A self-circulating micropump structure and control method for chip drive

Abstract

The present invention provides a self-circulating micropump structure and control method for chip driving. The structure includes an injection and aspiration component, a piping component, a liquid storage component, and a microfluidic chip. The two syringes of the injection and aspiration component respectively complete the injection and aspiration operations. The injection and aspiration amounts are always equal. The solution injected by the syringe reaches the liquid storage component through the injection circuit, flows through the micro-operation area of ​​the microfluidic chip to complete the particle drive and naturally unload, and is recovered to the other syringe through the aspiration circuit. The two syringes alternately complete the injection and aspiration to achieve long-term self-circulation. The method includes the following steps: 1. Installing the microfluidic chip and adjusting the microfluidic chip to the top surface level; 2. Filling the fluid and exhausting the air. Complete the fluid filling of the syringe and the liquid storage component, and use the fluid to exhaust the air in the circuit; 3. Start the micropump and enter the self-circulation working state. The present invention provides a guarantee for the long-term capture and movement of cells.

Description

Technical Field

[0001] The present invention relates to the research field of microfluidic experimental device design and control method, and in particular to a self-circulating micropump structure and control method for chip driving. Background Art

[0002] Since its introduction, microfluidics, a technology that manipulates small amounts of fluids within microchannels ranging in size from tens to hundreds of micrometers, combines various micromanipulation processes, and achieves automation and complex system integration. Microfluidics systems generally consist of a fluid drive system, a control system, a monitoring system, and a detection and analysis system. The fluid drive system often uses a micropump to drive the microfluidic chip. With the deepening of microfluidics research, the long-term capture and movement of microparticles such as cells has become a research hotspot, placing higher demands on the effectiveness and stability of micropump operations.

[0003] Commonly used pumps in microfluidic technology include peristaltic pumps, pressure pumps, and syringe pumps. The working principle of a peristaltic pump is based on the compression and relaxation of a flexible tube. By rotating the peristaltic wheel, the flexible tube is alternately compressed and relaxed to achieve cyclic suction and propulsion of the fluid. However, the compression of the flexible tube will cause large pulses, affecting the accuracy of the experiment. The pressure pump applies external pressure to the sealed liquid reservoir containing the sample (pumping in non-corrosive gases such as CO2 and N2), and uses the pressure difference between the inlet and outlet of the sealed liquid reservoir to pump out the sample fluid. It requires an additional pressure source and is prone to backflow when shut down. The syringe pump uses a motor to push (or pull) the moving piston in the syringe to achieve fluid drive. There is a certain time pause between each step of the motor movement. Therefore, "oscillation" will occur when driving microfluidics, and the stability of the output flow needs to be further controlled.

[0004] A microfluidic device based on a syringe pump (CN112916063A) includes an input device, an output device, a microfluidic control device, and a cell co-culture device. The input device includes an input syringe and the output device includes an output syringe. The microfluidic control device includes a movable screw. The cell co-culture device includes a box body. The box body contains a non-experimental culture dish, an inflow culture dish, and an outflow culture dish. The inflow culture dish is connected to the first syringe by an inflow capillary, and the outflow culture dish is connected to the second syringe by an outflow capillary. The inflow culture dish and the outflow culture dish are arranged diagonally and a buffer zone is enclosed between the two adjacent non-experimental culture dishes. The device can be used for simultaneous culture experiments of multiple cells. Although this technical solution realizes the integration of injection and aspiration on the micropump, there are still problems. First, the micropump operates in a single stroke, which limits the microfluidic time. Second, the working solution is not easy to reuse. Third, the output flow rate cannot be quantitatively controlled. Summary of the Invention

[0005] To overcome the shortcomings of the aforementioned technologies, the present invention provides a chip-driven, self-circulating micropump structure. This structure controls two syringes to perform injection and aspiration operations, respectively, with the injection and aspiration volumes always being equal. The solution injected by each syringe travels through an injection circuit to a reservoir assembly and microfluidic chip, where it is then recovered by an aspiration circuit to the other syringe. The two syringes alternately perform injection and aspiration, achieving long-term self-circulation.

[0006] The present invention is achieved through at least one of the following technical solutions.

