High-pressure microfluidic air pressure pump flow fine regulation device and multi-machine collaborative control system

Abstract

The application discloses a high-pressure micro-fluid gas pressure pump flow fine regulation device and a multi-machine cooperative control system. The device comprises a liquid storage pool, which is internally connected with liquid and gas phases; the liquid and gas phases are respectively connected with a liquid guide pipeline of a micro-fluid chip and a gas guide pipeline of a gas pressure pump; a first adjustable flow valve and a second adjustable flow valve are connected in series, and the liquid storage pool is arranged between the two valves; a first switch valve is arranged in parallel at two ends of the first adjustable flow valve; a second switch valve is connected in series with the second adjustable flow valve, and an outlet of the second switch valve is connected with the atmosphere. Compared with the prior art, the device has the beneficial effects that: the first switch valve and the second switch valve are used to realize the switching of a common control mode and a flow fine control mode, and the flow control precision of a large-range proportional valve of the high-pressure micro-fluid gas pressure pump under a low-pressure small-flow condition is improved; the device has few parts and low cost; the multi-machine parallel mode is convenient for users to control multiple channels; and the device has good expansibility, flexibility and reliability.

Description

Technical Field

[0001] This invention belongs to the field of microfluidic control technology, specifically relating to a high-pressure microfluidic pneumatic pump flow fine control device and a multi-machine collaborative control system. Background Technology

[0002] Microfluidic driven sample introduction devices are widely used in biological and chemical experiments. According to different types of pumps, they can be roughly divided into peristaltic pumps, diaphragm pumps, syringe pumps, and in some cases, pneumatic pumps are used. Compared with other methods, pneumatic pumps have better stability, with very slight or no pressure and flow pulsation, and better dynamic response capabilities.

[0003] Currently, the mainstream pneumatic pumps on the market are mainly divided into piezoelectric pumps with control valve groups and compressed air sources with proportional valves in terms of gas pressure regulation and control.

[0004] Piezoelectric pumps generate high-amplitude, high-frequency acoustic standing waves within a specially designed acoustic cavity. These waves are then rectified by an ultra-fast valve to create the required airflow. A typical example is the disc pump from TTP Ventus in the UK. Currently, these piezoelectric pumps are limited by their working principle to pump or draw in gas in only one direction. This means that when a positive pressure pump wants to reduce pressure (or a negative pressure pump wants to increase pressure), it generally needs to be equipped with a pipeline switching valve or continuously connected to a vent with a suitable orifice. However, equipping an additional valve assembly complicates the system, and continuously connecting to a vent reduces pump efficiency and response speed. Furthermore, if the orifice size cannot be adjusted, the actual dynamic response of gas pressure and flow control will differ significantly for liquid reservoirs of different volumes.

[0005] Traditional compressed air source paired with a proportional valve solution offers greater control convenience. Because the proportional valve has a built-in vent, it can flexibly increase or decrease the outlet pressure within the adjustment range according to analog electrical signal commands. Therefore, controlling fluid flow rate by increasing or decreasing air pressure is more flexible. The disadvantages of proportional valves are that they require an air source, such as an air compressor, diaphragm pump, or compressed air cylinder. Some proportional valves consume a large amount of air. Furthermore, large-range proportional valves have poor control accuracy, especially when operating at low output air pressure, and may even have a control dead zone. Therefore, it is difficult to simultaneously achieve both large-range control and precise control of low flow rates under low air pressure. Consequently, some devices may install separate high-pressure and low-pressure control channels, increasing hardware costs to meet the needs of different application scenarios. Summary of the Invention

[0006] Details of one or more embodiments of the present invention are set forth in the following drawings and description to make other features, objects and advantages of the present application more readily apparent.

[0007] This invention provides a high-pressure microfluidic pneumatic pump flow fine control device and a multi-machine collaborative control system. By opening and closing the first and second switching valves, the device can switch between ordinary control mode and flow fine control mode, allowing customers to choose the appropriate mode for flexible operation according to their needs.

[0008] This invention discloses a device for finely controlling the flow rate of a high-pressure microfluidic pneumatic pump, comprising:

[0009] The liquid storage tank is a closed structure, with a liquid phase and a gas phase connected inside; the liquid phase and the gas phase are respectively connected to a liquid guiding pipe for connecting to the microfluidic chip and a gas guiding pipe for connecting to the pneumatic pump.

