Microfluidic systems for target pairing

Abstract

This invention discloses a microfluidic system for target pairing, comprising a first channel, a second channel, an oil channel, a buffer channel, a pairing channel, a pairing microvalve, a first microvalve, a second microvalve, and a buffer microvalve. The pairing channel is connected to the oil channel, and the first channel, the second channel, and the buffer channel are all connected to the pairing channel. The first channel includes a first flow section distinct from the first microvalve, and the second channel includes a second flow section distinct from the second microvalve. The upper and lower inner wall surfaces of the first and second flow sections are parallel planes, reducing the distance difference between different target objects and the upper inner wall surface, thereby reducing the flow velocity difference caused by this distance difference and narrowing the target object's interception range. Therefore, the pressure and volume of the buffer solution can be correspondingly reduced, thus helping to improve the capture success rate.

Description

Technical Field

[0001] This invention relates to the field of single-cell sequencing technology, and in particular to a microfluidic system for target pairing. Background Technology

[0002] Single-cell RNA sequencing (scRNA-seq) technology reveals the heterogeneity of cells within tissues. Compared to traditional gene sequencing technologies, single-cell sequencing offers advantages such as high accuracy and high resolution, providing information at the single-cell level and revealing the heterogeneity and complexity of expression within tissues. It has wide applications in fields such as cancer, reproduction, immunity, and development. Unlike traditional sequencing, single-cell sequencing requires separating cell populations from tissues or body fluids into individual cells. Currently, a cell pairing system exists, which includes cell channels, microsphere channels, pairing channels, buffer channels, oil channels, a detection module, and corresponding control microvalves. The cell channels contain a first liquid containing cells, while the microsphere channels contain a second liquid containing microspheres. When the detection module detects a cell or microsphere, it controls the corresponding microvalves to close the channels at certain intervals, causing the single cell and single microsphere to stop in the pairing channel. Then, the buffer solution in the separate buffer channel propels the single cell and single microsphere into the oil in the oil channel to be encapsulated into droplets.

[0003] However, this cell pairing system has the following drawbacks:

[0004] 1. Due to the cross-sectional shape of the cell or microsphere flow channels, different cells or microspheres may have different flow velocities when flowing in the channels with liquid as the carrier. Taking cells as an example, some cells are relatively close to the channel wall and move relatively slowly, while others are relatively far from the channel wall and move relatively quickly. The interval between the detection module detecting a cell and the microvalve closing is fixed. This increases the interception range for different cells. To compensate for this, the pressure of the buffer solution used to flush the cells needs to be increased. However, this will increase the droplet size after pairing, reducing the probability of the cell-released mRNA colliding with the microspheres and affecting the microspheres' capture of cell mRNA.

[0005] 2. Cells or microspheres that have entered the pairing channel are easily affected by the liquid flow and are at risk of being washed out of the pairing channel. Taking cells as an example, when a single cell enters the pairing channel but the microsphere has not yet entered, the liquid in the microsphere channel still needs to continue to flow and pass through the pairing space. The disturbance of the liquid may wash away the single cell in the pairing space, resulting in the encapsulated droplet containing only microspheres.

[0006] 3. After encapsulation, the droplets are prone to large-area contact with the flow channel wall of the oil flow channel, and the droplets are easily broken under the action of wetting effect. Summary of the Invention

[0007] This invention aims to address at least one of the technical problems existing in the prior art. To this end, this invention proposes a microfluidic system for target pairing.

[0008] According to a first embodiment of the present invention, a microfluidic system for target pairing includes a first channel, a second channel, an oil channel, a buffer channel, and a pairing channel. The pairing channel is connected to the oil channel. The first channel, the second channel, and the buffer channel are all connected to the pairing channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through.

[0009] The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, and a buffer microvalve corresponding to the buffer flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, and the buffer microvalve is used to control the opening and closing of the buffer flow channel.

[0010] The microfluidic system is configured such that when a single first target and a single second target exist in the paired flow channel, the first microvalve and the second microvalve are in a closed state, and the paired microvalve and the buffer microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets;

[0011] The first flow channel includes a first microvalve section corresponding to the first microvalve, and a first flow section different from the first microvalve section. The upper inner wall surface and the lower inner wall surface of the first flow section are planes that are parallel to each other.

[0012] And / or, the second flow channel includes a second microvalve section corresponding to the second microvalve, and a second flow section distinct from the second microvalve section, wherein the upper inner wall surface and the lower inner wall surface of the second flow section are mutually parallel planes.

[0013] The microfluidic system for target pairing according to embodiments of the present invention has at least the following beneficial effects:

[0014] In this embodiment, by setting the upper inner wall and the lower inner wall of the first flow section as parallel planes, the distance difference between different targets and the upper inner wall is reduced, thereby reducing the flow velocity difference caused by this distance difference, and thus narrowing the interception range of the target. Therefore, the pressure of the buffer solution and the volume of the liquid can be reduced accordingly, which helps to improve the capture success rate.

[0015] In other embodiments of the present invention, the cross-section of the first flow section is set to a rectangle, and / or the cross-section of the second flow section is set to a rectangle.

[0016] In other embodiments of the invention, the width of the first flow section is 50 micrometers to 150 micrometers, and / or the width of the second flow section is 50 micrometers to 150 micrometers.

[0017] In other embodiments of the present invention, the upper inner wall surface of the first microvalve segment is configured as an arc surface protruding away from the first microvalve, and / or, the upper inner wall surface of the second microvalve segment is configured as an arc surface protruding away from the second microvalve.

[0018] In other embodiments of the present invention, the cross-section of the first micro-valve segment is set to a semi-circular shape, and / or the cross-section of the second micro-valve segment is set to a semi-circular shape.

[0019] In other embodiments of the invention, the maximum height of the oil flow channel is 80 micrometers to 200 micrometers.

[0020] In other embodiments of the present invention, the microfluidic system further includes a first sheath fluid channel, which is connected to the first channel and is used to input a first sheath fluid encapsulating the first liquid into the first channel;

[0021] And / or, the microfluidic system further includes a second sheath fluid channel, which is connected to the second channel and is used to input a second sheath fluid encapsulating the second liquid into the second channel.

[0022] In other embodiments of the present invention, the microfluidic system further includes a waste liquid channel and a waste liquid microvalve corresponding to the waste liquid channel, the waste liquid channel being connected to the paired channel, and the waste liquid microvalve being used to control the opening and closing of the waste liquid channel;

[0023] When the paired microvalve is in the closed state and the first microvalve and the waste liquid microvalve are in the open state, the liquid in the first flow channel can flow out through the paired flow channel and the waste liquid flow channel;

[0024] And / or, when the paired microvalve is in the closed state and the second microvalve and the waste liquid microvalve are in the open state, the liquid in the second flow channel can flow out through the paired flow channel and the waste liquid flow channel.

[0025] In other embodiments of the present invention, the waste liquid channel is located between the first channel and the second channel along the flow direction of the buffer solution within the paired channel, and the microfluidic system further includes a first shut-off microvalve for controlling the opening and closing of the paired channel located between the waste liquid channel and the first channel.

[0026] In other embodiments of the present invention, the microfluidic system is configured such that: when the single first target object is located in the paired flow channel, the first shut-off microvalve switches from an open state to a closed state; and when a single first target object and a single second target object are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the first shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target object and the single second target object in the paired flow channel into the oil in the oil flow channel to form droplets.

[0027] In other embodiments of the present invention, the waste liquid channel is located between the first channel and the second channel along the flow direction of the buffer solution within the paired channel, and the microfluidic system further includes a second shut-off microvalve for controlling the opening and closing of the paired channel located between the waste liquid channel and the second channel.

[0028] In other embodiments of the present invention, the microfluidic system is configured such that: when the single second target is located in the paired flow channel, the second shut-off microvalve switches from an open state to a closed state; and when a single first target and a single second target are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the second shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets.

[0029] In other embodiments of the present invention, the waste liquid channel, the second channel and the first channel are arranged sequentially along the flow direction of the buffer solution in the paired channel, and the microfluidic system is configured such that when the single first target object is located in the paired channel, the second microvalve is then closed to allow the single second target object to be located in the paired channel;

[0030] Alternatively, along the flow direction of the buffer solution within the paired flow channels, the waste liquid flow channel, the first flow channel, and the second flow channel are sequentially arranged, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel;

[0031] Alternatively, along the flow direction of the buffer solution within the paired flow channels, the second flow channel, the first flow channel, and the waste liquid flow channel are arranged sequentially, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel;

[0032] Alternatively, along the flow direction of the buffer solution within the paired flow channels, the first flow channel, the second flow channel, and the waste liquid flow channel are arranged sequentially, and the microfluidic system is configured such that when the single first target object is located in the paired flow channel, the second microvalve is then closed to allow the single second target object to be located in the paired flow channel.

[0033] According to a second embodiment of the present invention, a microfluidic system for target pairing includes a first channel, a second channel, an oil channel, a buffer channel, and a pairing channel. The pairing channel is connected to the oil channel. The first channel, the second channel, and the buffer channel are all connected to the pairing channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through.

[0034] The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, and a buffer microvalve corresponding to the buffer flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, and the buffer microvalve is used to control the opening and closing of the buffer flow channel.

[0035] The microfluidic system is configured such that when a single first target and a single second target exist in the paired flow channel, the first microvalve and the second microvalve are in a closed state, and the paired microvalve and the buffer microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets;

[0036] The maximum height of the oil flow channel is 80 micrometers to 200 micrometers.

[0037] The microfluidic system for target pairing according to embodiments of the present invention has at least the following beneficial effects:

[0038] This embodiment reduces the probability of droplets contacting the channel wall by setting the maximum height of the oil flow channel, thereby reducing the risk of droplet breakage.

[0039] In other embodiments of the present invention, the upper inner wall surface and the lower inner wall surface of the oil flow channel are parallel planes.

[0040] In other embodiments of the present invention, the cross-section of the oil flow channel is set to rectangular.

[0041] According to a third embodiment of the present invention, a microfluidic system for target pairing includes a first channel, a second channel, an oil channel, a buffer channel, and a pairing channel. The pairing channel is connected to the oil channel. The first channel, the second channel, and the buffer channel are all connected to the pairing channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through.

[0042] The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, and a buffer microvalve corresponding to the buffer flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, and the buffer microvalve is used to control the opening and closing of the buffer flow channel.

[0043] The microfluidic system is configured such that when a single first target and a single second target exist in the paired flow channel, the first microvalve and the second microvalve are in a closed state, and the paired microvalve and the buffer microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets;

[0044] The microfluidic system further includes a first sheath fluid channel, which is connected to the first channel and is used to input a first sheath fluid encapsulating the first liquid into the first channel;

[0045] And / or, the microfluidic system further includes a second sheath fluid channel, which is connected to the second channel and is used to input a second sheath fluid encapsulating the second liquid into the second channel.

[0046] The microfluidic system for target pairing according to embodiments of the present invention has at least the following beneficial effects:

[0047] This embodiment, by setting a sheath fluid to constrain the first liquid and / or the second liquid, enables the first liquid and / or the second liquid to flow in the central region of the flow channel, avoiding the first target object in the first liquid and / or the target object in the second liquid from being too close to the inner wall of the flow channel, thus preventing a large difference in flow velocity.

