Pressing pump and microfluidic chip

Abstract

The present invention discloses a press pump and a microfluidic chip, belonging to the field of microfluidic technology. The press pump includes: a press airbag, a brake chamber, and two one-way valves. In the brake chamber and the one-way valve, the fluid layer and the gas layer are separated by an elastic membrane and a double-sided adhesive film attached to the elastic membrane and cut out a circular area, and the remaining film layers are all thermoplastic material films. In the one-way valve, a layer of thermoplastic material film below the elastic membrane is also cut out with a circular area, and the two cut areas are the same size and are both located directly below the cylindrical microvalve. In the brake chamber, a layer of thermoplastic material film above and below the elastic membrane is also cut out with a circular area, and the three cut areas are the same size and position. The fluid layer of the first one-way valve, the fluid layer of the brake chamber, and the fluid layer of the second one-way valve are connected in sequence. The gas layers of the first one-way valve and the brake chamber are both connected to the press airbag. The present invention can reduce the production time, production cost, and production complexity of the press pump.

Description

Technical Field

[0001] The present invention belongs to the field of microfluidics technology, and more specifically, relates to a pressure pump and a microfluidics chip. Background Art

[0002] Advances in microfluidics have made the driving and control of microfluidics more flexible, accurate, and convenient, promoting the development of point-of-care diagnostics, biochemical analysis, cell culture, and other related fields. Traditional fluid drive methods rely on expensive equipment and require conventional fluid pumps such as peristaltic pumps and syringe pumps. While these methods offer the advantage of precise control of flow rate and flow velocity, they hinder the miniaturization of microfluidic devices and their application in point-of-care diagnostics. As the core and typical component of microfluidic systems, micropumps have attracted widespread attention due to their advantages such as miniaturization and integration. The development of high-performance micropumps that are smaller, less expensive, and easier to manufacture is of great significance.

[0003] Micropumps are categorized as either requiring an external power source or not. Micropumps requiring an external power source are driven by a small external power source or actuator platform, such as small peristaltic pumps, electrowetting, electroosmotic pumps, centrifugal pumps, and magnetic pumps. Micropumps requiring an external power source are smaller and more integrated than traditional fluid pumps, but their reliance on an external power source and actuator platform significantly limits their use in limited environments. Micropumps requiring no external power source can be driven autonomously by physical principles such as capillary action, siphon action, osmotic pressure, and gravity, or by a combination of human power and specific mechanical structures, such as manually driven syringe pumps, manual centrifugal pumps, and finger-operated pumps. Because they are free of reliance on external power sources and actuator platforms, micropumps requiring no external power have broad applications in point-of-care diagnostics.

[0004] The finger-press pump is a typical micropump that does not require an external power supply. It is small in size, highly editable, and can be integrated with the microfluidic system without the need for cumbersome connections, reducing the risk of contamination while making the application prospects of the microfluidic system more diverse.

[0005] The finger press pump includes a button, a deformable chamber and various microvalves. By pressing and releasing the button, the deformable chamber can be deformed regularly. By combining with the microvalves, the fluid can be driven. The most classic finger press pump is made based on PDMS material, because PDMS, as an elastic material, is suitable for making deformable chambers and microvalves, and has high processing precision and strong structural stability. A press-type microfluidic chip, microfluidic device and bacterial detection method published by Tsinghua University and Shenzhen Green Poetry Source Biotechnology Co., Ltd. (application publication number: CN114480096A), and a microfluidic chip and microbial detection method published by China Agricultural University (application publication number: CN114225978A), both use classic soft lithography methods to process and manufacture finger press pumps and press chips. Such as Figure 1 As shown in the figure, in the finger press pump made of PDMS material, each layer of material is made of PDMS material. In order to avoid the microvalve and the elastic membrane below adhering to each other, soft photolithography PDMS needs to be processed with plasma to assemble the multi-layer structure, which is easy to damage the structure of the microvalve by mistake and the valve body is also easy to damage during the demolding process (Lab Chip, 2024, 24, 843-853). Therefore, it is difficult to achieve rapid batch production of press pumps by soft photolithography processing of PDMS. In addition, due to the poor rigidity of PDMS, when the deformable chamber is deformed, its top and bottom membranes may also be affected by the elastic membrane and deform, affecting the structural stability and the accuracy of liquid pumping.

[0006] The thermoplastic material PMMA can be manufactured in large quantities at low cost through reproducible and direct manufacturing technologies such as injection molding, compression molding, casting, hot pressing molding, micro-milling, and laser ablation. It can replace PDMS in some microfluidic devices. A study used PMMA and partially blocked pressure-sensitive adhesive to make a finger press pump (Lab Chip, 2023, 23, 4579-4591). Its structure is as follows Figure 2 Compared to PDMS-based finger-press pumps, PMMA-based top and bottom membranes offer greater rigidity and do not require plasma treatment, reducing production time, cost, and complexity. However, some small units still require additional processing and modification with blocking agents, which is not simple and unsuitable for rapid mass production.