[0010] The first adjustable flow valve and the second adjustable flow valve are connected in series;

[0011] The liquid storage tank is connected between the first adjustable flow valve and the second adjustable flow valve, and the liquid storage tank is connected to the air outlet of the first adjustable flow valve and the air inlet of the second adjustable flow valve through the air guide pipe.

[0012] The first switching valve is connected in parallel at both ends of the first adjustable flow valve;

[0013] The second switching valve is connected in series with the second adjustable flow valve, and the outlet of the second switching valve is open to the atmosphere;

[0014] With the first switch valve open and the second switch valve closed, the output gas pressure of the gas pump directly acts on the gas phase to form the pressurized injection gas pressure for the microfluidic chip.

[0015] With the first switch valve closed and the second switch valve open, the output gas pressure adjusted by the proportional valve in the gas pump is divided by the joint control of the first and second adjustable flow valves. The gas pressure pulsation in the output gas pressure is attenuated by the first adjustable flow valve and then canceled out by gas compression with the gas phase in the liquid storage tank, so as to form a constant injection gas pressure for the microfluidic chip.

[0016] In some embodiments, both the first switching valve and the second switching valve are solenoid valves.

[0017] In some embodiments, the first switching valve is a normally open two-position two-way solenoid valve; the second switching valve is a normally closed two-position two-way solenoid valve.

[0018] In some implementations, it also includes:

[0019] A liquid flow control valve is installed on the liquid delivery pipeline.

[0020] In some implementations, it also includes:

[0021] A pressure gauge is installed on the air guide line between the first adjustable flow valve and the second adjustable flow valve, so as to adjust the second adjustable flow valve by means of the reading of the pressure gauge;

[0022] A gas flow meter is installed at the inlet of the first adjustable flow valve to adjust the adjustable flow valve by means of the reading of the gas flow meter.

[0023] This invention discloses a multi-machine collaborative high-pressure microfluidic pneumatic pump control system, comprising: several high-pressure microfluidic pneumatic pump flow fine control devices and a host computer, which are connected in parallel as described in any of the above embodiments;

[0024] The host computer is connected to the air pump control unit external to each of the high-pressure microfluidic air pump flow fine control devices via a CAN BUS twisted pair cable, and the two achieve bidirectional communication and control through a compatible application layer protocol.

[0025] The host computer is connected to the control unit of each air pump; the host computer sends commands to the control unit of the air pump to control the opening and closing of the first and second switching valves and to adjust the first and second adjustable flow valves, so as to realize the closing of the first switching valve and the opening of the second switching valve in the fine control mode or the opening of the first switching valve and the closing of the second switching valve in the normal control mode.

[0026] In some implementations, it also includes:

[0027] In the rapid pressure scan mode with the first switch valve open and the second switch valve closed, the control unit of the pneumatic pump no longer reads data or communicates. The instructions from the host computer are directly converted into analog signals from the proportional valve in the pneumatic pump.

[0028] This invention also discloses a microfluidic chip sample introduction control system, comprising:

[0029] The storage tank is a closed structure, with a liquid phase and a gas phase connected inside; the liquid phase and the gas phase are respectively connected to a liquid guide pipe and a gas guide pipe.

[0030] The microfluidic chip and the pneumatic pump are respectively connected to the liquid guiding line and the gas guiding line;

[0031] The first adjustable flow valve and the second adjustable flow valve are connected in series;

[0032] The liquid storage tank is connected between the first adjustable flow valve and the second adjustable flow valve, and the liquid storage tank is connected to the air outlet of the first adjustable flow valve and the air inlet of the second adjustable flow valve through the air guide pipe.

[0033] The first switching valve is connected in parallel at both ends of the first adjustable flow valve;

[0034] The second switching valve is connected in series with the second adjustable flow valve, and the outlet of the second switching valve is open to the atmosphere;

[0035] A host computer is connected to the control unit of the pneumatic pump. The host computer sends commands to the control unit of the pneumatic pump to control the opening and closing of the first and second switching valves, and to adjust the first and second adjustable flow valves.