[0048] In other embodiments of the present invention, the first sheath fluid flow channel includes two first branch flow channels, the two first branch flow channels respectively communicating with the first flow channel from both sides of the first flow channel;

[0049] And / or, the second sheath fluid flow channel includes two second branch flow channels, which are respectively connected to the second flow channel from both sides of the second flow channel.

[0050] According to a fourth embodiment of the present invention, a microfluidic system for target pairing includes a first channel, a second channel, an oil channel, a buffer channel, a pairing channel, and a waste liquid channel. The pairing channel is connected to the oil channel. The first channel, the second channel, the buffer channel, and the waste liquid channel are all connected to the pairing channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through.

[0051] The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, a buffer microvalve corresponding to the buffer flow channel, and a waste liquid microvalve corresponding to the waste liquid flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, the buffer microvalve is used to control the opening and closing of the buffer flow channel, and the waste liquid microvalve is used to control the opening and closing of the waste liquid flow channel.

[0052] The microfluidic system is configured such that: when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, liquid in the first channel can flow out through the paired channel and the waste liquid channel; when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, liquid in the second channel can flow out through the paired channel and the waste liquid channel; when a single first target and a single second target exist in the paired channel, the first microvalve, the second microvalve, and the waste liquid microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution channel delivers the single first target and the single second target in the paired channel into the oil in the oil channel to form droplets;

[0053] Wherein, along the flow direction of the buffer solution in the paired flow channel, the waste liquid flow channel is located between the first flow channel and the second flow channel, and the microfluidic system further includes a first shut-off microvalve, which is used to control the opening and closing of the paired flow channel located between the waste liquid flow channel and the first flow channel.

[0054] The microfluidic system for target pairing according to embodiments of the present invention has at least the following beneficial effects:

[0055] This embodiment, by setting a first shut-off micro-valve, can prevent the first target object that has entered the pairing flow channel from being driven out of the pairing flow channel by the second liquid, resulting in the encapsulated droplet containing only the second target object, thereby ensuring the encapsulation success rate.

[0056] In other embodiments of the present invention, the microfluidic system is configured such that: when the single first target object is located in the paired flow channel, the first shut-off microvalve switches from an open state to a closed state; and when a single first target object and a single second target object are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the first shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target object and the single second target object in the paired flow channel into the oil in the oil flow channel to form droplets.

[0057] In other embodiments of the present invention, when there is no single first target object in the paired flow channel, the paired microvalve is in a closed state and the first microvalve, the first shut-off microvalve and the waste liquid microvalve are in an open state, so that the liquid in the first flow channel can flow out through the paired flow channel and the waste liquid flow channel;

[0058] And / or, when the single second target object is not present in the paired flow channel, the paired microvalve is in a closed state and the second microvalve and the waste liquid microvalve are in an open state, so that the liquid in the second flow channel can flow out through the paired flow channel and the waste liquid flow channel.

[0059] According to a fifth embodiment of the present invention, a microfluidic system for target pairing includes a first channel, a second channel, an oil channel, a buffer channel, a pairing channel, and a waste liquid channel. The pairing channel is connected to the oil channel. The first channel, the second channel, the buffer channel, and the waste liquid channel are all connected to the pairing channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through.

[0060] The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, a buffer microvalve corresponding to the buffer flow channel, and a waste liquid microvalve corresponding to the waste liquid flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, the buffer microvalve is used to control the opening and closing of the buffer flow channel, and the waste liquid microvalve is used to control the opening and closing of the waste liquid flow channel.

[0061] The microfluidic system is configured such that: when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, liquid in the first channel can flow out through the paired channel and the waste liquid channel; when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, liquid in the second channel can flow out through the paired channel and the waste liquid channel; when a single first target and a single second target exist in the paired channel, the first microvalve, the second microvalve, and the waste liquid microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution channel delivers the single first target and the single second target in the paired channel into the oil in the oil channel to form droplets;

[0062] Wherein, along the flow direction of the buffer solution in the paired flow channel, the waste liquid flow channel is located between the first flow channel and the second flow channel, and the microfluidic system further includes a second shut-off microvalve, which is used to control the opening and closing of the paired flow channel located between the waste liquid flow channel and the second flow channel.

[0063] The microfluidic system for target pairing according to embodiments of the present invention has at least the following beneficial effects:

[0064] This embodiment, by setting a second shut-off micro-valve, can prevent the second target object that has entered the pairing flow channel from being driven out of the pairing flow channel by the first liquid, resulting in the encapsulated droplet containing only the first target object, thereby ensuring the encapsulation success rate.

[0065] In other embodiments of the present invention, the microfluidic system is configured such that: when the single second target is located in the paired flow channel, the second shut-off microvalve switches from an open state to a closed state; and when a single first target and a single second target are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the second shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets.

[0066] In other embodiments of the present invention, when there is no single first target object in the paired flow channel, the paired microvalve is in a closed state and the first microvalve and the waste liquid microvalve are in an open state, so that the liquid in the first flow channel can flow out through the paired flow channel and the waste liquid flow channel;

[0067] And / or, when there is no single second target object in the paired flow channel, the paired microvalve is in a closed state and the second microvalve, the second shut-off microvalve and the waste liquid microvalve are in an open state, so that the liquid in the second flow channel can flow out through the paired flow channel and the waste liquid flow channel.

[0068] According to a sixth embodiment of the present invention, a microfluidic system for target pairing includes a first channel, a second channel, an oil channel, a buffer channel, a pairing channel, and a waste liquid channel. The pairing channel is connected to the oil channel. The first channel, the second channel, the buffer channel, and the waste liquid channel are all connected to the pairing channel, and the waste liquid channel is located between the first channel and the second channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through. The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, a buffer microvalve corresponding to the buffer flow channel, and a waste microvalve corresponding to the waste flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, the buffer microvalve is used to control the opening and closing of the buffer flow channel, and the waste microvalve is used to control the opening and closing of the waste flow channel.

[0069] The microfluidic system is configured such that: when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, liquid in the first channel can flow out through the paired channel and the waste liquid channel; when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, liquid in the second channel can flow out through the paired channel and the waste liquid channel; when a single first target and a single second target exist in the paired channel, the first microvalve, the second microvalve, and the waste liquid microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution channel delivers the single first target and the single second target in the paired channel into the oil in the oil channel to form droplets;

[0070] In this configuration, the waste liquid channel, the second channel, and the first channel are sequentially arranged along the flow direction of the buffer solution within the paired flow channels. The microfluidic system is configured such that when a single first target object is located in the paired flow channel, the second microvalve is closed to allow the single second target object to be located in the paired flow channel. Because the waste liquid channel is located near the second channel, the second liquid will flow towards the waste liquid channel instead of towards the already interrupted first channel, thus preventing the single first target object A from being carried away by the second liquid.

[0071] Alternatively, along the flow direction of the buffer solution within the paired flow channels, the waste liquid flow channel, the first flow channel, and the second flow channel are sequentially arranged, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel. Since the waste liquid flow channel is located near the first flow channel, the first liquid will flow towards the waste liquid flow channel and not towards the already interrupted second flow channel, thus preventing the single second target object B from being carried away by the first liquid.

[0072] Alternatively, along the flow direction of the buffer solution within the paired flow channels, the second flow channel, the first flow channel, and the waste liquid flow channel are sequentially arranged, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to remain in the paired flow channel. Since the waste liquid flow channel is located near the first flow channel, the first liquid will flow towards the waste liquid flow channel and not towards the already interrupted second flow channel, thus preventing the single second target object B from being carried away by the first liquid.

[0073] Alternatively, along the flow direction of the buffer solution within the paired flow channels, the first flow channel, the second flow channel, and the waste liquid flow channel are sequentially arranged, and the microfluidic system is configured such that when a single first target object is located in the paired flow channel, the second microvalve is then closed to allow the single second target object to be located in the paired flow channel. Since the waste liquid flow channel is located near the second flow channel, the second liquid will flow towards the waste liquid flow channel and not towards the already interrupted first flow channel, thus preventing the single first target object A from being carried away by the second liquid.

[0074] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0075] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0076] Figure 1 This is a schematic diagram of the microfluidic system in the first embodiment of the present invention;

[0077] Figure 2 for Figure 1 The image shows an enlarged schematic diagram of the paired flow channels;

[0078] Figure 3 This is a schematic diagram of the process by which the microfluidic system achieves pairing between a first target object and a second target object in the first embodiment of the present invention;

[0079] Figure 4 This is an exploded view of the microfluidic chip in the first embodiment of the present invention;

[0080] Figure 5 This is a schematic diagram of the microvalve of the microfluidic system in the first embodiment of the present invention in the open and closed states.

[0081] Figure 6 This is a schematic cross-sectional view of the first flow channel section in the first embodiment of the present invention;

[0082] Figure 7 This is a schematic diagram showing the relative positions of the first flow channel, the second flow channel, the waste liquid flow channel, and the first shut-off microvalve in the fifth embodiment of the present invention;

[0083] Figure 8 This is a schematic diagram showing the relative positional relationship between the first flow channel, the second flow channel, and the waste liquid flow channel in the sixth embodiment of the present invention;

[0084] Figure 9 This is a schematic diagram showing the relative positional relationship between the first flow channel, the second flow channel, and the waste liquid flow channel in the seventh embodiment of the present invention;

[0085] Figure 10 This is a schematic diagram showing the relative positional relationship between the first flow channel, the second flow channel, and the waste liquid flow channel in the eighth embodiment of the present invention;

[0086] Figure 11 This is a schematic diagram showing the relative positions of the first flow channel, the second flow channel, and the waste liquid flow channel in the ninth embodiment of the present invention.

[0087] Figure label:

[0088] Microfluidic chip 100, base layer 110, control layer 120, first microvalve 121, diaphragm 1211, second microvalve 122, oil microvalve 123, buffer microvalve 124, waste liquid microvalve 125, paired microvalve 126, first shut-off microvalve 127, second shut-off microvalve 128, flow channel layer 130, first flow channel 131, first microvalve section 1311, first flow section 1312, second flow channel 132, second microvalve section 1321, second flow section 1322, oil flow channel 133, buffer flow channel 134, fourth part 1341, waste liquid flow channel 135, paired flow channel 136, first sheath fluid flow channel 137, first branch flow channel 1371, second sheath fluid flow channel 138, second branch flow channel 1381, first microvalve control flow channel 139;

[0089] Single primary target A;

[0090] A single second target object B;

[0091] Droplet C;

[0092] First detection light D

[0093] The second detection light E. Detailed Implementation

[0094] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0095] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0096] In the description of this invention, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0097] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0098] In the description of this invention, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0099] The first embodiment of the present invention proposes a microfluidic system for target pairing, referring to... Figures 1 to 3The system includes a first flow channel 131, a second flow channel 132, an oil flow channel 133, a buffer flow channel 134, and a pairing flow channel 136. The first flow channel 131 is for the passage of a first liquid containing a first target object; the second flow channel 132 is for the passage of a second liquid containing a second target object; the buffer flow channel 134 is for the passage of a buffer solution; the oil flow channel 133 is for the passage of an oil solution that is immiscible with the first liquid, the second liquid, and the buffer solution; and the pairing flow channel 136 is for the residence of a single first target object A and a single second target object B. The pairing flow channel 136 is connected to the oil flow channel 133, and the first flow channel 131, the second flow channel 132, and the buffer flow channel 134 are all connected to the pairing flow channel 136. In this embodiment, the first target object is a cell, and the second target object is a microsphere. Those skilled in the art will understand that the first target object can be a cell, and the second target object can also be a cell.