[0007] Generally speaking, due to the limitations of its structure, the existing finger press pumps have a long production time, high production cost and high production complexity. Summary of the Invention

[0008] In response to the defects of the prior art and the need for improvement, the present invention provides a finger-pressing pump and a microfluidic chip, the purpose of which is to reduce the manufacturing time, cost and complexity of the finger-pressing pump by improving its structure.

[0009] To achieve the above object, according to one aspect of the present invention, a pressing pump is provided, comprising: a pressing airbag, a brake chamber, and two one-way valves; the two one-way valves are respectively a first one-way valve and a second one-way valve;

[0010] The one-way valve comprises: a first thermoplastic film, a second thermoplastic film, a first elastic film, and a first double-sided adhesive film attached in sequence from bottom to top; a third thermoplastic film fixed to the first double-sided adhesive film via a first support column; and a cylindrical microvalve with its upper bottom surface attached to the lower surface of the third thermoplastic film; the cylindrical microvalve is made of thermoplastic material, and the height of the first support column is no less than that of the cylindrical microvalve; a circular area with a radius of r1 directly below the cylindrical microvalve is cut in both the first double-sided adhesive film and the second thermoplastic film; the structure above the first elastic film forms the fluid layer of the one-way valve, and the structure below the first elastic film forms the gas layer of the one-way valve;

[0011] The brake chamber includes: a fourth thermoplastic film, a fifth thermoplastic film, a second elastic film, a second double-sided adhesive film, attached sequentially from bottom to top; a sixth thermoplastic film secured to the second double-sided adhesive film via a second support column; and a seventh thermoplastic film attached to the upper surface of the sixth thermoplastic film; circular areas with a radius of r2 are cut at the same position in the fifth thermoplastic film, the second double-sided adhesive film, and the sixth thermoplastic film; the structure above the second elastic film forms the fluid layer of the brake chamber, and the structure below the second elastic film forms the gas layer of the brake chamber;

[0012] The fluid layer of the first one-way valve, the fluid layer of the brake chamber, and the fluid layer of the second one-way valve are connected in sequence. The inlet of the fluid layer of the first one-way valve serves as the fluid inlet of the pressing pump, and the outlet of the fluid layer of the second one-way valve serves as the fluid outlet of the pressing pump. The cut circular areas in the gas layers of the first one-way valve and the brake chamber are all connected to the pressing airbag through air path microchannels.

[0013] Among them, r0≤r1≤r2, r0 is the bottom radius of the cylindrical valve.

[0014] Furthermore, the first thermoplastic film, the second thermoplastic film, the third thermoplastic film, the fourth thermoplastic film, the fifth thermoplastic film, the sixth thermoplastic film, the seventh thermoplastic film and the cylindrical microvalve are all made of PMMA.

[0015] Furthermore, the first elastic film and the second elastic film are both made of silicone.

[0016] According to another aspect of the present invention, a microfluidic chip is provided, comprising: N1 pressing pumps; the pressing pumps are the above-mentioned pressing pumps provided by the present invention;

[0017] The fluid inlet and fluid outlet of each pressing pump are independent of each other, and the pressing airbags of N1 pressing pumps are the same pressing airbag; N1≥2.

[0018] According to one aspect of the present invention, a microfluidic chip is provided, comprising: N2 press pumps, the press pumps being the press pumps provided by the present invention;

[0019] Among them, the fluid inlets of each pressing pump are independent of each other, the fluid outlets of N2 pressing pumps are connected to one point, and the pressing airbags of the N2 pressing pumps are the same pressing airbag; N2≥2.

[0020] According to another aspect of the present invention, there is provided a microfluidic chip comprising: the above-mentioned pressing pump and liquid separation module provided by the present invention;

[0021] The liquid separation module includes an inlet flow channel, a liquid separation chamber, and N3 outlet flow channels; one end of the inlet flow channel is connected to the liquid separation chamber, and the other end is connected to the fluid outlet of the press pump as the inlet of the liquid separation module; one end of the outlet flow channel is connected to the liquid separation chamber, and the other end serves as an outlet of the liquid separation module;

[0022] Among them, N3≥2.

[0023] According to another aspect of the present invention, a microfluidic chip is provided, comprising: N4 liquid storage chambers and N4 press pumps; the press pumps are the press pumps provided by the present invention;

[0024] The fluid layers of N4 compression pumps are connected in sequence, and the fluid outlet of the last compression pump is connected to the fluid inlet of the first compression pump. A liquid storage chamber is provided at the connection of the fluid layers of adjacent compression pumps; the compression airbags of adjacent compression pumps are different;

[0025] Among them, N4≥3.

[0026] According to another aspect of the present invention, a microfluidic chip is provided, comprising: a reaction chamber and N5 press pumps; the press pump is the press pump provided by the present invention;

[0027] The fluid inlet and the pressing airbag of each pressing pump are independent of each other, and the fluid outlets of N5 pressing pumps are all connected to the reaction chamber;

[0028] Among them, N3≥2.

