A pre-filling method based on microfluidic chip

Abstract

The present invention provides a pre-filling method based on a microfluidic chip, wherein the reagents introduced into the microfluidic chip include a reagent 1 flowing through a main channel and a reagent 2 flowing through an auxiliary channel; after the reagent 1 is input through a corresponding input port, it flows in the main channel of the microfluidic chip; after the reagent 2 is input through a corresponding input port, it flows in the auxiliary channel of the microfluidic chip; there is an intersection between the main channel and the auxiliary channel, so that the reagents of the main channel and the auxiliary channel can intersect at the intersection; the pre-filling method also includes a reagent 1 and reagent 2 confluence step, in which the reagent 1 and / or the reagent 2 are intercepted by an interception structure. The beneficial effect of the present invention is that when the microfluidic chip is pre-filled, the present invention avoids the generation of bubbles, thereby ensuring the safety of cells.

Description

Technical Field

[0001] The present invention relates to the technical field of cell processing, and in particular to a pre-filling method based on a microfluidic chip. Background Art

[0002] Before formal operation, most microfluidic chips usually need to be pre-filled with one or more specific liquids (also called reagents). In other words, the microfluidic chip is pre-charged. During the pre-charge process, at the intersection of two channels, the first reagent to arrive in one channel will block the other channel, causing bubbles to form as the other reagent flows from the other channel to the intersection.

[0003] The presence of bubbles can disrupt the pressure distribution of fluid control within the microfluidic chip. For microfluidic chips containing cells, they can also squeeze the cells, or even cause cell death. Because bubble generation is quite random and the process of removing bubbles is difficult and difficult to standardize, it is best to completely avoid bubble generation during the priming process. Summary of the Invention

[0004] The present invention provides a pre-filling method based on a microfluidic chip, wherein the reagents introduced into the microfluidic chip include a reagent 1 flowing through a main channel and a reagent 2 flowing through an auxiliary channel;

[0005] After reagent 1 is input through the corresponding input port, it flows in the main channel of the microfluidic chip; after reagent 2 is input through the corresponding input port, it flows in the auxiliary channel of the microfluidic chip;

[0006] There is an intersection between the main channel and the auxiliary channel, so that the reagents of the main channel and the auxiliary channel can intersect at the intersection;

[0007] The pre-filling method further includes a confluence step of reagent 1 and reagent 2, in which reagent 1 and / or reagent 2 are intercepted by an interception structure.

[0008] As a further improvement of the present invention, in the converging step, the intercepting structure is a dam, which controls the flow of reagents in the main channel and the auxiliary channel so that the reagent 2 input from the auxiliary channel reaches the intersection first. The dam is provided at the intersection, and the reagent 2 is intercepted by the dam so that the reagent 2 cannot cross the dam.

[0009] Then the reagent 1 input from the main channel also reaches the intersection;

[0010] After reagent 1 passes the dam at the intersection, it contacts reagent 2 and merges into a composite flow, which continues to flow downstream.

[0011] As a further improvement of the present invention, the intersection is approximately rectangular.

[0012] As a further improvement of the present invention, the width of the intersection is wider than the width of the main channel.

[0013] As a further improvement of the present invention, the intersections are symmetrically arranged.

[0014] As a further improvement of the present invention, there is a smooth transition between the intersection and the main channel.

[0015] As a further improvement of the present invention, the dam body is provided with a groove.

[0016] As a further improvement of the present invention, the dam body is roughly in the shape of the letter N.

[0017] As a further improvement of the present invention, the dam body is arranged at the bottom end of the intersection.

[0018] As a further improvement of the present invention, the height of the upper end of the dam body does not exceed the height of the main channel.

[0019] As a further improvement of the present invention, the height of the dam body accounts for more than 50% of the height of the main channel, which facilitates the manufacture of the dam body and the microfluidic chip and achieves a more obvious interception effect.

[0020] As a further improvement of the present invention, the height of the dam body accounts for 85-95% of the height of the main channel. Since the interception effect of the dam body 2 is negatively correlated with the size of the space, the higher the dam body 2, the narrower the space between it and the upper wall of the channel, and the better the interception effect. Therefore, the present invention preferably has the height of the dam body 2 account for 85-95% of the height of the main channel 4.

[0021] As a further improvement of the present invention, the dam body and the liquid channel of the microfluidic chip are formed into an integral structure in an integrally formed manner.

[0022] As a further improvement of the present invention, the dam body and the liquid channel of the microfluidic chip are arranged at the intersection by bonding, preferably bonding at the bottom end.

[0023] As a further improvement of the present invention, the dam body and the microfluidic chip are made of the same material. If the dam body 2 and the microfluidic chip are made of the same material, the process difficulty is lower and the cost is lower. The microfluidic chip in the present invention can be made of various commonly used materials for microfluidic chips.

[0024] As a further improvement to the present invention, the dam is made of PDMS (polydimethylsiloxane). The PDMS microstructure is formed on the surface of the microfluidic chip through molding. This high mold accuracy, reaching the nanometer (nm) level, significantly improves the control accuracy of the microfluidic chip.

[0025] As a further improvement of the present invention, the dam body is roughly in the shape of the letter N, with two legs on one side of the dam body, and a groove is formed between the two legs. The groove corresponds to the position of the auxiliary channel in the microfluidic chip so that the reagent 2 in the auxiliary channel can reach the groove.

[0026] As a further improvement of the present invention, the two supporting legs of the dam body are symmetrically arranged.

[0027] As a further improvement of the present invention, the width between the two supporting feet of the dam body exceeds half of the width of the entire dam body.

[0028] As a further improvement of the present invention, an elastic film is further provided on the microfluidic chip. The elastic film is provided on the end surface of the main channel and the auxiliary channel opening of the microfluidic chip.

[0029] As a further improvement of the present invention, there is a gap between the elastic film and the dam body.

[0030] As a further improvement of the present invention, the elastic film covers the intersection.

[0031] As a further improvement of the present invention, the elastic film covers all the main channels and auxiliary channels.

[0032] As a further improvement of the present invention, the elastic film covers the entire range of the microfluidic chip.

[0033] As a further improvement of the present invention, the thickness of the elastic film is 50 to 250 microns, preferably 75 to 150 microns, because at 75 to 150 microns, it is easy to manufacture and can also have better elasticity and higher response sensitivity during control.