[0036] With the first switch valve open and the second switch valve closed, the output gas pressure of the gas pump directly acts on the gas phase to form the pressurized injection gas pressure for the microfluidic chip.

[0037] With the first switch valve closed and the second switch valve open, the output gas pressure adjusted by the proportional valve in the gas pump is divided by the joint control of the first and second adjustable flow valves. The gas pressure pulsation in the output gas pressure is attenuated by the first adjustable flow valve and then canceled out by gas compression with the gas phase in the liquid storage tank, so as to form a constant injection gas pressure for the microfluidic chip.

[0038] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0039] 1. Unlike other methods that use fluid throttling valves (flow resistance regulators) to increase flow resistance and avoid the poor operating area of ​​proportional valves, this application uses two switching valves and two adjustable flow valves, together with a liquid storage tank to form a T-shaped pressure attenuation network. The liquid storage tank is used as a pulsation damper for the gas path, filtering pressure fluctuations when the proportional valve outputs a small pressure, improving the stability of fluid flow control, and avoiding damage to the sample from the strong shear flow caused by forcibly increasing the flow resistance in the sample liquid flow channel.

[0040] This device features three operating modes: normal, fine, and rapid pressure scanning. Different control strategies and parameters are used, and these modes are controlled by switching between the first and second switching valves. In normal control mode, the first and second adjustable flow valves are inactive, and the pressure in the reservoir is directly controlled by the proportional valve. In fine control mode, both the first and second adjustable flow valves are activated, and the reservoir pressure is determined by the T-type pressure attenuation network, rather than the proportional valve outlet pressure.

[0041] The cover structure of the liquid storage tank has been optimized and a corresponding adapter structure has been added, thereby increasing the applicability of the equipment. The adapter can be used to adapt to liquid storage tank openings of different sizes.

[0042] 4. Compared to piezoelectric pumps, this solution using proportional valves has advantages in overall manufacturing costs and supplier selection, reducing the performance requirements for proportional valves, broadening the selection range, and avoiding the risk of relying on a single source for core components. Because it employs a T-type pressure attenuation network air path designed to address pressure pulsations in the proportional valve, a more economical, slightly lower-performance proportional valve can be installed when requirements are not high, creating a cost-effective product series.

[0043] 5. As long as the user needs, any number of pneumatic pump slave devices or other slave devices with CAN communication ports can be connected within the addressing range supported by the CAN application layer protocol, provided the bus electrical characteristics allow. It offers excellent scalability, facilitating equipment upgrades or user purchases. Connection is simple, requiring only two wires connected in parallel to the CAN twisted-pair bus, offering flexibility and convenience. If any node experiences a communication failure, it will automatically exit communication mode without affecting the operation of other slave devices. The device can also be sold independently for offline use when not connected to a host computer. Attached Figure Description

[0044] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention.

[0045] Figure 1 This is a schematic diagram of the structure of the present invention.

[0046] Figure 2 This is a schematic diagram of the liquid storage tank of the present invention.

[0047] Figure 3 This is a schematic diagram of the communication connection structure of the present invention.

[0048] Figure descriptions: 1.1 Air pump, 1.2 Pressure reducing valve, 1.3 Proportional valve, 1.4 First adjustable flow valve, 1.5 Second adjustable flow valve, 1.6 Second switching valve, 1.7 First switching valve, 1.8 Pressure gauge, 1.9 Liquid storage tank, 1.10 Microfluidic chip, 1.11 Gas flow meter, 1.12 Liquid circuit throttle valve, 1.13 Host computer, 1.14 External equipment, 1.15 CAN BUS twisted pair cable, 2.1 Top cover, 2.2 Cylinder body, 2.3 Liquid inlet, 2.4 Air inlet, 2.5 Adapter, 2.6 First sealing ring, 2.7 Second sealing ring. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described and illustrated below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments provided by this invention without inventive effort are within the scope of protection of this invention.

[0050] Obviously, the accompanying drawings described below are merely some examples or embodiments of the present invention. Those skilled in the art can apply the present invention to other similar scenarios based on these drawings without any inventive effort. Furthermore, it is understood that although the efforts made in this development process may be complex and lengthy, for those skilled in the art related to the content disclosed in this invention, modifications to design, manufacturing, or production based on the technical content disclosed in this invention are merely conventional technical means and should not be construed as insufficient disclosure of the present invention.