[0029] According to another aspect of the present invention, a microfluidic chip is provided, comprising: a concentration gradient generating module and two pressing pumps; the pressing pump is the above-mentioned pressing pump provided by the present invention;

[0030] The concentration gradient generation module is provided with a Christmas tree-shaped fluid microchannel; the Christmas tree-shaped fluid microchannel comprises multiple layers of longitudinal microchannels and multiple layers of transverse microchannels; the number of longitudinal microchannels in the first layer is two, and the number of longitudinal microchannels in each subsequent layer is one more than the number of longitudinal microchannels in the previous layer; the transverse microchannel is provided at the junction of two adjacent layers of longitudinal microchannels and is connected to the adjacent longitudinal microchannels;

[0031] The fluid inlet of each pressing pump is independent of each other, and the fluid outlets of the two pressing pumps are respectively connected to the two longitudinal microchannels located in the first layer of the concentration gradient generation module, and the pressing airbags of the two pressing pumps are the same pressing airbag.

[0032] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0033] (1) The press pump provided by the present invention utilizes thermoplastic materials to manufacture the one-way valve and the microvalve structure and the rigid structure in the brake chamber, which can avoid deformation of the top membrane and the bottom membrane when the elastic membrane is deformed; by using a non-sticky elastic membrane and arranging a layer of specially cut double-sided adhesive film thereon, the deformation area of ​​the silicone membrane can be controlled while ensuring structural stability, and the elastic membrane will not adhere to the thermoplastic material structure when deformed, so there is no need for modification, no need for separate processing of small units, and no need for precise alignment, which greatly reduces the production cost and processing complexity of the press pump and also reduces the production time.

[0034] (2) The present invention combines the provided press pump with the microchannel to form different microfluidic structures, which can realize complex functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 Schematic diagram of the structure, elastic membrane manufacturing method and working process of the existing PDMS-based finger press pump;

[0036] Figure 2 Schematic diagram of the structure, elastic membrane manufacturing method and working process of the existing PMMA-based finger press pump;

[0037] Figure 3 Schematic diagram of the structure of the one-way valve and the brake chamber, the elastic membrane manufacturing method, and the working process of the press pump provided in Example 1 of the present invention;

[0038] Figure 4 Schematic diagram of the compression pump structure and its pumping process provided in Example 1 of the present invention; wherein (a) is a schematic diagram of the compression pump structure, (b) is a plan view schematic diagram of the pumping process, and (c) is a three-dimensional schematic diagram of the pumping process;

[0039] Figure 5 Schematic diagram of a press test provided in Example 1 of the present invention; wherein (a) is a comparison diagram of the pumping effects of the press pump using two different pressing methods, (b) is the results of multiple tests of the pumping effect of the press pump, (c) is the pumping effect of the press pump with different brake chamber sizes, (d) is a graph showing the relationship between the pumping effect of the press pump and the square of the brake chamber radius, (e) is a schematic diagram of the reciprocating flow of liquid during the press pump pumping process, and (f) is the actual test result of the liquid pumping distance during the press pump operation;

[0040] Figure 6 A schematic diagram showing the relationship between the number of presses and the volume of pumped liquid provided in Example 1 of the present invention;

[0041] Figure 7 Schematic diagram of a microfluidic chip provided in Example 2 of the present invention; wherein (a) is a schematic diagram of the microfluidic chip structure, and (b) is a schematic diagram of liquid release within the microfluidic chip;

[0042] Figure 8 Schematic diagram of a microfluidic chip provided in Example 3 of the present invention; wherein (a) is a schematic diagram of the microfluidic chip structure, and (b) is a schematic diagram of liquid release within the microfluidic chip;

[0043] Figure 9 Schematic diagram of a microfluidic chip provided in Example 4 of the present invention; wherein (a) is a schematic diagram of the microfluidic chip structure, and (b) is a schematic diagram of liquid release within the microfluidic chip;

[0044] Figure 10 Schematic diagram of a microfluidic chip provided in Example 5 of the present invention; wherein (a) is a schematic diagram of the microfluidic chip structure, and (b) is a schematic diagram of liquid release within the microfluidic chip;

[0045] Figure 11 Schematic diagram of a microfluidic chip provided in Example 6 of the present invention; wherein (a) is a schematic diagram of the microfluidic chip structure, and (b) is a schematic diagram of liquid release within the microfluidic chip;

[0046] Figure 12 Schematic diagram of the microfluidic chip provided in Example 7 of the present invention; wherein (a) is a schematic diagram of the three-dimensional structure of the microfluidic chip, (b) is a schematic diagram of the dimensions of the microfluidic chip, (c) is a schematic diagram of the operation of generating a concentration gradient, (d) is a schematic diagram of the gradient generated using Comsol simulation results; (e) is a schematic diagram of the actual generated concentration gradient results;

[0047] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0048] 1-first thermoplastic film, 2-second thermoplastic film, 3-first elastic film, 4-first double-sided adhesive film, 4-first double-sided adhesive film, 5-cylindrical microvalve, 6-third thermoplastic film, 7-fourth thermoplastic film, 8-fifth thermoplastic film, 9-second elastic film, 10-second double-sided adhesive film, 11-sixth thermoplastic film, 12-seventh thermoplastic film. DETAILED DESCRIPTION

[0049] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0050] It should be noted that, in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present invention. In addition, it should be noted that, in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two elements. The terms "first", "second" and the like (if any) in the present invention and the accompanying drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0051] In order to solve the technical problems that the existing finger press pump needs special modification treatment during production due to structural limitations, resulting in long production time, high production cost and high production complexity, the present invention proposes a new press pump, which improves the one-way valve structure of the press pump and the elastic membrane layer structure in the brake chamber. The original single-layer elastic and sticky membrane layer is improved into a structure composed of a non-sticky elastic membrane layer and a specially cut double-sided sticky membrane layer. In this structure, the elastic membrane layer will not adhere to other structures when deformed. Therefore, there is no need for modification, no need for individual processing of small units, and no need for precise alignment. It can be quickly mass-produced with low production cost.