[0034] As a further improvement of the present invention, the elastic film is made of PDMS, and a PDMS microstructure is formed on the surface of the microfluidic chip by molding. The molding accuracy is high and can reach the nanometer (nm) level, which can greatly improve the control accuracy of the microfluidic chip in the present invention.

[0035] As a further improvement of the present invention, the microfluidic chip further includes an air path layer, the air path layer having an air path channel connected to an external air pressure source, the air path layer and the elastic film cooperate to form a pneumatic microvalve, the pneumatic microvalve including a first pneumatic microvalve and a second pneumatic microvalve, the dam body is roughly in the shape of the letter n, the dam body has two legs, a groove is formed between the two legs, the groove corresponds to the position of the auxiliary channel in the microfluidic chip, the two legs are respectively a first leg and a second leg, the first leg is located on the side where reagent 1 flows in, and the second leg is located on the side where reagent 1 and reagent 2 converge and flow out, the first pneumatic microvalve covers a part of the first leg, and the second pneumatic microvalve covers a part of the groove; in the confluence step, reagent 1 is introduced into the main channel, and when the reagent 1 in the main channel moves to the dam body, positive pressure is applied to the first pneumatic microvalve, closing the first pneumatic microvalve, and the elastic film of the first pneumatic microvalve contacts the dam body downward, thereby closing the main channel;

[0036] Reagent 2 is introduced into the auxiliary channel. When reagent 2 reaches the dam, positive pressure is applied to the second pneumatic microvalve, closing the second pneumatic microvalve and stopping the driving pressure of reagent 2.

[0037] The positive pressure of the first pneumatic microvalve is removed, and the elastic film of the first pneumatic microvalve returns to a planar state, driving reagent 1 to cross the dam and continue to move forward. When it moves to the second pneumatic microvalve, the positive pressure of the second pneumatic microvalve is removed, and reagent 1 completes confluence with reagent 2 when passing over it. The confluent reagents cross the dam and enter the waste liquid channel.

[0038] As a further improvement of the present invention, the air path layer is provided with a recessed portion in an area corresponding to the intersection, through which the air path layer can be connected to an external air pressure source.

[0039] As a further improvement of the present invention, the area of ​​the concave portion of the gas path layer is not less than the area of ​​the intersection.

[0040] As a further improvement of the present invention, the shape of the concave portion of the air path layer is substantially consistent with the shape of the intersection.

[0041] As a further improvement of the present invention, the concave portion of the air path layer is rectangular or circular in shape.

[0042] As a further improvement of the present invention, in the confluence step, by controlling the flow of reagents in the main channel and the auxiliary channel, the reagent 2 inputted from the auxiliary channel reaches the intersection first. A dam is provided at the intersection, and the reagent 2 is first intercepted by the groove of the dam, so that the reagent 2 cannot cross the groove of the dam.

[0043] Then the reagent 1 input from the main channel also reaches the intersection;

[0044] When reagent 1 passes over the groove, it contacts reagent 2 in the groove and completes the confluence. Then the two reagents merge to form a composite flow, which finally crosses the dam and continues to flow downstream.

[0045] As a further improvement of the present invention, there are two auxiliary channels, and the dam body is provided with two grooves. The two auxiliary channels are respectively located on the left and right sides of the main channel, one groove corresponds to one auxiliary channel, and the other groove corresponds to the other auxiliary channel. By controlling the flow of reagents in the main channel and the two auxiliary channels, the reagent 2 input from the two auxiliary channels reaches the intersection first. A dam body is provided at the intersection, and the two grooves of the dam body are used to intercept the reagent 2 first, so that the reagent 2 cannot cross the two grooves of the dam body.

[0046] Then the reagent 1 input from the main channel also reaches the intersection;

[0047] When reagent 1 passes over the two grooves, it contacts reagent 2 in the two grooves to complete the confluence, and then the two reagents merge to form a composite flow, which finally crosses the dam and continues to flow downstream.

[0048] As a further improvement of the present invention, in the converging step, the reagent 1 is introduced into the main channel. When the reagent 1 in the main channel reaches the dam, positive pressure is applied to the first pneumatic microvalve to close the first pneumatic microvalve. The elastic membrane of the first pneumatic microvalve contacts the dam downward, thereby sealing the main channel.

[0049] Reagent 2 is introduced into the auxiliary channel. When reagent 2 reaches the dam, positive pressure is applied to the second pneumatic microvalve, closing the second pneumatic microvalve and stopping the driving pressure of reagent 2.

[0050] Negative pressure is applied to the first pneumatic microvalve, causing the elastic film of the first pneumatic microvalve to bulge upward, driving reagent 1 to cross the dam and continue to move forward. When it reaches the second pneumatic microvalve, negative pressure is applied to the second pneumatic microvalve, causing the elastic film of the second pneumatic microvalve to bulge upward, and reagent 1 completes confluence with reagent 2 when passing above it.

[0051] When the converging reagents pass over the dam body and enter the waste liquid channel, the negative pressure of the first pneumatic microvalve is removed, and the waste liquid channel continues to be filled.

[0052] As a further improvement of the present invention, the length of the groove is greater than 0% of the length of the dam body, and the length of the groove is less than 100% of the length of the dam body.

[0053] As a further improvement of the present invention, the length of the groove accounts for 20-80% of the length of the dam body.

[0054] As a further improvement of the present invention, the interception structure is a single-channel dam. A single-channel dam refers to a dam that can only perform an interception function on a single channel, such as a main channel or an auxiliary channel. There are two single-channel dams, a first single-channel dam and a second single-channel dam. The first single-channel dam is arranged on the auxiliary channel, and the second single-channel dam is arranged on the main channel. In the confluence step, by controlling the flow of reagents in the main channel and the auxiliary channel, the reagent 2 input into the auxiliary channel is intercepted by the first single-channel dam before reaching the intersection, so that the reagent 2 cannot cross the first single-channel dam.

[0055] Reagent 1 input from the main channel is intercepted by the second single-channel dam before reaching the intersection, so that reagent 2 cannot cross the second single-channel dam;

[0056] Reagent 1 and reagent 2 are controlled to pass through the first single-channel dam and the second single-channel dam at the same time, so that reagent 1 and reagent 2 reach the intersection at the same time. After reagent 1 and reagent 2 contact, they merge to form a composite flow, and the composite flow continues to flow downstream.

