping part, the second overlapping part is communicated with the first flow channel and the third flow channel, the projection of the second overlapping part on the plane of the first substrate is located in the projection of the first flow channel on the plane of the first substrate, and the projection of the second overlapping part on the plane of the first substrate is located in the projection of the third flow channel on the plane of the first substrate.

In step S1, the first substrate, the second substrate, and the third substrate are provided at the same time; step S2, etching the first substrate, and completing the step S21 after the first substrate is etched; step S2, step S3, and step S31 may be performed simultaneously.

It should be noted that, in step S4, when the third substrate, the first substrate and the second substrate are bonded in sequence, the first flow channel on the first substrate and the second flow channel on the second substrate are bonded in a face-to-face manner, so that the first overlapping portion communicates with the first flow channel and the second flow channel, and the first flow channel on the first substrate and the third flow channel on the third substrate are bonded in a face-to-face manner, so that the second overlapping portion communicates with the first flow channel and the third flow channel.

Based on the same inventive concept, an embodiment of the present invention further provides a method for screening microbeads using a microfluidic device, fig. 19 is a method for screening microbeads using a microfluidic device according to the present invention, please refer to fig. 19, in which the method for screening microbeads includes:

t1, preparing a sample, wherein the sample comprises liquid and first microbeads and second microbeads with different densities, so that the first microbeads sink in the liquid and the second microbeads float upwards in the liquid;

t2, injecting the sample into the first input flow channel and flowing into the first flow channel in the liquid injection stage;

t3, screening, wherein when a first substrate and a second substrate are sequentially arranged in the gravity direction, the first microbeads enter the second flow channel through the first overlapping part; or when the second substrate and the first substrate are arranged in sequence in the gravity direction, the second microbeads enter the second flow channel through the overlapping part;

t4, extraction stage, injecting liquid into the second input flow channel, so that the microbeads in the second flow channel are discharged through the second output flow channel.

In this embodiment, please refer to fig. 1, step T1 is a stage of preparing a sample, where the sample includes a liquid and a first bead M and a second bead N with different densities, and the density of the first bead M > the density of the sample liquid > the density of the second bead N, so that the first bead M sinks in the liquid and the second bead N floats in the liquid;

step T2 is a priming stage, in which the sample enters the first flow channel 11 from the first input flow channel 12;

step T3 is a screening stage, in which when the second substrate 2 and the first substrate 1 are sequentially disposed in the gravity direction, the second beads N enter the second flow channel 21 through the first overlapping portion 50, specifically, the first beads M sink due to the different bead densities, the first beads M continue to remain in the flow channel of the first substrate 1, and the first beads M flow out of the first output flow channel 13 and are extracted as the bead sample flows to the first output flow channel 13; the second microbeads N float upward, and at this time, the second microbeads N are still positioned in the flow channel of the first substrate 1, and when the second microbeads N pass through the position having the first overlapping portion 50, the second microbeads N float upward and enter the second flow channel 21 through the first overlapping portion 50, thereby completing the screening of the first microbeads M and the second microbeads N;

step T4 is an extraction stage, in which liquid is injected into the second input flow channel 22, so that the microbeads in the second flow channel 21 are discharged through the second output flow channel 23, optionally, a sample liquid without microbeads is introduced into the second input flow channel 22, and as the sample liquid flows to the second output flow channel 23, the second microbeads N flow out of the second output flow channel 23 and are extracted, thereby finally realizing the screening and extraction of the first microbeads M and the second microbeads N.

In order to improve the efficiency of bead screening and bead extraction, a sample containing first beads M and second beads N may be introduced into the first input flow channel 12 and the second input flow channel 22 at the same time, the density of the first beads M > the density of the sample liquid > the density of the second beads N, the second beads N in the flow channels of the first substrate 1 float up and enter the flow channels of the second substrate 2 through the first overlapping portion 50, the first beads M in the flow channels of the first substrate 1 continue to remain in the first substrate 1, the first beads M in the flow channels of the second substrate 2 sink and enter the flow channels of the first substrate 1 through the first overlapping portion 50, the second beads N in the flow channels of the second substrate 2 continue to remain in the second substrate 2, the second beads N flow out and are extracted from the second output flow channels 23 of the second substrate 2 along with the flow of the sample liquid, the first beads M flow out and are extracted from the first output flow channels 13 of the first substrate 1, finally, screening and extracting the first bead M and the second bead N are realized.

Optionally, in the screening stage of step T3, when the first substrate and the second substrate are sequentially arranged in the gravity direction, the first microbeads M with a relatively high density enter the second flow channel through the first overlapping portion, and the second microbeads N with a relatively low density remain in the first flow channel, so as to finally realize the screening and extraction of the first microbeads M and the second microbeads N.

The embodiment of the invention provides a microfluidic device which is mainly used for screening and extracting target microbeads from microbead samples with different densities so as to facilitate the subsequent work of chemical reaction, detection and the like of the target microbeads.