[0007] A self-circulating micropump structure for chip-driven operation includes an injection and aspiration assembly, a piping assembly, a liquid storage assembly, and a microfluidic chip. The injection and aspiration assembly is connected to the liquid storage assembly and the microfluidic chip via the piping assembly to form a circulation loop. Furthermore, the injection and aspiration assembly includes a linear motor module, a first support plate, two limit switches, a second support plate, two syringes, a syringe clamp, and a sliding plate.

[0008] The two syringes are respectively installed on the top surfaces of the second support plate and the first support plate through syringe clamps, and the two syringe push rods are connected to the sliding plate; the two limit switches are respectively connected to the linear motor module to limit the travel range of the sliding plate, and the linear motor drives the sliding plate to move back and forth, thereby driving the two syringes to synchronously complete the injection and aspiration operations.

[0009] Furthermore, the two syringes are of the same size and model. The first support plate and the second support plate are both H-shaped plates with a height difference of 10 to 50 mm.

[0010] Furthermore, the pipeline assembly includes a syringe diverter assembly, an injection pipeline assembly, and a suction pipeline assembly; the syringe diverter assembly includes a first diverter Y-shaped valve and a second diverter Y-shaped valve, and the first diverter Y-shaped valve and the second diverter Y-shaped valve are respectively connected to the two syringes through a hose;

[0011] The liquid injection pipeline assembly includes a first positive one-way valve, a second positive one-way valve, a first converging Y-shaped valve, a second converging Y-shaped valve, a flow stabilizer and a liquid injection pipeline main circuit;

[0012] The liquid suction pipeline assembly includes a first reverse one-way valve, a second reverse one-way valve, and a recovery pipe main;

[0013] The first forward check valve and the second reverse check valve are each connected to the second diverter Y-shaped valve via a flexible hose. The second forward check valve and the first reverse check valve are each connected to the first diverter Y-shaped valve via a flexible hose. The dual-channel end of the first converging Y-shaped valve is connected to the first and second forward check valves via flexible hoses. The single-channel end of the first converging Y-shaped valve is connected to the inlet of the flow stabilizer via a flexible hose, and the outlet of the flow stabilizer is connected to the main injection pipe. The dual-channel end of the second converging Y-shaped valve is connected to the first and second reverse check valves via flexible hoses, and the single-channel end of the second converging Y-shaped valve is connected to the second converging Y-shaped valve.

[0014] Furthermore, during the operation of the pipeline assembly: in the forward stroke, the positive one-way valve of the injection circuit is turned on, and the negative one-way valve of the suction circuit is turned on; in the reverse stroke, the positive one-way valve of the injection circuit is turned on, and the negative one-way valve of the suction circuit is turned on. The flow stabilizer connected to the main line of the injection pipe can effectively offset the pulsation of the output flow of the injection and suction assembly, and play an obvious buffering role when the flow changes suddenly.

[0015] Furthermore, in the pipeline assembly, for the self-circulating forward stroke, the syringe on one side injects liquid and the syringe on the other side aspirates liquid. The fluid in the injection circuit passes through the diverter Y-shaped valve, the forward one-way valve, the converging Y-shaped valve and the flow stabilizer in sequence to reach the injection pipe main line, and then connects to the microfluidic assembly to complete the micro-operation. After the micro-operation is completed, the recovered liquid passes through the recovery pipe main line, the converging Y-shaped valve, the reverse one-way valve and the diverter Y-shaped valve in sequence to return to the syringe on the other side.

[0016] For the self-circulating reverse stroke, the syringe on one side injects liquid and the syringe on the other side aspirates liquid. The fluid in the injection circuit passes through the diversion Y-shaped valve, the positive one-way valve, the converging Y-shaped valve and the flow stabilizer in sequence to reach the injection pipe main line, and connects to the microfluidic component to complete the micro-operation; after the micro-operation is completed, the recovered liquid passes through the recovery pipe main line, the converging Y-shaped valve, the reverse one-way valve and the diversion Y-shaped valve in sequence to return to the syringe on the other side.

