A corrosion-resistant syringe for microfluidic micropressure measurement and its application method

Abstract

The present invention discloses a corrosion-resistant syringe for microfluidic micropressure measurement and an application method, which relates to the field of microfluidic technology. In order to solve the problems of easy corrosion and easy clogging of sensor channels in traditional microfluidic syringe equipment and pressure element sensor probes for micropressure measurement, the following technical solution is proposed: comprising a syringe, a microfluidic chip, and an injection pump, wherein the interior of the syringe is divided into a head unit, a middle unit, and a tail unit, a double-headed pull rod is provided in the syringe, and a threaded pull rod is provided in the tail unit; a closed cavity is formed between the double-headed pull rod and the closed injection port, and the injection pump injects a first solution into the closed cavity; the injection pump injects a second solution into the middle unit, and the first solution and the second solution respectively form a pressure equilibrium state on both sides of the double-headed pull rod. The present invention has shown significant beneficial effects in protecting measuring elements, extending equipment life, avoiding contamination, improving experimental applicability, simplifying operating procedures, and promoting the development of microfluidic technology.

Description

Technical Field

[0001] The invention relates to the technical field of microfluidics, and in particular to a corrosion-resistant syringe for microfluidics micropressure measurement. Background Art

[0002] In today's era of rapid technological advancement, microfluidics, through the precise control and manipulation of fluids in tiny channels, enables the transport, mixing, separation, and detection of trace samples. It has shown broad application prospects in fields such as biomedicine, chemical analysis, and environmental monitoring. The micropressure generated by injection, a key indicator of microfluidic manipulation and control, is of great significance to research in fluid dynamics, drug delivery, and biological sample mixing.

[0003] However, traditional microfluidic syringe devices and pressure cell sensors for micropressure measurement often reveal their inherent limitations when used with corrosive samples or suspensions, such as sensor probe corrosion and sensor channel clogging. Furthermore, the syringe pump cannot control the injection pressure after setting the injection speed. When injecting suspensions prone to precipitation, the high pressure generated by the precipitate clogging the microfluidic chip channel can easily exceed the pressure cell sensor's range, causing the pressure cell sensor to operate at high pressure for a long time, leading to sensor failure. These problems can lead to a decrease in sensor monitoring accuracy or even render the sensor useless.

[0004] Furthermore, traditional microfluidic syringes are primarily made of glass or polypropylene plastic. Polypropylene plastic easily expands and deforms under prolonged high-pressure conditions, compromising its seal with the stopper and allowing corrosive liquids to leak, leading to deviations in injection pressure and reduced accuracy. Glass, on the other hand, easily generates new chemical substances such as sodium silicate under highly alkaline conditions, introducing new impurities into the injection fluid and making the reaction products impure.

[0005] These shortcomings limit the accuracy and reliability of microfluidic technology in measuring micro-pressures, and may damage high-precision measuring instruments such as pressure sensors, thereby increasing monitoring costs and reducing the accuracy and reproducibility of monitoring results, thereby limiting the development of microfluidic technology in chemistry, medicine, biology, fluid mechanics and other fields. Summary of the Invention

[0006] The purpose of the present invention is to provide a corrosion-resistant syringe for microfluidic micropressure measurement and an application method thereof, so as to solve the problems that the pressure element sensor probe of traditional microfluidic syringe equipment and micropressure measurement is easily corroded and the sensor channel is easily blocked.

[0007] The technical solution of the present invention to solve the above technical problems is as follows:

[0008] A corrosion-resistant syringe for microfluidic micropressure measurement, comprising: an injection tube, a microfluidic chip, and an injection pump; the head of the injection tube is connected to a first injection port and an injection port, respectively; the first injection port is connected to the injection pump through a pipeline, and the injection port is connected to the microfluidic chip through a pipeline;

[0009] The interior of the injection tube is divided into a head unit, a middle unit and a tail unit by a plurality of limit buckles. A double-headed pull rod is provided in the injection tube, which can move left and right along the head unit and the middle unit, and a threaded pull rod is provided in the tail unit, which can move left and right along the tail unit.