[0051] In this invention, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this invention may be combined with other embodiments without conflict.

[0052] This invention discloses a high-pressure microfluidic pneumatic pump flow fine control device, comprising: a liquid storage tank 1.9, a first adjustable flow valve 1.4, a second adjustable flow valve 1.5, a second switching valve 1.6, and a first switching valve 1.7. The liquid storage tank 1.9 is a closed structure, with a liquid phase and a gas phase connected inside. The liquid phase and the gas phase are respectively connected to a liquid guide pipe for connecting to the microfluidic chip 1.10 and a gas guide pipe for connecting to the pneumatic pump. The first adjustable flow valve 1.4 and the second adjustable flow valve 1.5 are connected in series. The liquid storage tank is connected between the first adjustable flow valve 1.4 and the second adjustable flow valve 1.5. The liquid storage tank 1.9 is connected to the outlet of the first adjustable flow valve 1.4 and the inlet of the second adjustable flow valve 1.5 through the gas guide pipe. The first switching valve 1.6 is connected in parallel at both ends of the first adjustable flow valve 1.4. The second switching valve 1.6 is connected in series with the second adjustable flow valve 1.5, and the outlet of the second switching valve 1.6 is open to the atmosphere.

[0053] With the first switch valve open and the second switch valve closed, the output gas pressure of the gas pump directly acts on the gas phase, thereby forming a fast-response pressurized injection gas pressure for microfluidic chips.

[0054] With the first switch valve closed and the second switch valve open, the output gas pressure of the gas pump after being regulated by the proportional valve is quasi-linearly divided by the joint regulation of the first and second adjustable flow valves. The gas pressure pulsation component in the output gas pressure is attenuated by the first adjustable flow valve and absorbed by the gas phase in the reservoir through compression and volume change, so as to form a low-pulsation constant injection gas pressure for microfluidic chips.

[0055] In some embodiments, both the first switching valve and the second switching valve are solenoid valves.

[0056] In some embodiments, the first switching valve is a normally open two-position two-way solenoid valve; the second switching valve is a normally closed two-position two-way solenoid valve.

[0057] In some embodiments, the system further includes: a pressure gauge 1.8, a gas flow meter 1.11, and a liquid flow throttle valve 1.12; the liquid flow throttle valve 1.12 is disposed on the liquid guide line. The pressure gauge 1.8 is disposed on the gas guide line between the first adjustable flow valve 1.4 and the second adjustable flow valve 1.5 to adjust the second adjustable flow valve 1.5 according to the pressure gauge reading; the gas flow meter 1.11 is disposed at the gas inlet of the first adjustable flow valve 1.4 to adjust the first adjustable flow valve according to the gas flow meter reading.

[0058] A multi-machine collaborative high-pressure microfluidic pneumatic pump control system includes: several high-pressure microfluidic pneumatic pump flow fine control devices and a host computer, which are connected in parallel as described in any of the above embodiments.

[0059] The host computer is connected to the air pump control unit external to each of the high-pressure microfluidic air pump flow fine control devices via a CAN BUS twisted pair cable, and the two achieve bidirectional communication and control through a compatible application layer protocol.

[0060] The host computer is also connected to an external protocol device via a CAN BUS twisted pair cable.

[0061] The host computer is connected to the control unit of each air pump; the host computer sends commands to the control unit of the air pump to control the opening and closing of the first and second switching valves and to adjust the first and second adjustable flow valves, so as to realize the closing of the first switching valve and the opening of the second switching valve in the fine control mode or the opening of the first switching valve and the closing of the second switching valve in the normal control mode.

[0062] Specifically, the pneumatic pump includes an air pump 1.1, a pressure reducing valve 1.2, and a proportional valve 1.3, which are connected in series at the air inlet of the first adjustable flow valve 1.4.