[0017] Furthermore, the liquid storage assembly includes a liquid storage tray, three fluid injection tubes, three fluid recovery tubes, two chip fixing devices and two chip positioning devices;

[0018] Two chip fixing devices are located in the liquid storage tray, each chip fixing device includes a spring piece, and each chip positioning device includes two positioning bosses; the three fluid injection tubes are 120° to each other and are 5 to 10 mm away from the bottom of the liquid storage tray. Each fluid injection tube is connected to a group of injection tube mains; the fluid recovery tubes are 120° to each other and are fixed to the inner bottom surface of the liquid storage tray by snaps. Each fluid recovery tube is connected to a recovery tube main, and the angle between each fluid injection tube and the adjacent fluid recovery tube is 60°; the three fluid injection tubes and the three fluid recovery tubes are all connected to the micropump through a pipeline assembly; during the circulation process, the working fluid pumped out by the micropump is pumped in by the fluid injection tube and sucked out by the fluid recovery tube back to the micropump.

[0019] Furthermore, the microfluidic chip includes three liquid injection microgrooves, three natural unloading grooves, two positioning grooves, three fluid injection holes and a micro-operation area. The three fluid injection holes are connected to three fluid injection tubes, and the three liquid injection microgrooves are respectively connected to the three fluid injection holes; the micro-operation area naturally flows out from the three natural unloading grooves to the liquid storage tray, and the two positioning grooves cooperate with two chip positioning devices and are clamped by two chip fixing devices.

[0020] Furthermore, the radial distance between the three natural unloading grooves and the fluid recovery tube on each side is greater than 30 mm; the three natural unloading grooves are the outlets of the micro-operation area. After the solution completes the micro-operation in the micro-operation area, it flows out naturally from the three natural unloading grooves to the liquid storage tray.

[0021] A control method for realizing the self-circulating micropump structure for chip driving includes the following steps:

[0022] ①. Microfluidic chip installation: The microfluidic chip is mounted on the fluid reservoir using a chip fixture. The fluid injection tube is connected to the fluid injection hole of the microfluidic chip. The microfluidic chip is adjusted so that the top surface of the chip is level.

[0023] ②. Fluid filling and air evacuation: Fill two syringes with fluid, connect the injection and aspiration components, piping components, reservoir components, and microfluidic chip as a whole, use fluid to evacuate all air from the pipes, and fill the reservoir components with fluid until the liquid level is flush with the top surface of the microfluidic chip to ensure quantitative control of the flow field parameters in the micromanipulation area;

[0024] ③. Start the micropump and enter the self-circulation working state. The self-circulation working process is as follows: first start the micropump, the stepper motor drives the sliding plate to move to one side, the syringe on one side is emptied, and the syringe on the other side absorbs the fluid to the full liquid level, and then starts the forward stroke, the stepper motor drives the sliding plate to move to the right, driving the syringe on one side to inject liquid, and the syringe on the other side to absorb liquid. The fluid passes through the injection circuit, the liquid storage component and the microfluidic chip, and the liquid absorption circuit in turn, and is recovered by the syringe on one side. This process continues until the sliding plate contacts the right limit switch. When the limit switch on the other side is triggered, the self-circulation switches to the reverse stroke, and the sliding plate moves forward, driving the syringe on one side to inject liquid, and the syringe on the other side to absorb liquid. The fluid passes through the injection circuit, the liquid storage component and the microfluidic chip, and the liquid absorption circuit in turn, and is recovered by the syringe on the other side until the sliding plate triggers the left limit switch. The above cycle process is repeated.

[0025] Compared with the existing technology, the beneficial effects of the present invention are:

[0026] (1) Self-circulation function. The chip can fully utilize the working fluid for self-circulation, which can effectively extend the time of micro-operation. By rationally arranging the positions of the injection and pipette tubes, the stability of the flow field within the chip is guaranteed, providing a guarantee for the long-term capture and movement of cells.

[0027] (2) Smooth operation. The impact of the motor's acceleration, deceleration, and direction conversion on the flow field during operation can be ignored. For micro-operation control such as cell capture and movement, it can provide an effective and stable control solution.

