Preparation method of micro-fluidic chip mold and micro-fluidic chip mold

Abstract

The invention belongs to the technical field of manufacturing of micro-fluidic chip molds, and particularly relates to a preparation method of a micro-fluidic chip mold and the micro-fluidic chip mold. The preparation method of the micro-fluidic chip mold comprises the following steps: preparing a mold, namely preparing a first template, and processing a runner groove in the plate surface of one side of the first template so as to prepare the first template into a female mold; mold reversing is conducted, a second mold plate is prepared, the female mold is fixed, the second mold plate is stacked on the female mold through a runner groove and covers the runner groove, and heating is conducted to soften the second mold plate; the second template is pressed towards the female die, so that part of the second template is extruded into the runner groove to form micro protrusions, and the second template is machined into a micro-fluidic chip die; demolding, and separating the micro-fluidic chip mold from the female mold. According to the micro-fluidic chip mold, the runner grooves are machined in the first mold plate, then the micro protrusions are machined on the second mold plate, the whole process is simple and high in efficiency, and the preparation cost of the micro-fluidic chip mold is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of microfluidic chip mold manufacturing, and in particular relates to a preparation method of a microfluidic chip mold and a microfluidic chip mold. Background Art

[0002] Microfluidic chips are programmable, controllable, miniature multifunctional devices composed of a network of microfluidic channels. Glass microfluidic chips play an important role in many fields such as life sciences, environmental monitoring, chemical synthesis, and advanced research due to their excellent material properties and versatility.

[0003] As the demand for miniaturization, precision and efficiency continues to grow, the application range of glass microfluidic chips is also expanding. Glass has good chemical inertness and can resist corrosion from a variety of chemicals, making it an ideal material for microfluidic devices that handle reactive or corrosive substances. It is widely used in applications with high-purity reagents or corrosive solvents. Among them, the preparation of the flow channel structure is the most critical step in glass microfluidic chips. Generally, the flow channel structure is prepared on the glass blank through a microfluidic chip mold. Therefore, it is particularly important to prepare a microfluidic chip mold for processing glass blanks.

[0004] The current microfluidic chip mold processing technologies include electrospark machining and ultra-precision cutting. Electrospark machining is to gradually remove tungsten carbide materials through high-frequency discharges generated between the workpiece and the electrode, but the wear of the electrode will lead to reduced precision and low processing efficiency; ultra-precision cutting can achieve high surface finish and high dimensional accuracy, but the tool wears quickly, and the processing cost is high during batch preparation. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide a method for preparing a microfluidic chip mold, aiming to solve the problem of how to improve the preparation accuracy of the microfluidic chip mold and reduce the preparation cost.

[0006] To achieve the above purpose, the technical solution adopted in this application is: In a first aspect, a method for preparing a microfluidic chip mold is provided, comprising the following steps: Molding, preparing a first mold plate, processing a flow channel groove on a side plate surface of the first mold plate to prepare the first mold plate into a master mold; Inverting the mold, preparing a second template and fixing the master mold, the flow channel groove is stacked on the master mold and covers the flow channel groove, heating to soften the second template; pressing the second template toward the master mold so that the second template is partially squeezed into the flow channel groove and forms micro protrusions, and processing the second template into a microfluidic chip mold; Demolding, separating the microfluidic chip mold from the master mold.

[0007] In some embodiments, a plurality of the second templates are prepared, and each of the second templates repeats the molding step and the demolding step in sequence to prepare a plurality of the microfluidic chip molds, and each of the micro-protrusions has a different height.

[0008] In some embodiments, the runner groove runs through both side surfaces of the first template, and the demoulding step includes: S31: Filling the flow channel with a flexible medium; S32: driving the flexible medium toward the microfluidic chip mold so that the flexible medium pushes the microfluidic chip mold to separate from the mother mold.

[0009] In some embodiments, the first template is provided with a plurality of spaced-apart material passing holes, both ends of the material passing holes respectively pass through two side surfaces of the first template, and at least one of the material passing holes is connected to the flow channel.