[0010] A closed cavity is formed between the head piston of the double-ended tie rod and the closed injection port, and an injection pump injects a first solution into the closed cavity; the intermediate unit is connected to the injection pump through a pipeline, and the injection pump injects a second solution into the intermediate unit, and the first solution and the second solution form a pressure equilibrium state on both sides of the double-ended tie rod;

[0011] The intermediate unit is connected to the pressure element sensor through a pipeline, and a pressure relief valve is provided on the pipeline connecting the intermediate unit and the pressure element sensor. All pipelines are provided with a pinch valve, and the pressure element sensor is communicatively connected to the control terminal.

[0012] Preferably, the injection pump is connected to the first solution tank and the second solution tank through pipelines respectively.

[0013] Preferably, a threaded cover is provided at the tail of the injection tube, and the threaded pull rod is connected to the threaded cover via a limiting nut provided on the rod.

[0014] Preferably, a microfluidic injection needle is provided at the end of the injection port, and a Luer lock is provided between the injection port and the microfluidic injection needle.

[0015] Preferably, a second liquid injection port is opened on the top of the intermediate unit, and the second liquid injection port is connected to the liquid injection pump through a pipeline. A liquid discharge port is opened on the top of the intermediate unit, and the liquid discharge port is connected to the pressure element sensor through a pipeline.

[0016] Preferably, the first liquid filling port, the second liquid filling port and the liquid discharge port are all provided with Luer adapters.

[0017] Preferably, a steel needle is provided at the outlet end of the microfluidic chip.

[0018] A method for applying the above-mentioned corrosion-resistant syringe for microfluidic micropressure measurement comprises the following steps:

[0019] S1. Push the threaded rod to the limit buckle of the tail unit and tighten the limit nut to fix the threaded rod on the threaded cover;

[0020] S2. Close the pinch valve on the pipe connecting the first injection port and the first solution tank, close the pinch valve on the pipe connecting the discharge port and the pressure sensor, open the pinch valve on the pipe connecting the injection port and the microfluidic chip, open the pinch valve on the pipe connecting the second injection port and the second solution tank, and use the injection pump to inject the second solution into the intermediate unit. The second solution pushes the double-ended pull rod to the side wall of the injection port.

[0021] S3, close the pinch valve on the pipe connecting the injection port and the microfluidic chip, open the pinch valve on the pipe connecting the discharge port and the pressure element sensor, exhaust the gas in the intermediate unit, and turn off the injection pump after the injection pipe reaches the initial injection state;

[0022] S4. Close the pinch valve on the pipe connecting the second liquid inlet and the second solution tank, close the pinch valve on the pipe connecting the liquid discharge port and the pressure relief valve, open the pinch valve on the pipe connecting the first liquid inlet and the first solution tank, loosen the limit nut and turn on the injection pump to pump the first solution into the enclosed chamber. The pumped first solution pushes the double-ended pull rod, the second solution, and the threaded pull rod to move rightward simultaneously until the left end of the double-ended pull rod contacts the limit buckle of the head unit.

[0023] S5, opening the pinch valve on the pipe connecting the injection port and the microfluidic chip, until the injection pipe reaches a grouting pressure equilibrium state, turning off the injection pump, and closing the pinch valve on the pipe connecting the first injection port and the first solution tank;

[0024] S6. Connect the microfluidic chip and the steel needle, open the micro-pressure acquisition software in the control terminal, and push the threaded rod to inject the first solution into the pipe connected to the injection port.

[0025] The present invention has the following beneficial effects:

[0026] Superior Protection and Measurement Capabilities: This device can effectively protect the pressure sensor while accurately measuring micro-pressures when injected with corrosive liquids or liquids containing sediment suspensions. This feature not only ensures measurement accuracy but also significantly improves the durability and safety of the device.