[0028] (3) The overall structure is simple, and the connection method is mostly hand-tightened screws and nuts, which is easy to disassemble and assemble. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the pipeline connection of the present invention;

[0030] Figure 2 This is an axonometric view of the overall structure of the liquid injection and pipetting assembly of the present invention;

[0031] Figure 3 is an axonometric view of the liquid storage assembly of the present invention;

[0032] Figure 4 is an axonometric perspective view of the microfluidic chip of the present invention;

[0033] In the figure: 1-liquid injection and aspiration component, 2-pipeline component, 3-liquid storage component, 4-microfluidic chip. 101- linear motor module, 102- first support plate, 103- limit switch, 104- second support plate, 105- syringe, 106- syringe clamp, 107- sliding plate, 201- first diversion Y-shaped valve, 202- second diversion Y-shaped valve, 211- first positive check valve, 212- second positive check valve; 221- first negative check valve, 222- second negative check valve, 213- first confluence Y-shaped valve, 223- second confluence Y-shaped valve, 224- main recovery pipe, 301- liquid storage tray, 302- fluid injection pipe, 303- fluid recovery pipe, 304- chip fixing device, 305- chip positioning device; 401- liquid injection micro groove, 402- natural unloading groove, 403- positioning groove, 404- fluid injection hole, 405- micro operation area. DETAILED DESCRIPTION

[0034] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] like Figures 1 to 4 As shown, a self-circulating micropump structure for chip driving includes a liquid injection and liquid aspiration component 1, a pipeline component 2, a liquid storage component 3, and a microfluidic chip 4. The liquid injection and liquid aspiration component 1 is connected to the liquid storage component 3 and the microfluidic chip 4 through the pipeline component 2 to form a circulation loop.

[0036] like Figure 2 As shown, the injection and aspiration assembly 1 comprises a linear motor module 101, a first support plate 102, two limit switches 103 mounted on the bottom plate of the linear motor module 101, a second support plate 104, two syringes 105, a syringe clamp 106, a sliding plate 107, and their connecting components. The syringe clamp 106 mounts the two syringes 105 on the top surfaces of the second support plate 104 and the first support plate 102, respectively. The push rods of the two syringes 105 are connected to the sliding plate 107. The two limit switches 103 are connected to the linear motor module 101. The linear motor drives the sliding plate 107 to reciprocate, thereby driving the two syringes 105 to complete the injection and aspiration operations synchronously, ensuring that the flow rates of the injected and aspirated fluids are always equal. The operating range of the sliding plate 107 is limited to the range determined by the two limit switches 103. The installation position of the two limit switches 103 is determined based on the principle of fully utilizing the travel of the sliding plate 107 while ensuring that the two syringes 105 do not overtravel during operation.

[0037] The orientation settings for the specific embodiment are as follows: With the injection and pipetting assembly 1 positioned horizontally, the side of the second support plate 104 is defined as the left side, the side of the first support plate 102 is defined as the right side, and the corresponding two syringes 105 are defined as the left syringe 105 and the right syringe 105. In the self-circulating forward stroke, the linear motor module 101 drives the sliding plate 107 to move from left to right.

[0038] The two syringes 105 are syringes of the same model and size. The first support plate 102 and the second support plate 104 are respectively a short H-shaped plate and a long H-shaped plate.

[0039] The height difference between the top surfaces of the second support plate 104 and the first support plate 102 is about 10 to 50 mm, which can avoid interference between the two syringes 106 when installed on the sliding plate 107 .

[0040] As a preferred embodiment of the present invention, Figure 1 As shown, the pipeline assembly 2 includes a syringe diversion assembly, an injection pipeline assembly and a suction pipeline assembly.

[0041] The syringe diversion assembly includes a first diversion Y-shaped valve 201 and a second diversion Y-shaped valve 202. The two diversion Y-shaped valves (201, 202) are connected to the two syringes 105 respectively through hoses. The injection and recovery of the fluid are completed through the two diversion Y-shaped valves (201, 202).

[0042] The liquid injection pipeline assembly comprises two positive one-way valves (211, 212), two converging Y-shaped valves (213, 223), a flow stabilizer 214 and a liquid injection pipeline main line 215.

[0043] The liquid suction pipeline assembly comprises two reverse-connection one-way valves (221, 222), the two converging Y-shaped valves (213, 223) and a recovery pipe main line 224.

