Corrosion-resistant injector for micro-fluidic micro-pressure measurement and application method

Abstract

The invention discloses a corrosion-resistant injector for micro-fluidic micro-pressure measurement and an application method, and relates to the technical field of microfluidics. In order to solve the problems that a traditional micro-fluidic injector device and a pressure element sensor probe for micro-pressure measurement are prone to corrosion, and a sensor channel is prone to blockage, the following technical scheme is provided: the device comprises an injection tube, a micro-fluidic chip and a liquid injection pump, the interior of the injection tube is divided into a head unit, a middle unit and a tail unit, and a double-end pull rod is arranged in the injection tube; the tail unit is provided with a threaded pull rod; a closed containing cavity is formed between the double-end pull rod and the closed injection port, and the liquid injection pump injects a first solution into the closed containing cavity; the liquid injection pump injects a second solution into the middle unit, and the first solution and the second solution form a pressure balance state on the two sides of the double-end pull rod correspondingly. The method has the remarkable beneficial effects of protecting a measuring element, prolonging the service life of equipment, avoiding pollution, improving the experimental applicability, simplifying the operation process, promoting the development of a microfluidic technology and the like.

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 development, microfluidics technology has achieved the carrying, mixing, separation and detection of trace samples through precise control and manipulation of fluids in tiny channels, and has shown broad application prospects in the fields of biomedicine, chemical analysis, environmental monitoring, etc. Among them, the tiny pressure generated by injection is an important influencing indicator of microfluidic manipulation and control, which is of great significance to the research of fluid dynamics, drug delivery and biological sample mixing.

[0003] However, traditional microfluidic syringe equipment and pressure cell sensors for micro-pressure measurement often reveal their inherent limitations when facing corrosive samples or suspensions, such as corrosion of sensor probes and blockage of sensor channels. In addition, the injection pump cannot control the injection pressure after setting the injection speed. When injecting suspensions that are prone to precipitation, the high pressure generated by the clogging of the microfluidic chip channel by the precipitate easily exceeds the range of the pressure cell sensor, causing the pressure cell sensor to be in a high-pressure operating state for a long time, and then the sensor collapses. The above problems will cause the sensor monitoring accuracy to decrease or even become scrapped.

[0004] In addition, because traditional microfluidic syringe equipment is mainly made of glass or polypropylene plastic materials. Polypropylene plastic is prone to expansion and deformation under long-term high-pressure environment, which reduces the sealing between it and the rubber plug, and corrosive liquid is easy to leak, resulting in deviation of grouting pressure and reduced accuracy. Glass materials are prone to generate new chemical substances such as sodium silicate under high alkaline conditions, which introduces new impurities into the grouting liquid and easily causes impure reaction products.

[0005] These shortcomings limit the accuracy and reliability of microfluidic technology in measuring tiny pressures, and will damage high-precision measuring instruments such as pressure sensors, thereby increasing monitoring costs and reducing the accuracy and reproducibility of monitoring results, thus 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 the traditional microfluidic syringe equipment and micropressure measurement is easy to corrode and the sensor channel is easy to be blocked.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: A corrosion-resistant syringe for microfluidic micropressure measurement, comprising: an injection tube, a microfluidic chip and an injection pump, wherein the head of the injection tube is respectively connected with a first injection port and an injection port, the first injection port is connected with the injection pump through a pipeline, and the injection port is connected with the microfluidic chip through a pipeline; 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 that can move left and right along the head unit and the middle unit is provided in the injection tube, and a threaded pull rod that can move left and right along the tail unit is provided; A closed cavity is formed between the head piston of the double-headed tie rod and the closed injection port, and the injection pump injects the first solution into the closed cavity; the middle unit is connected to the injection pump through a pipeline, and the injection pump injects the second solution into the middle unit, and the first solution and the second solution form a pressure balance state on both sides of the double-headed tie rod respectively; 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.