[0052] Based on the proposed new press pump, the present invention also designs a variety of microfluidic structures composed of press pumps and microchannels, which can realize more complex liquid operation functions, meet different microfluidic application requirements, and develop the application potential of press pumps.

[0053] The following are examples.

[0054] Example 1:

[0055] A compression pump, such as Figure 3 and Figure 4 As shown, it includes: a pressing airbag, a braking chamber and two one-way valves; the two one-way valves are respectively a first one-way valve and a second one-way valve.

[0056] In order to prevent the top membrane and the bottom membrane from being deformed when the elastic membrane layer is deformed, in this embodiment, thermoplastic materials with good rigidity are used to make the one-way valve and the microvalve structure and rigid structure in the brake chamber.

[0057] like Figure 3 As shown, in this embodiment, the one-way valve includes: a first thermoplastic film 1, a second thermoplastic film 2, a first elastic film 3, and a first double-sided adhesive film 4 attached in sequence from bottom to top; a third thermoplastic film 6 fixed to the first double-sided adhesive film 4 via a first support column; and a cylindrical microvalve 5 whose upper bottom surface is attached to the lower surface of the third thermoplastic film 6; the cylindrical microvalve 5 is made of thermoplastic material, and the height of the first support column is not less than the height of the cylindrical microvalve 5; a circular area with a radius of r1 located directly below the cylindrical microvalve 5 in the first double-sided adhesive film 4 and the second thermoplastic film 2 is cut; the structure above the first elastic film 3 forms the fluid layer of the one-way valve, and the structure below the first elastic film 3 forms the gas layer of the one-way valve;

[0058] like Figure 3 As shown, in this embodiment, the brake chamber includes: a fourth thermoplastic film 7, a fifth thermoplastic film 8, a second elastic film 9, and a second double-sided adhesive film 10 attached sequentially from bottom to top; a sixth thermoplastic film 11 fixed to the second double-sided adhesive film via a second support column; and a seventh thermoplastic film 12 attached to the upper surface of the sixth thermoplastic film 11; circular areas with a radius of r2 at the same position in the fifth thermoplastic film 8, the second double-sided adhesive film 10, and the sixth thermoplastic film 11 are cut; the structure above the second elastic film 9 forms the fluid layer of the brake chamber, and the structure below the second elastic film 9 forms the gas layer of the brake chamber;

[0059] like Figure 4As shown in (a), the fluid layer of the first one-way valve, the fluid layer of the brake chamber, and the fluid layer of the second one-way valve are connected in sequence. The inlet of the fluid layer of the first one-way valve serves as the fluid inlet of the pressing pump, and the outlet of the fluid layer of the second one-way valve serves as the fluid outlet of the pressing pump. The cut circular areas in the gas layers of the first one-way valve and the brake chamber are both connected to the pressing airbag through air path microchannels.

[0060] Among them, r0≤r1≤r2, r0 is the bottom radius of the cylindrical valve.

[0061] In practical applications, the thermoplastic material film and the cylindrical microvalve can be made of thermoplastic materials such as PMMA and PC. Optionally, PMMA is used in this embodiment. The elastic film and the double-sided adhesive film can be made of elastic materials and double-sided adhesive materials according to actual needs. Optionally, in this embodiment, the elastic film is made of silicone and the double-sided adhesive film is made of commonly used double-sided adhesive. The dimensional parameters of each film layer are as follows:

[0062] In the one-way valve, the bottommost first thermoplastic film is 0.4mm thick PMMA, the second thermoplastic film is 0.4mm thick PMMA cut into a circular area with a radius of 1mm, the first elastic film is a 0.1mm thick silicone film, the first double-sided adhesive film is double-sided adhesive cut into a circular area with a radius of 1mm, the cylindrical microvalve has a radius of 1mm and a valve width of 1mm, and is cut from 0.4mm thick PMMA. The topmost third thermoplastic film is 0.4mm thick PMM;

[0063] In the brake chamber, the fourth thermoplastic material film at the bottom layer is 0.4 mm thick PMMA, the fifth thermoplastic material film is 0.4 mm thick PMMA with a circular area cut out with a radius of 2 mm, the second elastic film is a 0.1 mm thick silicone film, the second double-sided adhesive film is a double-sided adhesive film with a circular area cut out with a radius of 2 mm, the sixth thermoplastic material film is 0.4 mm thick PMMA with a circular area cut out with a radius of 2 mm, and the topmost seventh thermoplastic material film is 0.4 mm thick PMMA.