[0057] As a further improvement of the present invention, the microfluidic chip further includes an air path layer, the air path layer having an air path channel connected to an external air pressure source, the air path layer and the elastic film cooperate to form a pneumatic microvalve, the pneumatic microvalve includes a third pneumatic microvalve and a fourth pneumatic microvalve, the third pneumatic microvalve corresponds to the position of the first single-channel dam, and the fourth pneumatic microvalve corresponds to the position of the second single-channel dam. In the confluence step, reagent 1 is introduced into the main channel. When reagent 1 moves in front of the second single-channel dam, positive pressure is applied to the fourth pneumatic microvalve, closing the fourth pneumatic microvalve. The elastic film of the fourth pneumatic microvalve moves downward to contact the second single-channel dam, thereby closing the main channel.

[0058] Reagent 2 is introduced into the auxiliary channel. When reagent 2 reaches the front of the first single-channel dam, positive pressure is applied to the third pneumatic microvalve to close the third pneumatic microvalve. The elastic membrane of the third pneumatic microvalve moves downward to contact the first single-channel dam, thereby sealing the auxiliary channel.

[0059] Remove the positive pressure of the third pneumatic microvalve and the fourth pneumatic microvalve to restore the elastic film of the third pneumatic microvalve and the elastic film of the fourth pneumatic microvalve to a planar state, or apply negative pressure to the third pneumatic microvalve and the fourth pneumatic microvalve to cause the elastic film of the third pneumatic microvalve and the elastic film of the fourth pneumatic microvalve to bulge upward, and then control reagent 1 and reagent 2 to cross the first single-channel dam and the second single-channel dam at the same time, so that reagent 1 and reagent 2 arrive at the intersection at the same time, and reagent 1 and reagent 2 come into contact and merge to form a composite flow, and the composite flow continues to flow downstream.

[0060] As a further improvement of the present invention, the single-channel dam body is roughly in the shape of an elongated strip.

[0061] As a further improvement of the present invention, the upper end height of the first single-channel dam body does not exceed the height of the auxiliary channel, and the upper end height of the second single-channel dam body does not exceed the height of the main channel.

[0062] As a further improvement of the present invention, the upper end height of the first single-channel dam body accounts for more than 50% of the height of the auxiliary channel, and the upper end height of the second single-channel dam body accounts for more than 50% of the height of the main channel.

[0063] As a further improvement of the present invention, the upper end height of the first single-channel dam body accounts for 85-95% of the height of the auxiliary channel, and the upper end height of the second single-channel dam body accounts for 85-95% of the height of the main channel.

[0064] As a further improvement of the present invention, the single-channel dam and the microfluidic chip are made of the same material.

[0065] As a further improvement of the present invention, the material of the single-channel dam is PDMS.

[0066] The beneficial effects of the present invention are as follows: the inventors have discovered that the gas mixing in the existing chip processing process is not only caused by the filled reagent solution itself, but also due to the convergence process of different reagent solutions when they are passed into the chip. The present invention adopts a chip with a specific dam structure, which fundamentally eliminates the mixing of gas when the reagent solutions converge, thereby avoiding the interference of bubbles in the cell processing process. When pre-filling the microfluidic chip, the present invention avoids the generation of bubbles, so that the cell processing process will no longer fail due to bubbles, greatly improving the cell processing efficiency and treatment effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 This is a schematic diagram of the liquid path layer structure with a dam body;

[0068] Figure 2 This is a schematic structural diagram of an embodiment of a liquid path layer provided with a dam body;

[0069] Figure 3 This is a schematic structural diagram of another embodiment of a liquid path layer provided with a dam body;

[0070] Figure 4 is a schematic diagram of the elastic film structure;

[0071] Figure 5 This is a schematic diagram of the principle of microfluidic chip;

[0072] Figure 6 This is a schematic diagram of the liquid path layer structure with a single-channel dam body. DETAILED DESCRIPTION

[0073] The main purpose of the present invention is to avoid the generation of bubbles when pre-filling a microfluidic chip.

[0074] The present invention discloses a pre-filling method based on a microfluidic chip, wherein the reagents introduced into the microfluidic chip include a reagent 1 flowing through a main channel 4 and a reagent 2 flowing through an auxiliary channel 5;

[0075] After reagent 1 is input through the corresponding input port, it flows in the main channel 4 in the microfluidic chip; after reagent 2 is input through the corresponding input port, it flows in the auxiliary channel 5 in the microfluidic chip;

[0076] There is an intersection between the main channel 4 and the auxiliary channel 5, so that the reagents in the main channel 4 and the auxiliary channel 5 can intersect at the intersection;

[0077] The pre-filling method further includes a confluence step, in which the reagents are intercepted by an interception structure, so that any one reagent overlaps with the channel of another reagent before confluence to a certain extent without blocking it.

[0078] As an embodiment of the priming method, the intercepting structure is a dam 2. In the converging step, by controlling the flow of reagents in the main channel 4 and the auxiliary channel 5, the reagent 2 inputted from the auxiliary channel 5 first reaches the intersection. The dam 2 is provided at the intersection, and the reagent 2 is first intercepted by the dam 2 so that the reagent 2 cannot cross the dam 2.

[0079] Then the reagent 1 input from the main channel 4 also reaches the intersection;

[0080] After reagent 1 passes through the dam 2 at the intersection, it contacts with reagent 2 and merges to form a composite flow, which continues to flow downstream.

[0081] The intersection is roughly rectangular, and its width is wider than that of the main channel 4. The intersection is symmetrically arranged, and a smooth transition is formed between the intersection and the main channel 4.

[0082] like Figure 1 As shown, the dam body 2 is provided with a groove 3, and the dam body 2 is roughly in the shape of the letter N, and the dam body 2 is arranged at the bottom end of the intersection.

[0083] The height of the upper end of the dam body 2 does not exceed the height of the main channel 4. For example, the height of the dam body 2 accounts for more than 50% of the height of the main channel 4. Preferably, the height of the dam body 2 accounts for 85-95% of the height of the main channel 4. Because the interception effect of the dam body 2 is negatively correlated with the size of the space, the higher the dam body 2, the narrower the space between it and the upper wall of the channel, and the better the interception effect. Therefore, the present invention preferably configures the height of the dam body 2 to account for 85-95% of the height of the main channel 4.

[0084] The dam body 2 and the liquid channel of the microfluidic chip can be an integral structure formed by an integral molding method. Alternatively, the dam body 2 and the liquid channel of the microfluidic chip are arranged at the intersection by bonding, preferably bonding at the bottom end.