[0010] In some embodiments, the flexible medium is a gas or a liquid.

[0011] In some embodiments, the S31 step further includes preparing a positioning seat having a receiving cavity, wherein the receiving cavity receives the flexible medium and has an opening, wherein the opening is upwardly disposed, the mother mold is sealed and fixed at the opening, and the flow channel groove is connected to the receiving cavity.

[0012] In some embodiments, a rotating mechanism is prepared, and the rotating mechanism is connected to the positioning seat; in the demolding step, the rotating mechanism drives the positioning seat to rotate 180 degrees so that the microfluidic chip mold is set downward, and then the microfluidic chip mold is separated from the mother mold.

[0013] In some embodiments, the shrinkage rate of the master mold is smaller than the shrinkage rate of the microfluidic chip mold. In the step S32, cooling gas is first filled into the upper surface of the microfluidic chip mold, and then the microfluidic chip mold is driven to separate from the master mold.

[0014] In some embodiments, the flow channel groove is machined on the first template using a wire electric discharge cutting process.

[0015] In a second aspect, a microfluidic chip mold is provided, which is prepared by the microfluidic chip mold preparation method.

[0016] The beneficial effects of the present application are as follows: by preparing a master mold with a flow channel groove, and then replicating the flow channel groove on the master mold through a first template, micro-protrusions are formed on the second template, and the replicated micro-protrusions can ensure dimensional accuracy and surface accuracy, ensuring accurate replication of the flow channel groove, and the master mold can be reused multiple times, thereby improving preparation efficiency and reducing preparation costs, and the preparation process is simple and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or exemplary technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 1 is a schematic diagram of a process for preparing a microfluidic chip mold provided in an embodiment of the present application; Figure 2 It is a schematic diagram of assembling the positioning seat and the microfluidic chip mold in the demoulding step provided in another embodiment of the present application; Figure 3 yes Figure 2 A cross-sectional schematic diagram of the separation of the positioning seat and the microfluidic chip mold in the demoulding step; Figure 4 is a schematic diagram of the three-dimensional structure of a master mold provided in yet another embodiment of the present application; Figure 5 is a schematic diagram of the three-dimensional structure of a microfluidic chip mold provided in yet another embodiment of the present application; Figure 6 is a schematic diagram of assembling a microfluidic chip and a glass blank provided by another embodiment of the present application; Figure 7 It is a schematic diagram of the structure of a microfluidic chip provided in another embodiment of the present application.

[0019] Among them, the reference numerals in the figure are: 101. mother mold; 102. microfluidic chip mold; 103. positioning seat; 104. micro protrusion; 105. flow channel; 1031. accommodating cavity; 106. air inlet; 107. material passing through hole; 108. glass blank. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present application.

[0021] It should be noted that when a component is referred to as being "fixed on" or "disposed on" another component, it may be directly on the other component or indirectly on the other component. When a component is referred to as being "connected to" another component, it may be directly or indirectly connected to the other component. The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances. The terms "first" and "second" are only used for the purpose of convenience of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features. The meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0022] See also Figures 1 to 3 The embodiment of the present application provides a method for preparing a microfluidic chip mold, which can prepare a microfluidic chip mold 102, and a glass blank 108 can be prepared into a microfluidic chip through the microfluidic chip mold 102.

[0023] See also Figures 1 to 3 The preparation method of the microfluidic chip mold comprises the following steps: S1: Molding, preparing a first template, processing a flow channel 105 on a side plate surface of the first template to prepare the first template into a master mold 101; the flow channel 105 is a groove structure, and the shape of its length extension can be set according to actual needs, such as straight extension, arc extension or serpentine extension. The size range of the flow channel is 0.1~2mm, for example, the groove width of the flow channel 105 can be 0.1mm, 0.2mm, 0.8mm, 1mm or 2mm.

[0024] It is understandable that the material of the first template can be tungsten carbide, silicon carbide or glassy carbon, etc., which have the characteristics of high hardness and high temperature resistance. In the embodiment of the present application, the material of the first template is tungsten carbide. In other embodiments, it can be selected according to actual conditions, and is not limited here.