According to the embodiment, the display module and the display device provided by the invention at least realize the following beneficial effects:

the microfluidic device provided by the invention comprises at least one first substrate and at least one second substrate, wherein the first substrate comprises at least one first flow channel, the second substrate comprises at least one second flow channel, and the first substrate and the second substrate are arranged in a stacked mode; the first substrate further comprises at least one first input flow channel and at least one first output flow channel, the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel; the second substrate further comprises at least one second input flow channel and at least one second output flow channel, the second input flow channel and the second output flow channel are positioned at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel; the first flow channel and the second flow channel comprise at least one first overlapping part, the first overlapping part is communicated with the first flow channel and the second flow channel, the projection of the first overlapping part on the plane of the first substrate is located in the projection of the first flow channel on the plane of the first substrate, and the projection of the first overlapping part on the plane of the first substrate is located in the projection of the second flow channel on the plane of the first substrate. The microfluidic device is formed by etching and bonding, and the structure is simple and easy to manufacture. After a sample containing at least two microbeads with different densities enters the first flow channel from the first input flow channel, part of the microbeads float or sink due to different densities, enter the second flow channel through the first overlapping part and are extracted through the second output flow channel, and the microbead screening and extracting process is simple and easy to operate, so that the risk of microbead pollution is reduced.

The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A microfluidic device comprising at least one first substrate and at least one second substrate, wherein the first substrate comprises at least one first flow channel, the second substrate comprises at least one second flow channel, and the first substrate and the second substrate are stacked;

the first substrate further comprises at least one first input flow channel and at least one first output flow channel, the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel;

the second substrate further comprises at least one second input flow channel and at least one second output flow channel, the second input flow channel and the second output flow channel are positioned at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel;

the first flow channel and the second flow channel comprise at least one first overlapping part, the first overlapping part is communicated with the first flow channel and the second flow channel, the projection of the first overlapping part on the plane of the first substrate is located in the projection of the first flow channel on the plane of the first substrate, and the projection of the first overlapping part on the plane of the first substrate is located in the projection of the second flow channel on the plane of the first substrate.

2. The microfluidic device according to claim 1, wherein the first flow channel extends in a Y-direction;

and/or the second flow channel extends along an X direction, and the Y direction is crossed with the X direction.

3. The microfluidic device according to claim 1, wherein a dimension of the first overlap in a direction perpendicular to the first substrate is greater than or equal to a sum of dimensions of the first flow channel and the second flow channel in the direction perpendicular to the first substrate.

4. The microfluidic device according to claim 1, wherein the second channel comprises a second main channel and a second sub-channel, the second sub-channel is located at an end of the second main channel close to the second input channel, and a width of the second sub-channel is smaller than or equal to a width of the second main channel, the width being a dimension of the channel in a plane of the second substrate perpendicular to an extending direction of the channel.

5. The microfluidic device according to claim 1, wherein the first substrate comprises at least two first flow channels arranged side by side, the first input flow channel comprises a first input flow channel subsection and a first input flow channel main body part, the first input flow channel subsection connects the two first flow channels and the first input flow channel main body part, and the first input flow channel subsection intersects with the extending direction of the first input flow channel main body part;

and/or the first output runner comprises a first output runner subsection and a first output runner main body part, the first output runner subsection is communicated with the two first runners and the first output runner main body part, and the first output runner subsection is crossed with the extending direction of the first output runner main body part;

and/or the second substrate comprises at least two second runners arranged in parallel, the second input runner comprises a second input runner subsection and a second input runner main body part, the second input runner subsection is communicated with the two second runners and the second input runner main body part, and the second input runner subsection is crossed with the extending direction of the second input runner main body part;

and/or the second output flow channel comprises a second output flow channel subsection and a second output flow channel main body part, the second output flow channel subsection is communicated with the two second flow channels and the second output flow channel main body part, and the second output flow channel subsection is crossed with the extending direction of the second output flow channel main body part.

6. The microfluidic device according to claim 5, wherein the first output flow channel further comprises a first sub-portion communicating the first sub-portion and the first output flow channel body portion, the first sub-portion extending in the same direction as the first output flow channel portion;

and/or the second output flow channel further comprises a second sub-portion, the second output flow channel sub-portion is communicated with the second sub-portion and the second output flow channel main body portion, and the extending direction of the second sub-portion is the same as that of the second output flow channel sub-portion.