[0100] The microfluidic system in this embodiment also includes multiple microvalves, specifically including a paired microvalves 126 corresponding to the paired flow channel 136, a first microvalves 121 corresponding to the first flow channel 131, a second microvalves 122 corresponding to the second flow channel 132, and a buffer microvalves 124 corresponding to the buffer flow channel 134. The paired microvalves 126 control the opening and closing of the paired flow channel 136, the first microvalves 121 control the opening and closing of the first flow channel 131, the second microvalves 122 control the opening and closing of the second flow channel 132, and the buffer microvalves 124... 124 is used to control the opening and closing of the buffer solution channel 134. Taking the first channel 131 and the first microvalve 121 as an example, the first microvalve 121 controlling the opening and closing of the first channel 131 means that the first microvalve 121 has an open state and a closed state. When the first microvalve 121 is in the open state, the first channel 131 is in the unobstructed state, and the first liquid can flow in the first channel 131. When the first microvalve 121 is in the closed state, the first channel 131 is in the closed state, and the first liquid cannot flow in the first channel 131.

[0101] For ease of understanding, please refer to... Figure 4 , Figure 5 The overall structure of the microfluidic system and the specific structure of the microvalve are described, such as... Figure 4As shown, the microfluidic system includes a microfluidic chip 100, which comprises a base layer 110, a control layer 120, and a channel layer 130 stacked sequentially. The base layer 110 can be made of glass, and the control layer 120 and the channel layer 130 can be made of polydimethylsiloxane (PDMS). The channel layer 130 contains the aforementioned first channel 131, second channel 132, oil channel 133, buffer channel 134, waste liquid channel 135, and paired channel 136. The control layer 120 contains the aforementioned first microvalve 121, second microvalve 122, buffer microvalve 124, waste liquid microvalve 125, and paired microvalve 126, as well as microvalve control channels corresponding to each microvalve. (Refer to...) Figure 5 Taking the first microvalve 121 as an example, the first microvalve 121 includes a diaphragm 1211 disposed between the first flow channel 131 (specifically, the first microvalve section 1311 described below) and the first microvalve control flow channel 139. When the first microvalve 121 is in such a state... Figure 5 When in the open state shown as 'a', diaphragm 1211 is in a horizontal state, allowing the first liquid to pass through the first micro-valve section 1311; when diaphragm 1211 is driven by the liquid or gas in the first micro-valve control channel 139 to bulge into the first channel 131 to be in a horizontal state... Figure 5 In the closed state shown by b, the diaphragm 1211 is close to the inner wall of the first flow channel 131 to block the first micro-valve section 1311, and the first liquid cannot pass through the first micro-valve section 1311. Figure 5 In the illustrated embodiment, the upper inner wall surface of the first microvalve segment 1311 is configured as an arc surface protruding away from the first microvalve 121, specifically a semi-circular arc surface, to facilitate its fit with the diaphragm 1211 protruding towards the first microvalve segment 1311, thereby ensuring the shut-off effect. The second microvalve segment 1321 of the second flow channel 132 can be understood with reference to the first microvalve segment 1311.

[0102] In this embodiment, refer to Figure 3In steps c to d, when a single first target A and a single second target B are present in the paired flow channel 136, the first microvalve 121 and the second microvalve 122 are in the closed state (the microvalve is indicated by black filling), and the paired microvalve 126 and the buffer microvalve 124 are in the open state (the microvalve is indicated by gray filling). At this time, the buffer in the buffer flow channel 134 can deliver the single first target A and the single second target B in the paired flow channel 136 into the oil in the oil flow channel 133 to form droplets C. Thus, through individual pairing... The flow channel 136 is used to temporarily store a single first target A and a single second target B, and is provided with a separate buffer flow channel 134. The buffer pushes the single first target A and the single second target B into the oil without the need for the first liquid and the second liquid to push the single first target A and the single second target B. Therefore, the first flow channel 131 and the second flow channel 132 can remain in a closed state during the encapsulation process, thereby completely preventing other first target objects and / or other second target objects from entering the droplet C, which is beneficial to improving the success rate of encapsulation and reducing cell loss caused by multiple encapsulation.

[0103] Based on this, refer to Figure 1 The first flow channel 131 includes a first microvalve section 1311 corresponding to the first microvalve 121, and a first flow section 1312 distinct from the first microvalve section 1311. The first flow section 1312 primarily functions to allow the first liquid to flow through. The first microvalve section 1311, in addition to allowing the first liquid to flow through, also functions to cooperate with the first microvalve 121 to achieve shut-off control. For example, viewed from a direction perpendicular to the microfluidic chip 100, the first microvalve section 1311 covers the first microvalve 121. Along the flow direction of the first liquid, the upstream (connected to the inlet portion of the first liquid) and downstream (connected to the paired flow channel 136) of the first microvalve section 1311 are both the first flow section 1312. In this embodiment, the cross-sectional shapes of the first microvalve section 1311 and the first flow section 1312 differ. The first microvalve section 1311 can be configured as follows: Figure 5 The flow channel shown has an arc-shaped upper wall, and the first flow section 1312 is as follows: Figure 6 As shown, its upper inner wall surface and lower inner wall surface are parallel planes. The purpose of this design is that if the first flow section 1312 adopts... Figure 5As shown in the flow channel with its arc-shaped upper wall, different cells or microspheres may exhibit different flow velocities when flowing through the channel with liquid as the carrier. Taking cells as an example, some cells located in the center of the flow channel are farther from the upper wall and flow relatively faster, while others located on the side of the flow channel are closer to the upper wall and move relatively slower. The interval between the detection module detecting a cell and the control microvalve closing is fixed. This increases the interception range of different cells within the paired flow channel 136. To ensure that cells stopped at different positions can be filled into the oil flow channel... 133. Increasing the pressure of the buffer solution used to flush cells would increase the droplet size after pairing, reducing the probability of cell-released mRNA colliding with the microspheres and affecting the microspheres' capture of cell mRNA. In this embodiment, by making the upper inner wall surface and the lower inner wall surface parallel to each other, the distance difference between different cells and the upper inner wall surface is reduced, thereby reducing the flow rate difference caused by this distance difference, and thus narrowing the cell trapping range. The pressure of the buffer solution and the volume of the liquid can be reduced accordingly, which helps to improve the capture success rate.

[0104] In some other embodiments, the second flow channel 132 includes a second microvalve section 1321 corresponding to the second microvalve 122, and a second flow section 1322 different from the second microvalve section 1321. The upper inner wall surface and the lower inner wall surface of the second flow section 1322 are parallel planes. The structure and function of the second microvalve section 1321 and the second flow section 1322 in this embodiment can be understood with reference to the first microvalve section 1311 and the first flow section 1312.

[0105] Based on the first embodiment, in some embodiments of the present invention, reference is made to Figure 6 The cross-section of the first flow section 1312 is set to a rectangle, which not only ensures that the upper inner wall surface and the lower inner wall surface of the first flow section 1312 are parallel to each other, but also reduces the difficulty of the flow channel preparation.

[0106] In other embodiments, the cross-section of the second flow section 1322 is set to rectangular, which not only ensures that the upper inner wall surface and the lower inner wall surface of the second flow section 1322 are parallel to each other, but also reduces the difficulty of fabricating the flow channel.

[0107] Based on the first embodiment, in some embodiments of the present invention, the width of the first flow section 1312 is 50 micrometers to 150 micrometers. That is, the first flow section 1312 has sufficient space in the width direction to prevent the first target object from getting too close to the left and right inner sides of the first flow section 1312, thus affecting the flow velocity. This reduces the flow velocity difference between different first target objects caused by this distance difference, thereby further improving the pairing success rate. For example, the width of the first flow section 1312 is 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, and 150 micrometers.

[0108] In other embodiments, the width of the second flow section 1322 is 50 micrometers to 150 micrometers. This means the second flow section 1322 has sufficient space in its width direction to prevent the second target object from getting too close to the left and right inner sides of the second flow section 1322, thus avoiding affecting the flow velocity. This reduces the flow velocity differences between different second target objects caused by these distance differences, thereby further improving the pairing success rate. For example, the width of the second flow section 1322 is 50 micrometers, 60 micrometers, 70 micrometers, 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, and 150 micrometers.

[0109] Based on the first embodiment, in some embodiments of the present invention, the maximum height of the oil flow channel 133 is 80 micrometers to 200 micrometers. In the actual encapsulation process, the encapsulated droplets may come into large-area contact with the flow channel wall of the oil flow channel 133, causing the droplets to adhere to the flow channel wall and be broken up as the oil flows. This embodiment, by setting the maximum height of the oil flow channel 133, can reduce the probability of droplets contacting the flow channel wall of the oil flow channel 133, thereby reducing the risk of droplet breakage. For example, the maximum height of the oil flow channel 133 is 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, 150 micrometers, 160 micrometers, 170 micrometers, 180 micrometers, 190 micrometers, and 200 micrometers.

[0110] In some specific embodiments, the upper inner wall surface of the oil flow channel 133 can be an arc surface similar to the first micro-valve section 1311, or a plane similar to the first flow section 1312. When it is an arc surface, the maximum height of the oil flow channel 133 is the height of the apex of the arc surface.

[0111] Based on the first embodiment, in some embodiments of the present invention, reference is made to Figure 1The microfluidic system also includes a first sheath fluid channel 137, which is connected to a first channel 131 and is used to input a first sheath flow encapsulating a first liquid into the first channel 131. In this embodiment, by setting the first liquid to be constrained by sheath fluid, the first liquid can flow in the central region of the channel, preventing the first target object within the first liquid from getting too close to the inner wall of the channel. It should be noted that, in conjunction with the aforementioned setting the upper and lower inner wall surfaces of the first flow section 1312 as mutually parallel planes, this embodiment can further ensure that the flow velocity of different first target objects remains stable.

[0112] In some specific embodiments, reference is made to Figure 1 The first sheath fluid flow channel 137 includes two first branch flow channels 1371, which are connected to the first flow channel 131 from both sides, thereby confining the first fluid between the two sheath flows.

[0113] In other embodiments, reference is made to Figure 1 The microfluidic system also includes a second sheath fluid channel 138, which is connected to the second channel 132 and is used to input a second sheath flow encapsulating the second liquid into the second channel 132. This embodiment, by setting the second liquid to be confined by the sheath fluid, enables the second liquid to flow in the central region of the channel, preventing the second target object within the second liquid from getting too close to the inner wall of the channel. It should be noted that, in conjunction with the aforementioned setting the upper and lower inner wall surfaces of the second flow section 1322 as mutually parallel planes, this embodiment can further ensure that the flow velocity of different second target objects remains stable.

[0114] In some specific embodiments, reference is made to Figure 1 The second sheath fluid flow channel 138 includes two second branch flow channels 1381, which are connected to the second flow channel 132 from both sides, thereby confining the second fluid between the two sheath flows.