[0025] See also Figures 2 to 5, S2: inverting the mold, prepare the second template and fix the mother mold 101, the surface of the mother mold 101 with the flow channel 105 is set upward, the second template is stacked on the mother mold 101 and covers the flow channel 105, and the second template is heated to soften the second template so that the second template has a certain plasticity; the second template is pressed toward the mother mold 101 so that the second template is partially squeezed into the flow channel 105, and hot pressing is used to form micro-protrusions 104, that is, the position of the second template corresponding to the flow channel 105 is squeezed due to pressure, so that part of the material enters the flow channel and forms the micro-protrusion 104, and the second template is processed into a microfluidic chip mold 102.

[0026] It is understandable that the material of the second template can be an amorphous alloy, such as zirconium-based metallic glass. The second template has a glass transition temperature Tg, and the second template is softened and its plasticity is improved by heating it to above its glass transition temperature, slightly above 10 degrees Celsius. Then, downward pressure is applied to squeeze part of the material of the second template into the flow channel groove 105, so that the second template replicates the shape of the flow channel groove 105, and forms micro-protrusions 104 on the second template after cooling, thereby processing a microfluidic chip mold 102 with micro-protrusions 104. The micro-protrusions 104 directly replicate the shape of the flow channel groove 105, so that it has higher processing accuracy, a simple process, and high efficiency, and the master mold 101 can be reused many times to prepare microfluidic chip molds 102 in batches, thereby effectively reducing the preparation cost of the microfluidic chip mold 102.

[0027] S3: demoulding, separating the microfluidic chip mold 102 and the mother mold 101.

[0028] See also Figures 2 to 5 In the embodiment of the present application, a mother mold 101 having a flow channel 105 is prepared, and the flow channel 105 on the mother mold 101 is replicated by a first template, so that micro protrusions 104 are formed on the second template. The replicated micro protrusions 104 can ensure dimensional accuracy and surface accuracy, and ensure accurate replication of the flow channel 105. The mother mold 101 can be reused multiple times, thereby improving preparation efficiency and reducing preparation costs. The preparation process is simple and efficient.

[0029] Optionally, the obtained microfluidic chip mold 102 is subjected to a crystallization treatment to improve its hardness and strength.

[0030] See also Figures 2 to 5 It can be understood that the glass blank 108 can be processed through the microfluidic chip mold 102 to transfer the flow channel groove 105 on the mother mold 101 to the glass blank 108, and the glass blank 108 can be processed into a microfluidic chip, which can reduce the processing cost of the microfluidic chip. The depth of the flow channel groove on the microfluidic chip is controlled by the height of the micro-protrusion 104 on the microfluidic chip mold 102.

[0031] It can be understood that a downward pressure head is provided on the second template, and the downward pressure head is connected to a force-applying mechanism, through which pressure can be applied to the second template. The pressure applied to the second template can range from 5MPa to 40MPa, such as 5MPa, 10MPa, 20MPa, 35MPa or 40MPa. There is no limitation here and it can be selected according to actual conditions.

[0032] In some embodiments, a plurality of second templates are prepared, and each second template repeats the molding step and the demolding step in sequence to prepare a plurality of microfluidic chip molds 102 , and each microfluidic chip mold 102 has a different height of the micro protrusions 104 .

[0033] See also Figures 2 to 5 By controlling the pressure applied to the second template, the amount of material of the second template entering the flow channel 105 can be controlled, thereby forming micro protrusions 104 of different heights. During the replication process, the pressure is evenly distributed on the force-bearing surface of the second template, so that the heights of the same micro protrusion 104 are the same at all positions. A plurality of different microfluidic chip molds 102 can be prepared in batches through a master mold 101, and different microfluidic chips can be manufactured, thereby reducing the preparation cost of the microfluidic chip.