[0027] Significantly Extends Equipment Life and Avoids Contamination: By utilizing corrosion-resistant materials and a specialized design, this equipment effectively avoids syringe deformation caused by corrosion and grouting liquid impurities caused by chemical impurities. This not only significantly extends the equipment's lifespan but also ensures the accuracy and reliability of experimental results.

[0028] Wide range of experimental applicability: This device can flexibly add corrosive liquids or suspensions according to specific biological, chemical, and other experimental requirements. This wide applicability enables the device to meet the needs of different fields and experimental conditions, providing researchers with a more convenient and efficient experimental tool.

[0029] High reliability and easy operation: This device has a reasonable design, compact structure and easy operation. Its high reliability ensures the stability and repeatability of experimental results, while the simple operation process reduces the difficulty and time cost of the experimenter.

[0030] Promoting the further development of microfluidic technology: The application of this device not only improves the accuracy and reliability of microfluidic pressure measurements, but also provides more precise and reliable experimental data support for researchers in fields such as chemistry, medicine, biology, and fluid mechanics. This will help promote in-depth research and widespread application of microfluidic technology in these fields, making a positive contribution to scientific and technological progress and industrial development. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic structural diagram of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention;

[0032] Figure 2 This is a schematic diagram of the initial grouting state of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention;

[0033] Figure 3 A schematic diagram of the grouting pressure equilibrium state of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention;

[0034] Figure 4 This is a schematic diagram of the double-head pull rod structure of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention;

[0035] Figure 5 A schematic diagram of the threaded rod structure of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention;

[0036] Figure 6 A schematic structural diagram of a threaded cover of a corrosion-resistant syringe device for microfluidic micropressure measurement according to the present invention;

[0037] Figures 1 to 6The reference numerals shown in the figure are respectively: 1-injection tube, 2-limiting buckle; 3-sealing ring; 4-double-headed pull rod; 51-first injection port, 52-second injection port; 6-discharge port; 7-Luer adapter; 8-Luer lock; 9-microfluidic injection needle; 10-1-pinch valve for the connection section between the microfluidic injection needle and the steel needle, 10-2-pinch valve for the connection section between the injection port at the head of the injection tube and the injection pump, 10-3-pinch valve for the connection section between the injection port in the middle of the injection tube and the injection pump, 10-4-pinch valve between the injection pump and the injection liquid, 10-5- The pinch valve between the injection pump and the distilled water, 10-6-the pinch valve between the discharge port and the pressure element sensor section, 10-7-the pinch valve between the pressure relief valve and the pressure element section; 11-steel needle; 12-microfluidic chip; 13-pressure element sensor; 14-control terminal; 15-pull rod cap; 16-threaded pull rod; 17-piston push head; 18-threaded cover; 19-tygon tube; 20-second solution tank; 22-first solution tank; 23-injection pump; 24-limiting nut; 25-anti-wear nut steel ring; 26-injection port; 27-pressure relief valve. DETAILED DESCRIPTION

[0038] The following is a clear and complete description of the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0039] Please refer to Figure 1 The present invention provides a corrosion-resistant syringe device for microfluidic micropressure measurement. The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0040] First, the corrosion-resistant syringe device of the present invention includes a syringe 1, a microfluidic chip 12, and an injection pump 23. The head of the syringe 1 is connected to a first injection port 51 and an injection port 26. The first injection port 51 is connected to the injection pump 23 via a pipe, and the injection port 26 is connected to the microfluidic chip 12 via a pipe. This design allows the syringe to easily receive and discharge liquid while simultaneously connecting to the microfluidic chip, enabling microfluidic injection operations.

[0041] The interior of the syringe 1 is divided into a head unit, a middle unit, and a tail unit by a plurality of limit buckles 2. This separation design allows the syringe to contain different types of liquids and achieve precise control of these liquids. The syringe 1 is provided with a double-ended pull rod 4 ( Figure 4 As shown), the tail unit is provided with a threaded rod 16 ( Figure 5The design of the double-ended pull rod 4 and the threaded pull rod 16 enables the syringe to accurately push and adjust different liquids.