[0008] Preferably, the injection pump is connected to the first solution tank and the second solution tank respectively through pipelines.

[0009] Preferably, a threaded cap is provided at the tail of the injection tube, and the threaded pull rod is connected to the threaded cap via a limit nut provided on the rod.

[0010] 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.

[0011] Preferably, a second liquid injection port is opened at 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 at the top of the intermediate unit, and the liquid discharge port is connected to the pressure element sensor through a pipeline.

[0012] Preferably, the first liquid injection port, the second liquid injection port and the liquid discharge port are all provided with Luer adapters.

[0013] Preferably, a steel needle is provided at the outlet end of the microfluidic chip.

[0014] A method for using the above-mentioned corrosion-resistant syringe for microfluidic micropressure measurement comprises the following steps: 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; 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 element 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 inject the second solution into the middle unit with the injection pump. The second solution pushes the double-headed pull rod to move to the side wall of the injection port; 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, discharge the gas in the intermediate unit, the syringe reaches the initial state of grouting, and close the injection pump; S4, close the pinch valve on the pipe connecting the second liquid injection port and the second solution tank, close the pinch valve on the pipe connecting the discharge port and the pressure relief valve, open the pinch valve on the pipe connecting the first liquid injection port and the first solution tank, unscrew the limit nut and turn on the injection pump, pump the first solution into the closed cavity, and the pumped first solution pushes the double-headed pull rod, the second solution and the threaded pull rod to move to the right at the same time until the left end of the double-headed pull rod contacts the limit buckle of the head unit; S5, opening the pinch valve on the pipe connecting the injection port and the microfluidic chip, the syringe 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; S6. Connect the microfluidic chip and the steel needle, open the micro-pressure acquisition software in the control terminal, and push the threaded pull rod to inject the first solution into the pipe connected to the injection port.

[0015] The present invention has the following beneficial effects: Excellent protection and measurement capabilities: This device can effectively protect the pressure sensor while accurately measuring the micro-pressure of corrosive liquids or suspended liquids with sediments. This feature not only ensures the accuracy of the measurement process, but also significantly improves the durability and safety of the equipment.

[0016] Significantly extend the life of the equipment and avoid pollution: By using corrosion-resistant materials and special design, this equipment effectively avoids the deformation of the syringe caused by material corrosion and the impurity of the grouting liquid caused by chemical impurities. This not only significantly extends the service life of the equipment, but also ensures the accuracy and reliability of the experimental results.

[0017] Wide range of experimental applicability: This equipment can flexibly add corrosive liquids or suspensions according to specific biological, chemical and other experimental requirements. This wide range of applicability enables this equipment to meet the needs of different fields and different experimental conditions, providing researchers with a more convenient and efficient experimental tool.

[0018] High reliability and easy operation: This equipment has a reasonable design, compact structure and easy operation. Its high reliability ensures the stability and repeatability of the experimental results, while the simple operation process reduces the operating difficulty and time cost of the experimenter.

[0019] Promote the further development of microfluidic technology: The application of this device not only improves the accuracy and reliability of micro-pressure measurement of microfluidic technology, but also provides more accurate and reliable experimental data support for researchers in the fields of chemistry, medicine, biology, fluid mechanics, etc. This will help promote the in-depth research and extensive application of microfluidic technology in these fields, and make positive contributions to scientific and technological progress and industrial development. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention; Figure 2 It is a schematic diagram of the initial state of grouting of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention; 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; Figure 4 A schematic diagram of a double-headed pull rod structure of a corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention; Figure 5 A schematic diagram of the threaded rod structure of the corrosion-resistant syringe device for microfluidic micropressure measurement of the present invention; Figure 6 A schematic diagram of the structure of a threaded cover of a corrosion-resistant syringe device for microfluidic micropressure measurement according to the present invention; Figures 1 to 6 The reference numerals shown in the figure are respectively represented as follows: 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 clamping valve between the injection pump and the distilled water, 10-6-the clamping valve between the discharge port and the pressure element sensor section, 10-7-the clamping 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

[0021] The technical solution of the present invention is described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the 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.