[0034] See also Figures 2 to 5 In some embodiments, the flow channel groove 105 passes through both side surfaces of the first template, that is, the flow channel groove 105 is a through groove structure, and the demoulding step includes: S31: Filling the flow channel 105 with a flexible medium; S32 : driving the flexible medium toward the microfluidic chip mold 102 , so that the flexible medium pushes the microfluidic chip mold 102 to separate from the mother mold 101 .

[0035] In some embodiments, the flexible medium may be a gas or a liquid.

[0036] For example, when the flexible medium is pure water, by connecting the hydraulic source to the flow channel 105 and then filling the flow channel 105 with high-pressure liquid, the flexible medium can uniformly apply pressure to the micro-protrusions 104 in the flow channel 105, and the micro-protrusions 104 are uniformly stressed at various positions, thereby loosening the microfluidic chip mold 102 relative to the mother mold 101 as a whole, and then manually or automatically removing the microfluidic chip mold 102. The pressure range of the high-pressure liquid can be 0.5MPa~4MPa to ensure the separation effect and the safety of the micro-protrusions 104. For example, the pressure of the high-pressure liquid can be 0.5MPa, 0.8MPa, 1MPa, 1.8MPa, 2.1MPa, 2.3MPa, 3.3MPa, 3.6MPa or 4MPa, which can be selected according to actual conditions and is not limited here.

[0037] See also Figures 2 to 5 In some embodiments, the flexible medium may also be gas, by connecting the air pressure source from the lower surface of the mother mold 101 to the flow channel 105, and then filling the flow channel 105 with high-pressure gas, the micro-protrusions 104 are evenly stressed at various positions, so that the microfluidic chip mold 102 is loosened relative to the mother mold 101 as a whole, and then the microfluidic chip mold 102 is manually or automatically removed. The pressure range of the high-pressure gas can be 1 MPa ~ 5MPa to ensure the separation effect and the safety of the micro-protrusions 104. For example, the pressure of the high-pressure gas can be 1 MPa, 1.5 MPa, 2 MPa, 2.3 MPa, 3 MPa, 3.6 MPa, 4 MPa, 4.8 MPa, or 5 MPa, which can be selected according to actual conditions and is not limited here.

[0038] Since the flexible medium is in flexible contact with the micro-protrusions 104, not only can the microfluidic chip mold 102 be separated from the mother mold 101, but also the micro-protrusions 104 will not be physically damaged during the separation process, thereby improving the reliability of separation of the microfluidic chip mold 102 from the mother mold 101.

[0039] In some embodiments, the positioning seat 103 is fixed on an ultrasonic vibration device. When the flexible medium is filled, the positioning seat 103 is subjected to micro-vibration by the ultrasonic vibration device. The vibration frequency can range from 20 kHz to 40 kHz, and the amplitude can be 1 μm to 5 μm, so as to weaken the static friction and adhesion between the micro-protrusion 104 and the flow channel 105 through vibration. The vibration direction can be perpendicular to the demolding direction. For example, when the demolding direction is vertically upward, the vibration direction is horizontal to avoid direct impact and compression of the micro-protrusion 104, thereby improving the reliability and convenience of demolding. Please refer to Figures 2 to 5 In some embodiments, the first template is provided with a plurality of spaced-apart material passing holes 107 , and both ends of the material passing holes 107 respectively pass through the two side surfaces of the first template; at least one material passing hole 107 is connected to the flow channel 105 .

[0040] Optionally, each feed through hole 107 is connected to the flow channel 105, and the flexible medium can smoothly enter the flow channel 105 through the feed through hole 107. The size of the feed through hole 107 is larger than the size of the flow channel 105. For example, the size of the feed through hole is three times the size of the flow channel 105, ensuring that the flexible medium can act evenly on the micro-protrusions 104, thereby ensuring the uniformity and stability of the demolding process.

[0041] See also Figures 2 to 5In some embodiments, step S31 further includes preparing a positioning seat 103 having a receiving cavity 1031, wherein the receiving cavity 1031 receives a flexible medium and has an opening, wherein the opening is upwardly arranged, and the edges around the mother mold 101 are sealed and fixed at the opening, and the flow channel groove 105 is connected to the receiving cavity 1031, so that the flexible medium in the receiving cavity 1031 can enter the flow channel groove 105, thereby ensuring that the flexible medium uniformly applies thrust to the micro-protrusion 104 during the demolding process, thereby improving the demolding efficiency.