[0115] Based on the first embodiment, referring to Figures 1 to 3In some embodiments of the present invention, the microfluidic system further includes a waste liquid channel 135, which is used to discharge the first liquid and the second liquid, and is connected to a paired channel 136. Furthermore, the microfluidic system also includes a waste liquid microvalve 125 corresponding to the waste liquid channel 135, which is used to control the opening and closing of the waste liquid channel 135. When the paired microvalve 126 is closed and the first microvalve 121 and the waste liquid microvalve 125 are open, the first liquid in the first channel 131 can flow out through the paired channel 136 and the waste liquid channel 135. In other embodiments, when the paired microvalve 126 is closed and the second microvalve 122 and the waste liquid microvalve 125 are open, the liquid in the second channel 132 can flow out through the paired channel 136 and the waste liquid channel 135. It should be noted that the first target and the second target will gradually approach and reach the matching flow channel 136 as they follow the flow of the first liquid and the second liquid, respectively. When the first target and the second target have not yet reached the matching flow channel 136, the first flow channel 131 and the second flow channel 132 will continuously discharge the first liquid and the second liquid, which need to be discharged as waste liquid.

[0116] Combining the above structure, Figures 1 to 3 The control of each micro-valve is described as follows:

[0117] During the pairing process, buffer microvalve 124 and pairing microvalve 126 are closed, while first microvalve 121, second microvalve 122, and waste liquid microvalve 125 are opened. The first liquid and the second liquid are discharged through pairing channel 136 and waste liquid channel 135 (e.g., Figure 3 (a) When a single first target object is detected, the first microvalve 121 closes, and the single first target object stops within the mating flow channel 136 (e.g., Figure 3 (b) When a single second target is detected, the second microvalve 122 closes, and the single second target stops within the mating flow channel 136 (e.g., ...). Figure 3 (c) When both the first and second target objects stop within the paired flow channel 136, the waste liquid micro-valve 125 closes.

[0118] During the encapsulation process, after the first microvalve 121, the second microvalve 122, and the waste liquid microvalve 125 are closed, the buffer microvalve 124 and the paired microvalve 126 are opened. The buffer delivers a single first target object and a single second target object from the paired flow channel 136 into the oil in the oil flow channel 133 to form droplets (e.g., Figure 3 (d in the text)

[0119] When the microfluidic system also includes a waste liquid channel 135, in some embodiments of the present invention, refer to Figure 1 , Figure 2 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 1 , Figure 2 In the direction from top to bottom, the waste liquid flow channel 135 is located between the first flow channel 131 and the second flow channel 132. Based on this, the microfluidic system also includes a first shut-off microvalve 127, which controls the opening and closing of the paired flow channel 136 located between the waste liquid flow channel 135 and the first flow channel 131. For example, along... Figure 1 , Figure 2 From top to bottom, the first shut-off microvalve 127 is disposed on the mating channel 136 between the waste liquid channel 135 and the first channel 131. In this embodiment, by setting the first shut-off microvalve 127, the first target object that has entered the mating channel 136 can be prevented from being driven out of the mating channel 136 by the second liquid, so that the encapsulated droplet contains only the second target object, thereby ensuring the success rate of encapsulation.

[0120] In some specific embodiments, combined with Figure 1 , Figure 2 To understand this, the microfluidic system is configured such that when a single first target A is located in the paired flow channel 136, the first shut-off microvalve 127 switches from the open state to the closed state. At this time, the paired flow channel 136 where the single first target A is located is isolated from the paired flow channel 136 through which the second liquid flows by through the first shut-off microvalve 127, and the flow of the second liquid will not carry the first target.

[0121] The microfluidic system is also configured such that when a single first target A and a single second target B are present in the paired channel 136, the first microvalve 121, the second microvalve 122, and the waste liquid microvalve 125 are closed, and the paired microvalve 126, the buffer microvalve 124, and the first shut-off microvalve 127 are open, so that the buffer in the buffer channel 134 delivers the single first target A and the single second target B in the paired channel 136 into the oil in the oil channel 133 to form droplets C.

[0122] In this embodiment, by controlling the opening and closing of the first cut-off micro-valve 127, the first target object can be stored in the pairing flow channel 136 during the waiting process for pairing, without affecting the pairing and packaging of the first target object and the second target object.

[0123] It should be noted that before the first shut-off microvalve 127 is closed, the second microvalve 122 can remain open, allowing the second liquid to continuously discharge from the waste liquid channel 135 (i.e., without capturing the second target B). Alternatively, the second microvalve 122 can be closed initially, and then opened again after the first shut-off microvalve 127 is closed to capture the subsequent single second target B.

[0124] When the microfluidic system also includes a waste liquid channel 135, in other embodiments of the present invention, refer to Figure 7 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 7 In the top-to-bottom direction, the waste liquid flow channel 135 is located between the first flow channel 131 and the second flow channel 132. Based on this, the microfluidic system also includes a second shut-off microvalve 128, which controls the opening and closing of the paired flow channel 136 located between the waste liquid flow channel 135 and the second flow channel 132. For example, along... Figure 7 From top to bottom, the second shut-off microvalve 128 is disposed on the mating channel 136 between the waste liquid channel 135 and the second channel 132. In this embodiment, by setting the second shut-off microvalve 128, the second target object that has entered the mating channel 136 can be driven out of the mating channel 136 by the first liquid, so that the encapsulated droplet contains only the first target object, thereby ensuring the success rate of encapsulation.

[0125] In some specific embodiments, combined with Figure 7 To understand this, the microfluidic system is configured such that when a single second target object B is located in the paired flow channel 136, the second shut-off microvalve 128 switches from the open state to the closed state. At this time, the paired flow channel 136 where the single second target object B is located is isolated from the paired flow channel 136 through which the first liquid flows by through the second shut-off microvalve 128, and the flow of the first liquid will not carry the second target object.

[0126] The microfluidic system is also configured such that when a single first target A and a single second target B are present in the paired channel 136, the first microvalve 121, the second microvalve 122, and the waste liquid microvalve 125 are closed, while the paired microvalve 126, the buffer microvalve 124, and the second shut-off microvalve 128 are open, so that the buffer in the buffer channel 134 delivers the single first target A and the single second target B in the paired channel 136 into the oil in the oil channel 133 to form droplets C.

[0127] In this embodiment, by controlling the on / off state of the second cut-off microvalve 128, the second target object can be stored in the pairing flow channel 136 during the waiting process for pairing, without affecting the pairing and packaging of the first and second target objects.

[0128] In other embodiments, the microfluidic system may not have a shut-off microvalve, see reference. Figure 8 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 8From top to bottom, the waste liquid flow channel 135, the second flow channel 132, and the first flow channel 131 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single first target A is located in the paired flow channel 136, the second microvalve 122 is closed to allow a single second target B to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that the single first target A is located in the paired flow channel 136 (at which point the first microvalve 121 is already closed), and then allow the single second target B to be located in the paired flow channel 136. For example, the second microvalve 122 is closed before the single first target A is located in the paired flow channel 136, and opens after the single first target A is located in the paired flow channel 136. When the detection module detects the single second target B, the second microvalve 122 closes again, thereby allowing the single second target B to stop within the paired flow channel 136.

[0129] In this embodiment, since the waste liquid channel 135 is located on the side close to the second channel 132, the second liquid will flow toward the waste liquid channel 135 instead of the first channel 131 that has been cut off. Therefore, it is possible to prevent the single first target A from being carried away by the second liquid.

[0130] In other embodiments, reference is made to Figure 9 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 9 From top to bottom, the waste liquid flow channel 135, the first flow channel 131, and the second flow channel 132 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single second target object B is located in the paired flow channel 136, the first microvalve 121 is closed to allow a single first target object A to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that a single second target object N is located in the paired flow channel 136 (at which time the second microvalve 122 is already closed), and then allow a single first target object A to be located in the paired flow channel 136. For example, the first microvalve 121 is closed before the single second target object B is located in the paired flow channel 136, and the first microvalve 121 is opened after the single second target object B is located in the paired flow channel 136. When the detection module detects the single first target object A, the first microvalve 121 is closed again, so that the single first target object A can be stopped in the paired flow channel 136.

[0131] In this embodiment, since the waste liquid channel 135 is located on the side close to the first channel 131, the first liquid will flow toward the waste liquid channel 135 and not toward the already cut-off second channel 132, thus preventing a single second target object B from being carried away by the first liquid.

[0132] In other embodiments, reference is made to Figure 10 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 10 From top to bottom, the second flow channel 132, the first flow channel 131, and the waste liquid flow channel 135 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single second target object B is located in the paired flow channel 136, the first microvalve 121 is closed to allow a single first target object A to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that a single second target object N is located in the paired flow channel 136 (at which time the second microvalve 122 is already closed), and then allow a single first target object A to be located in the paired flow channel 136. For example, the first microvalve 121 is closed before a single second target object B is located in the paired flow channel 136, and the first microvalve 121 is opened after a single second target object B is located in the paired flow channel 136. When the detection module detects a single first target object A, the first microvalve 121 is closed again, thereby allowing a single first target object A to stop in the paired flow channel 136.

[0133] In this embodiment, since the waste liquid channel 135 is located on the side close to the first channel 131, the first liquid will flow toward the waste liquid channel 135 and not toward the already cut-off second channel 132, thus preventing a single second target object B from being carried away by the first liquid.

[0134] In other embodiments, reference is made to Figure 11 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 11 From top to bottom, the first flow channel 131, the second flow channel 132, and the waste liquid flow channel 135 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single first target A is located in the paired flow channel 136, the second microvalve 122 is closed to allow a single second target B to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that the single first target A is located in the paired flow channel 136 (at which time the first microvalve 121 is already closed), and then allow the single second target B to be located in the paired flow channel 136. For example, the second microvalve 122 is closed before the single first target A is located in the paired flow channel 136, and the second microvalve 122 opens after the single first target A is located in the paired flow channel 136. When the detection module detects the single second target B, the second microvalve 122 closes again, thereby allowing the single second target B to stop in the paired flow channel 136.

[0135] In this embodiment, since the waste liquid channel 135 is located on the side close to the second channel 132, the second liquid will flow toward the waste liquid channel 135 instead of the first channel 131 that has been cut off. Therefore, it is possible to prevent the single first target A from being carried away by the second liquid.

[0136] Based on the first embodiment, some embodiments of the microfluidic system of the present invention further include a detection module. The detection module is configured to identify a single first target A within the first flow channel 131. When the detection module identifies the single first target A, both the first microvalve 121 and the paired microvalve 126 are in a closed state to keep the single first target A within the paired flow channel 136. It should be noted that in this embodiment, the first microvalve 121 being in a closed state specifically means switching from an open state to a closed state, and the paired microvalve 126 being in a closed state specifically means remaining in a closed state.

[0137] In other embodiments, the detection module is configured to identify a single second target object B within the second flow channel 132. When the detection module identifies the single second target object B, both the second microvalve 122 and the paired microvalve 126 are in a closed state to keep the single second target object B within the paired flow channel 136. It should be noted that in this embodiment, the second microvalve 122 being in a closed state specifically means switching from an open state to a closed state, and the paired microvalve 126 being in a closed state specifically means remaining in a closed state.

[0138] In some specific embodiments, the detection module is a visual detection module, which includes a camera and a controller. The controller is configured to control the camera to capture images. After the camera captures images, the controller is also configured to identify a single first target A and a single second target B based on the images.