[0044] The first forward check valve 211 and the second reverse check valve 222 are each connected to the second diverter Y-shaped valve 202 via a flexible hose. The second forward check valve 212 and the first reverse check valve 221 are each connected to the first diverter Y-shaped valve 201 via a flexible hose. The dual-channel end of the first converging Y-shaped valve 213 is connected to the first forward check valve 211 and the second forward check valve 212 via a flexible hose. The single-channel end of the first converging Y-shaped valve 213 is connected to the inlet of the flow stabilizer 214 via a flexible hose. The outlet of the flow stabilizer 214 is connected to the main injection pipe 215. The dual-channel end of the second converging Y-shaped valve 223 is connected to the first reverse check valve 221 and the second reverse check valve 222 via a flexible hose. The single-channel end of the second converging Y-shaped valve 223 is connected to the second converging Y-shaped valve 223.

[0045] In the forward stroke, the first positive one-way valve 211 of the injection circuit is turned on, and the first negative one-way valve 221 of the suction circuit is turned on; in the reverse stroke, the second positive one-way valve 212 of the injection circuit is turned on, and the second negative one-way valve 222 of the suction circuit is turned on. The flow stabilizer 214 connected to the injection pipe main line 215 can effectively offset the pulsation of the output flow of the injection and suction assembly 1, and play an obvious buffering role when the flow suddenly changes. For the self-circulating forward stroke, the right syringe 105 injects liquid and the left syringe 105 aspirates liquid. The fluid in the injection circuit passes through the second diversion Y-shaped valve 202, the first positive one-way valve 211, the first converging Y-shaped valve 213 and the flow stabilizer 214 in sequence, and reaches the injection pipe main line 215, which is used to connect the microfluidic assembly to complete micro-operation. After the micro-operation is completed, the recovery liquid returns to the left syringe 105 through the recovery pipe main 224, the second converging Y-shaped valve 223, the first reverse one-way valve 221 and the first diverting Y-shaped valve 201 in sequence.

[0046] During the reverse stroke of the self-circulation, the left syringe 105 injects liquid, while the right syringe 105 aspirates liquid. The injection circuit fluid sequentially passes through the first diverter Y-shaped valve 201, the second forward check valve 212, the first converging Y-shaped valve 213, and the flow stabilizer 214, reaching the injection pipe main line 215 for connecting to the microfluidic component to complete the micro-operation. After the micro-operation is completed, the recovered liquid returns to the right syringe 105 through the recovery pipe main line 224, the second converging Y-shaped valve 223, the second reverse check valve 222, and the second diverter Y-shaped valve 202.

[0047] As another preferred embodiment of the present invention, Figure 3As shown, the liquid reservoir assembly 3 includes a liquid reservoir tray 301, three fluid injection tubes 302, three fluid recovery tubes 303, two chip fixtures 304, and two chip positioning devices 305. The two chip fixtures 304 consist of two springs fixed to symmetrical positions on either side of the liquid reservoir tray 301 via screws, with the mounting holes of the two springs 70 mm apart. The chip positioning devices 305 consist of two positioning bosses 20 mm apart. The chip fixtures 304 and chip positioning devices 305 respectively secure and position the microfluidic chip 4 within the liquid reservoir tray 301.

[0048] The three fluid injection pipes 302 are 120 degrees apart from each other and are 5 to 10 mm away from the bottom surface of the liquid storage tray 301. Each fluid injection pipe 302 is connected to a group of liquid injection pipe main lines 215, and a total of three groups of liquid injection pipe main lines 215 are connected.

[0049] The three fluid recovery pipes 303 are 120 degrees apart from each other, and each fluid recovery pipe 303 is connected to a recovery pipe main line 224, for a total of three groups of recovery pipe main lines 224. The angle between each fluid injection pipe 302 and its adjacent fluid recovery pipe 303 is 60 degrees.

[0050] The three fluid recovery pipes 303 are fixed to the inner bottom surface of the liquid storage tray 301 by buckles, and the pipe openings are always below the working liquid level.

[0051] The three fluid injection pipes 302 and the three fluid recovery pipes 303 are all connected to the micro pump through the pipeline assembly 2. During the circulation process, the working fluid pumped out by the micro pump is pumped into the three fluid injection pipes 302 and sucked out by the fluid recovery pipe 303 and returned to the micro pump.