[0085] The dam body 2 and the microfluidic chip can be made of the same material, or the dam body 2 can be made of PDMS, which is polydimethylsiloxane in Chinese.

[0086] One side of the dam body 2 has two legs, and a groove 3 is formed between the two legs. The groove 3 corresponds to the position of the auxiliary channel 5 in the microfluidic chip, so that the reagent 2 in the auxiliary channel 5 can reach the groove 3.

[0087] The two legs of the dam body 2 are symmetrically arranged, and the width between the two legs of the dam body 2 exceeds half the width of the entire dam body 2. The width between the legs, that is, the width of the groove 3 should not be too narrow, otherwise unnecessary resistance will be generated. Therefore, the width of the groove 3 maintains the width of the auxiliary channel 5. The width of the left leg corresponds to the length of the path of the reagent 1 passing through the top of the dam body 2, and the right leg corresponds to the length of the path of the solution after confluence passing through the top of the dam body 2. For resistance considerations, the width of the legs should not be too large, so the width between the two legs of the dam body 2 of the present invention exceeds half the width of the entire dam body 2.

[0088] The microfluidic chip is further provided with an elastic film 7 , which is arranged on the end surface of the main channel 4 and the auxiliary channel 5 of the microfluidic chip, with a gap between the elastic film 7 and the dam 2 .

[0089] The elastic film 7 may only cover the intersection, or the elastic film 7 may cover all the main channels 4 and the auxiliary channels 5; or the elastic film 7 may cover the entire range of the microfluidic chip.

[0090] The thickness of the elastic film 7 is 50 to 250 micrometers, and the material of the elastic film 7 is PDMS.

[0091] The microfluidic chip also includes an air path layer 6, which has an air path channel connected to an external air pressure source. The air path layer 6 and the elastic film 7 cooperate to form a pneumatic microvalve, which includes a first pneumatic microvalve and a second pneumatic microvalve. The dam body 2 is roughly in the shape of the letter n. The dam body 2 has two legs, and a groove 3 is formed between the two legs. The groove 3 corresponds to the position of the auxiliary channel 5 in the microfluidic chip. The two legs are respectively a first leg 31 and a second leg 32. The first leg 31 is located on the side where the reagent 1 flows in, and the second leg 32 is located on the side where the reagent 1 and the reagent 2 converge and flow out. The first pneumatic microvalve controls the main channel 4. The first pneumatic microvalve only covers a portion of the first leg 31; the second pneumatic microvalve controls the auxiliary channel 5 and covers a portion of the groove 3. The second pneumatic microvalve does not block the entire auxiliary channel 5 and the cross-section of the groove 3, preventing the reagent 1 from being sealed when the second pneumatic microvalve is closed. In order to spatially accommodate the two pneumatic microvalves, the first leg 31 is extended. In the converging step, the reagent 1 is introduced into the main channel 4. When the reagent 1 in the main channel 4 reaches the dam body 2, positive pressure is applied to the first pneumatic microvalve, closing the first pneumatic microvalve. The elastic membrane 7 of the first pneumatic microvalve contacts the dam body 2 downward, thereby sealing the main channel 4.

[0092] The reagent 2 is introduced into the auxiliary channel 5. When the reagent 2 reaches the dam body 2, positive pressure is applied to the second pneumatic microvalve, the second pneumatic microvalve is closed, and the driving pressure of the reagent 2 is stopped.

[0093] Negative pressure is applied to the first pneumatic microvalve, causing the elastic film 7 of the first pneumatic microvalve to bulge upward (or, the positive pressure of the first pneumatic microvalve is removed, causing the elastic film 7 of the first pneumatic microvalve to return to a flat state), driving the reagent 1 to cross the dam 2 and continue to move forward. When the reagent 1 reaches the second pneumatic microvalve, the positive pressure of the second pneumatic microvalve is removed (or, negative pressure is applied to the second pneumatic microvalve, causing the elastic film 7 of the second pneumatic microvalve to bulge upward), and the reagent 1 completes confluence with the reagent 2 when passing above it.

[0094] When the combined reagents pass over the dam 2 and enter the waste liquid channel, the negative pressure of the first pneumatic microvalve is removed, and the waste liquid channel continues to be filled.

[0095] The gas path layer 6 has a recessed portion in the area corresponding to the intersection, which allows for connection to an external air pressure source. The area of ​​the recessed portion of the gas path layer 6 is no less than the area of ​​the intersection. The shape of the recessed portion of the gas path layer 6 is substantially consistent with the shape of the intersection. The recessed portion of the gas path layer 6 is preferably rectangular or circular.

[0096] The position of the pneumatic microvalve corresponds to the position of the dam body 2. When negative pressure is applied to the air path channel in the air path layer 6, the elastic film 7 under the air path channel bends upward and shrinks toward the air path channel space in the air path layer 6, thereby enlarging the passage between the dam body 2 and the elastic film 7.

[0097] By controlling the flow of reagents in the main channel 4 and the auxiliary channel 5, the reagent 2 input from the auxiliary channel 5 reaches the intersection first. A dam 2 is provided at the intersection, and the reagent 2 is intercepted by the groove 3 of the dam 2 so that the reagent 2 cannot cross the groove 3 of the dam 2. Then, the reagent 1 input from the main channel 4 also reaches the intersection. When the reagent 1 passes over the groove 3, it contacts the reagent 2 in the groove 3 to complete the confluence, and then the two reagents merge to form a composite flow, which finally crosses the dam 2 and continues to flow downstream.

[0098] The length L1 of the groove 3 is greater than 0% of the length L2 of the dam body 2 and less than 100% of the length L2 of the dam body 2 ; preferably, the length L1 of the groove 3 accounts for 20-80% of the length L2 of the dam body 2 .

[0099] As an embodiment of the priming method, there are two auxiliary channels 5, and the dam body 2 is provided with two grooves 3. The two auxiliary channels 5 are respectively located on the left and right sides of the main channel 4, wherein one groove 3 corresponds to one auxiliary channel 5, and the other groove 3 corresponds to the other auxiliary channel 5. By controlling the flow of the reagents in the main channel 4 and the two auxiliary channels 5, the reagents 2 inputted from the two auxiliary channels 5 first reach the intersection, where the dam body 2 is provided. The reagents 2 are first intercepted by the two grooves 3 of the dam body 2, so that the reagents 2 cannot cross the two grooves 3 of the dam body 2.