[0064] In the one-way valve and brake chamber, the bottom layer is closed, and the cut circular area in the gas layer forms a closed gas cavity with the upper elastic membrane and the lower thermoplastic material membrane. By controlling the air pressure in the gas cavity, the deformation of the elastic membrane can be controlled. Figure 3 As shown in the figure, when the pressure airbag is pressed, the air pressure in the gas cavity of the one-way valve increases, the elastic membrane passes through the cut area in the double-sided tape and deforms upward and contacts the bottom surface of the cylindrical microvalve, blocking the fluid layer, making the one-way valve and the fluid unable to pass through the fluid layer therein; when the pressure airbag is released, negative pressure is formed in the gas cavity of the one-way valve, the elastic membrane deforms downward, the fluid layer is conductive, the one-way valve opens, and the fluid can pass through the fluid layer therein smoothly. Similarly, as Figure 3 As shown, when the pressing airbag is pressed, the air pressure in the gas cavity in the brake chamber increases, the elastic membrane deforms upward through the cut area in the double-sided tape and contacts the lower bottom surface of the seventh thermoplastic material film on the top layer, and the fluid layer is blocked; when the pressing airbag is released, negative pressure is formed in the gas cavity in the brake chamber, the elastic membrane deforms downward, the fluid layer is connected, and the fluid can pass through the fluid layer smoothly.

[0065] In this embodiment, a silicone membrane is used as the elastic membrane, and a layer of specially cut double-sided tape is provided on it. While ensuring structural stability, the deformation area of ​​the silicone membrane can be controlled. Moreover, the silicone membrane will not adhere to PMMA, and does not require modification, individual processing of small units, or precise alignment. This greatly reduces the production cost and processing complexity of the pump. Based on the pump structure provided by this embodiment, a laser cutting machine is first used to cut and process each layer of material according to the structure designed in the drawing, and then assembled in sequence. After assembly is completed, hot pressing and bonding can be performed. A set of finger pumps can be processed within 10 minutes. In contrast, traditional soft lithography technology often requires a production cycle of several days. In comparison, this embodiment greatly shortens the production cycle.

[0066] The pressing pump provided in this embodiment has a pumping process as follows Figure 4 As shown in (b) and (c) above, when the pressure bladder is released from its pressed state, the elastic membranes in the first one-way valve and the brake chamber both deform downward, while the elastic membrane in the second one-way valve deforms upward, closing the second one-way valve. After the fluid is pumped from the inlet to the second one-way valve, it cannot continue to be pumped forward and is temporarily stored in the brake chamber. At this time, when the pressure bladder is pressed, the elastic membranes in the first one-way valve and the brake chamber both deform upward, closing the first one-way valve, while the elastic membrane in the second one-way valve deforms downward, opening the second one-way valve. As the elastic membrane in the brake chamber deforms upward, the temporarily stored fluid is pumped to both sides. Since the first one-way valve is closed, the fluid is pumped forward through the second one-way valve. By alternately pressing and releasing the pressure bladder, the above process allows the fluid to be continuously pumped from the fluid inlet to the fluid outlet.

[0067] It should be noted that the material selection and dimensional parameters of the aforementioned film layers are merely illustrative and should not be construed as limiting the present invention. In practical applications, the thermoplastic film may be made of materials other than PMMA, and the elastic film may be made of other materials that exhibit elasticity and prevent adhesion to the upper and lower layers. Furthermore, the aforementioned parameters can be flexibly adjusted based on actual fluid pumping requirements. Typically, the cutout area within the brake chamber is larger than that within the one-way valve to ensure sufficient fluid storage capacity.

[0068] In order to further verify the pumping performance of the pressing pump provided in this embodiment, two pressing modes were tested in this embodiment. The test results are as follows: Figure 5 As shown, pressing method 1 is a random pressing method. Each time the airbag is pressed, it is not required to press to the maximum deformation range. Only fingers are used for natural pressing. Figure 5 In the figure, (a) compares the pumping effects of the two different pressing methods, (b) shows the results of multiple tests of the pumping effect, (c) shows the pumping effect of the pump with different brake chamber sizes, (d) shows the relationship between the pumping effect and the square of the brake chamber radius, (e) shows the reciprocating flow of liquid during the pumping process, and (f) shows the actual test results of the liquid pumping distance during the operation of the pump. Pressing method 2 controls the contact between the upper and lower surfaces of the airbag during each press, achieving the maximum deformation range possible. Figure 5 The results shown in the figure show that compression method 2 has a more stable pumping effect.

[0069] This embodiment further tests the relationship between the number of presses and the volume of pumped liquid. The results are as follows: Figure 6 As shown, it can be seen that the number of presses of the press pump provided in this embodiment shows an obvious linear relationship between the volume of the pumped liquid and the number of presses, which shows that the press pump proposed in this embodiment has the ability to pump liquid stably and can be used as a driving force in the microfluidic chip to perform liquid manipulation and other complex functions.

[0070] In general, the press pump provided in this embodiment can achieve accurate and convenient liquid pumping while reducing the production cost and processing complexity of the press pump and greatly shortening the production cycle.

