A microfluidic control structure and a pressure-type microfluidic instrument

Abstract

The present application relates to the field of microfluidics, and specifically discloses a microflow control structure and a pressure-type microfluidic instrument. A microflow control structure includes a top plate, a chip is arranged below the top plate, a liquid-carrying tank for loading liquid is provided on the chip, and a discharge port is provided on the liquid-carrying tank; a quantitative liquid discharge mechanism is provided on the top plate, and the quantitative liquid discharge mechanism includes a piston rod slidably connected to the top plate, a pressure hammer adapted to the liquid-carrying tank is fixedly connected to one end of the piston rod facing the chip, and a power part for driving the sliding in a direction away from or close to the liquid-carrying tank is provided at one end of the piston rod away from the pressure hammer; the surface of the pressure hammer is elastic, and a drainage groove is provided on the side of the pressure hammer facing the liquid-carrying tank. The present application has the advantage of improving the accuracy of liquid volume control.

Description

Technical Field

[0001] The present application relates to the field of microfluidics, and more specifically, to a micro-flow control structure and a pressure-type microfluidics instrument. Background Art

[0002] Microfluidics is a scientific technology that precisely controls and manipulates microscale fluids, with the manipulation of fluids in micro-nanoscale space as its main feature. It has the ability to miniaturize basic laboratory functions in biology, chemistry, and other fields, such as sample preparation, reaction, separation, and detection, onto a chip of a few square centimeters.

[0003] Microfluidics technology is widely used in industries such as in vitro diagnostics. Common microfluidic driving methods include pressure-driven microfluidics, centrifugal microfluidics, digital microfluidics, and capillary-driven microfluidics. Among them, pressure-driven microfluidics has been widely used in many in vitro diagnostics due to its advantages such as direct driving force, stable driving force, and little interference.

[0004] However, pressure-based microfluidics currently has the disadvantages of inaccurate liquid volume control and high residual volume. Summary of the invention

[0005] In order to improve the accuracy of liquid volume control in microfluidic reactions and reduce liquid residue, the present application provides a micro flow control structure and a pressure-type microfluidic instrument.

[0006] In the first aspect, the present application provides a micro flow control structure, which adopts the following technical solution:

[0007] A micro flow control structure comprises a top plate, a chip is arranged below the top plate, a liquid carrying tank for loading liquid is provided on the chip, and a discharge port is provided on the liquid carrying tank;

[0008] The top plate is provided with a quantitative liquid discharge mechanism, which includes a piston rod slidably connected to the top plate, an end of the piston rod facing the chip is fixedly connected to a pressure hammer adapted to the liquid carrier tank, and an end of the piston rod away from the pressure hammer is provided with a power member for driving the sliding movement in a direction away from or close to the liquid carrier tank;

[0009] The surface of the pressure hammer is elastic, and a drainage groove is provided on the side of the pressure hammer facing the liquid-carrying tank. The drainage groove includes a connecting section, and a lead-out section is provided at each end of the connecting section. The end of the lead-out section away from the connecting section is a liquid outlet, and the liquid outlet is arranged toward the discharge port of the liquid-carrying tank, and when the pressure hammer is pressed toward the liquid-carrying tank, the liquid outlet is connected with the discharge port.

[0010] Through the above technical scheme, when the staff needs to control the outflow of liquid from the liquid carrying tank, the power part drives the piston rod to move, so that the pressure hammer squeezes the liquid carrying tank and squeezes out the liquid stored in the liquid carrying tank. According to the sliding length of the piston rod driven by the power part, the volume of the pressure hammer and the volume of the liquid carrying tank, the outflow of the liquid can be quantitatively controlled. The setting of the drainage groove, when the pressure hammer is close to the bottom wall of the liquid carrying tank, the liquid in the liquid carrying tank can flow in the extension direction of the drainage groove towards the discharge port, thereby facilitating the emptying of the liquid in the liquid carrying tank, thereby improving the accuracy of liquid addition during the reaction process.