[0022] 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 in conjunction with the accompanying drawings and embodiments.

[0023] 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 respectively connected with a first injection port 51 and an injection port 26, 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. This design allows the syringe to conveniently receive and discharge liquid, and at the same time connect with the microfluidic chip to realize microfluidic grouting operation.

[0024] 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-headed pull rod 4 ( Figure 4 As shown, the tail unit is provided with a threaded rod 16 ( Figure 5 The design of the double-ended pull rod 4 and the threaded pull rod 16 enables the syringe to accurately push and adjust different liquids.

[0025] A closed cavity is formed between the head piston of the double-headed pull rod 4 and the closed injection port 26, and the injection pump 23 injects the first solution into the closed cavity. This design allows the syringe to achieve precise control of the first solution and push it into the microfluidic chip 12. The intermediate unit is connected to the injection pump 23 through a pipeline, and the injection pump 23 injects the second solution into the intermediate unit. The first solution and the second solution form a pressure balance state on both sides of the double-headed pull rod 4. This pressure balance state design allows the syringe to achieve pressure control of different liquids, thereby achieving precise regulation of the microfluidic grouting process.

[0026] 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 all pipelines, and the pressure element sensor 13 is connected to the control terminal 14 for communication. This design allows the syringe to monitor the pressure changes in the intermediate unit in real time and accurately control it through the control terminal. At the same time, the design of the pressure relief valve 27 can protect the pressure element sensor 13 from being damaged by high pressure.

[0027] The injection pump 23 is connected to 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.

[0028] The tail of the injection tube 1 is provided with a threaded cap 18 ( Figure 6 As shown in FIG. 1 , the threaded rod 16 is connected to the threaded cap 18 through 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 to be precisely adjusted through the limit nut 24.

[0029] 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 can ensure a firm connection between the injection needle and the injection port, prevent slurry extravasation or needle slippage, and close the injection port 26 when necessary.

[0030] A second injection port 52 is provided at the top of the intermediate unit, and the second injection port 52 is connected to the injection pump 23 through a pipeline. This design allows the syringe to conveniently receive the second solution and achieve accurate control of the second solution. A discharge port 6 is also provided at the top of the intermediate unit, and the discharge port 6 is connected to the pressure element sensor 13 through a pipeline. This design can conveniently discharge the gas and liquid in the intermediate unit, ensure the normal operation of the syringe, and protect the pressure element sensor 13.

[0031] 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 conveniently connect pipes and accessories and ensure the firmness and reliability of the connection.

[0032] The outlet end of the microfluidic chip 12 is provided with a steel needle 11. This design can conveniently connect the microfluidic chip and other equipment to achieve precise control of the microfluidic grouting process.

[0033] 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.

[0034] The application of the corrosion-resistant syringe device of the present invention will be described in detail below in conjunction with specific embodiments.

[0035] Embodiment 1: First, push the threaded rod 16 to the limit buckle 2 of the tail unit, tighten the limit nut 24, and fix the threaded rod 16 on the threaded cover 18. This operation can ensure that the threaded rod 16 will not move in subsequent operations, thereby achieving precise control of the syringe 1.

[0036] Then, close the pinch valve (i.e. 10-2) on the pipe connecting the first injection port 51 and the first solution tank 22, close the pinch valve (i.e. 10-6) on the pipe connecting the discharge port 6 and the pressure element sensor 13, open the pinch valve (i.e. 10-1) on the pipe connecting the injection port 26 and the microfluidic chip 12, and open the pinch valve (i.e. 10-3) on the pipe connecting the second injection port 52 and 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-headed pull rod 4 to move to the side wall of the injection port 26 to form a closed cavity.

[0037] 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 in the intermediate unit. At this time, the syringe 1 reaches the initial injection state (e.g. Figure 2 Turn off the injection pump 23.