[0100] Then the reagent 1 input from the main channel 4 also reaches the intersection;

[0101] When reagent 1 passes over the two grooves 3 , it contacts with reagent 2 in the two grooves 3 to complete the confluence, and then the two reagents merge to form a composite flow, which finally passes over the dam body 2 and continues to flow downstream.

[0102] As an embodiment of the priming method, the interception structure is a single-channel dam 17, and there are two single-channel dams 17, namely a first single-channel dam and a second single-channel dam. The first single-channel dam is arranged on the auxiliary channel 5, and the second single-channel dam is arranged on the main channel 4. In the confluence step, by controlling the flow of the reagents in the main channel 4 and the auxiliary channel 5, the reagent 2 input into the auxiliary channel 5 is intercepted by the first single-channel dam before reaching the intersection, so that the reagent 2 cannot cross the first single-channel dam;

[0103] Reagent 1 input from main channel 4 is intercepted by the second single channel dam before reaching the intersection, so that reagent 2 cannot cross the second single channel dam;

[0104] Reagent 1 and reagent 2 are controlled to pass through the first single-channel dam and the second single-channel dam at the same time, so that reagent 1 and reagent 2 reach the intersection at the same time. After reagent 1 and reagent 2 contact, they merge to form a composite flow, and the composite flow continues to flow downstream.

[0105] A single-channel dam is positioned on either the primary channel 4 or the secondary channel 5 for interception. Dam 2 is positioned at the intersection of two channels. Dam 2 is a physical structure that intercepts liquids (e.g., various reagents) or solids (e.g., cells to be processed) in the channels of a microfluidic chip. Because dam 2 creates resistance or obstruction to the passage of liquids or solids, it can be of various shapes and can also be other components or mechanisms that can perform an interception function.

[0106] The microfluidic chip further includes an air path layer 6 having an air path channel connected to an external air pressure source. The air path layer 6 and the elastic film 7 cooperate to form a pneumatic microvalve. The pneumatic microvalve includes a third pneumatic microvalve and a fourth pneumatic microvalve. The third pneumatic microvalve corresponds to the position of the first single-channel dam, and the fourth pneumatic microvalve corresponds to the position of the second single-channel dam. In the confluence step, the reagent 1 is introduced into the main channel 4. When the reagent 1 moves in front of the second single-channel dam, positive pressure is applied to the fourth pneumatic microvalve, closing the fourth pneumatic microvalve. The elastic film 7 of the fourth pneumatic microvalve moves downward to contact the second single-channel dam, thereby sealing the main channel 4.

[0107] The reagent 2 is introduced into the auxiliary channel 5. When the reagent 2 reaches the front of the first single-channel dam, positive pressure is applied to the third pneumatic microvalve, closing the third pneumatic microvalve. The elastic membrane 7 of the third pneumatic microvalve moves downward to contact the first single-channel dam, thereby sealing the auxiliary channel 5.

[0108] The positive pressure of the third pneumatic microvalve and the fourth pneumatic microvalve is removed to restore the elastic film 7 of the third pneumatic microvalve and the elastic film 7 of the fourth pneumatic microvalve to a planar state, or, negative pressure is applied to the third pneumatic microvalve and the fourth pneumatic microvalve to cause the elastic film 7 of the third pneumatic microvalve and the elastic film 7 of the fourth pneumatic microvalve to bulge upward, and then control reagent 1 and reagent 2 to cross the first single-channel dam and the second single-channel dam at the same time, so that reagent 1 and reagent 2 arrive at the intersection at the same time, and reagent 1 and reagent 2 come into contact and merge together to form a composite flow, and the composite flow continues to flow downstream.

[0109] The single-channel dam 17 is substantially in the shape of a long strip.

[0110] The upper end height of the first single-channel dam body does not exceed the height of the auxiliary channel 5, and the upper end height of the second single-channel dam body does not exceed the height of the main channel 4; for example, the upper end height of the first single-channel dam body accounts for more than 50% of the height of the auxiliary channel 5, and the upper end height of the second single-channel dam body accounts for more than 50% of the height of the main channel 4; preferably, the upper end height of the first single-channel dam body accounts for 85-95% of the height of the auxiliary channel 5, and the upper end height of the second single-channel dam body accounts for 85-95% of the height of the main channel 4.

[0111] The single-channel dam 17 is made of the same material as the microfluidic chip, and preferably the single-channel dam 17 is made of PDMS.

[0112] The present invention also discloses a microfluidic chip with a pre-filling function, comprising a liquid path layer 1;

[0113] A liquid channel is provided in the liquid channel layer 1, through which the reagents in the microfluidic chip flow, and the liquid channel has a main channel 4 and an auxiliary channel 5 that intersect;

[0114] The interception structure is used to intercept the reagents in the liquid channel. The interception structure is set at the intersection of two liquid channels, so that any one reagent can overlap with the channel where the other reagent is located before converging without blocking it.

[0115] As an embodiment of the microfluidic chip, the intercepting structure is a dam body 2 , and the dam body 2 is provided with a groove 3 , and the groove 3 corresponds to the auxiliary channel 5 .

[0116] The intersection is roughly rectangular, and its width is wider than that of the main channel 4. The intersection is symmetrically arranged, and a smooth transition is formed between the intersection and the main channel 4.

[0117] The length L1 of the groove 3 is greater than 0% of the length L2 of the dam body 2 and less than 100% of the length L2 of the dam body 2 ; preferably, the length L1 of the groove 3 accounts for 20-80% of the length L2 of the dam body 2 .

[0118] The dam body 2 is substantially in the shape of the letter N, and is arranged at the bottom end of the intersection.

[0119] The upper end height of the dam body 2 does not exceed the height of the main channel 4. For example, the height of the dam body 2 accounts for more than 50% of the height of the main channel 4. Preferably, the height of the dam body 2 accounts for 85-95% of the height of the main channel 4.

[0120] The dam body 2 and the liquid channel of the microfluidic chip can be an integral structure formed by an integral molding method. Alternatively, the dam body 2 and the liquid channel of the microfluidic chip are arranged at the intersection by bonding, preferably bonding at the bottom end.

[0121] The material of the dam body 2 and the microfluidic chip can be the same, or the material of the dam body 2 can be PDMS.

[0122] One side of the dam body 2 has two legs, and a groove 3 is formed between the two legs. The groove 3 corresponds to the position of the auxiliary channel 5 in the microfluidic chip, so that the reagent 2 in the auxiliary channel 5 can reach the groove 3.