[0011] Preferably, the connecting section in the drainage groove is arc-shaped, and the plane where the arc is located is perpendicular to the sliding direction of the piston rod.

[0012] The plane where the arc of the drainage groove is located is perpendicular to the sliding direction of the piston rod, so that when the pressure hammer moves with the piston rod, liquid at the same liquid level height can enter the drainage groove at the same time, thereby reducing the liquid from the side of the liquid-carrying tank away from the discharge port, improving the liquid flow and ensuring the accuracy of the liquid flow direction and liquid outflow volume.

[0013] Preferably, the depth of the drainage groove gradually decreases as it moves away from the liquid outlet.

[0014] Since the surface of the pressure hammer is elastic, when the pressure hammer slides toward the liquid-carrying tank and the surface of the pressure hammer receives the reaction force of the inner wall of the liquid-carrying tank and deforms, the liquid in the shallower part of the drainage groove is injected into the deeper part of the pressure groove, and with the continuous squeezing of the pressure hammer, the liquid in this part gradually flows to the discharge port of the liquid-carrying tank. Thus, the liquid in the liquid-carrying tank can be further guided to flow to the discharge port as much as possible, reducing the residual liquid in the liquid-carrying tank.

[0015] Preferably, a plurality of drainage grooves are provided on the surface of the pressure hammer.

[0016] Preferably, the pressure hammer surface is provided with a plurality of through grooves, the through grooves connecting the plurality of drainage grooves.

[0017] Preferably, a side of the chip facing the top plate is covered with an isolation film.

[0018] In a second aspect, the present application provides a pressure-type microfluidic instrument.

[0019] A pressure-type microfluidic instrument comprises the above-mentioned micro-flow control structure, wherein a bottom plate is arranged below the chip, the top plate is fixedly connected to the bottom plate, and the chip is detachably connected and plugged between the bottom plate and the top plate.

[0020] Preferably, a plurality of liquid-carrying tanks are provided on the chip, channels are provided between the liquid-carrying tanks, two adjacent liquid-carrying tanks are connected through the channels, a control valve for controlling the opening and closing of the channels is provided on the top plate, and the control valve includes a pressure block and a driving member for driving the pressure block to slide and extrude the channel.

[0021] The driving member drives the pressing block to slide and squeeze the channel, thereby closing the channel. When the driving member drives the pressing block away from the channel, the channel is reconnected. Through the cooperation of the control valve and the quantitative liquid discharge mechanism, the flow of the liquid can be accurately controlled, so that the liquid enters different liquid carrier tanks in turn according to the reaction requirements for reaction, thereby improving the accuracy of the reaction.

[0022] Preferably, the bottom plate is provided with a magnet head for controlling the liquid carrier tank to elute the magnetic particles, and the magnet head is provided with a rotating motor for controlling the magnet head to approach the liquid carrier tank.

[0023] Preferably, the chip is also provided with a fixing component for fixing the chip to the bottom plate and the top plate, the fixing component includes an ear plate fixedly connected to the chip, the bottom plate and the top plate are both fixedly connected to a fixing plate, and a fixing pin is pierced through both the fixing plate and the ear plate.

[0024] In summary, this application has the following beneficial effects:

[0025] 1. Since the present application adopts a pressure hammer to extrude the liquid-carrying tank, the liquid in the liquid-carrying tank can flow out in a directional manner, and by controlling the sliding distance of the pressure hammer, the extrusion amount of the liquid can be accurately controlled, thereby improving the accuracy of the reaction.

[0026] 2. The setting of the drainage groove on the surface of the pressure hammer allows the residual liquid in the liquid-carrying tank to flow in the liquid-carrying tank and enter and exit from the discharge port through the drainage in the liquid-carrying tank, so that the liquid in the liquid-carrying tank can be completely squeezed out, thereby improving the accuracy of the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the micro-flow control structure in Example 1 of the present application.

[0028] Figure 2 It is a schematic diagram of the internal structure of the micro-flow control structure in Example 1 of the present application.

[0029] Figure 3 It is a schematic diagram of the pressure hammer and the control valve in Example 1 of the present application.