[0038] Then, close the clamp valve (i.e. 10-3) on the pipeline connecting the second injection port 52 and the second solution tank 20, close the clamp valve (i.e. 10-7) on the pipeline connecting the discharge port 6 and the pressure relief valve 27, and open the clamp valve (i.e. 10-2) on the pipeline connecting the first injection port 51 and the first solution tank 22. Unscrew the limit nut 24 and turn on the injection pump 23 to pump the first solution into the closed cavity. 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. At this time, the syringe reaches the grouting preparation state.

[0039] 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 (ie 10-2) on the pipeline connecting the first injection port 51 and the first solution tank 22.

[0040] Finally, the microfluidic chip 12 is connected to the steel needle 11, and the micro-pressure acquisition software in the control terminal 14 is opened. The threaded pull rod 16 is pushed to inject the first solution into the pipeline connected to the injection port 26. At this time, the injector starts the grouting operation and monitors the pressure changes during the grouting process in real time.

[0041] Based on Example 1, the following optimizations and improvements can also be made: The pipeline is preferably a tygon tube (chemical peristaltic pump tube). Tygon tube has corrosion resistance and biochemical compatibility, and is a preferred pipeline for transporting biochemical slurries. This pipeline can effectively prevent the corrosive liquid from eroding the pipeline, thereby ensuring the normal operation of the syringe 1.

[0042] The pinch valve does not directly contact the corrosive liquid and can effectively cut off the transport channel of gas and liquid, avoiding the erosion of the valve by the corrosive liquid. This design can ensure the reliability and service life of the pinch valve.

[0043] The Luer adapter 7 has a certain pressure resistance and is easy to disassemble and assemble. This design can ensure the firm connection and convenient disassembly and assembly of the syringe and other devices.

[0044] 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. The syringe 1 is made of plastic steel resistant to acid and alkali corrosion. This design can effectively prevent acid and alkali corrosive liquids from corroding the tube wall, thereby preventing slurry leakage caused by deformation of the tube wall.

[0045] The distance between the limit buckle 2 of the piston push head 17 and the injection port 26 is greater than twice the length of the double-headed pull rod 4. By setting the limit buckle 2, it is possible to effectively prevent the piston push head 17 from exceeding the set range during movement, ensuring that the corrosive liquid or suspended liquid in the syringe 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.

[0046] A drain port 6 and a second injection port 52 are provided at a distance from the injection port 26 by twice the length of the double-headed pull rod 4. The drain port 6 is connected to the pressure element connected to the power supply through the Luer adapter 7, and the other end of the pressure element is connected to the data acquisition computer. A pressure relief valve 27 of 95% of the maximum value of the pressure element sensor is provided between the drain port 6 and the pressure element sensor. The second injection port 52 is connected to the injection pump 23 through the Luer adapter 7. This design can effectively prevent corrosive liquids from entering the pressure element sensor 13 under the premise of ensuring that distilled water enters the pressure element sensor 13 at all times, thereby preventing corrosive liquids from corroding the sensor elements or blocking the pressure transmission channel of the sensor. At the same time, the pressure relief valve 27 can effectively avoid the high-pressure operation problem caused by the inability to control the pressure during the grouting process, thereby protecting the sensor from being damaged by high pressure.

[0047] The threaded cap 18 that tightens the tail of the syringe has a wear-resistant nut steel ring 25. This design can effectively avoid 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 syringe 1.

[0048] The threaded pull rod 16 with scale can accurately adjust the suction and discharge amount of the liquid in the cavity through the limit nut 24. This design can improve the accuracy and controllability of the operation.