[0052] Each fluid injection tube 302 is connected to a set of liquid injection and liquid suction components 1 through a set of pipeline components 2, that is, a set of liquid storage components 3 is connected to three sets of pipeline components 2 and three sets of liquid injection and liquid suction components 1. Each set of liquid injection and liquid suction components 1 and pipeline components 2 work independently without interfering with each other.

[0053] Without loss of generality, the inner diameters of the fluid injection tube 302 and the fluid recovery tube 303 are kept consistent. When the inner diameter range is 0.5 to 2.5 mm, the stability of the flow field in the chip can be guaranteed.

[0054] As a preferred embodiment of the present invention, Figure 4 As shown, the microfluidic chip 4 includes three liquid injection microgrooves 401, three natural unloading grooves 402, two positioning grooves 403, three fluid injection holes 404, and a micro-manipulation area 405. The three fluid injection holes 404 are connected to the three fluid injection tubes 302, and the three liquid injection microgrooves 401 are connected to the three fluid injection holes 404 through the hollow structure inside the chip.

[0055] The micro-operation area 405 is an equilateral triangle area with a side length of 0.5 to 4 mm, connecting the outlet endpoints of the three liquid injection micro-grooves 401.

[0056] The solutions flowing out of the three liquid injection microgrooves 401 converge in the micro-operation area 405 , and the fluids couple with each other to form a vortex field, thereby completing microfluidic operations such as capturing, moving, and adjusting the posture of the particles.

[0057] The radial distance between the three natural unloading grooves 402 and the fluid recovery pipe 303 on each side is greater than 30 mm. The three natural unloading grooves 402 serve as the outlets of the micro-manipulation area 405. After the solution completes the micro-manipulation in the micro-manipulation area 405, it naturally flows out of the three natural unloading grooves 402 to the liquid storage tray 301.

[0058] The two positioning grooves 403 cooperate with the two chip positioning devices 305 of the liquid reservoir assembly 3 to position the microfluidic chip 4 so that the micro-operation area 405 of the microfluidic chip 4 is located in the center of the liquid reservoir tray 3. The microfluidic chip 4 is fixed to the liquid reservoir tray 3 through the clamping force of the springs of the two chip fixing devices 304.

[0059] A self-circulating control method for chip driving, comprising the following steps:

[0060] 1. Installation of the microfluidic chip 4: The microfluidic chip 4 is mounted on the liquid reservoir 301 via the chip fixture 304. The fluid injection tube 302 is connected to the microfluidic chip fluid injection port 404. Adjust the microfluidic chip 4 to ensure that the top surface of the chip is level.

[0061] 2. Fluid filling and air exhaust: Fill the two syringes 105 with fluid, connect the liquid injection and aspiration assembly 1, the pipeline assembly 2, and the liquid storage assembly 3 as a whole, and use the fluid to exhaust the air in all pipelines.

[0062] According to Q=SV, that is, under the condition of a constant flow rate, the flow velocity V is related to the wetted area S of the flow outlet. When the fluid is poured into the liquid storage component 3, it is ensured that the fluid is poured until the liquid surface is flush with the top surface of the microfluidic chip 4 to ensure that the wetted area S of the flow outlet is a constant value (that is, the hydraulic radius is constant), so that the relationship between the flow velocity output V and the flow rate Q can be quantitatively determined, ensuring that the flow field parameters in the micro-operation area 405 can be quantitatively controlled.

[0063] 3. Start the micropump and enter the self-circulating state. The self-circulating operation process is as follows: First, the micropump is started, and the stepper motor drives the sliding plate 107 to the left. The left syringe 105 empties, and the right syringe 105 draws fluid to the full level. Then, the forward stroke is initiated, and the stepper motor drives the sliding plate 107 to the right, driving the right syringe 105 to inject fluid and the left syringe 105 to aspirate fluid. The fluid passes through the injection circuit, the liquid reservoir assembly 3, the microfluidic chip 4, the aspiration circuit, and is then aspirated and recovered by the left syringe 105. This process continues until the sliding plate 107 contacts the right limit switch 103. When the right limit switch 103 is triggered, the self-circulating state switches to the reverse stroke, and the sliding plate 107 moves forward, driving the left syringe 105 to inject fluid and the right syringe 105 to aspirate fluid. The fluid passes through the injection circuit, the liquid reservoir assembly 3, the microfluidic chip 4, the aspiration circuit, and is finally aspirated and recovered by the right syringe 105. This cycle repeats until the sliding plate 107 triggers the left limit switch 103. Theoretically, there is no limit on working hours, but the actual working hours are set and changed according to the experimental time.