[0139] In other specific embodiments, the detection module is specifically a fluorescence detection module, which includes a first light source, a second light source, a first light detection device, a second light detection device, and a controller, as shown below. Figure 3 The controller is configured to control a first light source to emit a first detection light D into a first flow channel 131. The first detection light D can excite a first fluorescence after irradiating a single first target object A. A first photodetector can receive the first fluorescence excited by the single first target object A. For example, the first light source is a laser, and the first photodetector is a photomultiplier tube. After receiving the first fluorescence emitted by the single first target object A, the photomultiplier tube can convert the light signal into an electrical signal and transmit it to the controller. The controller is also configured to control a second light source to emit a second detection light E into a second flow channel 132. The second detection light E can excite a second fluorescence after irradiating a single second target object B. When the second photodetector detects the second fluorescence, the controller identifies the single second target object B.

[0140] In some specific embodiments, the detection module is specifically an electrode detection module, which includes a first detection electrode, a second detection electrode, and a controller. The first detection electrode extends into the first flow channel 131, and the second detection electrode extends into the second flow channel 132. When a single first target object A passes through the first detection electrode, the first detection electrode generates a corresponding signal. The controller is configured to identify the single first target object A based on the signal detected by the first detection electrode. Specifically, the first detection electrode includes a positive electrode and a negative electrode, which are arranged side by side. When the microfluidic system includes a microfluidic chip 100, the first detection electrode can be a metal layer disposed between the control layer 120 and the flow channel layer 130 of the microfluidic chip 100. The second detection electrode can be understood with reference to the first detection electrode.

[0141] The second embodiment of the present invention discloses a microfluidic system for target pairing, referring to... Figures 1 to 3 The system includes a first flow channel 131, a second flow channel 132, an oil flow channel 133, a buffer flow channel 134, and a pairing flow channel 136. The first flow channel 131 is for the passage of a first liquid containing a first target object; the second flow channel 132 is for the passage of a second liquid containing a second target object; the buffer flow channel 134 is for the passage of a buffer solution; the oil flow channel 133 is for the passage of an oil solution that is immiscible with the first liquid, the second liquid, and the buffer solution; and the pairing flow channel 136 is for the residence of a single first target object A and a single second target object B. The pairing flow channel 136 is connected to the oil flow channel 133, and the first flow channel 131, the second flow channel 132, and the buffer flow channel 134 are all connected to the pairing flow channel 136. In this embodiment, the first target object is a cell, and the second target object is a microsphere. Those skilled in the art will understand that the first target object can be a cell, and the second target object can also be a cell.

[0142] The microfluidic system in this embodiment also includes multiple microvalves, specifically including a paired microvalves 126 corresponding to the paired flow channel 136, a first microvalves 121 corresponding to the first flow channel 131, a second microvalves 122 corresponding to the second flow channel 132, and a buffer microvalves 124 corresponding to the buffer flow channel 134. The paired microvalves 126 control the opening and closing of the paired flow channel 136, the first microvalves 121 control the opening and closing of the first flow channel 131, the second microvalves 122 control the opening and closing of the second flow channel 132, and the buffer microvalves 124... 124 is used to control the opening and closing of the buffer solution channel 134. Taking the first channel 131 and the first microvalve 121 as an example, the first microvalve 121 controlling the opening and closing of the first channel 131 means that the first microvalve 121 has an open state and a closed state. When the first microvalve 121 is in the open state, the first channel 131 is in the unobstructed state, and the first liquid can flow in the first channel 131. When the first microvalve 121 is in the closed state, the first channel 131 is in the closed state, and the first liquid cannot flow in the first channel 131.

[0143] For ease of understanding, please refer to... Figure 4 , Figure 5 The overall structure of the microfluidic system and the specific structure of the microvalve are described, such as... Figure 4 As shown, the microfluidic system includes a microfluidic chip 100, which comprises a base layer 110, a control layer 120, and a channel layer 130 stacked sequentially. The base layer 110 can be made of glass, and the control layer 120 and the channel layer 130 can be made of polydimethylsiloxane (PDMS). The channel layer 130 contains the aforementioned first channel 131, second channel 132, oil channel 133, buffer channel 134, waste liquid channel 135, and paired channel 136. The control layer 120 contains the aforementioned first microvalve 121, second microvalve 122, buffer microvalve 124, waste liquid microvalve 125, and paired microvalve 126, as well as microvalve control channels corresponding to each microvalve. (Refer to...) Figure 5 Taking the first microvalve 121 as an example, the first microvalve 121 includes a diaphragm 1211 disposed between the first flow channel 131 (specifically, the first microvalve section 1311 described below) and the first microvalve control flow channel 139. When the first microvalve 121 is in such a state... Figure 5 When in the open state shown as 'a', diaphragm 1211 is in a horizontal state, allowing the first liquid to pass through the first micro-valve section 1311; when diaphragm 1211 is driven by the liquid or gas in the first micro-valve control channel 139 to bulge into the first channel 131 to be in a horizontal state... Figure 5 In the closed state shown by b, the diaphragm 1211 is close to the inner wall of the first flow channel 131 to block the first micro-valve section 1311, and the first liquid cannot pass through the first micro-valve section 1311. Figure 5In the illustrated embodiment, the upper inner wall surface of the first microvalve segment 1311 is configured as an arc surface protruding away from the first microvalve 121, specifically a semi-circular arc surface, to facilitate its fit with the diaphragm 1211 protruding towards the first microvalve segment 1311, thereby ensuring the shut-off effect. The second microvalve segment 1321 of the second flow channel 132 can be understood with reference to the first microvalve segment 1311.

[0144] In this embodiment, refer to Figure 3 In steps c to d, when a single first target A and a single second target B are present in the paired flow channel 136, the first microvalve 121 and the second microvalve 122 are in the closed state (the microvalve is indicated by black filling), and the paired microvalve 126 and the buffer microvalve 124 are in the open state (the microvalve is indicated by gray filling). At this time, the buffer in the buffer flow channel 134 can deliver the single first target A and the single second target B in the paired flow channel 136 into the oil in the oil flow channel 133 to form droplets C. Thus, through individual pairing... The flow channel 136 is used to temporarily store a single first target A and a single second target B, and is provided with a separate buffer flow channel 134. The buffer pushes the single first target A and the single second target B into the oil without the need for the first liquid and the second liquid to push the single first target A and the single second target B. Therefore, the first flow channel 131 and the second flow channel 132 can remain in a closed state during the encapsulation process, thereby completely preventing other first target objects and / or other second target objects from entering the droplet C, which is beneficial to improving the success rate of encapsulation and reducing cell loss caused by multiple encapsulation.

[0145] Based on this, the maximum height of the oil flow channel 133 in this embodiment is 80 micrometers to 200 micrometers. In the actual encapsulation process, the encapsulated droplets may come into large-area contact with the channel wall of the oil flow channel 133, causing the droplets to adhere to the channel wall and be broken up as the oil flows. This embodiment, by setting the maximum height of the oil flow channel 133, can reduce the probability of droplets contacting the channel wall of the oil flow channel 133, thereby reducing the risk of droplet breakage. For example, the maximum height of the oil flow channel 133 is 80 micrometers, 90 micrometers, 100 micrometers, 110 micrometers, 120 micrometers, 130 micrometers, 140 micrometers, 150 micrometers, 160 micrometers, 170 micrometers, 180 micrometers, 190 micrometers, and 200 micrometers.

[0146] Based on the second embodiment, in some embodiments of the present invention, the upper inner wall surface and the lower inner wall surface of the oil flow channel 133 are parallel planes, which can further reduce the probability of droplets contacting the flow channel wall of the oil flow channel 133. In some specific embodiments, the cross-section of the oil flow channel 133 is set as rectangular, which facilitates the preparation of the flow channel.

[0147] The third embodiment of the present invention discloses a microfluidic system for target pairing, referring to... Figures 1 to 3 The system includes a first flow channel 131, a second flow channel 132, an oil flow channel 133, a buffer flow channel 134, and a pairing flow channel 136. The first flow channel 131 is for the passage of a first liquid containing a first target object; the second flow channel 132 is for the passage of a second liquid containing a second target object; the buffer flow channel 134 is for the passage of a buffer solution; the oil flow channel 133 is for the passage of an oil solution that is immiscible with the first liquid, the second liquid, and the buffer solution; and the pairing flow channel 136 is for the residence of a single first target object A and a single second target object B. The pairing flow channel 136 is connected to the oil flow channel 133, and the first flow channel 131, the second flow channel 132, and the buffer flow channel 134 are all connected to the pairing flow channel 136. In this embodiment, the first target object is a cell, and the second target object is a microsphere. Those skilled in the art will understand that the first target object can be a cell, and the second target object can also be a cell.

[0148] The microfluidic system in this embodiment also includes multiple microvalves, specifically including a paired microvalves 126 corresponding to the paired flow channel 136, a first microvalves 121 corresponding to the first flow channel 131, a second microvalves 122 corresponding to the second flow channel 132, and a buffer microvalves 124 corresponding to the buffer flow channel 134. The paired microvalves 126 control the opening and closing of the paired flow channel 136, the first microvalves 121 control the opening and closing of the first flow channel 131, the second microvalves 122 control the opening and closing of the second flow channel 132, and the buffer microvalves 124... 124 is used to control the opening and closing of the buffer solution channel 134. Taking the first channel 131 and the first microvalve 121 as an example, the first microvalve 121 controlling the opening and closing of the first channel 131 means that the first microvalve 121 has an open state and a closed state. When the first microvalve 121 is in the open state, the first channel 131 is in the unobstructed state, and the first liquid can flow in the first channel 131. When the first microvalve 121 is in the closed state, the first channel 131 is in the closed state, and the first liquid cannot flow in the first channel 131.

[0149] For ease of understanding, please refer to... Figure 4 , Figure 5 The overall structure of the microfluidic system and the specific structure of the microvalve are described, such as... Figure 4As shown, the microfluidic system includes a microfluidic chip 100, which comprises a base layer 110, a control layer 120, and a channel layer 130 stacked sequentially. The base layer 110 can be made of glass, and the control layer 120 and the channel layer 130 can be made of polydimethylsiloxane (PDMS). The channel layer 130 contains the aforementioned first channel 131, second channel 132, oil channel 133, buffer channel 134, waste liquid channel 135, and paired channel 136. The control layer 120 contains the aforementioned first microvalve 121, second microvalve 122, buffer microvalve 124, waste liquid microvalve 125, and paired microvalve 126, as well as microvalve control channels corresponding to each microvalve. (Refer to...) Figure 5 Taking the first microvalve 121 as an example, the first microvalve 121 includes a diaphragm 1211 disposed between the first flow channel 131 (specifically, the first microvalve section 1311 described below) and the first microvalve control flow channel 139. When the first microvalve 121 is in such a state... Figure 5 When in the open state shown as 'a', diaphragm 1211 is in a horizontal state, allowing the first liquid to pass through the first micro-valve section 1311; when diaphragm 1211 is driven by the liquid or gas in the first micro-valve control channel 139 to bulge into the first channel 131 to be in a horizontal state... Figure 5 In the closed state shown by b, the diaphragm 1211 is close to the inner wall of the first flow channel 131 to block the first micro-valve section 1311, and the first liquid cannot pass through the first micro-valve section 1311. Figure 5 In the illustrated embodiment, the upper inner wall surface of the first microvalve segment 1311 is configured as an arc surface protruding away from the first microvalve 121, specifically a semi-circular arc surface, to facilitate its fit with the diaphragm 1211 protruding towards the first microvalve segment 1311, thereby ensuring the shut-off effect. The second microvalve segment 1321 of the second flow channel 132 can be understood with reference to the first microvalve segment 1311.