[0042] A closed cavity is formed between the head piston of the double-ended tie rod 4 and the closed injection port 26, into which the injection pump 23 injects the first solution. This design allows the syringe to precisely control the first solution and push it into the microfluidic chip 12. The intermediate unit is connected to the injection pump 23 via a pipeline, which injects the second solution into the intermediate unit. The first and second solutions form a pressure equilibrium state on either side of the double-ended tie rod 4. This pressure equilibrium design allows the syringe to control the pressure of different liquids, thereby achieving precise regulation of the microfluidic grouting process.

[0043] The intermediate unit is connected to the pressure sensor 13 via a pipe, and a pressure relief valve 27 is installed on the pipe connecting the intermediate unit and the pressure sensor 13. Pinch valves are installed on all pipes, and the pressure sensor 13 is connected to the control terminal 14 for communication. This design allows the syringe to monitor pressure changes within the intermediate unit in real time and precisely control them through the control terminal. Furthermore, the pressure relief valve 27 protects the pressure sensor 13 from damage caused by high pressure.

[0044] The injection pump 23 is communicated with the first solution tank 22 and the second solution tank 20 through pipelines. This design allows the syringe to easily receive different types of solutions and achieve accurate control of these solutions.

[0045] The tail of the injection tube 1 is provided with a threaded cap 18 ( Figure 6 As shown in FIG, the threaded rod 16 is connected to the threaded cap 18 by a limit nut 24 provided on the rod. This design allows the threaded rod 16 to be firmly fixed to the tail of the injection tube 1 and accurately adjusted by the limit nut 24.

[0046] A microfluidic injection needle 9 is provided at the end of the injection port 26, and a Luer lock 8 is provided between the injection port 26 and the microfluidic injection needle 9. This design ensures a secure connection between the injection needle and the injection port, prevents extravasation of slurry or needle slippage, and closes the injection port 26 when necessary.

[0047] A second injection port 52 is provided at the top of the intermediate unit, connected to the injection pump 23 via a pipe. This design allows the syringe to conveniently receive the second solution and precisely control its flow. A drainage port 6 is also provided at the top of the intermediate unit, connected to the pressure sensor 13 via a pipe. This design facilitates the discharge of gas and liquid from the intermediate unit, ensuring proper function of the syringe and protecting the pressure sensor 13.

[0048] The first liquid injection port 51, the second liquid injection port 52 and the liquid discharge port 6 are all provided with a Luer adapter 7. This design can easily connect pipes and accessories and ensure the firmness and reliability of the connection.

[0049] The outlet end of the microfluidic chip 12 is provided with a steel needle 11. This design can easily connect the microfluidic chip and other equipment to achieve precise control of the microfluidic grouting process.

[0050] The first solution can be a common liquid, a corrosive liquid such as an acid or alkali, or a suspension, and the second solution can be distilled water.

[0051] The application of the corrosion-resistant syringe device of the present invention will be described in detail below with reference to specific embodiments.

[0052] Example 1:

[0053] First, push the threaded rod 16 to the limit buckle 2 of the tail unit and tighten the limit nut 24 to fix the threaded rod 16 on the threaded cover 18. This operation ensures that the threaded rod 16 will not move during subsequent operations, thereby achieving precise control of the injection tube 1.

[0054] Next, close the pinch valve (i.e., 10-2) on the pipe connecting the first injection port 51 to the first solution tank 22, close the pinch valve (i.e., 10-6) on the pipe connecting the discharge port 6 to the pressure sensor 13, open the pinch valve (i.e., 10-1) on the pipe connecting the injection port 26 to the microfluidic chip 12, and open the pinch valve (i.e., 10-3) on the pipe connecting the second injection port 52 to the second solution tank 20. Start the injection pump 23 to inject the second solution into the intermediate unit. The second solution pushes the double-ended pull rod 4 to the side wall of the injection port 26, forming a closed cavity.