[0064] Without loss of generality, in step 3, the output flow of the liquid injection microgrooves 401 and the recovery flow of the fluid recovery pipe 303 can be adjusted online synchronously by adjusting the moving speed of the stepper motor of the linear motor module 101 .

[0065] The present invention is not limited to the specific embodiments described above. It is obvious to those skilled in the art that modifications or improvements may be made thereto based on the present invention. Therefore, any design that adopts the design structure and concept of the present invention and makes some simple changes or modifications falls within the scope of protection claimed by the present invention.

Claims

1. A self-circulating micropump structure for chip driving, characterized by: The invention comprises a liquid injection and liquid aspiration component (1), a pipeline component (2), a liquid storage component (3) and a microfluidic chip (4); the liquid injection and liquid aspiration component (1) is connected to the liquid storage component (3) and the microfluidic chip (4) through the pipeline component (2), thereby forming a circulation loop; The pipeline assembly (2) includes a syringe diverter assembly, an injection pipeline assembly, and a suction pipeline assembly; the syringe diverter assembly includes a first diverter Y-shaped valve (201) and a second diverter Y-shaped valve (202); the first diverter Y-shaped valve (201) and the second diverter Y-shaped valve (202) are respectively connected to the two syringes (105) through flexible pipes; The liquid injection pipeline assembly comprises a first positive one-way valve (211), a second positive one-way valve (212), a first converging Y-shaped valve (213), a second converging Y-shaped valve (223), a flow stabilizer (214) and a liquid injection pipeline main line (215); The liquid suction pipeline assembly comprises a first reverse one-way valve (221), a second reverse one-way valve (222), and a recovery pipe main line (224); The first positive one-way valve (211) and the second negative one-way valve (222) are respectively connected to the second diverter Y-shaped valve (202) through a hose; the second positive one-way valve (212) and the first negative one-way valve (221) are respectively connected to the first diverter Y-shaped valve (201) through a hose; the dual-channel ends of the first converging Y-shaped valve (213) are respectively connected to the first positive one-way valve (211) and the second positive one-way valve (212) through a hose. The single-channel end of a converging Y-shaped valve (213) is connected to the inlet end of a flow stabilizer (214) via a flexible pipe, and the outlet end of the flow stabilizer (214) is connected to the injection pipe main line (215); the dual-channel end of a second converging Y-shaped valve (223) is connected to the first reverse one-way valve (221) and the second reverse one-way valve (222) via flexible pipes, respectively, and the single-channel end of the second converging Y-shaped valve (223) is connected to the second converging Y-shaped valve (223); The liquid storage assembly (3) includes a liquid storage tray (301), three fluid injection pipes (302), and three fluid recovery pipes (303). The three fluid injection pipes (302) are arranged at 120 degrees to each other and are 5 to 10 mm away from the bottom surface of the liquid storage tray (301). Each fluid injection pipe (302) is connected to a group of liquid injection pipe main lines (215); each fluid recovery pipe (303) is connected to a recovery pipe main line (224); the three fluid injection pipes (302) and the three fluid recovery pipes (303) are all connected to the micro pump through the pipeline assembly (2); during the circulation process, the working fluid pumped out by the micro pump is pumped in by the fluid injection pipe (302) and sucked out by the fluid recovery pipe (303) and returned to the micro pump; The microfluidic chip (4) comprises three liquid injection microgrooves (401), three natural unloading grooves (402), two positioning grooves (403), three fluid injection holes (404) and a micro-operation area (405). The three fluid injection holes (404) are connected to three fluid injection tubes (302), and the three liquid injection microgrooves (401) are respectively connected to the three fluid injection holes (404); the micro-operation area (405) naturally flows out from the three natural unloading grooves (402) to the liquid storage tray (301), and the two positioning grooves (403) cooperate with two chip positioning devices (305) and are clamped by two chip fixing devices (304).