[0150] In this embodiment, refer to Figure 3In steps c to d, when a single first target A and a single second target B are present in the paired flow channel 136, the first microvalve 121 and the second microvalve 122 are in the closed state (the microvalve is indicated by black filling), and the paired microvalve 126 and the buffer microvalve 124 are in the open state (the microvalve is indicated by gray filling). At this time, the buffer in the buffer flow channel 134 can deliver the single first target A and the single second target B in the paired flow channel 136 into the oil in the oil flow channel 133 to form droplets C. Thus, through individual pairing... The flow channel 136 is used to temporarily store a single first target A and a single second target B, and is provided with a separate buffer flow channel 134. The buffer pushes the single first target A and the single second target B into the oil without the need for the first liquid and the second liquid to push the single first target A and the single second target B. Therefore, the first flow channel 131 and the second flow channel 132 can remain in a closed state during the encapsulation process, thereby completely preventing other first target objects and / or other second target objects from entering the droplet C, which is beneficial to improving the success rate of encapsulation and reducing cell loss caused by multiple encapsulation.

[0151] Based on this, the microfluidic system in this embodiment also includes a first sheath fluid channel 137, which is connected to a first channel 131 and is used to input a first sheath flow encapsulating a first liquid into the first channel 131. This embodiment, by setting the sheath fluid to constrain the first liquid, enables the first liquid to flow in the central region of the channel, preventing the first target object within the first liquid from being too close to the inner wall of the channel, thus avoiding significant velocity differences between different first target objects.

[0152] In some specific embodiments, reference is made to Figure 1 The first sheath fluid flow channel 137 includes two first branch flow channels 1371, which are connected to the first flow channel 131 from both sides, thereby confining the first fluid between the two sheath flows.

[0153] In other embodiments, reference is made to Figure 1 The microfluidic system also includes a second sheath fluid channel 138, which is connected to the second channel 132 and is used to input a second sheath flow containing a second liquid into the second channel 132. In this embodiment, by setting the second liquid to be confined by sheath fluid, the second liquid can flow in the central region of the channel, resulting in a significant difference in flow velocity between different second target objects.

[0154] In some specific embodiments, reference is made to Figure 1The second sheath fluid flow channel 138 includes two second branch flow channels 1381, which are connected to the second flow channel 132 from both sides, thereby confining the second fluid between the two sheath flows.

[0155] The fourth embodiment of the present invention discloses a microfluidic system for target pairing, referring to... Figures 1 to 3 The system includes a first flow channel 131, a second flow channel 132, an oil flow channel 133, a buffer flow channel 134, and a pairing flow channel 136. The first flow channel 131 is for the passage of a first liquid containing a first target object; the second flow channel 132 is for the passage of a second liquid containing a second target object; the buffer flow channel 134 is for the passage of a buffer solution; the oil flow channel 133 is for the passage of an oil solution that is immiscible with the first liquid, the second liquid, and the buffer solution; and the pairing flow channel 136 is for the residence of a single first target object A and a single second target object B. The pairing flow channel 136 is connected to the oil flow channel 133, and the first flow channel 131, the second flow channel 132, and the buffer flow channel 134 are all connected to the pairing flow channel 136. In this embodiment, the first target object is a cell, and the second target object is a microsphere. Those skilled in the art will understand that the first target object can be a cell, and the second target object can also be a cell.

[0156] The microfluidic system in this embodiment also includes multiple microvalves, specifically including a paired microvalves 126 corresponding to the paired flow channel 136, a first microvalves 121 corresponding to the first flow channel 131, a second microvalves 122 corresponding to the second flow channel 132, and a buffer microvalves 124 corresponding to the buffer flow channel 134. The paired microvalves 126 control the opening and closing of the paired flow channel 136, the first microvalves 121 control the opening and closing of the first flow channel 131, the second microvalves 122 control the opening and closing of the second flow channel 132, and the buffer microvalves 124... 124 is used to control the opening and closing of the buffer solution channel 134. Taking the first channel 131 and the first microvalve 121 as an example, the first microvalve 121 controlling the opening and closing of the first channel 131 means that the first microvalve 121 has an open state and a closed state. When the first microvalve 121 is in the open state, the first channel 131 is in the unobstructed state, and the first liquid can flow in the first channel 131. When the first microvalve 121 is in the closed state, the first channel 131 is in the closed state, and the first liquid cannot flow in the first channel 131.

[0157] For ease of understanding, please refer to... Figure 4 , Figure 5 The overall structure of the microfluidic system and the specific structure of the microvalve are described, such as... Figure 4As shown, the microfluidic system includes a microfluidic chip 100, which comprises a base layer 110, a control layer 120, and a channel layer 130 stacked sequentially. The base layer 110 can be made of glass, and the control layer 120 and the channel layer 130 can be made of polydimethylsiloxane (PDMS). The channel layer 130 contains the aforementioned first channel 131, second channel 132, oil channel 133, buffer channel 134, waste liquid channel 135, and paired channel 136. The control layer 120 contains the aforementioned first microvalve 121, second microvalve 122, buffer microvalve 124, waste liquid microvalve 125, and paired microvalve 126, as well as microvalve control channels corresponding to each microvalve. (Refer to...) Figure 5 Taking the first microvalve 121 as an example, the first microvalve 121 includes a diaphragm 1211 disposed between the first flow channel 131 (specifically, the first microvalve section 1311 described below) and the first microvalve control flow channel 139. When the first microvalve 121 is in such a state... Figure 5 When in the open state shown as 'a', diaphragm 1211 is in a horizontal state, allowing the first liquid to pass through the first micro-valve section 1311; when diaphragm 1211 is driven by the liquid or gas in the first micro-valve control channel 139 to bulge into the first channel 131 to be in a horizontal state... Figure 5 In the closed state shown by b, the diaphragm 1211 is close to the inner wall of the first flow channel 131 to block the first micro-valve section 1311, and the first liquid cannot pass through the first micro-valve section 1311. Figure 5 In the illustrated embodiment, the upper inner wall surface of the first microvalve segment 1311 is configured as an arc surface protruding away from the first microvalve 121, specifically a semi-circular arc surface, to facilitate its fit with the diaphragm 1211 protruding towards the first microvalve segment 1311, thereby ensuring the shut-off effect. The second microvalve segment 1321 of the second flow channel 132 can be understood with reference to the first microvalve segment 1311.

[0158] In this embodiment, refer to Figure 3In steps c to d, when a single first target A and a single second target B are present in the paired flow channel 136, the first microvalve 121 and the second microvalve 122 are in the closed state (the microvalve is indicated by black filling), and the paired microvalve 126 and the buffer microvalve 124 are in the open state (the microvalve is indicated by gray filling). At this time, the buffer in the buffer flow channel 134 can deliver the single first target A and the single second target B in the paired flow channel 136 into the oil in the oil flow channel 133 to form droplets C. Thus, through individual pairing... The flow channel 136 is used to temporarily store a single first target A and a single second target B, and is provided with a separate buffer flow channel 134. The buffer pushes the single first target A and the single second target B into the oil without the need for the first liquid and the second liquid to push the single first target A and the single second target B. Therefore, the first flow channel 131 and the second flow channel 132 can remain in a closed state during the encapsulation process, thereby completely preventing other first target objects and / or other second target objects from entering the droplet C, which is beneficial to improving the success rate of encapsulation and reducing cell loss caused by multiple encapsulation.

[0159] In addition, the microfluidic system also includes a waste liquid channel 135, which is used to discharge the first liquid and the second liquid, and is connected to a paired channel 136. Furthermore, the microfluidic system also includes a waste liquid microvalve 125 corresponding to the waste liquid channel 135, which is used to control the opening and closing of the waste liquid channel 135. When the paired microvalve 126 is closed and the first microvalve 121 and the waste liquid microvalve 125 are open, the first liquid in the first channel 131 can flow out through the paired channel 136 and the waste liquid channel 135. In other embodiments, when the paired microvalve 126 is closed and the second microvalve 122 and the waste liquid microvalve 125 are open, the liquid in the second channel 132 can flow out through the paired channel 136 and the waste liquid channel 135. It should be noted that the first target and the second target will gradually approach and reach the matching flow channel 136 as they follow the flow of the first liquid and the second liquid, respectively. When the first target and the second target have not yet reached the matching flow channel 136, the first flow channel 131 and the second flow channel 132 will continuously discharge the first liquid and the second liquid, which need to be discharged as waste liquid.

[0160] Based on this, refer to Figure 1 , Figure 2 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 1 , Figure 2In this embodiment, the waste liquid flow channel 135 is located between the first flow channel 131 and the second flow channel 132, in a top-to-bottom direction. The microfluidic system also includes a first shut-off microvalve 127, which controls the opening and closing of the paired flow channel 136 located between the waste liquid flow channel 135 and the first flow channel 131. For example, along... Figure 1 , Figure 2 From top to bottom, a first shut-off microvalve 127 is disposed on a mating channel 136 between the waste liquid channel 135 and the first channel 131. In this embodiment, by setting the first shut-off microvalve 127, the first target material that has entered the mating channel 136 can be prevented from being carried out of the mating channel 136 by the second liquid, thus ensuring that the encapsulated droplet contains only the second target material, thereby guaranteeing the encapsulation success rate. It should be noted that when the first target material is, for example, tumor cells, its quantity in the sample is small and the cost is high. This embodiment, by setting the first shut-off microvalve 127, can also reduce the waste of the first target material.

[0161] Based on the fourth embodiment, in some embodiments of the present invention, combined with Figure 1 , Figure 2 To understand this, the microfluidic system is configured such that when a single first target A is located in the paired flow channel 136, the first shut-off microvalve 127 switches from the open state to the closed state. At this time, the paired flow channel 136 where the single first target A is located is isolated from the paired flow channel 136 through which the second liquid flows by through the first shut-off microvalve 127, and the flow of the second liquid will not carry the first target.

[0162] The microfluidic system is also configured such that when a single first target A and a single second target B are present in the paired channel 136, the first microvalve 121, the second microvalve 122, and the waste liquid microvalve 125 are closed, and the paired microvalve 126, the buffer microvalve 124, and the first shut-off microvalve 127 are open, so that the buffer in the buffer channel 134 delivers the single first target A and the single second target B in the paired channel 136 into the oil in the oil channel 133 to form droplets C.

[0163] In this embodiment, by controlling the opening and closing of the first cut-off micro-valve 127, the first target object can be stored in the pairing flow channel 136 during the waiting process for pairing, without affecting the pairing and packaging of the first target object and the second target object.

[0164] It should be noted that before the first shut-off microvalve 127 is closed, the second microvalve 122 can remain open, allowing the second liquid to continuously discharge from the waste liquid channel 135 (i.e., without capturing the second target B). Alternatively, the second microvalve 122 can be closed initially, and then opened again after the first shut-off microvalve 127 is closed to capture the subsequent single second target B.

