Preparation of micro-valve micro-channel chip based on corrosion-resistant material ethylene propylene diene monomer rubber

Abstract

The invention discloses a preparation method of an EPDM (ethylene propylene diene monomer) micro-valve micro-channel chip based on a corrosion-resistant material, and the method comprises the following steps: S1, preparing a die-casting model of an Epdm chip, employing a brass plate with a thickness of 6 mm, a hole in the middle, a positioning groove in the hole, and a top needle with a small capillary connection vacancy on a lower cover plate, and taking the top needle as a pipeline interface of a rubber two-position three-way joint; s2, heating the model and filling; s3, demolding is conducted; s4, opening a valve pipeline; s5, plugging is conducted through a glass ball, and a three-way valve is formed; and S6, pipeline connection is integrated in cooperation with a chip. The novel microfluid chip is built by adopting the ethylene propylene diene monomer elastomer through meticulous design and mold reverse molding in cooperation with a semi-circular ejector rod valve, a pipeline plug and a chip external wiring layer framework, the maximum pressure borne by a microfluid through pipeline can be increased, driving force is more sufficient, and the microfluid through pipeline is more stable. And meanwhile, the problems that the applicable surface of the material is first and the valve is adhered can be effectively solved.

Description

Technical Field

[0001] The invention relates to the field of chip preparation, and in particular to the preparation of a microvalve microchannel chip based on a corrosion-resistant material EPDM rubber. Background Art

[0002] The preparation of microfluidic chips based on silicone rubber (PDMS) has been promoted and applied since its invention, and it is mainly used in general analytical conditions.

[0003] Existing silicone rubber has the following disadvantages: 1. Silicone rubber materials will undergo acid hydrolysis when exposed to acid, and will undergo both hydrolysis and polymerization when exposed to alkali. The application surface of this material is limited. The acid hydrolyzate may bring impurities to the chip application. The polymerization of silicone rubber will cause the valve material to adhere. The valve that is adhered cannot be opened and reset; 2. The high-pressure resistance of valves made of silicone rubber materials (bubble valves) is limited. The maximum pressure resistance of compressed gas is 2.5 bar. The micro bubble valve works under a maximum pressure of 2.5 atmospheres. The liquid pressure of the microfluidic pipeline must not exceed 1.0 bar, which manifests as insufficient driving force. Summary of the invention

[0004] The purpose of the present invention is to solve the shortcomings existing in the prior art, such as: silicone rubber materials will undergo acid hydrolysis when encountering acid, and will undergo both hydrolysis and polymerization when encountering alkali. The application surface of this material is limited, the acid hydrolyzate may bring impurities to the application of the chip, and the polymerization of silicone rubber will cause the valve material to adhere, and the valve that is adhered cannot be opened and reset; the valve (bubble valve) made of silicone rubber is limited in its high pressure resistance, the maximum pressure resistance of compressed gas is 2.5 bar, the micro bubble valve works under the condition of a maximum pressure of 2.5 atmospheres, and the liquid pressure of the microfluidic channel shall not exceed 1.0 bar, which manifests as insufficient driving force. A preparation method of a microvalve microchannel chip based on the corrosion-resistant material EPDM rubber is proposed.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A preparation method of a microvalve microchannel chip based on a corrosion-resistant material EPDM rubber comprises the following steps:

[0007] S1. Prepare a die-casting model of the Epdm chip. The model is made of a 6mm thick brass plate with a hole in the middle. A positioning groove is opened in the hole. A micro capillary is opened on the lower cover plate to connect the top pin of the vacant position, which serves as the pipeline interface of the rubber two-position three-way connection;

[0008] S2, heating the model and filling it;

[0009] S3, demoulding;

[0010] S4, open the valve pipeline;

[0011] S5, plug the valve with a glass ball to form a three-way valve;

[0012] S6. Integrate the pipeline connections with the chip.

[0013] Preferably, the positioning groove is 1.0mm wide and 0.5mm deep, and each positioning groove is parallel, and can be installed with a prefabricated semicircular strip with a semicircular cross-section and a radius of 0.5mm, and the upper and lower brass pressure plates are 6mm thick respectively, the upper cover plate is slightly flat, and a top pin is set at an interval of 7mm along the direction of the semicircular tube channel, for a total of 24 pins. The rubber chip of the manufactured micro-channel microvalve is 6.0mm thick, and the plane of the semicircular cavity is 0.5mm away from the outer surface of the rubber block.

[0014] Preferably, the EPDM compound rubber core is preheated at 70°C and then vulcanized at 168° and kept warm for 50-60 minutes.

[0015] Preferably, the liquid pipeline uses a 1 mm diameter punch to open the capillary connection pipeline and the valve pipeline.

[0016] Preferably, a 1mm flat-headed top rod is used to push three glass balls with a diameter of 2.0mm into the second section and the center position along the semicircular cross-section pipe. The glass balls stay and block the pipe to act as a plug.

[0017] Preferably, every eight three-way valve groups are integrated into a combined valve group, which is connected to the functional pipeline set above the chip.