2. A self-circulating micropump structure for chip driving according to claim 1, characterized in that: The liquid injection and aspiration assembly (1) comprises a linear motor module (101), a first support plate (102), two limit switches (103), a second support plate (104), two syringes (105), a syringe clamp (106), and a sliding plate (107); The two syringes (105) are respectively mounted on the top surfaces of the second support plate (104) and the first support plate (102) through syringe clamps (106), and the push rods of the two syringes (105) are connected to the sliding plate (107); the two limit switches (103) are respectively connected to the linear motor module (101) to limit the travel range of the sliding plate (107), and the linear motor drives the sliding plate (107) to move back and forth, thereby driving the two syringes (105) to synchronously complete the injection and aspiration operations.

3. A self-circulating micropump structure for chip driving according to claim 2, characterized in that: The two syringes (105) are of completely identical model and size; the first support plate (102) and the second support plate (104) are both H-shaped plates, with a height difference of 10 to 50 mm.

4. The self-circulating micropump structure for chip driving according to claim 1, characterized in that: The liquid storage assembly (3) further includes two chip fixing devices (304) and two chip positioning devices (305); Two chip fixing devices (304) are located in the liquid storage tray (301), each chip fixing device (304) includes a spring piece, and each chip positioning device (305) includes two positioning bosses; the fluid recovery tubes (303) are 120 degrees apart and are fixed to the inner bottom surface of the liquid storage tray (301) by snap fasteners, and the angle between each fluid injection tube (302) and the adjacent fluid recovery tube (303) is 60 degrees.

5. The self-circulating micropump structure for chip driving according to claim 1, characterized in that: The radial distance between the three natural unloading grooves (402) and the fluid recovery tube (303) on each side is greater than 30 mm; the three natural unloading grooves (402) are the outlets of the micro-operation area (405), and after the solution completes the micro-operation in the micro-operation area (405), it naturally flows out from the three natural unloading grooves (402) to the liquid storage tray (301).

6. A control method for implementing the chip-driven self-circulating micropump structure according to claim 2, characterized in that: The following steps are involved: ①. Installation of the microfluidic chip (4): The microfluidic chip (4) is installed on the liquid storage tray (301) through the chip fixing device (304), the fluid injection tube (302) is connected to the fluid injection hole (404) of the microfluidic chip, and the microfluidic chip (4) is adjusted so that the top surface of the chip is horizontal; ②. Fluid filling and air exhaust: two syringes (105) are filled with fluid, and the liquid injection and aspiration assembly (1), the pipeline assembly (2), the liquid storage assembly (3) and the microfluidic chip (4) are connected as a whole. The air in all the pipelines is exhausted by the fluid, and the fluid is perfused into the liquid storage assembly (3) until the liquid level is flush with the top surface of the microfluidic chip (4) to ensure that the flow field parameters in the micro-operation area (405) can be quantitatively controlled; ③. Start the micro pump and enter the self-circulation working state. The self-circulation working process is as follows: first start the micro pump, the stepper motor drives the sliding plate (107) to move to one side, the syringe (105) on one side is emptied, and the syringe (105) on the other side absorbs the fluid to the full liquid level, and then starts the forward stroke, the stepper motor drives the sliding plate (107) to move to the right, driving the syringe (105) on one side to inject liquid, and the syringe (105) on the other side to absorb liquid. The fluid passes through the injection circuit, the liquid storage component (3) and the microfluidic chip (4), the aspiration circuit, and passes through the syringe (105) on one side. The liquid is sucked and recovered. This process continues until the sliding plate (107) contacts the right limit switch (103). When the limit switch (103) on the other side is triggered, the self-circulation switches to the reverse stroke, and the sliding plate (107) moves forward, driving the syringe (105) on one side to inject liquid and the syringe (105) on the other side to suck liquid. The fluid passes through the injection circuit, the liquid storage component (3) and the microfluidic chip (4), the suction circuit, and is sucked and recovered by the syringe (105) on the other side until the sliding plate (107) triggers the limit switch (103) on the left side. The above-mentioned cycle process is repeated.

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