[0123] The two supporting legs of the dam body 2 are symmetrically arranged, and the width between the two supporting legs of the dam body 2 exceeds half of the width of the entire dam body 2.

[0124] The microfluidic chip is further provided with an elastic film 7 , which is arranged on the end surface of the main channel 4 and the auxiliary channel 5 of the microfluidic chip, with a gap between the elastic film 7 and the dam 2 .

[0125] The elastic film 7 may only cover the intersection, or the elastic film 7 may cover all the main channels 4 and the auxiliary channels 5; or the elastic film 7 may cover the entire range of the microfluidic chip.

[0126] The thickness of the elastic film 7 is 50 to 250 micrometers, and the material of the elastic film 7 is PDMS.

[0127] The microfluidic chip further includes an air path layer 6 having an air path channel connected to an external air pressure source. The air path layer 6 and the elastic film 7 cooperate to form a pneumatic microvalve.

[0128] The gas path layer 6 has a recessed portion in the area corresponding to the intersection, which allows for connection to an external air pressure source. The area of ​​the recessed portion of the gas path layer 6 is no less than the area of ​​the intersection. The shape of the recessed portion of the gas path layer 6 is substantially consistent with the shape of the intersection. The recessed portion of the gas path layer 6 is preferably rectangular or circular.

[0129] The position of the pneumatic microvalve corresponds to the position of the dam body 2. When negative pressure is applied to the air path channel in the air path layer 6, the elastic film 7 under the air path channel bends upward and shrinks toward the air path channel space in the air path layer 6, thereby enlarging the passage between the dam body 2 and the elastic film 7.

[0130] like Figure 2 As shown, as an embodiment of the liquid path layer 1, there are two auxiliary channels 5 and two grooves 3. The two auxiliary channels 5 are respectively located on the left and right sides of the main channel 4, one groove 3 corresponds to one auxiliary channel 5, and the other groove 3 corresponds to the other auxiliary channel 5.

[0131] like Figure 3 As shown, as another embodiment of the liquid path layer 1 , there are two auxiliary channels 5 , the two auxiliary channels 5 are located on the same side of the main channel 4 , and the groove 3 corresponds to the two auxiliary channels 5 .

[0132] During operation, the reagent input from the auxiliary channel 5 stays in the groove 3, and the reagent input from the main channel 4 contacts the reagent in the groove 3 when passing over the groove 3, and then the two reagents merge to form a synthetic flow, which finally passes over the dam body 2 and continues to flow downstream. Since the reagents in the main channel 4 and the auxiliary channel 5 can be completely merged into a synthetic flow at the dam body 2, the introduction of gas will not be caused by the convergence of different liquids in two different channels, thereby completely eliminating the gas mixing caused by the convergence of different solutions. In principle, the entire convergence process eliminates the generation of bubbles.

[0133] like Figure 4 As shown, the microfluidic chip also includes an elastic film 7. Because the height of the dam body 2 does not exceed the height of the liquid channels of the liquid path layer 1, a certain gap is left between the elastic film 7 and the dam body 2. When the elastic film 7 is placed on the upper side of the liquid path layer 1, it will not interfere with the flow of reagent liquid in the various liquid channels of the liquid path layer 1.

[0134] like Figure 5 As shown, the microfluidic chip also includes an air path layer 6, which can be connected to an external controllable air pressure source to provide a certain pressure to the air path layer 6, for example, positive pressure or negative pressure; the air path layer 6 and the elastic film 7 cooperate to form a pneumatic microvalve, which is used to control the opening and closing of each liquid path channel of the liquid path layer 1.

[0135] As another embodiment of the microfluidic chip, Figure 6 As shown, the interception structure is a single-channel dam body 17 , and there are two single-channel dam bodies 17 , namely a first single-channel dam body and a second single-channel dam body. The first single-channel dam body is arranged on the auxiliary channel 5 , and the second single-channel dam body is arranged on the main channel 4 .

[0136] The single-channel dam 17 is substantially in the shape of a long strip.

[0137] The upper end height of the first single-channel dam body does not exceed the height of the auxiliary channel 5, and the upper end height of the second single-channel dam body does not exceed the height of the main channel 4; for example, the upper end height of the first single-channel dam body accounts for more than 50% of the height of the auxiliary channel 5, and the upper end height of the second single-channel dam body accounts for more than 50% of the height of the main channel 4; preferably, the upper end height of the first single-channel dam body accounts for 85-95% of the height of the auxiliary channel 5, and the upper end height of the second single-channel dam body accounts for 85-95% of the height of the main channel 4.

[0138] The single-channel dam 17 is made of the same material as the microfluidic chip. Preferably, the single-channel dam 17 is made of PDMS.

[0139] The microfluidic chip also includes an air path layer 6, which has an air path channel connected to an external air pressure source. The air path layer 6 and the elastic film 7 cooperate to form a pneumatic microvalve. The pneumatic microvalve includes a third pneumatic microvalve and a fourth pneumatic microvalve. The third pneumatic microvalve corresponds to the position of the first single-channel dam body, and the fourth pneumatic microvalve corresponds to the position of the second single-channel dam body.

[0140] The principle of the pneumatic microvalve: when negative pressure is applied to the air path channel in the air path layer 6, the elastic film 7 under the air path channel bends upward and contracts toward the air path channel space in the air path layer 6, which can enlarge the passage between the dam body 2 of the liquid path layer or the single-channel dam body 17 and the elastic film 7, so that more fluids and cells that are convenient to process can pass through; when positive pressure is injected into the air path channel in the air path layer 6, the elastic film 7 under the air path channel bends downward, squeezing the liquid path channel below the elastic film 7; when the positive pressure is removed, the elastic film 7 recovers, thereby realizing the control of the pneumatic microvalve.

[0141] The present invention uses the dam body 2 or the single-channel dam body 17 to prevent the generation of bubbles when the reagents converge, thereby avoiding the interference of bubbles on the cell treatment process.

[0142] The present invention avoids the generation of bubbles when pre-filling the microfluidic chip, thereby ensuring the safety of cells.

[0143] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention should not be considered to be limited to these descriptions. For those skilled in the art of the present invention, without departing from the concept of the present invention, several simple deductions or substitutions can be made, which should be considered to fall within the scope of protection of the present invention.