[0071] Example 2:

[0072] A microfluidic chip, such as Figure 7 As shown in (a), it includes: 5 pressing pumps; the pressing pumps are the pressing pumps provided in the above embodiment 1;

[0073] The fluid inlet and fluid outlet of each pressing pump are independent of each other. Accordingly, the microfluidic chip has 5 fluid inlets and 5 fluid outlets. The pressing airbags of the 5 pressing pumps are the same pressing airbag.

[0074] The microfluidic chip provided in this embodiment is composed of 5 push pumps connected in parallel, and the fluid layers in the 5 push pumps are connected in parallel. At the same time, the 5 push pumps in the microfluidic chip are controlled by the same push airbag, so that 5-way fluid pumping can be achieved simultaneously through one operation. Figure 7As shown in (b), "1," "2," and "3" represent the three different states the chip reaches during the pumping process. In practical applications, this can both increase the throughput of microfluidic analysis and enable repeated analysis of the same fluid.

[0075] It should be noted that the number of compression pumps included in the microfluidic chip in this embodiment is merely an exemplary illustration and should not be construed as the sole limitation of the present invention. In actual applications, the number of compression pumps connected in parallel can be adjusted according to specific analysis requirements.

[0076] Example 3:

[0077] A microfluidic chip, such as Figure 8 As shown in (a), it includes: 5 pressing pumps, which are the pressing pumps provided in the above embodiment 1;

[0078] Among them, the fluid inlet of each pressing pump is independent of each other, and the fluid outlets of the five pressing pumps are connected to one point. Accordingly, the microfluidic chip has five fluid inlets and one fluid outlet; the pressing airbags of the five pressing pumps are the same pressing airbag.

[0079] The microfluidic chip provided in this embodiment is composed of 5 pumps. The fluid layers in the 5 pumps are connected in parallel, and the flow channel outlets are connected to one point. At the same time, the 5 pumps in the microfluidic chip are controlled by the same pressure airbag, so that 5 fluids can be pumped to the same point at the same time through one operation. Figure 8 As shown in (b), it is convenient for subsequent mixing, reaction and other operations. Figure 8 In (b), “1”, “2” and “3” represent the three different states that the chip reaches in sequence during the pumping process.

[0080] It should be noted that the number of compression pumps included in the microfluidic chip in this embodiment is merely an exemplary illustration and should not be construed as the sole limitation of the present invention. In actual applications, the number of compression pumps connected in parallel can be adjusted according to specific analysis requirements.

[0081] Example 4:

[0082] A microfluidic chip, such as Figure 9 As shown in (a), it includes: the pressing pump and liquid separation module provided in the above embodiment 1;

[0083] The liquid separation module includes an inlet flow channel, a liquid separation chamber and 6 outlet flow channels; one end of the inlet flow channel is connected to the liquid separation chamber, and the other end is connected to the fluid outlet of the pressing pump as the inlet of the liquid separation module; one end of the outlet flow channel is connected to the liquid separation chamber, and the other end serves as an outlet of the liquid separation module.

[0084] In this embodiment, a liquid separation chamber is connected to the outlet of the press pump, and the liquid separation chamber divides the fluid pumped by the press pump into 6 paths, which flow out through different outlets. In practical applications, different test papers can be directly set at the 6 outlets, or each outlet can be connected to a different analysis device, such as Figure 9 As shown in (b), different tests are performed on the same fluid. Figure 9 In (b), “1”, “2” and “3” represent the three different states that the chip reaches in sequence during the pumping process.

[0085] It should be noted that the number of outlet flow channels in this embodiment is merely an exemplary illustration and should not be construed as the sole limitation of the present invention. In actual applications, the number of outlet flow channels may be adjusted according to specific analysis requirements.

[0086] Example 5:

[0087] A microfluidic chip, such as Figure 10 As shown in (a), it includes: 4 liquid storage chambers and 4 pressing pumps, and the pressing pumps are the pressing pumps provided in the above embodiment 1;

[0088] The fluid layers of the four pressing pumps are connected in sequence, and the fluid outlet of the last pressing pump is connected to the fluid inlet of the first pressing pump. A liquid storage chamber is set at the connection of the fluid layers of adjacent pressing pumps; the pressing airbags of adjacent pressing pumps are different.

[0089] The microfluidic chip provided in this embodiment forms a flow channel structure that can control the circulation of liquid in four chambers by connecting the fluid layers of four pressure pumps end to end. Optionally, in this embodiment, the four pressure pumps are connected in sequence to form a square circulation channel structure, and the four liquid storage chambers are arranged at the four corners of the square, and the pressure pumps are arranged on the four sides. The two pressure pumps on the upper and lower opposite sides are grouped as a group and controlled by a common pressure airbag A, and the two pressure pumps on the left and right opposite sides are grouped as a group and controlled by a common pressure airbag B.