[0042] Optionally, an air inlet hole 106 communicating with the accommodating cavity 1031 is opened at the bottom of the positioning seat 103 , and the air pressure source or the hydraulic pressure source is connected to the positioning seat 103 at the air inlet hole 106 .

[0043] See also Figures 2 to 5 In some embodiments, a rotating mechanism is prepared, and the rotating mechanism is connected to the positioning seat 103; in the demolding step, the rotating mechanism drives the positioning seat 103 to rotate 180 degrees so that the microfluidic chip mold 102 is set downward, and then the microfluidic chip mold 102 is separated from the mother mold 101 downward.

[0044] Optionally, when the flexible medium is a liquid, the positioning seat 103 is flipped 180 degrees, so that the microfluidic chip mold 102 is also flipped 180 degrees, and the mother mold 101 is located above the microfluidic chip mold 102. The microfluidic chip mold 102 is demoulded by the gravity of the microfluidic chip mold 102, the gravity of the flexible medium and the pressure applied to the flexible medium. Under the action of gravity and pressure, the microfluidic chip mold 102 becomes loose relative to the mother mold 101, or falls on the flexible receiving platform below. The flexible receiving platform can be a container loaded with liquid, and the microfluidic chip mold 102 falls into the liquid in the container, which can be an aqueous solution. It is avoided that when demoulding upwards, the microfluidic chip mold 102 first separates from the mother mold 101 upwards under the action of pressure, and then falls downwards on the mother mold 101 due to its own gravity, thereby causing irreversible physical damage to the micro protrusions 104.

[0045] See also Figures 2 to 5 In some embodiments, the shrinkage rate of the mother mold 101 is smaller than the shrinkage rate of the microfluidic chip mold 102. In step S32, cooling gas is first filled into the upper surface of the microfluidic chip mold 102, and then the microfluidic chip mold 102 is driven to separate from the mother mold 101.

[0046] Optionally, the cooling gas may be nitrogen, and the temperature range of the nitrogen may be -100°C to 0°C. The microfluidic chip mold 102 is cooled by blowing low-temperature nitrogen gas onto the upper surface of the microfluidic chip mold 102. Since the microfluidic chip mold 102 and the master mold 101 are made of different materials and have different shrinkage rates, under the action of the cooling gas, the micro-protrusions 104 shrink relative to the inner wall of the flow channel 105, so that the micro-protrusions 104 form a pre-demolding in the flow channel 105, and then the microfluidic chip mold 102 and the master mold 101 are separated by a flexible medium, thereby improving the efficiency and convenience of demolding.

[0047] See also Figures 2 to 5 In some embodiments, the flow channel groove 105 is machined on the first template using an electric spark wire cutting process.

[0048] Optionally, a slow-feeding EDM machine can be used to machine the runner groove 105 on the first template, with a discharge pulse interval of 10 μs and a flow rate of 7 L / min for the spark oil. During the pulsed EDM process, the first template is immersed in the oil to prevent the machining interface from being oxidized by air and to accelerate the discharge of debris. In order to improve the surface quality of the master mold 101, the runner groove 105 is finely cut at least 3 times.

[0049] Optionally, after the first template is processed by electrical discharge machining, it is necessary to perform surface polishing and ultrasonic vibration cleaning using alcohol.

[0050] See also Figures 2 to 5 The present application also proposes a microfluidic chip mold 102, which is prepared by the above-mentioned microfluidic chip mold preparation method.

[0051] The microfluidic chip mold 102 prepared by the above preparation method has the characteristics of high precision, high stability, low cost, etc., thereby promoting the further development of microfluidic chip technology.