Claims

1. A pre-filling method based on a microfluidic chip, characterized in that: The reagents introduced into the microfluidic chip include reagent 1 flowing through the main channel (4) and reagent 2 flowing through the auxiliary channel (5); After reagent 1 is input through the corresponding input port, it flows in the main channel (4) in the microfluidic chip; after reagent 2 is input through the corresponding input port, it flows in the auxiliary channel (5) in the microfluidic chip; there is an intersection between the main channel (4) and the auxiliary channel (5), so that the reagents in the main channel (4) and the auxiliary channel (5) can intersect at the intersection; The priming method further includes a step of converging reagent 1 and reagent 2, in which reagent 1 and / or reagent 2 are intercepted by an interception structure; The interception structure is a dam (2), which controls the flow of reagents in the main channel (4) and the auxiliary channel (5) so that the reagent 2 inputted from the auxiliary channel (5) first reaches the intersection, where the dam (2) is provided. The dam (2) intercepts the reagent 2 first, so that the reagent 2 cannot pass through the dam (2); Then the reagent 1 inputted from the main channel (4) is also allowed to reach the intersection; After reagent 1 passes through the dam (2) at the intersection, it contacts reagent 2 and merges to form a composite flow, which continues to flow downstream.

2. The pre-charging method according to claim 1, wherein: The dam body (2) is provided with a groove (3).

3. The pre-charging method according to claim 1 or 2, characterized in that: The dam body (2) is arranged at the bottom end of the intersection.

4. The pre-charging method according to any one of claims 1 to 3, characterized in that: The height of the upper end of the dam body (2) does not exceed the height of the main channel (4), and the height of the dam body (2) accounts for more than 50% of the height of the main channel (4).

5. The pre-charging method according to any one of claims 1 to 4, characterized in that: The height of the dam body (2) accounts for 85-95% of the height of the main channel (4).

6. The pre-charging method according to any one of claims 1 to 5, characterized in that: The dam body (2) and the liquid channel of the microfluidic chip are an integrated structure.

7. The pre-charging method according to any one of claims 1 to 6, characterized in that: The dam body (2) and the liquid channel of the microfluidic chip are arranged at the intersection by bonding.

8. The pre-charging method according to any one of claims 1 to 7, characterized in that: The dam body (2) is in the shape of the letter N, and one side of the dam body (2) has two legs, a groove (3) is formed between the two legs, and the groove (3) corresponds to the position of the auxiliary channel (5) in the microfluidic chip.

9. The pre-charging method according to any one of claims 1 to 8, characterized in that: The width between the two supporting feet of the dam body (2) exceeds half of the width of the entire dam body (2).

10. The pre-charging method according to any one of claims 1 to 9, characterized in that: An elastic film (7) is also provided on the microfluidic chip. The elastic film (7) is provided on the end surface of the main channel (4) and the auxiliary channel (5) of the microfluidic chip on one side of the opening.

11. The pre-charging method according to any one of claims 1 to 10, characterized in that: There is a gap between the elastic film (7) and the dam body (2).

12. The pre-charging method according to any one of claims 1 to 11, characterized in that: The thickness of the elastic film (7) is 50 to 250 microns.

13. The pre-charging method according to any one of claims 1 to 12, characterized in that: The thickness of the elastic film (7) is 75 to 150 microns.

14. The pre-charging method according to any one of claims 1 to 13, characterized in that: The elastic film (7) is made of PDMS.

15. The pre-charging method according to any of the preceding items, characterized in that: The microfluidic chip further comprises an air path layer (6), the air path layer (6) having an air path channel connected to an external air pressure source, the air path layer (6) and the elastic film (7) cooperate to form a pneumatic microvalve, the pneumatic microvalve comprising a first pneumatic microvalve and a second pneumatic microvalve, the dam body (2) being in the shape of the letter n, the dam body (2) having two legs, a groove (3) formed between the two legs, the groove (3) corresponding to the position of the auxiliary channel (5) in the microfluidic chip, the two legs being a first leg (31) and a second leg (32), the first leg ( 31) is located on the side where the reagent 1 flows in, the second leg (32) is located on the side where the reagent 1 and the reagent 2 converge and flow out, the first pneumatic microvalve covers a part of the first leg (31), and the second pneumatic microvalve covers a part of the groove (3); in the confluence step, the reagent 1 is introduced into the main channel (4), and when the reagent 1 in the main channel (4) moves to the dam body (2), positive pressure is applied to the first pneumatic microvalve to close the first pneumatic microvalve, and the elastic film (7) of the first pneumatic microvalve contacts the dam body (2) downward, thereby closing the main channel (4); The reagent 2 is introduced into the auxiliary channel (5), and when the reagent 2 reaches the dam body (2), positive pressure is applied to the second pneumatic microvalve, the second pneumatic microvalve is closed, and the driving pressure of the reagent 2 is stopped; The positive pressure of the first pneumatic microvalve is removed, and the elastic film (7) of the first pneumatic microvalve returns to a planar state, driving the reagent 1 to cross the dam body (2) and continue to move forward. When the reagent 1 reaches the second pneumatic microvalve, the positive pressure of the second pneumatic microvalve is removed, and the reagent 1 completes the confluence with the reagent 2 when passing above the reagent 2.

16. The pre-charging method according to claim 15, wherein: The air path layer (6) is provided with a recessed portion in an area corresponding to the intersection.

17. The pre-charging method according to any of the preceding items, characterized in that: In the confluence step, by controlling the flow of the reagents in the main channel (4) and the auxiliary channel (5), the reagent 2 inputted from the auxiliary channel (5) first reaches the intersection, where a dam (2) is provided, and the reagent 2 is first intercepted by the groove (3) of the dam (2), so that the reagent 2 cannot cross the groove (3) of the dam (2); Then the reagent 1 inputted from the main channel (4) is also allowed to reach the intersection; When reagent 1 passes over the groove (3), it contacts with reagent 2 in the groove (3) to complete the confluence, and then the two reagents merge to form a composite flow, which finally passes over the dam (2) and continues to flow downstream.