[0018] Compared with the prior art, the invention has the following beneficial effects: the invention adopts EPDM rubber elastomer, is carefully designed and molded, and is matched with a semicircular top stem valve, a pipe plug, and a chip external wiring layer structure to form a novel microfluidic chip, which can increase the maximum pressure that the microfluidic pipeline can withstand, and the driving force is more sufficient;

[0019] EPDM is a terpolymer of ethylene, propylene and non-conjugated dienes, which has excellent resistance to oxidation, ozone and corrosion. EPDM is essentially non-polar, resistant to polar solutions and chemicals, has low water absorption, and has good insulation properties. In addition, EPDM has self-lubricating properties and no self-adhesion, which can effectively solve the problem of material application surface first and valve adhesion. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A schematic diagram of an EPDM mold for preparing a microvalve microchannel chip made of a corrosion-resistant material EPDM rubber is provided in the present invention;

[0021] Figure 2 A schematic diagram of the three-dimensional structure of an EPDM mold for preparing a microvalve microchannel chip made of a corrosion-resistant material EPDM rubber proposed in the present invention;

[0022] Figure 3 This is a schematic structural diagram of a brass base plate for preparing a micro-channel chip of an EPDM micro-valve based on a corrosion-resistant material proposed by the present invention;

[0023] Figure 4 A schematic diagram of the three-dimensional structure of a brass base plate for preparing a micro-channel chip of an EPDM micro-valve based on the corrosion-resistant material proposed by the present invention;

[0024] Figure 5 A schematic diagram of the opening and closing states of a microvalve prepared based on a corrosion-resistant EPDM rubber microvalve microchannel chip proposed by the present invention;

[0025] Figure 6 A schematic diagram of an EPDM vascular microvalve integrated chip proposed by the present invention, which is prepared based on a corrosion-resistant material EPDM rubber microvalve microchannel chip;

[0026] Figure 7 A schematic diagram of an EPDM rubber chip integrated with multiple groups of three-way valves based on the preparation of a corrosion-resistant EPDM rubber microvalve microchannel chip proposed by the present invention;

[0027] Figure 8 This is a schematic diagram of injection molding of a brass mold for preparing a microvalve microchannel chip made of corrosion-resistant EPDM rubber proposed by the present invention;

[0028] Fig. 9 A schematic diagram of an EPDM three-way microvalve channel integrated chip based on the preparation of a corrosion-resistant EPDM microvalve microchannel chip proposed by the present invention;

[0029] Fig.10 A connection diagram of a liquid capillary prepared based on a corrosion-resistant material EPDM rubber microvalve microchannel chip proposed by the present invention;

[0030] Fig.11 The present invention is a schematic diagram of the installation of a chip pressing plate for preparing a microvalve microchannel chip made of corrosion-resistant EPDM rubber. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0032] Reference Figure 1-Figure 11 , a preparation method of a microvalve microchannel chip based on corrosion-resistant material EPDM rubber, the following steps:

[0033] S1. Prepare a die-casting model of the Epdm chip. The model is made of a 6mm thick brass plate with a hole in the middle. A positioning groove is opened in the hole. A micro capillary is opened on the lower cover plate to connect the top pin of the vacant position, which serves as the pipeline interface of the rubber two-position three-way connection;

[0034] The brass plate is 60*80mm in size, and the hole is 35*45mm in size. The hole is made by a metal milling machine. The ejector pin has a diameter of 0.8mm and a length of 4.5mm.

[0035] S2, heating the model and filling it;

[0036] S3, demoulding;

[0037] S4, open the valve pipeline;

[0038] S5, plug the valve with a glass ball to form a three-way valve;

[0039] S6. Use chips to connect pipelines for integration

[0040] The positioning groove is 1.0mm wide and 0.5mm deep, and each positioning groove is parallel. It can be limited to a prefabricated semicircular strip with a semicircular cross section of 0.5mm radius, and the upper and lower brass pressing plates are 6mm thick, and the upper cover plate is slightly flat. A top pin is set at an interval of 7mm along the direction of the semicircular tube channel, with a total of 24 pins. The rubber chip of the manufactured micro-pipe microvalve is 6.0mm thick, and the semicircular cavity plane is 0.5mm away from the outer surface of the rubber block;

[0041] There are 4 positioning grooves in total, each groove is 7mm apart, and the error between the semicircular cavity plane and the outer surface of the rubber block is 0.1mm;

[0042] The EPDM compound rubber chip is preheated at 70℃, then vulcanized at 168℃ and kept warm for 50-60 minutes. The EPDM compound rubber adopts the specification of 55 Shore hardness.

[0043] The liquid pipeline uses a 1mm diameter puncher to open the capillary connection pipeline and the valve pipeline. The puncher is a hollow needle with an outer diameter of 1mm and an inner diameter of 0.8mm, and a sharp blade at one end;

[0044] Use a 1mm flat-head push rod to push three glass balls with a diameter of 2.0mm into the second section and the center of the semicircular cross-section pipe. The glass balls stay and block the pipe to act as a plug.