[0030] Figure 4 It is a schematic diagram of the overall structure of the drainage groove on the surface of the pressure hammer in Example 1 of the present application.

[0031] Figure 5It is a schematic diagram of the bottom structure of the pressure hammer in Example 1 of the present application.

[0032] Figure 6 It is a schematic diagram of the fixing component in Example 2 of the present application.

[0033] Figure 7 It is a schematic diagram of the internal structure of the microfluidic instrument in Example 4 of the present application.

[0034] In the figure, 1, card box; 11, top plate; 12, bottom plate; 13, connecting plate; 14, accommodating groove; 15, slideway; 16, through hole; 2, chip; 21, liquid carrying tank; 211, feed port; 212, discharge port; 22, channel; 23, isolation membrane; 3, quantitative liquid discharge mechanism; 31, piston rod; 32, pressure hammer; 33, power part; 331, first stepping motor; 332, first lifting screw; 333, slider; 4, control valve; 41, driving part; 411, limiting cylinder; 412, second lifting screw; 413, second stepping motor; 42, pressing block; 5, drainage groove; 51, connecting section; 52, lead-out section; 53, through groove; 54, liquid outlet; 6, fixing component; 61, fixing plate; 62, ear plate; 63, fixing pin; 7, ultrasonic generator; 8, magnet head; 81, rotating motor. DETAILED DESCRIPTION

[0035] The present application is further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Example 1

[0037] A micro flow control structure, such as Figure 1 As shown, the card box 1 includes a chip 2 inserted therein. The card box 1 includes a top plate 11 located above the chip 2 and a bottom plate 12 located below the chip 2. A connecting plate 13 is provided between the top plate 11 and the bottom plate 12, and the connecting plate 13 connects and fixes the top plate 11 and the bottom plate 12.

[0038] like Figure 2 As shown, a plurality of liquid-carrying grooves 21 are provided on one side of the chip 2 facing the top plate 11, and a feed port 211 and a discharge port 212 are provided on both sides of the liquid-carrying grooves 21. A plurality of channels 22 for connecting the liquid-carrying grooves 21 are also provided on the chip 2. The surface of the chip 2 is covered with an isolation film 23 made of a polymer material, and the isolation film 23 is bonded to the chip 2, so that the isolation film 23 seals the liquid in the liquid-carrying grooves 21 and the channels 22 of the chip 2. Specifically, the isolation film 23 can be made of PP material or PE material, etc.

[0039] like Figure 2 and Figure 3As shown, a quantitative liquid discharging mechanism 3 is provided on the top plate 11, and the quantitative liquid discharging mechanism 3 includes a piston rod 31 slidably connected to the top plate 11, a pressure hammer 32 is fixedly connected to one end of the piston rod 31 facing the chip 2, and a power piece 33 is provided at one end of the piston rod 31 away from the pressure hammer 32. The power piece 33 can drive the piston rod 31 to slide along its own axial direction, so that the pressure hammer 32 fixed to one end of the piston rod 31 squeezes the isolation membrane 23 and presses the isolation membrane 23 into the liquid loading tank 21, so that the liquid in the liquid loading tank 21 is squeezed out from the discharge port 212, and the squeezed liquid circulates in the channel 22 and enters the next liquid loading tank 21.

[0040] like Figure 2 and Figure 3 As shown, the power member 33 can be a linear drive member 41 such as a small air cylinder or oil cylinder, or a rotary drive member such as a stepper motor or servo motor in combination with a transmission structure such as a ball screw.

[0041] like Figure 2 and Figure 3 As shown, specifically in this embodiment, a receiving groove 14 for accommodating a pressure hammer 32 is provided on a side of the top plate 11 facing the chip 2, the opening of the receiving groove 14 is arranged toward the chip 2, and a slideway 15 is provided on the bottom wall of the receiving groove 14 away from the chip 2. The power member 33 includes a first stepper motor 331, a first lifting screw 332, and a slider 333; the first lifting screw 332 and the slider 333 are arranged in the slideway 15, the slider 333 is threadedly matched with the first lifting screw 332, and the slider 333 can only slide along the length direction of the slideway 15 in the slideway 15 but cannot rotate around the first lifting screw 332; the end of the first lifting screw 332 away from the chip 2 extends out of the top plate 11 and is coaxially fixed with the output end of the first stepper motor 331; the first stepper motor 331 is fixed to the top plate 11.