[0049] Grouting liquid (ordinary liquid, corrosive liquid such as acid and alkali, or suspension) is added to the closed cavity between the double-headed pull rod and the injection port through the injection pump 23, and distilled water is added between the double-headed pull rod 4 and the piston push head 17. By using the principle that the liquid pressure on both sides of the double-headed pull rod is equal at the same height, the displacement of the threaded pull rod 16 is precisely controlled to achieve accurate grouting and micro-pressure measurement of the grouting liquid in the microfluidic chip 12. When the threaded pull rod 16 pushes the piston push head 17 to move, the distilled water between the piston push head 17 and the double-headed pull rod 4 is compressed, thereby generating a certain pressure, which is monitored in real time by the pressure element sensor 13 and transmitted to the control terminal 14, so as to achieve precise control of the pressure during the grouting process.

[0050] Example 2: Application of micro-pressure measurement and precise grouting In experiments on the microfluidic chip 12, it is often necessary to accurately control and measure a tiny volume of liquid. This purpose can be achieved by using the corrosion-resistant syringe device of the present invention.

[0051] First, the injector 1 is adjusted to a grouting preparation state according to the steps of Example 1. Then, according to the experimental requirements, the target pressure and grouting speed of the grouting are set through the control terminal 14.

[0052] When grouting starts, the injection pump 23 will inject grouting liquid into the closed cavity, and the threaded rod 16 will gradually move under the action of pressure. At this time, the pressure element sensor 13 will monitor the pressure changes during the grouting process in real time and transmit the data to the control terminal 14. The control terminal 14 will automatically adjust the pumping rate of the injection pump 23 and the moving speed of the threaded rod 16 according to the set target pressure and grouting speed, so as to achieve accurate grouting and micro-pressure measurement of the grouting liquid.

[0053] During the experiment, if the pressure or speed of grouting 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.

[0054] 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 principle of the present invention should be included in the protection scope 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 respectively 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 pipeline, and the injection port (26) is connected to the microfluidic chip (12) via a pipeline; The interior of the injection tube (1) is divided into a head unit, a middle unit and a tail unit by means of a plurality of limit buckles (2); a double-headed pull rod (4) is provided in the injection tube (1) and can move left and right along the head unit and the middle unit; and a threaded pull rod (16) is provided in the tail unit and can move left and right along the head unit and the middle unit; A closed cavity is formed between the head of the double-headed pull rod (4) and the closed injection port (26), and an injection pump (23) injects a first solution into the closed cavity; the intermediate unit is connected to the injection pump (23) via 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) via 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, and the pressure element sensor (13) is communicatively connected to the control terminal (14).

2. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 1, characterized in that: The injection pump (23) is connected to the first solution tank (22) and the second solution tank (20) respectively through pipelines.

3. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 1, characterized in that: 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.

4. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 1, characterized in that: 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).

5. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 1, characterized in that: 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.

6. The corrosion-resistant syringe for microfluidic micropressure measurement according to claim 5, 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).

7. 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).

8. A method for using the corrosion-resistant syringe for microfluidic micropressure measurement according to any one of claims 1 to 7, 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, closing the clamp valve on the pipe connecting the first injection port (51) and the first solution tank (22), closing the clamp valve on the pipe connecting the discharge port (6) and the pressure element sensor (13), opening the clamp valve on the pipe connecting the injection port (26) and the microfluidic chip (12), opening the clamp valve on the pipe connecting the second injection port (52) and the second solution tank (20), and injecting the second solution into the intermediate unit with the injection pump (23), so that 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 syringe (1) reaches the initial injection state, and close the injection pump (23); S4, close the clamp valve on the pipe connecting the second liquid injection port (52) and the second solution tank (20), close the clamp valve on the pipe connecting the liquid discharge port (6) and the pressure relief valve (27), open the clamp 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 liquid injection pump (23), pump the first solution into the closed cavity, 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), allowing the syringe (1) to reach 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, connecting the microfluidic chip (12) and the steel needle (11), opening the micro-pressure acquisition software in the control terminal (14), and pushing the threaded pull rod (16) to inject the first solution into the pipeline connected to the injection port (26).

Images