[0055] Next, close the pinch valve (i.e. 10-1) on the pipe connecting the injection port 26 and the microfluidic chip 12, open the pinch valve (i.e. 10-6) on the pipe connecting the discharge port 6 and the pressure element sensor 13, and discharge the gas from the intermediate unit. At this time, the injection tube 1 reaches the initial state of grouting (e.g. Figure 2 Turn off the priming pump 23.

[0056] Next, close the pinch valve (i.e., 10-3) on the pipe connecting the second inlet 52 to the second solution tank 20, close the pinch valve (i.e., 10-7) on the pipe connecting the discharge port 6 to the pressure relief valve 27, and open the pinch valve (i.e., 10-2) on the pipe connecting the first inlet 51 to the first solution tank 22. Unscrew the limit nut 24 and turn on the inlet pump 23 to pump the first solution into the enclosed chamber. The pumped first solution pushes the double-ended tie rod 4, the second solution, and the threaded tie rod 16 simultaneously to the right until the left end of the double-ended tie rod 4 contacts the limit buckle 2 of the head unit. At this point, the syringe is ready for grouting.

[0057] Next, the pinch valve (i.e. 10-1) on the pipe connecting the injection port 26 and the microfluidic chip 12 is opened, and the syringe reaches a grouting pressure equilibrium state (e.g. Figure 3 Turn off the injection pump 23 and close the pinch valve (i.e. 10-2) on the pipe connecting the first injection port 51 and the first solution tank 22.

[0058] Finally, connect the microfluidic chip 12 to the steel needle 11, and start the micropressure acquisition software in the control terminal 14. Push the threaded rod 16 to inject the first solution into the pipe connected to the injection port 26. At this point, the syringe begins the grouting operation and monitors the pressure changes during the grouting process in real time.

[0059] Based on Example 1, the following optimizations and improvements can be made:

[0060] The tubing is preferably Tygon tubing (chemical peristaltic pump tubing). Tygon tubing is corrosion-resistant and biochemically compatible, making it an ideal tubing for transporting biochemical slurries. This tubing effectively prevents corrosion from corrosive liquids, thereby ensuring the proper functioning of the syringe 1.

[0061] The pinch valve does not come into direct contact with corrosive liquids and effectively cuts off the transport path between gas and liquid, preventing corrosive liquids from corroding the valve. This design ensures the pinch valve's reliability and service life.

[0062] The Luer adapter 7 has a certain pressure resistance and is easy to disassemble and assemble. This design can ensure a firm connection between the syringe and other devices and convenient disassembly and assembly.

[0063] Both ends of the double-ended pull rod 4 and the inner end of the threaded pull rod 16 are equipped with piston pushers 17. Both the piston pusher 17 and the buckle are made of plastic steel, and the outer ring of the piston pusher 17 is equipped with a sealing ring 3. The injection tube 1 is made of plastic steel that is resistant to acid and alkali corrosion. This design effectively prevents corrosion of the tube wall by acidic and alkaline corrosive liquids, thereby preventing slurry leakage caused by tube wall deformation.

[0064] The distance between the stopper 2, which restricts the piston push head 17, and the injection port 26 is greater than twice the length of the double-ended pull rod 4. By setting the stopper 2, the piston push head 17 can be effectively prevented from exceeding the set range during movement, ensuring that corrosive liquids or suspended liquids in the injection tube 1 will not enter the pressure transmission pipeline of the pressure element sensor 13 due to over-range operation, thereby maintaining the normal operation of the instrument.