[0165] Based on the fourth embodiment, in some embodiments of the present invention, when there is no single first target A in the paired flow channel 136, the paired micro valve 126 is in a closed state and the first micro valve 121, the first shut-off micro valve 127 and the waste liquid micro valve 125 are in an open state, so that the liquid in the first flow channel 131 can flow out through the paired flow channel 136 and the waste liquid flow channel 135, thereby causing the first target to flow into the paired flow channel 136.

[0166] In other embodiments, when there is no single second target object B in the paired flow channel 136, the paired micro valve 126 is in a closed state and the second micro valve 122 and the waste liquid micro valve 125 are in an open state, so that the liquid in the second flow channel 132 can flow out through the paired flow channel 136 and the waste liquid flow channel 135, thereby causing the second target object to flow into the paired flow channel 136.

[0167] The fifth embodiment of the present invention discloses a microfluidic system for target pairing, which differs from the fourth embodiment in that: the fourth embodiment includes a first shut-off microvalve 127, which controls the opening and closing of the pairing channel 136 located between the waste liquid channel 135 and the first channel 131; this embodiment includes a second shut-off microvalve 128, which controls the opening and closing of the pairing channel 136 located between the waste liquid channel 135 and the second channel 132. For example, along... Figure 7 From top to bottom, the second shut-off microvalve 128 is disposed on the mating channel 136 between the waste liquid channel 135 and the second channel 132. In this embodiment, by setting the second shut-off microvalve 128, the second target object that has entered the mating channel 136 can be driven out of the mating channel 136 by the first liquid, so that the encapsulated droplet contains only the first target object, thereby ensuring the success rate of encapsulation.

[0168] In some specific embodiments, combined with Figure 7 To understand this, the microfluidic system is configured such that when a single second target object B is located in the paired flow channel 136, the second shut-off microvalve 128 switches from the open state to the closed state. At this time, the paired flow channel 136 where the single second target object B is located is isolated from the paired flow channel 136 through which the first liquid flows by through the second shut-off microvalve 128, and the flow of the first liquid will not carry the second target object.

[0169] The microfluidic system is also configured such that when a single first target A and a single second target B are present in the paired channel 136, the first microvalve 121, the second microvalve 122, and the waste liquid microvalve 125 are closed, while the paired microvalve 126, the buffer microvalve 124, and the second shut-off microvalve 128 are open, so that the buffer in the buffer channel 134 delivers the single first target A and the single second target B in the paired channel 136 into the oil in the oil channel 133 to form droplets C.

[0170] In this embodiment, by controlling the on / off state of the second cut-off microvalve 128, the second target object can be stored in the pairing flow channel 136 during the waiting process for pairing, without affecting the pairing and packaging of the first and second target objects.

[0171] Based on the fifth embodiment, in some embodiments of the present invention, when there is no single first target A in the paired flow channel 136, the paired micro valve 126 is in a closed state and the first micro valve 121 and the waste liquid micro valve 125 are in an open state, so that the liquid in the first flow channel 131 can flow out through the paired flow channel 136 and the waste liquid flow channel 135, thereby causing the first target to flow into the paired flow channel 136.

[0172] In other embodiments, when there is no single second target object B in the paired flow channel 136, the paired microvalve 126 is in the closed state and the second microvalve 122, the second shut-off microvalve 128 and the waste liquid microvalve 125 are in the open state, so that the liquid in the second flow channel 132 can flow out through the paired flow channel 136 and the waste liquid flow channel 135, thereby causing the second target object to flow into the paired flow channel 136.

[0173] The sixth embodiment of the present invention discloses a microfluidic system for target pairing, which differs from the fourth embodiment in that: in the fourth embodiment, the waste liquid channel 135 is located between the first channel 131 and the second channel 132, and a first shut-off microvalve 127 is provided. The first shut-off microvalve 127 is used to control the opening and closing of the pairing channel 136 located between the waste liquid channel 135 and the first channel 131. In this embodiment, no shut-off microvalve is provided, but the positional relationship of the channels is used to maintain a single first target position A.

[0174] Specifically, refer to Figure 8 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 8From top to bottom, the waste liquid flow channel 135, the second flow channel 132, and the first flow channel 131 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single first target A is located in the paired flow channel 136, the second microvalve 122 is closed to allow a single second target B to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that the single first target A is located in the paired flow channel 136 (at which point the first microvalve 121 is already closed), and then allow the single second target B to be located in the paired flow channel 136. For example, the second microvalve 122 is closed before the single first target A is located in the paired flow channel 136, and opens after the single first target A is located in the paired flow channel 136. When the detection module detects the single second target B, the second microvalve 122 closes again, thereby allowing the single second target B to stop within the paired flow channel 136.

[0175] In this embodiment, since the waste liquid channel 135 is located on the side close to the second channel 132, the second liquid will flow toward the waste liquid channel 135 instead of the first channel 131 that has been cut off. Therefore, it is possible to prevent the single first target A from being carried away by the second liquid.

[0176] The seventh embodiment of the present invention discloses a microfluidic system for target pairing, which differs from the fourth embodiment in that: in the fourth embodiment, the waste liquid channel 135 is located between the first channel 131 and the second channel 132, and a first shut-off microvalve 127 is provided. The first shut-off microvalve 127 is used to control the opening and closing of the pairing channel 136 located between the waste liquid channel 135 and the first channel 131. In this embodiment, no shut-off microvalve is provided, but the positional relationship of the channels is used to maintain a single first target position A.

[0177] Specifically, refer to Figure 9 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 9 From top to bottom, the waste liquid flow channel 135, the first flow channel 131, and the second flow channel 132 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single second target object B is located in the paired flow channel 136, the first microvalve 121 is closed to allow a single first target object A to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that a single second target object N is located in the paired flow channel 136 (at which time the second microvalve 122 is already closed), and then allow a single first target object A to be located in the paired flow channel 136. For example, the first microvalve 121 is closed before the single second target object B is located in the paired flow channel 136, and the first microvalve 121 is opened after the single second target object B is located in the paired flow channel 136. When the detection module detects the single first target object A, the first microvalve 121 is closed again, so that the single first target object A can be stopped in the paired flow channel 136.

[0178] In this embodiment, since the waste liquid channel 135 is located on the side close to the first channel 131, the first liquid will flow toward the waste liquid channel 135 and not toward the already cut-off second channel 132, thus preventing a single second target object B from being carried away by the first liquid.

[0179] The eighth embodiment of the present invention discloses a microfluidic system for target pairing, which differs from the fourth embodiment in that: in the fourth embodiment, the waste liquid channel 135 is located between the first channel 131 and the second channel 132, and a first shut-off microvalve 127 is provided. The first shut-off microvalve 127 is used to control the opening and closing of the pairing channel 136 located between the waste liquid channel 135 and the first channel 131. In this embodiment, no shut-off microvalve is provided, but the positional relationship of the channels is used to maintain a single first target position A.

[0180] Specifically, refer to Figure 10 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 10 From top to bottom, the second flow channel 132, the first flow channel 131, and the waste liquid flow channel 135 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single second target object B is located in the paired flow channel 136, the first microvalve 121 is closed to allow a single first target object A to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that a single second target object N is located in the paired flow channel 136 (at which time the second microvalve 122 is already closed), and then allow a single first target object A to be located in the paired flow channel 136. For example, the first microvalve 121 is closed before a single second target object B is located in the paired flow channel 136, and the first microvalve 121 is opened after a single second target object B is located in the paired flow channel 136. When the detection module detects a single first target object A, the first microvalve 121 is closed again, thereby allowing a single first target object A to stop in the paired flow channel 136.

[0181] In this embodiment, since the waste liquid channel 135 is located on the side close to the first channel 131, the first liquid will flow toward the waste liquid channel 135 and not toward the already cut-off second channel 132, thus preventing a single second target object B from being carried away by the first liquid.

[0182] The ninth embodiment of the present invention discloses a microfluidic system for target pairing, which differs from the fourth embodiment in that: in the fourth embodiment, the waste liquid channel 135 is located between the first channel 131 and the second channel 132, and a first shut-off microvalve 127 is provided. The first shut-off microvalve 127 is used to control the opening and closing of the pairing channel 136 located between the waste liquid channel 135 and the first channel 131. In this embodiment, no shut-off microvalve is provided, but the positional relationship of the channels is used to maintain a single first target position A.

[0183] Specifically, refer to Figure 11 Along the flow direction of the buffer solution within the paired flow channel 136, for example Figure 11 From top to bottom, the first flow channel 131, the second flow channel 132, and the waste liquid flow channel 135 are arranged sequentially. Based on this, the microfluidic system is configured such that when a single first target A is located in the paired flow channel 136, the second microvalve 122 is closed to allow a single second target B to be located in the paired flow channel 136. That is, in this embodiment, it is necessary to first ensure that the single first target A is located in the paired flow channel 136 (at which time the first microvalve 121 is already closed), and then allow the single second target B to be located in the paired flow channel 136. For example, the second microvalve 122 is closed before the single first target A is located in the paired flow channel 136, and the second microvalve 122 opens after the single first target A is located in the paired flow channel 136. When the detection module detects the single second target B, the second microvalve 122 closes again, thereby allowing the single second target B to stop in the paired flow channel 136.

[0184] In this embodiment, since the waste liquid channel 135 is located on the side close to the second channel 132, the second liquid will flow toward the waste liquid channel 135 instead of the first channel 131 that has been cut off. Therefore, it is possible to prevent the single first target A from being carried away by the second liquid.

[0185] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments, and various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A microfluidic system for target pairing, characterized in that, The microfluidic system includes a first channel, a second channel, an oil channel, a buffer channel, a waste liquid channel, and a paired channel. The paired channel is connected to the oil channel. The first channel, the second channel, the waste liquid channel, and the buffer channel are all connected to the paired channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through. The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, a waste liquid microvalve corresponding to the waste liquid flow channel, and a buffer liquid microvalve corresponding to the buffer liquid flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, the buffer liquid microvalve is used to control the opening and closing of the buffer liquid flow channel, and the waste liquid microvalve is used to control the opening and closing of the waste liquid flow channel. The microfluidic system is configured such that: when a single first target and a single second target are present in the paired flow channels, the first microvalve and the second microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution flow channel delivers the single first target and the single second target in the paired flow channels into the oil in the oil flow channel to form droplets; when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, the liquid in the first flow channel can flow out through the paired flow channel and the waste liquid flow channel; and / or, when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, the liquid in the second flow channel can flow out through the paired flow channel and the waste liquid flow channel; The first flow channel includes a first microvalve section corresponding to the first microvalve, and a first flow section different from the first microvalve section. The upper inner wall surface and the lower inner wall surface of the first flow section are planes that are parallel to each other. And / or, the second flow channel includes a second microvalve section corresponding to the second microvalve, and a second flow section distinct from the second microvalve section, wherein the upper inner wall surface and the lower inner wall surface of the second flow section are mutually parallel planes.

2. The microfluidic system for target pairing according to claim 1, characterized in that, The cross-section of the first flow section is set to a rectangle, and / or the cross-section of the second flow section is set to a rectangle.

3. The microfluidic system for target pairing according to claim 2, characterized in that, The width of the first flow section is 50 micrometers to 150 micrometers, and / or the width of the second flow section is 50 micrometers to 150 micrometers.