[0042] When the first stepper motor 331 is working, the first stepper motor 331 drives the first lifting screw 332 to rotate, and the first lifting screw 332 cooperates with the thread of the slider 333 to accurately control the sliding of the piston rod 31, thereby controlling the depth of the pressure hammer 32 pressed into the liquid loading tank 21, thereby achieving quantitative extrusion of the liquid in the liquid loading tank 21.

[0043] The channel 22 is provided on the surface of the chip 2 facing the top plate 11, and the side of the channel 22 facing the top plate 11 is open. When the isolation film 23 covers the surface of the chip 2, the isolation seals the opening of the channel 22 on the side facing the top plate 11. In order to control the liquid in the liquid carrier tank 21 to flow out from the discharge port 212 of the liquid carrier tank 21 in a directional manner when the pressure hammer 32 is pressed down, a control valve 4 for controlling the opening and closing of the channel 22 is also provided on the channel 22.

[0044] like Figure 2 and Figure 3 As shown, the control valve 4 includes a pressing block 42 and a driving member 41 for driving the pressing block 42 to close the channel 22. The driving member 41 can be a linear driving member 41 such as a small air cylinder, oil cylinder or electric push rod, or a rotating driving member 41 such as a stepping motor or servo motor in combination with a transmission structure such as a ball screw. When the control valve 4 needs to close the channel 22, the driving member 41 drives the pressing block 42 to press down and squeeze the isolation membrane 23 on the channel 22, thereby closing the channel 22.

[0045] Specifically in this embodiment, a through hole 16 is provided on the top plate 11, and a pressure block 42 is arranged in the through hole 16. A limiting cylinder 411 is fixedly connected to the side of the slider 333 away from the chip 2. The limiting cylinder 411 can slide in the through hole 16 along the length direction of the through hole 16, and the limiting cylinder 411 is limited by the inner wall of the through hole 16 and cannot rotate around its own axis. A second lifting screw 412 is inserted in the limiting cylinder 411, and the limiting cylinder 411 cooperates with the second lifting screw 412. A second stepping motor 413 is fixedly connected to the top plate 11, and the output shaft of the second stepping motor 413 is coaxially fixedly connected to the end of the second lifting screw 412 away from the pressure block 42. Therefore, when the second stepping motor 413 is working, the second stepping motor 413 can drive the pressure block 42 to slide in the height direction. When the pressure block 42 slides toward the chip 2 and the pressure block 42 is pressed into the inside of the channel 22, the control valve 4 closes the channel 22.

[0046] When it is necessary to control the outflow of liquid in the liquid-carrying tank 21, the control valve 4 on the channel 22 on the side of the feed port 211 of the liquid-carrying tank 21 closes the channel 22, and the channel 22 on the side of the discharge port 212 of the liquid-carrying tank 21 is normally connected. Then the power part 33 drives the pressure hammer 32 to press down in the direction of the liquid-carrying tank 21, and the pressure hammer 32 squeezes the isolation membrane 23. Since the isolation membrane 23 itself is flexible and elastic, the isolation membrane 23 is deformed and squeezes the liquid in the liquid-carrying tank 21 out of the discharge port 212, and the liquid enters the next liquid-carrying tank 21 through the channel 22.