18. The pre-charging method according to any of the preceding items, characterized in that: There are two auxiliary channels (5), and the dam body (2) is provided with two grooves (3). The two auxiliary channels (5) are respectively located on the left and right sides of the main channel (4), one groove (3) corresponds to one auxiliary channel (5), and the other groove (3) corresponds to the other auxiliary channel (5). By controlling the flow of reagents in the main channel (4) and the two auxiliary channels (5), the reagents 2 inputted from the two auxiliary channels (5) first reach the intersection, where the dam body (2) is provided. The reagents 2 are first intercepted by the two grooves (3) of the dam body (2), so that the reagents 2 cannot cross the two grooves (3) of the dam body (2); Then the reagent 1 inputted from the main channel (4) is also allowed to reach the intersection; When reagent 1 passes over the two grooves (3), it contacts with reagent 2 in the two grooves (3) to complete the confluence, and then the two reagents merge to form a composite flow, which finally passes over the dam body (2) and continues to flow downstream.

19. The pre-charging method according to any of the preceding items, characterized in that: In the confluence step, the reagent 1 is introduced into the main channel (4). When the reagent 1 in the main channel (4) reaches the dam body (2), positive pressure is applied to the first pneumatic microvalve to close the first pneumatic microvalve. The elastic film (7) of the first pneumatic microvalve contacts the dam body (2) downward, thereby closing the main channel (4). The reagent 2 is introduced into the auxiliary channel (5), and when the reagent 2 reaches the dam body (2), positive pressure is applied to the second pneumatic microvalve, the second pneumatic microvalve is closed, and the driving pressure of the reagent 2 is stopped; Negative pressure is applied to the first pneumatic microvalve, and the elastic film (7) of the first pneumatic microvalve bulges upward, driving the reagent 1 to cross the dam body (2) and continue to move forward. When the reagent 1 reaches the second pneumatic microvalve, negative pressure is applied to the second pneumatic microvalve, and the elastic film (7) of the second pneumatic microvalve bulges upward. When the reagent 1 passes above the reagent 2, it completes the confluence with the reagent 2; When the converging reagents pass over the dam body (2) and enter the waste liquid channel, the negative pressure of the first pneumatic microvalve is removed, and the waste liquid channel continues to be filled.

20. The pre-charging method according to any one of claims 2 to 19, characterized in that: The length (L1) of the groove (3) accounts for 20-80% of the length (L2) of the dam body (2).

21. A pre-filling method based on a microfluidic chip, characterized by: The reagents introduced into the microfluidic chip include reagent 1 flowing through the main channel (4) and reagent 2 flowing through the auxiliary channel (5); After reagent 1 is input through the corresponding input port, it flows in the main channel (4) in the microfluidic chip; after reagent 2 is input through the corresponding input port, it flows in the auxiliary channel (5) in the microfluidic chip; there is an intersection between the main channel (4) and the auxiliary channel (5), so that the reagents in the main channel (4) and the auxiliary channel (5) can intersect at the intersection; The priming method further includes a step of converging reagent 1 and reagent 2, in which reagent 1 and / or reagent 2 are intercepted by an interception structure; The interception structure is a single-channel dam (17), and there are two single-channel dams (17), namely a first single-channel dam and a second single-channel dam. The first single-channel dam is arranged on the auxiliary channel (5), and the second single-channel dam is arranged on the main channel (4). In the confluence step, by controlling the flow of reagents in the main channel (4) and the auxiliary channel (5), the reagent 2 inputted from the auxiliary channel (5) is intercepted by the first single-channel dam before reaching the intersection, so that the reagent 2 cannot pass through the first single-channel dam; the reagent 1 inputted from the main channel (4) is intercepted by the second single-channel dam before reaching the intersection, so that the reagent 2 cannot pass through the second single-channel dam; Reagent 1 and reagent 2 are controlled to pass through the first single-channel dam and the second single-channel dam at the same time, so that reagent 1 and reagent 2 reach the intersection at the same time. After reagent 1 and reagent 2 contact, they merge to form a composite flow, and the composite flow continues to flow downstream.

22. The pre-charging method according to claim 21, characterized in that: The microfluidic chip further comprises an air path layer (6), the air path layer (6) having an air path channel connected to an external air pressure source, the air path layer (6) and the elastic film (7) cooperate to form a pneumatic microvalve, the pneumatic microvalve comprising a third pneumatic microvalve and a fourth pneumatic microvalve, the third pneumatic microvalve corresponding to the position of the first single-channel dam body, and the fourth pneumatic microvalve corresponding to the position of the second single-channel dam body, in the confluence step, the reagent 1 is introduced into the main channel (4), when the reagent 1 moves to the front of the second single-channel dam body, positive pressure is applied to the fourth pneumatic microvalve, the fourth pneumatic microvalve is closed, and the elastic film (7) of the fourth pneumatic microvalve contacts the second single-channel dam body downward, thereby closing the main channel (4); The reagent 2 is introduced into the auxiliary channel (5). When the reagent 2 moves in front of the first single-channel dam, positive pressure is applied to the third pneumatic microvalve to close the third pneumatic microvalve. The elastic film (7) of the third pneumatic microvalve moves downward to contact the first single-channel dam, thereby closing the auxiliary channel (5). The positive pressure of the third pneumatic microvalve and the fourth pneumatic microvalve is removed, so that the elastic film (7) of the third pneumatic microvalve and the elastic film (7) of the fourth pneumatic microvalve are restored to a planar state, or negative pressure is applied to the third pneumatic microvalve and the fourth pneumatic microvalve, so that the elastic film (7) of the third pneumatic microvalve and the elastic film (7) of the fourth pneumatic microvalve are convex upward, and then the reagent 1 and the reagent 2 are controlled to cross the first single-channel dam and the second single-channel dam at the same time, so that the reagent 1 and the reagent 2 arrive at the intersection at the same time, and the reagent 1 and the reagent 2 meet and merge to form a composite flow, and the composite flow continues to flow downstream.

23. The pre-filling method according to claim 21 or 22, characterized in that: The single-channel dam body (17) is in the shape of a long strip.

24. The pre-charging method according to any one of claims 21 to 23, characterized in that: The upper end height of the first single-channel dam body does not exceed the height of the auxiliary channel (5), the upper end height of the second single-channel dam body does not exceed the height of the main channel (4), the upper end height of the first single-channel dam body accounts for more than 50% of the height of the auxiliary channel (5), and the upper end height of the second single-channel dam body accounts for more than 50% of the height of the main channel (4).

25. The pre-charging method according to any one of claims 21 to 24, characterized in that: The upper end height of the first single-channel dam body accounts for 85-95% of the height of the auxiliary channel (5), and the upper end height of the second single-channel dam body accounts for 85-95% of the height of the main channel (4).

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