[0090] In practical applications, by placing different reaction test papers or reactants in the liquid storage chamber, the corresponding reactions can be controlled to occur in sequence when the fluid flows along the circulation channel structure. In practical applications, any liquid storage chamber port can be selected as the inlet of the entire microfluidic chip. After the fluid circulates for a week, it can also flow out through the inlet, which is convenient for reagent recovery. Figure 10 As shown in (b), "1", "2" and "3" represent the three different states that the chip reaches in sequence during the pumping process.

[0091] To control the movement of fluid in the circulation channel structure, adjacent compression pumps are controlled by different compression airbags. To reduce the number of compression airbags, non-adjacent compression pumps can share the same compression airbag. In actual applications, each compression pump can also be controlled by a separate compression airbag.

[0092] It should be noted that, in this embodiment, the number of the pressing pumps and the liquid storage chambers is merely an exemplary description and should not be construed as the sole limitation of the present invention. In actual application, the number of the pressing pumps and the liquid storage chambers can be adjusted according to specific analysis requirements.

[0093] Example 6:

[0094] A microfluidic chip, such as Figure 11 As shown in (a), it includes: a reaction chamber and 5 pressing pumps; the pressing pumps are the pressing pumps provided in the above embodiment 1;

[0095] The fluid inlet and the pressing airbag of each pressing pump are independent of each other, and the fluid outlets of the five pressing pumps are all connected to the reaction chamber.

[0096] The microfluidic chip provided in this embodiment includes 5 press pumps. The fluid inlet and press airbag of each press pump are independent of each other, and the fluid outlet of each press pump is connected to the same reaction chamber. Therefore, the order in which each press pump pumps fluids can be independently controlled, thereby controlling the order in which each fluid is released into the reaction chamber, thereby realizing complex analytical reactions, such as Figure 11 As shown in (b), "1", "2" and "3" represent the three different states that the chip reaches in sequence during the pumping process.

[0097] It should be noted that the number of outlet flow channels in this embodiment is merely an exemplary illustration and should not be construed as the sole limitation of the present invention. In actual applications, the number of outlet flow channels may be adjusted according to specific analysis requirements.

[0098] Example 7:

[0099] A microfluidic chip, such as Figure 12 As shown, it includes: a concentration gradient generating module and two pressing pumps; the pressing pump is the pressing pump provided in the above embodiment 1;

[0100] The concentration gradient generation module is provided with a fluid microchannel having a Christmas tree structure; Figure 12As shown in (c) and (d) in the figure, the fluid microchannels of the Christmas tree structure include multiple layers of longitudinal microchannels and multiple layers of transverse microchannels; the number of longitudinal microchannels in the first layer is 2, and the number of longitudinal microchannels in each subsequent layer is 1 more than the number of longitudinal microchannels in the previous layer; the transverse microchannels are arranged at the junction of two adjacent layers of longitudinal microchannels and are connected to the adjacent longitudinal microchannels; the fluid inlet of each pressing pump is independent of each other, and the fluid outlet of the two pressing pumps is respectively connected to the two longitudinal microchannels located in the first layer in the concentration gradient generation module, and the pressing airbags of the two pressing pumps are the same pressing airbag.

[0101] In practical applications, the two pressing pumps are used to pump the original liquid to be diluted and the diluent used to dilute the original liquid respectively. After the pressing airbag is pressed, the original liquid and the diluent will be pumped forward along the fluid microchannel of the Christmas tree structure; based on the microfluidic channel structure of the Christmas tree structure, after the fluid flows through the previous level longitudinal flow channel to the transverse flow channel, it will be diverted to both sides along the transverse flow channel and then converge to flow into the next level longitudinal flow channel. Finally, the concentration of the liquid output from each outlet will increase from the diluent to the original liquid, thereby forming a concentration gradient, such as Figure 12 As shown in (c) and (d) in the figure. By fitting the concentration of the output liquid of each outlet, it can be found that the concentration of the output liquid of each outlet has a good linear relationship, as shown in (c) and (d) in the figure. Figure 12 As shown in (e), it is shown that the microfluidic analysis chip provided in this embodiment can generate a standard concentration gradient through the combination of the pressure pump and the microchannel.

[0102] As an optional implementation method, this embodiment adopts a layered design solution for the chip, such as Figure 12 As shown in (a), the first layer of PMMA is used to expand the liquid storage capacity of the inlet chamber, the second layer is a silicone membrane that serves as a button, and the third and fourth layers of PMMA form a fluid channel, which includes two sets of push pumps and a Christmas tree gradient generation structure. Each set of push pumps includes a push-on check valve, a brake chamber, and two passive check valves. The fifth layer is a double-sided tape that limits the deformation of the silicone membrane, the sixth layer is a thin silicone membrane, and the seventh layer is a pneumatic layer. The button connects the push-on check valve and the brake chamber through the airway. The overall structural dimensions of the chip are shown in Figure 1. Figure 12 As shown in (b) in .

[0103] It should be noted that in practical applications, the microfluidic chip may adopt other layered design schemes, and the chip size may also be adjusted accordingly according to actual needs.