[0065] A drain port 6 and a second injection port 52 are provided at a position twice the length of the double-ended pull rod 4 away from the injection port 26. The drain port 6 is connected to a pressure cell connected to a power supply via a Luer adapter 7, and the other end of the pressure cell is connected to a data acquisition computer. A pressure relief valve 27 with a value of 95% of the maximum value of the pressure cell sensor is provided between the drain port 6 and the pressure cell sensor. The second injection port 52 is connected to the injection pump 23 via a Luer adapter 7. This design can effectively prevent corrosive liquids from entering the pressure cell sensor 13 while ensuring that distilled water enters the pressure cell sensor 13 at all times, thereby preventing corrosive liquids from corroding the sensor elements or clogging the sensor pressure transmission channel. At the same time, the pressure relief valve 27 can effectively avoid high-pressure operation problems caused by the inability to control pressure during the grouting process, thereby protecting the sensor from being damaged by high pressure.

[0066] The threaded cap 18 at the tail of the injection tube 1 is provided with a wear-resistant nut steel ring 25. This design can effectively prevent the scale wear caused by the movement of the threaded pull rod 16 with scale and the situation that the rod shaft is separated from the injection tube 1.

[0067] The threaded pull rod 16 with scale can accurately adjust the suction and discharge volume of the liquid in the cavity through the limit nut 24. This design can improve the accuracy and controllability of the operation.

[0068] Grouting liquid (ordinary liquid, corrosive liquid such as acid or alkali, or suspension) is added to the closed cavity between the double-ended tie rod and the injection port via the injection pump 23. Distilled water is then added between the double-ended tie rod 4 and the piston push head 17. By precisely controlling the displacement of the threaded tie rod 16 and utilizing the principle of equal liquid pressure on both sides of the double-ended tie rod at the same height, precise grouting and micro-pressure measurement of the grouting liquid within the microfluidic chip 12 are achieved. When the threaded tie rod 16 pushes the piston push head 17 to move, it compresses the distilled water between the piston push head 17 and the double-ended tie rod 4, generating a certain pressure. This pressure is monitored in real time by the pressure element sensor 13 and transmitted to the control terminal 14, enabling precise control of pressure during the grouting process.

[0069] Example 2: Application of micro-pressure measurement and precise grouting

[0070] In experiments on the microfluidic chip 12, it is often necessary to accurately control and measure a small volume of liquid. This purpose can be achieved by using the corrosion-resistant syringe device of the present invention.

[0071] First, the injection pipe 1 is adjusted to a grouting preparation state according to the steps of Example 1. Then, the target grouting pressure and grouting speed are set through the control terminal 14 according to the experimental requirements.

[0072] When grouting begins, the injection pump 23 injects grouting fluid into the enclosed cavity, while the threaded rod 16 gradually moves under the action of pressure. At this time, the pressure element sensor 13 monitors the pressure changes during the grouting process in real time and transmits the data to the control terminal 14. The control terminal 14 automatically adjusts the pumping rate of the injection pump 23 and the movement speed of the threaded rod 16 based on the set target pressure and grouting speed, thereby achieving accurate grouting of the grouting fluid and micro-pressure measurement.