[0047] like Figure 4 and Figure 5 As shown, in order to facilitate the liquid to flow out of the liquid-carrying tank 21 and reduce liquid residue, the surface of the pressure hammer 32 is elastic. For example, the pressure hammer 32 can be made of rubber material. A plurality of drainage grooves 5 are also provided on the side of the pressure hammer 32 facing the chip 2. The drainage grooves 5 include a connecting section 51 and lead-out sections 52 provided at both ends of the connecting section 51. The connecting section 51 is an arc, and the plane where the arc of the connecting section 51 is located is perpendicular to the sliding direction of the piston rod 31. The end of the lead-out section 52 away from the connecting section 51 is a liquid outlet 54. The liquid outlets 54 on the two lead-out sections 52 converge at a point on the pressure hammer 32 at the same time. After the pressure hammer 32 is pressed into the liquid-carrying tank 21, the liquid outlet 54 is connected to the discharge port 212 of the liquid-carrying tank 21.

[0048] A plurality of drainage grooves 5 are distributed on the surface of the pressure hammer 32 along the axis of the piston rod 31 , and the liquid outlets 54 of the outlet sections 52 in the plurality of drainage grooves 5 overlap and communicate with each other.

[0049] When the pressure hammer 32 is pressed into the liquid loading tank 21 in the direction of the chip 2 and the pressure hammer 32 is close to the bottom wall of the liquid loading tank 21, the liquid on the bottom wall of the liquid loading tank 21 can flow to the discharge port 212 of the liquid loading tank 21 through the guide groove. This reduces the situation where the pressure hammer 32 squeezes the liquid into the side of the feed port 211 of the liquid loading tank 21 when the pressure hammer 32 is pressed down, causing liquid residue, thereby affecting the accuracy of the liquid extrusion amount.

[0050] The depth of the drainage groove 5 gradually becomes shallower as the distance from the liquid outlet 54 of the outlet section 52 increases. The deepest depth in the drainage groove 5 is 1-1.2 mm, and the shallowest depth is 0.05-0.1 mm.

[0051] Since the pressure hammer 32 is elastic, when the pressure hammer 32 slides toward the liquid-carrying tank 21 and the surface of the pressure hammer 32 receives the reaction force of the inner wall of the liquid-carrying tank 21 and deforms, the liquid in the shallower part of the drainage tank 5 is injected into the deeper part of the pressure tank, and with the continuous squeezing of the pressure hammer 32, the liquid in this part gradually flows toward the discharge port 212 of the liquid-carrying tank 21. Thus, the liquid in the liquid-carrying tank 21 can be further guided to flow to the discharge port 212 as much as possible, reducing the residual liquid in the liquid-carrying tank 21.

[0052] The surface of the pressure hammer 32 is also provided with a plurality of through grooves 53, which intersect with the connecting sections 51 of the plurality of drainage grooves 5 at the same time, so that the through grooves 53 connect the plurality of drainage grooves 5. The provision of the through grooves 53 allows the liquid to flow in different drainage grooves 5, thereby further facilitating the liquid to flow to the discharge port 212.

[0053] Example 2

[0054] A pressure-type microfluidic instrument, such as Figure 6 As shown, it includes the above-mentioned micro-flow control structure and also includes a microcomputer control system for controlling the working time and sequence of the pressure hammer 32 and the control valve 4.

[0055] In the pressure-type microfluidic instrument, a plurality of liquid-carrying tanks 21 are provided on the chip 2 according to the reaction requirements, and the various liquids involved in the reaction are quantitatively discharged by the liquid-discharging mechanism 3 in a specific order and sequentially enter different liquid-carrying tanks 21 for reaction, thereby realizing a series of experiments and tests.

[0056] The microcomputer system includes a processor and an actuator. The processor starts timing after the instrument is started. When the set time is reached, the processor sends a signal to the actuator. The actuator controls the corresponding power member 33 and / or driving member 41 to work according to the signal, so that the control valve 4 located at the feed port 211 of the required liquid carrier tank 21 works and closes the channel 22. Then the pressure hammer 32 squeezes the liquid carrier tank 21, thereby transferring the reaction liquid to the next liquid carrier tank 21. The reaction liquid reacts in the next liquid carrier tank 21. When the reaction meets the preset time of the processor, the processor sends a signal to the actuator again, and the actuator controls the corresponding control valve 4 and pressure hammer 32 to work, thereby transferring the reaction liquid to the next reaction node.