[0045] Every 8 three-way valve groups integrate a combined valve group, which connects the pipeline with the function set above the chip.

[0046] In the present invention, a 6mm thick brass plate is first used, the size of the brass plate is 60*80mm, a hole is opened in the middle of the brass plate, the specification of the hole is 35*45mm, and a metal milling machine is used to complete the hole opening of the brass plate. Four positioning grooves are opened in the hole, the four positioning grooves are parallel, and each positioning groove is 7mm apart. The positioning groove is 1.0mm wide and 0.5mm deep, and can be limited to a prefabricated semicircular strip with a semicircular cross-section of 0.5mm radius. A 6mm thick 60*80mm brass pressing plate is set on the upper and lower sides respectively, and the setting position is as follows Figure 8 As shown, the upper cover plate is slightly flat, and the lower cover plate has a tiny capillary connecting vacant ejector pin, the ejector pin has a diameter of 0.8 mm and a length of 4.5 mm, and serves as a pipeline interface of a rubber two-position three-way pipe. An ejector pin is set at an interval of 7 mm along the direction of the semicircular pipe channel, and a total of 24 ejector pins are set;

[0047] The rubber chip of the manufactured micro-channel microvalve is 6.0 mm thick, and the semicircular cavity plane is 0.5 mm away from the outer surface of the rubber block (the error is 0.1 mm);

[0048] The EPDM compound rubber (Shore hardness 55) chip is preheated at 70℃ and then vulcanized at 168℃. After molding, it is kept warm for 50-60 minutes and then demoulded.

[0049] After the prefabricated rubber block is demoulded, the capillary connection pipe and the valve pipe (semicircular section prefabricated pipe) are opened with a 1mm diameter puncher (the puncher is a hollow needle with an outer diameter of 1mm and an inner diameter of 0.8mm, and one end of the hollow needle is a sharp blade) for the liquid pipe. Pay special attention to the rubber particles must be taken out and not left in the pipe, which may block the pipe. Then, the mechanical energy of each gas and liquid channel is tested to ensure that the gas and liquid channels are normal.

[0050] Then use a 1mm flat-head push rod to push three glass balls with a diameter of 2.0mm to the second section and the center position of the semicircular cross-section pipeline. The glass balls stay to block the pipeline and play a plugging role, thus forming two independent two-position three-way valves (pipeline deformation valves); every 8 three-way valve groups integrate a combined valve group, which connects the pipeline with the function set above the chip (the pipeline here is connected by a woolen pipeline jumper to meet the function of multi-channel micro-pipeline);

[0051] For this purpose, it is integrated into a multi-microvalve and multi-microtube chip, becoming a key component of the micro-drug synthesis module.

[0052] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A preparation method for a microvalve microchannel chip based on corrosion-resistant EPDM rubber, characterized in that: The following steps are involved: S1. Prepare a die-casting model of the Epdm chip. The model is made of a 6mm thick brass plate with a hole in the middle. A positioning groove is opened in the hole. A micro capillary is opened on the lower cover plate to connect the top pin of the vacant position, which serves as the pipeline interface of the rubber two-position three-way connection; S2, heating the model and filling it; S3, demoulding; S4, open the valve pipeline; S5, plug the valve with a glass ball to form a three-way valve; S6. Integrate the pipeline connections with the chip.

2. The preparation of a microvalve microchannel chip based on corrosion-resistant material EPDM rubber according to claim 1, characterized in that: The positioning groove is 1.0mm wide and 0.5mm deep, and each positioning groove is parallel. It can be installed with prefabricated semicircular strips with a semicircular cross-section and a radius of 0.5mm, and has 6mm thick brass pressure plates on the top and bottom. The upper cover plate is slightly flat, and a top pin is set at an interval of 7mm along the direction of the semicircular tube channel, with a total of 24 pins. The rubber chip of the manufactured micro-channel microvalve is 6.0mm thick, and the plane of the semicircular cavity is 0.5mm away from the outer surface of the rubber block.

3. The preparation of a microvalve microchannel chip based on corrosion-resistant material EPDM rubber according to claim 1, characterized in that: The EPDM compound rubber chip is preheated at 70°C and then vulcanized at 168° and kept warm for 50-60 minutes.

4. The preparation of a microvalve microchannel chip based on corrosion-resistant material EPDM rubber according to claim 1, characterized in that: The liquid pipeline uses a 1mm diameter punch to open the capillary connecting pipe and the valve pipe.

5. The preparation of a microvalve microchannel chip based on corrosion-resistant material EPDM rubber according to claim 1, characterized in that: Use a 1mm flat-head push rod to push three glass balls with a diameter of 2.0mm into the second section and the center of the semicircular cross-section pipe. The glass balls stay in the pipe to block it and act as a plug.

6. The preparation of a microvalve microchannel chip based on corrosion-resistant material EPDM rubber according to claim 1, characterized in that: Every 8 three-way valve groups integrate a combined valve group, which connects the pipeline with the function set above the chip.

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