[0063] Specifically, the host computer 1.13 and multiple slave devices (control units of the air pump) are connected in parallel via CAN BUS twisted-pair cables in a main-branch configuration. This means that, within the limits of the bus electrical characteristics and the addressing range supported by the CAN application layer protocol, any number of slave devices (control units of the air pump) or other slave devices with CAN communication ports (such as electric pipeline switchers or temperature controllers) can be connected. It offers excellent scalability, facilitating equipment upgrades or user purchases. Connection is simple, requiring only two wires connected in parallel to the CAN twisted-pair bus, offering flexibility and convenience. If any node experiences a communication failure, it automatically exits the communication state without affecting the operation of other slave devices. The device can also be sold separately and used offline when not connected to the host computer.

[0064] Specifically, the liquid storage tank 1.8 includes: a cover 2.1, a cylinder 2.2, a liquid inlet 2.3, a gas inlet 2.4, and an adapter 2.5; the cover 2.1 is located at the upper end of the cylinder 2.2; the adapter 2.5 is located between the cover 2.1 and the cylinder 2.2; the liquid inlet 2.3 and the gas inlet 2.4 are located on the cover 2.1 and the adapter 2.5 and are positioned correspondingly, and the liquid inlet 2.3 and the gas inlet 2.4 are respectively connected to the liquid guiding pipeline and the gas guiding pipeline. By providing corresponding adapters, the adaptability of the equipment is increased. The cover 2.1 and the adapter 2.5 are threadedly connected; the adapter 2.5 and the cylinder 2.2 are threadedly connected. Threaded connections are preferred for easy connection and fixation. Specifically, it also includes: a first sealing ring 2.6 and a second sealing ring 2.7; the first sealing ring 2.6 is disposed between the top cover 2.1 and the adapter 2.5; the second sealing ring 2.7 is disposed between the adapter 2.5 and the cylinder 2.2. Based on the threaded connection, by setting the corresponding sealing ring structure, the sealing effect is ensured by compression.

[0065] The switching of the following modes is achieved by opening and closing the second switching valve 1.6 and the first switching valve 1.7, specifically including:

[0066] 1. Fine Flow Control Mode: When users require flow control accuracy higher than ±0.1 μL / min but do not want to increase the sample liquid flow resistance by adjusting the liquid path throttle valve (as this may create strong shear flow in the sample liquid flow channel and damage the sample), it is necessary to reduce the fluctuation component of the output gas pressure of proportional valve 1.3. At this time, the first switching valve 1.7 is closed and the second switching valve 1.6 is opened. Part of the gas flow output from the outlet of proportional valve 1.3 will flow through the first adjustable flow valve 1.4 and the second adjustable flow valve 1.5, and finally be discharged to the atmosphere through the second adjustable flow valve 1.5. Because of the limitation of the maximum working gas pressure within this equipment, the gas flow within the throttle valve is considered to be isentropic, and there is no supersonic flow. Furthermore, since the two throttle valves are connected in series, the gas flow rate is primarily a function of the pressure difference between the inlet and outlet of each throttle valve. In this gas path, the first adjustable flow valve 1.4 is mainly used to control gas consumption, while the second adjustable flow valve 1.5 is mainly used to provide appropriate back pressure, while also considering auxiliary control of gas consumption. The actual air pressure in the storage tank is determined by this back pressure. By appropriately adjusting the orifices of the two throttle valves, while considering gas consumption, the pressure in the storage tank 1.8 can maintain an approximately linear relationship with the outlet pressure of the proportional valve 1.3, less than 1. This achieves a pressure reduction effect on the outlet pressure of the proportional valve, avoiding the dead zone or poor linearity zone that exists in large-range proportional valves when outputting small pressures. The enclosed space inside the liquid storage tank contains a certain volume of air. Due to the compressibility of gas, the pressure pulsation component of the output gas of the proportional valve 1.3 is attenuated by the first adjustable flow valve 1.4 and then absorbed by the air in the liquid storage tank by changing its volume. In effect, the liquid storage tank containing air inside becomes a pulsation damper for the gas path. When the proportional valve outputs a small pressure, it further filters the pressure fluctuations. Finally, the pressure fluctuations acting on the surface of the driven liquid are much smaller than the pressure pulsation output by the proportional valve, thus stabilizing the liquid flow and improving the control accuracy.