[0052] See also Figure 6 to Figure 7 , the present application also proposes a hot pressing method, which uses the above-mentioned microfluidic chip mold 102 to prepare the microfluidic chip 200, and the hot pressing method includes the following steps; T1: placing a glass blank 108 on the microfluidic chip mold 102, wherein the glass transition temperature of the glass blank 108 is lower than the glass transition temperature of the microfluidic chip mold 102; the material of the glass blank 108 may be D-K9, and the glass transition point temperature thereof is about 550 degrees Celsius; T2: heating the microfluidic chip mold 102 and the glass blank 108 to the glass transition temperature of the glass blank 108 to soften the glass blank 108; T3: A downward pressure is applied to the glass blank 108 by a pressing head, and a microchannel 201 is processed on the glass blank 108 through the micro-protrusions 104 on the microfluidic chip mold 102 to process the glass blank 108 into a microfluidic chip 200; the microchannel 201 on the glass blank 108 is a blind groove structure.

[0053] T4: Cooling and separating the microfluidic chip 200 and the microfluidic chip mold 102 .

[0054] The hot pressing method provided in the present application can improve the processing efficiency of the microfluidic chip 200 and reduce its manufacturing cost, thereby promoting the widespread application and rapid development of microfluidic technology in the fields of life sciences, environmental monitoring, chemical analysis, etc.

[0055] The above are only optional embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A method for preparing a microfluidic chip mold, characterized in that: The steps include: Molding, preparing a first mold plate, processing a flow channel groove on a side plate surface of the first mold plate to prepare the first mold plate into a master mold; Inverting the mold, preparing a second template and fixing the master mold, the flow channel groove is stacked on the master mold and covers the flow channel groove, heating to soften the second template; pressing the second template toward the master mold so that the second template is partially squeezed into the flow channel groove and forms micro protrusions, and processing the second template into a microfluidic chip mold; Demolding, separating the microfluidic chip mold from the master mold.

2. The method for preparing a microfluidic chip mold according to claim 1, characterized in that: A plurality of the second templates are prepared, and the molding step and the demoulding step are repeated in sequence for each of the second templates to prepare a plurality of the microfluidic chip molds, and the height of each micro-protrusion is different.

3. The method for preparing a microfluidic chip mold according to claim 1, characterized in that: The runner groove passes through the two side surfaces of the first template, and the demoulding step includes: S31: Filling the flow channel groove with a flexible medium; S32: driving the flexible medium toward the microfluidic chip mold so that the flexible medium pushes the microfluidic chip mold to separate from the mother mold.

4. The method for preparing a microfluidic chip mold according to claim 3, characterized in that: The first template is provided with a plurality of material passing through holes arranged at intervals, the two ends of the material passing through holes respectively pass through the two side plate surfaces of the first template, and at least one of the material passing through holes is connected to the flow channel groove.

5. The method for preparing a microfluidic chip mold according to claim 3, characterized in that: The flexible medium is gas or liquid.

6. The method for preparing a microfluidic chip mold according to claim 3, characterized in that: The step S31 further includes preparing a positioning seat having a receiving cavity, wherein the receiving cavity receives the flexible medium and has an opening, the opening is arranged upward, the mother mold is sealed and fixed at the opening, and the flow channel groove is connected to the receiving cavity.

7. The method for preparing a microfluidic chip mold according to claim 6, characterized in that: A rotating mechanism is prepared, and the rotating mechanism is connected to the positioning seat; in the demoulding step, the rotating mechanism drives the positioning seat to rotate 180 degrees so that the microfluidic chip mold is set downward, and then the microfluidic chip mold is separated from the mother mold.

8. The method for preparing a microfluidic chip mold according to claim 3, characterized in that: The shrinkage rate of the master mold is smaller than the shrinkage rate of the microfluidic chip mold. In the step S32, cooling gas is firstly filled into the upper surface of the microfluidic chip mold, and then the microfluidic chip mold is driven to separate from the master mold.

9. The method for preparing a microfluidic chip mold according to any one of claims 3 to 8, characterized in that: The flow channel groove is processed on the first template by using an electric spark wire cutting process.

10. A microfluidic chip mold, characterized in that: The microfluidic chip mold is prepared by the preparation method of any one of claims 1-9.

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