4. The microfluidic system for target pairing according to claim 1, characterized in that, The upper inner wall surface of the first micro-valve segment is configured as an arc surface protruding away from the first micro-valve, and / or the upper inner wall surface of the second micro-valve segment is configured as an arc surface protruding away from the second micro-valve.

5. The microfluidic system for target pairing according to claim 4, characterized in that, The cross-section of the first micro-valve segment is set to be semi-circular, and / or the cross-section of the second micro-valve segment is set to be semi-circular.

6. The microfluidic system for target pairing according to claim 1, characterized in that, The maximum height of the oil flow channel is 80 micrometers to 200 micrometers.

7. The microfluidic system for target pairing according to claim 1, characterized in that, The microfluidic system further includes a first sheath fluid channel, which is connected to the first channel and is used to input a first sheath fluid encapsulating the first liquid into the first channel. And / or, the microfluidic system further includes a second sheath fluid channel, which is connected to the second channel and is used to input a second sheath flow that encapsulates the second liquid into the second channel.

8. The microfluidic system for target pairing according to claim 1, characterized in that, The first target material flowing in the first channel is a cell, and the second target material flowing in the second channel is a microsphere. Along the flow direction of the buffer solution in the paired channels, the waste liquid channel is located between the first channel and the second channel. The microfluidic system also includes a first shut-off microvalve, which is used to control the opening and closing of the paired channels located between the waste liquid channel and the first channel.

9. The microfluidic system for target pairing according to claim 8, characterized in that, The microfluidic system is configured such that: when the single first target object is located in the paired flow channel, the first shut-off microvalve switches from an open state to a closed state; and when a single first target object and a single second target object are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the first shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target object and the single second target object in the paired flow channel into the oil in the oil flow channel to form droplets.

10. The microfluidic system for target pairing according to claim 1, characterized in that, The first target material flowing in the first channel is a cell, and the second target material flowing in the second channel is a microsphere. Along the flow direction of the buffer solution in the paired channels, the waste liquid channel is located between the first channel and the second channel. The microfluidic system also includes a second shut-off microvalve, which is used to control the opening and closing of the paired channels located between the waste liquid channel and the second channel.

11. The microfluidic system for target pairing according to claim 10, characterized in that, The microfluidic system is configured such that: when the single second target is located in the paired flow channel, the second shut-off microvalve switches from an open state to a closed state; and when a single first target and a single second target are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the second shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets.

12. The microfluidic system for target pairing according to claim 1, characterized in that, The first target substance flowing in the first channel is a cell, and the second target substance flowing in the second channel is a microsphere. Along the flow direction of the buffer solution in the paired channels, the waste liquid channel, the second channel, and the first channel are arranged sequentially, and the microfluidic system is configured such that when a single first target substance is located in the paired channel, the second microvalve is closed to allow the single second target substance to be located in the paired channel. Alternatively, along the flow direction of the buffer solution within the paired flow channels, the waste liquid flow channel, the first flow channel, and the second flow channel are sequentially arranged, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel; Alternatively, along the flow direction of the buffer solution within the paired flow channels, the second flow channel, the first flow channel, and the waste liquid flow channel are arranged sequentially, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel; Alternatively, along the flow direction of the buffer solution within the paired flow channels, the first flow channel, the second flow channel, and the waste liquid flow channel are arranged sequentially, and the microfluidic system is configured such that when the single first target object is located in the paired flow channel, the second microvalve is then closed to allow the single second target object to be located in the paired flow channel.

13. A microfluidic system for target pairing, characterized in that, The microfluidic system includes a first channel, a second channel, an oil channel, a buffer channel, a paired channel, and a waste channel. The paired channel is connected to the oil channel. The first channel, the second channel, the buffer channel, and the waste channel are all connected to the paired channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through. The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, a buffer microvalve corresponding to the buffer flow channel, and a waste liquid microvalve corresponding to the waste liquid flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, the buffer microvalve is used to control the opening and closing of the buffer flow channel, and the waste liquid microvalve is used to control the opening and closing of the waste liquid flow channel. The microfluidic system is configured such that: when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, liquid in the first channel can flow out through the paired channel and the waste liquid channel; when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, liquid in the second channel can flow out through the paired channel and the waste liquid channel; when a single first target and a single second target exist in the paired channel, the first microvalve, the second microvalve, and the waste liquid microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution channel delivers the single first target and the single second target in the paired channel into the oil in the oil channel to form droplets; Wherein, the first target material flowing in the first channel is a cell, and the second target material flowing in the second channel is a microsphere. Along the flow direction of the buffer solution in the paired channels, the waste liquid channel is located between the first channel and the second channel. The microfluidic system also includes a first shut-off microvalve, which is used to control the opening and closing of the paired channels located between the waste liquid channel and the first channel.

14. The microfluidic system for target pairing according to claim 13, characterized in that, The microfluidic system is configured such that: when the single first target object is located in the paired flow channel, the first shut-off microvalve switches from an open state to a closed state; and when a single first target object and a single second target object are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the first shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target object and the single second target object in the paired flow channel into the oil in the oil flow channel to form droplets.

15. The microfluidic system for target pairing according to claim 14, characterized in that, When there is no single first target object in the paired flow channel, the paired micro valve is in the closed state and the first micro valve, the first shut-off micro valve and the waste liquid micro valve are in the open state, so that the liquid in the first flow channel can flow out through the paired flow channel and the waste liquid flow channel. And / or, when the single second target object is not present in the paired flow channel, the paired microvalve is in a closed state and the second microvalve and the waste liquid microvalve are in an open state, so that the liquid in the second flow channel can flow out through the paired flow channel and the waste liquid flow channel.

16. A microfluidic system for target pairing, characterized in that, The microfluidic system includes a first channel, a second channel, an oil channel, a buffer channel, a paired channel, and a waste channel. The paired channel is connected to the oil channel. The first channel, the second channel, the buffer channel, and the waste channel are all connected to the paired channel. The first channel is used to allow a first liquid containing a first target to pass through, and the second channel is used to allow a second liquid containing a second target to pass through. The microfluidic system further includes a pairing microvalve corresponding to the paired flow channel, a first microvalve corresponding to the first flow channel, a second microvalve corresponding to the second flow channel, a buffer microvalve corresponding to the buffer flow channel, and a waste liquid microvalve corresponding to the waste liquid flow channel. The pairing microvalve is used to control the opening and closing of the paired flow channel, the first microvalve is used to control the opening and closing of the first flow channel, the second microvalve is used to control the opening and closing of the second flow channel, the buffer microvalve is used to control the opening and closing of the buffer flow channel, and the waste liquid microvalve is used to control the opening and closing of the waste liquid flow channel. The microfluidic system is configured such that: when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, liquid in the first channel can flow out through the paired channel and the waste liquid channel; when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, liquid in the second channel can flow out through the paired channel and the waste liquid channel; when a single first target and a single second target exist in the paired channel, the first microvalve, the second microvalve, and the waste liquid microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution channel delivers the single first target and the single second target in the paired channel into the oil in the oil channel to form droplets; Wherein, the first target material flowing in the first channel is a cell, and the second target material flowing in the second channel is a microsphere. Along the flow direction of the buffer solution in the paired channels, the waste liquid channel is located between the first channel and the second channel. The microfluidic system also includes a second shut-off microvalve, which is used to control the opening and closing of the paired channels located between the waste liquid channel and the second channel.

17. The microfluidic system for target pairing according to claim 16, characterized in that, The microfluidic system is configured such that: when the single second target is located in the paired flow channel, the second shut-off microvalve switches from an open state to a closed state; and when a single first target and a single second target are present in the paired flow channel, the first microvalve, the second microvalve, and the waste liquid microvalve are in a closed state, and the paired microvalve, the buffer microvalve, and the second shut-off microvalve are in an open state, so that the buffer in the buffer flow channel delivers the single first target and the single second target in the paired flow channel into the oil in the oil flow channel to form droplets.

18. The microfluidic system for target pairing according to claim 17, characterized in that, When there is no single first target object in the paired flow channel, the paired micro valve is in the closed state and the first micro valve and the waste liquid micro valve are in the open state, so that the liquid in the first flow channel can flow out through the paired flow channel and the waste liquid flow channel. And / or, when there is no single second target object in the paired flow channel, the paired microvalve is in a closed state and the second microvalve, the second shut-off microvalve and the waste liquid microvalve are in an open state, so that the liquid in the second flow channel can flow out through the paired flow channel and the waste liquid flow channel.

19. A microfluidic system for target pairing, characterized in that, The microfluidic system includes a first channel, a second channel, an oil channel, a buffer channel, a paired channel, and a waste channel. The paired channel is connected to the oil channel. The first channel, the second channel, the buffer channel, and the waste channel are all connected to the paired channel, and the waste channel is located between the first channel and the second channel. The first channel is used to allow a first liquid containing a first target substance to pass through, and the second channel is used to allow a second liquid containing a second target substance to pass through. The microfluidic system also includes a paired microvalve corresponding to the paired channel, a first microvalve corresponding to the first channel, a second microvalve corresponding to the second channel, a buffer microvalve corresponding to the buffer channel, and a waste microvalve corresponding to the waste channel. The paired microvalve is used to control the opening and closing of the paired channel, the first microvalve is used to control the opening and closing of the first channel, the second microvalve is used to control the opening and closing of the second channel, the buffer microvalve is used to control the opening and closing of the buffer channel, and the waste microvalve is used to control the opening and closing of the waste channel. The microfluidic system is configured such that: when the paired microvalve is closed and the first microvalve and the waste liquid microvalve are open, liquid in the first channel can flow out through the paired channel and the waste liquid channel; when the paired microvalve is closed and the second microvalve and the waste liquid microvalve are open, liquid in the second channel can flow out through the paired channel and the waste liquid channel; when a single first target and a single second target exist in the paired channel, the first microvalve, the second microvalve, and the waste liquid microvalve are closed, and the paired microvalve and the buffer solution microvalve are open, so that the buffer solution in the buffer solution channel delivers the single first target and the single second target in the paired channel into the oil in the oil channel to form droplets; The first target material flowing in the first flow channel is a cell, and the second target material flowing in the second flow channel is a microsphere; Wherein, along the flow direction of the buffer solution in the paired flow channel, the waste liquid flow channel, the second flow channel and the first flow channel are arranged sequentially, and the microfluidic system is configured such that: when the single first target object is located in the paired flow channel, the second microvalve is then closed to allow the single second target object to be located in the paired flow channel; Alternatively, along the flow direction of the buffer solution within the paired flow channels, the waste liquid flow channel, the first flow channel, and the second flow channel are sequentially arranged, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel; Alternatively, along the flow direction of the buffer solution within the paired flow channels, the second flow channel, the first flow channel, and the waste liquid flow channel are arranged sequentially, and the microfluidic system is configured such that when the single second target object is located in the paired flow channel, the first microvalve is then closed to allow the single first target object to be located in the paired flow channel; Alternatively, along the flow direction of the buffer solution within the paired flow channels, the first flow channel, the second flow channel, and the waste liquid flow channel are arranged sequentially, and the microfluidic system is configured such that when the single first target object is located in the paired flow channel, the second microvalve is then closed to allow the single second target object to be located in the paired flow channel.

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