[0067] 2. In normal control mode, when the user needs to use higher air pressure to drive liquid to complete tasks such as microchannel wetting, impurity flushing, bubble dissolution, and blockage clearing, the higher air pressure output from the proportional valve needs to be applied directly to the liquid storage tank without attenuation. In this case, the first switching valve 1.7 is opened and the second switching valve 1.6 is closed. The opening of the first switching valve 1.7 short-circuits the first adjustable flow valve 1.4, rendering it ineffective. Similarly, the closing of the second switching valve 1.6 also renders it ineffective. The air pressure output from the proportional valve 1.3 is applied directly to the liquid storage tank 1.8 without attenuation, driving the liquid into the microfluidic chip 1.10. In this situation, the system has a faster dynamic response, and a well-tuned ordinary PID controller can generally achieve good control results.

[0068] When switching between normal control mode and fine flow control mode, users do not need to plug or unplug pipelines; the gas path is switched directly by the internal solenoid valve, achieving an integrated high and low pressure gas path design. Regardless of the control mode, flow-pressure closed-loop feedback control can be achieved, stabilizing the final flow rate at the user's desired value. In fine control mode, because the pressure pulsation is significantly smaller than in normal control mode and the adverse operating range of proportional valves is avoided, it has higher control accuracy for small flow rates without significantly increasing flow resistance and driving pressure.

[0069] 3. Rapid Pressure Scanning Mode: When the user needs the proportional valve to rapidly and dynamically adjust the output pressure according to the host computer's instructions, the first switch valve 1.7 is opened and the second switch valve 1.6 is closed. The rapidly changing gas pressure output by the proportional valve 1.3 is directly applied to the storage tank to drive the sample liquid without attenuation. Unlike the ordinary control mode, the control unit of the gas pump no longer communicates with the digital flow meter, no longer refreshes the display content, and no longer reads real-time pressure data through the pressure gauge. All resources are concentrated on quickly converting the host computer instructions into analog signals input to the proportional valve, which improves the processing speed of the host computer instructions per unit time. Therefore, it improves the dynamic response speed and control accuracy of the system to continuously changing pressure, resulting in a smoother and more continuous change in actual gas pressure and liquid flow.

[0070] During the production and debugging of this product, first connect the entire gas circuit, connect a 50mL storage tank to the end of the gas circuit and seal it. Then, adjust the output pressure of proportional valve 1.3 to its maximum. Next, prioritize adjusting the first adjustable flow valve 1.4 to maintain the flow rate reading of the compressed air flow meter at 2-5mL / min. Then, set the output pressure of proportional valve 1.3 to half of the rated maximum output pressure, for example, 250mbar for a 500mbar proportional valve. Finally, adjust the second adjustable flow valve 1.5 to bring the pressure reading of the pressure gauge to approximately 100±3mbar. This adjustment method can balance the compressed air consumption and the actual partial pressure requirement. This example is only a special case under certain circumstances. In practice, these parameters can be modified according to the actual effect. Combined with the reasonable design of the control scheme and the reasonable tuning of the control parameters under the fine flow control mode, better results can be achieved.

[0071] In addition, the present invention also discloses a microfluidic chip sample introduction control system, comprising:

[0072] The storage tank is a closed structure, with a liquid phase and a gas phase connected inside; the liquid phase and the gas phase are respectively connected to a liquid guide pipe and a gas guide pipe.

[0073] The microfluidic chip and the pneumatic pump are respectively connected to the liquid guiding line and the gas guiding line;

[0074] The first adjustable flow valve and the second adjustable flow valve are connected in series;

[0075] The liquid storage tank is connected between the first adjustable flow valve and the second adjustable flow valve, and the liquid storage tank is connected to the air outlet of the first adjustable flow valve and the air inlet of the second adjustable flow valve through the air guide pipe.

[0076] The first switching valve is connected in parallel at both ends of the first adjustable flow valve;

[0077] The second switching valve is connected in series with the second adjustable flow valve, and the outlet of the second switching valve is open to the atmosphere;

[0078] A host computer is connected to the control unit of the pneumatic pump. The host computer sends commands to the control unit of the pneumatic pump to control the opening and closing of the first and second switching valves, and to adjust the first and second adjustable flow valves.

[0079] With the first switch valve open and the second switch valve closed, the output air pressure of the pneumatic pump acts directly on the gas phase, thereby forming a fast-response pressurized air pressure for microfluidic chips, with a pressure range of 0-500 mbar.