[0057] The microcomputer system can also be used to control the quantitative liquid discharge of the quantitative liquid discharge mechanism 3. The specific method is as follows: first, the relationship between the depth of descent of the pressure hammer 32 and the amount of liquid extruded is calibrated according to the experiment, and the relationship between the number of rotation steps of the stepper motor and the depth of descent of the pressure hammer 32 is converted. When it is necessary to complete the quantitative liquid discharge, it is only necessary to preset the working parameters of the required stepper motor after conversion in the microcomputer system. When working, the processor sends a control signal to the actuator accordingly, so that the stepper motor outputs a specific number of steps, thereby controlling the descent depth of the pressure hammer 32 to achieve quantitative liquid discharge.

[0058] like Figure 6 As shown, the side wall of the card box 1 is also provided with a fixing component 6 for fixing the chip 2, and the fixing component 6 includes two fixing plates 61 fixedly connected to the top plate 11 and the bottom plate 12 of the card box 1, respectively, and an ear plate 62 fixedly connected to the side wall of the chip 2. When the chip 2 is inserted into the card box 1, a fixing pin 63 is inserted into the chip 2 and the two top plates 11 at the same time, so that the fixing pin 63 can fix the chip 2, and at this time, the pressure hammer 32 is located directly above the corresponding liquid carrier tank 21. The setting of the fixing component 6 improves the stability of the chip 2 inserted into the card box 1, and also improves the accuracy of the chip 2 installed in the card box 1.

[0059] Example 3

[0060] A pressure-type microfluidic instrument is used for molecular diagnostic testing in the field of in vitro diagnosis. In this embodiment, a plurality of liquid-carrying tanks 21 are provided on the chip 2, which specifically include:

[0061] Sample injection hole: used to inject the sample to be tested, and the sample to be tested flows into the sample lysis pool for lysis reaction.

[0062] Sample lysis pool: used to store lysis solution and lyse the added samples.

[0063] Washing solution pool: used to store washing solution, which flows into the main magnetic bead reaction pool to wash the magnetic beads.

[0064] Main magnetic bead reaction pool: used to adsorb, mix, wash, remove impurities from magnetic beads, and elute nucleic acids (DNA / RNA).

[0065] Attached magnetic bead reaction pool: used for washing, mixing, and temporary storage of magnetic beads.

[0066] Elution pool: used to store the eluent, which flows into the main magnetic bead reaction pool to elute the nucleic acid (DNA / RNA).

[0067] Eluent surplus reservoir: used to receive excess eluent.

[0068] Amplification mixed pool: used to mix primers, probes and amplification solution in preparation for PCR reaction.

[0069] Amplification liquid pool: used to store amplification liquid, which flows into the amplification mixing pool for PCR reaction.

[0070] Primer probe pool: used to store primer probes, which flow into the amplification mixing pool for PCR reaction.

[0071] In this embodiment, the isolation film 23 is bonded to the surface of the chip 2, and each channel 22 of the chip 2 before use is bonded and sealed by the isolation film 23, so as to prevent the pre-installed reagents in different liquid-carrying tanks 21 from mixing and affecting normal detection during the transportation and movement of the chip 2. When it is necessary to control the extrusion of the reagents in different reaction pools, the pressure provided by the pressure hammer 32 can destroy the bonding between the chip 2 and the isolation film 23 at the channel 22, so that the liquid can smoothly flow from the channel 22 into the next reaction pool.

[0072] Example 4

[0073] The difference from Example 3 is that:

[0074] like Figure 7 As shown, an ultrasonic generator 7 is also arranged on the bottom plate 12, and the ultrasonic generator 7 is used for lysing the sample.

[0075] The bottom plate 12 is also provided with a magnetic head 8 for controlling the elution of magnetic particles in the liquid-carrying tank 21. A rotating motor is fixedly connected to the bottom plate 12, and the output shaft of the rotating motor is fixedly connected to the magnetic head 8. When the magnetic particles need to be eluted, the rotating motor drives the magnetic head 8 to rotate until the magnetic pole faces the corresponding liquid-carrying tank 21, and the magnetic particle elution operation is performed. After the elution is completed, the rotating motor works, and the magnetic head 8 rotates the magnetic pole away from the liquid-carrying tank 21.