7. The microfluidic device according to claim 1, wherein the first substrate comprises at least two first flow channels arranged side by side, the first input flow channel comprises a first input flow channel subsection and a first input flow channel main body part, the first input flow channel subsection connects the two first flow channels and the first input flow channel main body part, and the first input flow channel subsection extends in the same direction as the first input flow channel main body part;

and/or the first output flow channel comprises a first output flow channel subsection and a first output flow channel main body part, the first output flow channel subsection is communicated with the two first flow channels and the first output flow channel main body part, and the extending direction of the first output flow channel subsection is the same as that of the first output flow channel main body part;

and/or the second substrate comprises at least two second runners arranged in parallel, the second input runner comprises a second input runner subsection and a second input runner main body part, the second input runner subsection is communicated with the two second runners and the second input runner main body part, and the extension direction of the second input runner subsection is the same as that of the second input runner main body part;

and/or the second output flow channel comprises a second output flow channel subsection and a second output flow channel main body part, the second output flow channel subsection is communicated with the two second flow channels and the second output flow channel main body part, and the extension direction of the second output flow channel subsection is the same as that of the second output flow channel main body part.

8. The microfluidic device according to claim 1, wherein the width of the second channel is smaller than or equal to the width of the first channel, and the width is a dimension of the channel perpendicular to the extending direction of the channel in the plane of the second substrate.

9. The microfluidic device according to claim 1, wherein the first flow channel, the first input flow channel, the first output flow channel, the second input flow channel, the second output flow channel, and the first overlapping portion constitute a flow channel array layer, the microfluidic device comprising a plurality of the flow channel array layers in cascade, the first output flow channel of an upper flow channel array layer communicating with the first input flow channel of a lower flow channel array layer, the second output flow channel of the upper flow channel array layer not communicating with the second input flow channel of the lower flow channel array layer;

or the second output flow channel of the upper flow channel array layer is communicated with the second input flow channel of the lower flow channel array layer, and the first output flow channel of the upper flow channel array layer is not communicated with the first input flow channel of the lower flow channel array layer.

10. The microfluidic device according to claim 1, further comprising at least one third substrate including at least one third flow channel, wherein the third substrate, the first substrate and the second substrate are sequentially stacked;

the first flow channel penetrates through the first substrate;

the third substrate further comprises at least one third input runner and at least one third output runner, the third input runner and the third output runner are positioned at two ends of the third runner, and the third runner is communicated with the third input runner and the third output runner;

the first flow channel and the third flow channel comprise at least one second overlapping part, the second overlapping part is communicated with the first flow channel and the third flow channel, the projection of the second overlapping part on the plane of the first substrate is located in the projection of the first flow channel on the plane of the first substrate, and the projection of the second overlapping part on the plane of the first substrate is located in the projection of the third flow channel on the plane of the first substrate.

11. A method of making a microfluidic device, comprising:

providing at least one first substrate and at least one second substrate;

etching the first substrate to form at least one first flow channel, at least one first input flow channel and at least one first output flow channel, wherein the first input flow channel and the first output flow channel are positioned at two ends of the first flow channel, and the first flow channel is communicated with the first input flow channel and the first output flow channel;

etching the second substrate to form at least one second flow channel, at least one second input flow channel and at least one second output flow channel, wherein the second input flow channel and the second output flow channel are positioned at two ends of the second flow channel, and the second flow channel is communicated with the second input flow channel and the second output flow channel;

bonding the first substrate and the second substrate, wherein the first substrate and the second substrate are arranged in a stacked mode, the first runner and the second runner comprise at least one first overlapping portion, the first overlapping portion is communicated with the first runner and the second runner, the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the first runner on the plane where the first substrate is located, and the projection of the first overlapping portion on the plane where the first substrate is located in the projection of the second runner on the plane where the first substrate is located.

12. The method of manufacturing according to claim 11, further comprising:

providing at least one third substrate;

etching the third substrate to form at least one third flow channel, at least one third input flow channel and at least one third output flow channel, wherein the third input flow channel and the third output flow channel are positioned at two ends of the third flow channel, and the third flow channel is communicated with the third input flow channel and the third output flow channel;

etching through the first substrate to form the first flow channel;

the third substrate, the first substrate and the second substrate are bonded in sequence, so that the third substrate, the first substrate and the second substrate are sequentially stacked, the first runner and the third runner comprise at least one second overlapping portion, the second overlapping portion is communicated with the first runner and the third runner, the projection of the second overlapping portion on the plane where the first substrate is located in the projection of the first runner on the plane where the first substrate is located, and the projection of the second overlapping portion on the plane where the first substrate is located in the projection of the third runner on the plane where the first substrate is located.

13. A method of bead screening using the microfluidic device according to any one of claims 1 to 10, comprising:

preparing a sample, wherein the sample comprises a liquid and first microbeads and second microbeads which are different in density, so that the first microbeads sink in the liquid and the second microbeads float up in the liquid;

a liquid injection stage, wherein the sample is injected into the first input flow channel and flows into the first flow channel;

a screening stage, wherein when the first substrate and the second substrate are sequentially arranged in the gravity direction, the first microbeads enter the second flow channel through the first overlapping part; or, when the second substrate and the first substrate are sequentially arranged in the gravity direction, the second beads enter the second flow channel through the overlapping part;

and an extraction stage, wherein the liquid is injected into the second input flow channel, so that the microbeads in the second flow channel are discharged through the second output flow channel.