[0073] During the experiment, if the grouting pressure or speed needs to be adjusted, it is only necessary to make corresponding settings through the control terminal 14. This design not only improves the efficiency and accuracy of the experiment, but also greatly simplifies the operation steps and reduces the labor intensity of the experimenters.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A corrosion-resistant syringe for microfluidic micropressure measurement, characterized in that: include: An injection tube (1), a microfluidic chip (12), and an injection pump (23), wherein the head of the injection tube (1) is connected to a first injection port (51) and an injection port (26), respectively; the first injection port (51) is connected to the injection pump (23) through a pipeline, and the injection port (26) is connected to the microfluidic chip (12) through a pipeline; The interior of the injection tube (1) is divided into a head unit, a middle unit, and a tail unit by a plurality of limit buckles (2). The injection tube (1) is provided with a double-headed pull rod (4) that can move left and right along the head unit and the middle unit, and the tail unit is provided with a threaded pull rod (16) that can move left and right along the tail unit. A closed cavity is formed between the head of the double-headed pull rod (4) and the closed injection port (26), and the injection pump (23) injects a first solution into the closed cavity; the intermediate unit is connected to the injection pump (23) through a pipeline, and the injection pump (23) injects a second solution into the intermediate unit, and the first solution and the second solution form a pressure balance state on both sides of the double-headed pull rod (4); The intermediate unit is connected to the pressure element sensor (13) through a pipeline, and a pressure relief valve (27) is provided on the pipeline connecting the intermediate unit and the pressure element sensor (13). A pinch valve is provided on each of the pipelines. The pressure element sensor (13) is communicatively connected to the control terminal (14); The injection pump (23) is connected to the first solution tank (22) and the second solution tank (20) through pipelines respectively; The tail of the injection tube (1) is provided with a threaded cover (18), and the threaded pull rod (16) is connected to the threaded cover (18) via a limiting nut (24) provided on the rod; A microfluidic injection needle (9) is provided at the end of the injection port (26), and a Luer lock (8) is provided between the injection port (26) and the microfluidic injection needle (9); A second liquid injection port (52) is provided at the top of the intermediate unit, and the second liquid injection port (52) is connected to the liquid injection pump (23) through a pipeline. A liquid discharge port (6) is provided at the top of the intermediate unit, and the liquid discharge port (6) is connected to the pressure element sensor (13) through a pipeline. Both ends of the double-headed pull rod (4) and the inner end of the threaded pull rod (16) are provided with piston push heads (17). The piston push head (17) and the buckle are both made of plastic steel, and the outer ring of the piston push head (17) is provided with a sealing ring (3).

2. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 1, characterized in that: The first liquid injection port (51), the second liquid injection port (52) and the liquid discharge port (6) are all provided with a Luer adapter (7).

3. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 1, characterized in that: A steel needle (11) is provided at the outlet end of the microfluidic chip (12).

4. A method for using the corrosion-resistant syringe for microfluidic micropressure measurement according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1. Push the threaded rod (16) to the limit buckle (2) of the tail unit, and tighten the limit nut (24) to fix the threaded rod (16) on the threaded cover (18); S2, close the clamping valve on the pipe connecting the first injection port (51) and the first solution tank (22), close the clamping valve on the pipe connecting the discharge port (6) and the pressure element sensor (13), open the clamping valve on the pipe connecting the injection port (26) and the microfluidic chip (12), open the clamping valve on the pipe connecting the second injection port (52) and the second solution tank (20), and inject the second solution into the middle unit with the injection pump (23). The second solution pushes the double-headed pull rod (4) to move to the side wall of the injection port (26); S3, close the pinch valve on the pipe connecting the injection port (26) and the microfluidic chip (12), open the pinch valve on the pipe connecting the discharge port (6) and the pressure element sensor (13), discharge the gas in the intermediate unit, and the injection tube (1) reaches the initial injection state, and close the injection pump (23); S4. Close the pinch valve on the pipe connecting the second liquid injection port (52) and the second solution tank (20), close the pinch valve on the pipe connecting the discharge port (6) and the pressure relief valve (27), open the pinch valve on the pipe connecting the first liquid injection port (51) and the first solution tank (22), unscrew the limit nut (24) and turn on the injection pump (23), pump the first solution into the closed chamber, and the pumped first solution pushes the double-headed pull rod (4), the second solution and the threaded pull rod (16) to move to the right at the same time until the left end of the double-headed pull rod (4) contacts the limit buckle (2) of the head unit; S5, opening the pinch valve on the pipe connecting the injection port (26) and the microfluidic chip (12), so that the injection tube (1) reaches a grouting pressure equilibrium state, closing the injection pump (23), and closing the pinch valve on the pipe connecting the first injection port (51) and the first solution tank (22); S6. Connect the microfluidic chip (12) and the steel needle (11), open the micro-pressure acquisition software in the control terminal (14), and push the threaded pull rod (16) to inject the first solution into the pipeline connected to the injection port (26).

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