[0104] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A compression pump, characterized in that: include: Pressing airbag, brake chamber and two one-way valves; the two one-way valves are respectively a first one-way valve and a second one-way valve; The one-way valve comprises: a first thermoplastic film, a second thermoplastic film, a first elastic film, a first double-sided adhesive film attached in sequence from bottom to top, a third thermoplastic film fixed to the first double-sided adhesive film via a first support column, and a cylindrical microvalve with an upper bottom surface attached to the lower surface of the third thermoplastic film; the cylindrical microvalve is made of thermoplastic material, and the height of the first support column is not less than the height of the cylindrical microvalve; a radius of 0.01 mm is provided between the first double-sided adhesive film and the second thermoplastic film directly below the cylindrical microvalve. r The circular areas of 1 are all cut; the structure above the first elastic membrane forms the fluid layer of the one-way valve, and the structure below the first elastic membrane forms the gas layer of the one-way valve; The brake chamber includes: a fourth thermoplastic film, a fifth thermoplastic film, a second elastic film, a second double-sided adhesive film attached in sequence from bottom to top, a sixth thermoplastic film fixed to the second double-sided adhesive film via a second support column, and a seventh thermoplastic film attached to the upper surface of the sixth thermoplastic film; a plurality of springs with a radius of 100 mm are provided at the same position among the fifth thermoplastic film, the second double-sided adhesive film, and the sixth thermoplastic film. r The circular areas of 2 are all cut; the structure above the second elastic membrane forms the fluid layer of the brake chamber, and the structure below the second elastic membrane forms the gas layer of the brake chamber; The fluid layer of the first one-way valve, the fluid layer of the brake chamber, and the fluid layer of the second one-way valve are connected in sequence. The fluid layer inlet of the first one-way valve serves as the fluid inlet of the pressing pump, and the fluid layer outlet of the second one-way valve serves as the fluid outlet of the pressing pump. The cut circular areas in the gas layers of the first one-way valve and the brake chamber are both connected to the pressing airbag via air path microchannels. in, r 0≤ r 1≤ r 2, r 0 is the bottom radius of the cylindrical microvalve.

2. The compression pump according to claim 1, wherein The first thermoplastic film, the second thermoplastic film, the third thermoplastic film, the fourth thermoplastic film, the fifth thermoplastic film, the sixth thermoplastic film, the seventh thermoplastic film and the cylindrical microvalve are all made of PMMA.

3. The pressing pump according to claim 1 or 2, wherein: The first elastic film and the second elastic film are both made of silicone.

4. A microfluidic chip, characterized in that: include: N 1 pressing pump; the pressing pump is the pressing pump according to any one of claims 1 to 3; The fluid inlet and fluid outlet of each pressing pump are independent of each other, and the N The compression airbag of one compression pump is the same; N 1≥2.

5. A microfluidic chip, characterized in that: include: N 2 compression pumps, wherein the compression pump is the compression pump according to any one of claims 1 to 3; Among them, the fluid inlets of each pressing pump are independent of each other. N The fluid outlets of the two compression pumps are connected to one point. N The compression airbags of the two compression pumps are the same; N 2≥2.

6. A microfluidic chip, characterized in that: include: The pressing pump and liquid dispensing module according to any one of claims 1 to 3; The liquid separation module includes an inlet flow channel, a liquid separation chamber and N 3 outlet channels; one end of the inlet channel is connected to the liquid separation chamber, and the other end is connected to the fluid outlet of the pressing pump as the inlet of the liquid separation module; one end of the outlet channel is connected to the liquid separation chamber, and the other end serves as an outlet of the liquid separation module; in, N 3≥2.

7. A microfluidic chip, characterized in that: include: N 4 liquid storage chambers and N 4 compression pumps; the compression pump is the compression pump according to any one of claims 1 to 3; described N The fluid layers of the four compression pumps are connected in sequence, and the fluid outlet of the last compression pump is connected to the fluid inlet of the first compression pump. A liquid storage chamber is set at the connection of the fluid layers of adjacent compression pumps; the compression airbags of adjacent compression pumps are different; in, N 4≥3.

8. A microfluidic chip, characterized in that: include: Reaction chamber and N 5 compression pumps; the compression pump is the compression pump according to any one of claims 1 to 3; The fluid inlet and the pressing airbag of each pressing pump are independent of each other, and the N The fluid outlets of the five pressure pumps are all connected to the reaction chamber; in, N 5≥2.

9. A microfluidic chip, characterized in that: include: A concentration gradient generation module and two pressing pumps; the pressing pump is the pressing pump according to any one of claims 1 to 3; The concentration gradient generation module is provided with a Christmas tree-shaped fluid microchannel; the Christmas tree-shaped fluid microchannel includes multiple layers of longitudinal microchannels and multiple layers of transverse microchannels; the number of longitudinal microchannels in the first layer is two, and the number of longitudinal microchannels in each subsequent layer is one more than the number of longitudinal microchannels in the previous layer; the transverse microchannel is provided at the junction of two adjacent layers of longitudinal microchannels and is connected to the adjacent longitudinal microchannels; The fluid inlet of each pressing pump is independent of each other, and the fluid outlets of the two pressing pumps are respectively connected to the two longitudinal microchannels located on the first layer of the concentration gradient generation module, and the pressing airbags of the two pressing pumps are the same pressing airbag.

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