[0076] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A micro flow control structure, characterized in that: It comprises a top plate (11), a chip (2) is arranged below the top plate (11), a liquid carrying tank (21) for carrying liquid is provided on the chip (2), and a discharge port (212) is provided on the liquid carrying tank (21); The top plate (11) is provided with a quantitative liquid discharge mechanism (3), the quantitative liquid discharge mechanism (3) comprising a piston rod (31) slidably connected to the top plate (11), one end of the piston rod (31) facing the chip (2) being fixedly connected to a pressure hammer (32) adapted to the liquid carrier tank (21), and one end of the piston rod (31) away from the pressure hammer (32) being provided with a power member (33) for driving the sliding movement in a direction away from or close to the liquid carrier tank (21); The surface of the pressure hammer (32) is elastic. A drainage groove (5) is provided on the side of the pressure hammer (32) facing the liquid-carrying tank (21). The drainage groove (5) includes a connecting section (51). Two ends of the connecting section (51) are respectively provided with a lead-out section (52). One end of the lead-out section (52) away from the connecting section (51) is a liquid outlet (54). The liquid outlet (54) is arranged toward a discharge port (212) of the liquid-carrying tank (21). When the pressure hammer (32) is pressed toward the liquid-carrying tank (21), the liquid outlet (54) is connected with the discharge port (212). The side of the chip (2) facing the top plate (11) is covered with an isolation film (23).

2. The micro-flow control structure according to claim 1, characterized in that: The connecting section (51) in the drainage groove (5) is in the shape of an arc, and the plane where the arc is located is perpendicular to the sliding direction of the piston rod (31).

3. The micro-flow control structure according to claim 1, characterized in that: The depth of the drainage groove (5) gradually decreases as it moves away from the liquid outlet (54).

4. The micro-flow control structure according to claim 2, characterized in that: A plurality of drainage grooves (5) are arranged on the surface of the pressure hammer (32).

5. The micro-flow control structure according to claim 4, characterized in that: A plurality of through grooves (53) are provided on the surface of the pressure hammer (32), and the through grooves (53) connect the plurality of drainage grooves (5).

6. A pressure-type microfluidic instrument, characterized in that: It comprises the micro-flow control structure described in any one of claims 1 to 5, wherein a bottom plate (12) is arranged below the chip (2), the top plate (11) and the bottom plate (12) are fixedly connected, and the chip (2) is detachably connected and plugged between the bottom plate (12) and the top plate (11).

7. A pressure-type microfluidic instrument according to claim 6, characterized in that: The chip (2) is provided with a plurality of liquid-carrying grooves (21), channels (22) are provided between the liquid-carrying grooves (21), two adjacent liquid-carrying grooves (21) are connected via the channels (22), and a control valve (4) for controlling the opening and closing of the channels (22) is provided on the top plate (11), the control valve (4) comprising a pressing block (42) and a driving member (41) for driving the pressing block (42) to slide and extrude the channels (22).

8. A pressure-type microfluidic instrument according to claim 6, characterized in that: The bottom plate (12) is provided with a magnetic head (8) for controlling the liquid carrier tank (21) to elute magnetic particles, and the magnetic head (8) is provided with a rotating motor (81) for controlling the magnetic head (8) to approach the liquid carrier tank (21).

9. A pressure-type microfluidic instrument according to claim 6, characterized in that: The chip (2) is also provided with a fixing component (6) for fixing the chip (2) to the bottom plate (12) and the top plate (11); the fixing component (6) comprises an ear plate (62) fixedly connected to the chip (2); the bottom plate (12) and the top plate (11) are both fixedly connected with a fixing plate (61); and a fixing pin (63) is simultaneously provided on the fixing plate (61) and the ear plate (62).

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