[0080] With the first switch valve closed and the second switch valve open, the output gas pressure of the gas pump, after being regulated by the proportional valve, achieves quasi-linear pressure division through the joint regulation of the first and second adjustable flow valves. The gas pressure pulsation component in the output gas pressure is attenuated by the first adjustable flow valve and absorbed by the gas phase in the liquid storage tank through compression and volume change, so as to form a low-pulsation gas pressure for smooth sample injection drive of microfluidic chip, with a pressure range of 0-200 mbar.

[0081] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for finely controlling the flow rate of a high-pressure microfluidic pneumatic pump, characterized in that, include: The liquid storage tank is a closed structure, with a liquid phase and a gas phase connected inside; the liquid phase and the gas phase are respectively connected to a liquid guiding pipe for connecting to the microfluidic chip and a gas guiding pipe for connecting to the pneumatic pump. The first adjustable flow valve and the second adjustable flow valve are connected in series; The liquid storage tank is connected between the first adjustable flow valve and the second adjustable flow valve, and the liquid storage tank is connected to the air outlet of the first adjustable flow valve and the air inlet of the second adjustable flow valve through the air guide pipe. The first switching valve is connected in parallel at both ends of the first adjustable flow valve; The second switching valve is connected in series with the second adjustable flow valve, and the outlet of the second switching valve is open to the atmosphere; With the first switch valve open and the second switch valve closed, the output gas pressure of the gas pump directly acts on the gas phase to form the pressurized injection gas pressure for the microfluidic chip. With the first switch valve closed and the second switch valve open, the output gas pressure adjusted by the proportional valve in the gas pump is divided by the joint control of the first adjustable flow valve and the second adjustable flow valve. The gas pressure pulsation in the output gas pressure is attenuated by the first adjustable flow valve and then canceled out by gas compression with the gas phase in the storage tank to form a constant injection gas pressure for the microfluidic chip. A pressure gauge is installed on the air guide line between the first adjustable flow valve and the second adjustable flow valve to adjust the second adjustable flow valve by means of the reading of the pressure gauge; A gas flow meter is installed at the inlet of the first adjustable flow valve to adjust the first adjustable flow valve based on the reading of the gas flow meter. The pressure in the storage tank and the outlet pressure of the proportional valve maintain an approximately linear relationship of less than 1, which can reduce the outlet pressure of the proportional valve and avoid the dead zone or poor linearity zone that exists in the large-range proportional valve when the pressure output is small.

2. The high-pressure microfluidic pneumatic pump flow fine control device according to claim 1, characterized in that, Both the first switching valve and the second switching valve are solenoid valves.

3. The high-pressure microfluidic pneumatic pump flow fine control device according to claim 2, characterized in that, The first switching valve is a normally open two-position two-way solenoid valve; the second switching valve is a normally closed two-position two-way solenoid valve.

4. The high-pressure microfluidic pneumatic pump flow fine control device according to claim 1, characterized in that, Also includes: A liquid flow control valve is installed on the liquid delivery pipeline.

5. A multi-machine collaborative high-pressure microfluidic pneumatic pump control system, characterized in that, include: A plurality of high-pressure microfluidic pneumatic pump flow fine control devices and a host computer as described in any one of claims 1-4, connected in parallel; The host computer is connected to the air pump control unit external to each of the high-pressure microfluidic air pump flow fine control devices via a CAN BUS twisted pair cable, and the two achieve bidirectional communication and control through a compatible application layer protocol. The host computer is connected to the control unit of each air pump; the host computer sends commands to the control unit of the air pump to control the opening and closing of the first and second switching valves and to adjust the first and second adjustable flow valves, so as to realize the closing of the first switching valve and the opening of the second switching valve in the fine control mode or the opening of the first switching valve and the closing of the second switching valve in the normal control mode.

6. The multi-machine collaborative high-pressure microfluidic pneumatic pump control system according to claim 5, characterized in that, Also includes: In the rapid pressure scan mode with the first switch valve open and the second switch valve closed, the control unit of the pneumatic pump no longer reads data or communicates. The instructions from the host computer are directly converted into analog signals from the proportional valve in the pneumatic pump.

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