Method and nozzle for manufacturing micro-nano injection nozzles by casting deposition self-sealing

Abstract

The present invention discloses a method and a micro-nano injection needle for manufacturing a micro-nano injection needle by a casting deposition self-sealing method. The manufacturing method includes: preparing an unbonded biological vein injection needle and an injection needle cover plate; replicating the micro-nano structure of biological setae veins by a casting method to manufacture a biological vein micro-nano injection needle substrate: depositing a polymer on the biological vein micro-nano injection needle substrate by a polymer deposition method to self-seal and form a biological vein injection needle nano-channel, and obtaining an unbonded biological vein injection needle; casting the injection needle cover plate mold to obtain an injection needle cover plate; aligning and bonding the unbonded biological vein injection needle and the injection needle cover plate to obtain a micro-nano injection needle. The present invention discloses a method and a micro-nano injection needle for manufacturing a micro-nano injection needle by a casting deposition self-sealing method. A micro-nano cross-scale injection needle nano-channel is obtained by replicating the micro-nano structure of biological setae veins by a casting method; an injection needle nano-channel is obtained by a polymer deposition method; the micro-nano channel of the biological vein injection needle is sealed by an oxygen plasma-assisted bonding method to obtain a micro-nano injection needle.

Description

Technical Field

[0001] The present invention relates to the field of microelectromechanical technology, and particularly relates to a method and a needle for manufacturing a micro-nano injection needle by a casting deposition self-sealing method. Background Art

[0002] Electrohydrodynamic printing is an additive manufacturing technology based on the electrohydrodynamic effect. By applying a high-voltage power supply between the injection needle and the substrate, a strong electric field is formed. The liquid forms a Taylor cone under the action of the electric field force. When the electric field force overcomes the liquid surface tension and viscous force, a stable and fine jet is ejected from the nozzle, realizing printing and manufacturing at the micro-nano scale. In view of the scale effect of the printing technology, achieving higher-resolution printed patterns mainly depends on reducing the inner diameter of the injection needle. Therefore, the current focus is on developing methods for preparing nano-injection needles to improve the printing resolution to the nano level.

[0003] The nano-channel of the injection needle is the core structure of the micro-nano injection needle. Although existing nano-manufacturing technologies can manufacture nano-channels with high precision and quality, these technologies usually rely on expensive processing equipment. They are limited by the processing characteristics of sequential execution and time consumption, which not only reduces production efficiency, prolongs the overall manufacturing cycle, but also increases the processing and manufacturing cost. Summary of the Invention

[0004] The present invention overcomes the deficiencies of the prior art and provides a method and a needle for manufacturing a micro-nano injection needle by a casting deposition self-sealing method. The micro-nano cross-scale injection needle nano-channel is obtained by replicating the micro-nano structure of biological bristle veins through a casting method; the injection needle nano-channel is obtained by using a polymer deposition method; finally, the micro-nano channel of the biological vein injection needle is sealed by an oxygen plasma-assisted bonding method to obtain a complete micro-nano injection needle.

[0005] To achieve the above object, the technical solution adopted by the present invention is: A method for manufacturing a micro-nano injection needle by a casting deposition self-sealing method, comprising the following steps:

[0006] Step S1, prepare an unbonded biological vein injection needle and an injection needle cover plate, and enter step S2;

[0007] The preparation method of the unbonded biological vein injection needle includes the following steps:

[0008] Step S1.1, replicate the micro-nano structure of biological bristle veins by a casting method to manufacture a biological vein micro-nano injection needle substrate:

[0009] Step S1.2, deposit a polymer deposition layer on the inner wall of the micro-nano channel of the biological vein micro-nano injection needle substrate by a polymer deposition method to form a biological vein injection needle nano-channel, and obtain an unbonded biological vein injection needle;

[0010] The preparation method of the needle cover plate includes the following steps:

[0011] Obtain the needle cover plate by casting the needle cover plate mold.

[0012] Step S2: Respectively perform oxygen plasma treatment on the unbonded biological vein needle and the needle cover plate, and then enter step S3.

[0013] Step S3: Align and bond the unbonded biological vein needle and the needle cover plate after being processed in step S2, seal the unbonded biological vein needle, form a biological vein needle micro-nano channel, and obtain a micro-nano needle.

[0014] In a preferred embodiment of the present invention, the steps for obtaining the biological vein micro-nano needle substrate include:

[0015] Step S1.1.1: Obtain an organism with a biological bristle vein micro-nano structure, and perform purification, drying, and hydrophobic treatment on the organism.

[0016] Step S1.1.2: Lay the purified and dried organism flat on a PMMA substrate, pour a PDMS curing agent mixed solution onto the organism on the PMMA substrate and cure it, separate the cured PDMS from the organism, and obtain the biological vein micro-nano needle substrate.

[0017] In a preferred embodiment of the present invention, the preparation method of the needle cover plate mold includes the following steps: Expose and develop the processed thermosetting photoresist through a mask using a lithography machine to obtain the needle cover plate mold.

[0018] Obtaining the needle cover plate by casting the needle cover plate mold includes the following steps: Pour the PDMS curing agent mixed solution into the needle cover plate mold and cure it, separate the cured PDMS solid from the PMMA substrate, and use the separated PDMS solid as the needle cover plate.

[0019] In a preferred embodiment of the present invention, the organism used is an organism in the order Araneae or the order Diptera of the class Insecta, and the biological bristle vein micro-nano structure is the leg bristles of an organism in the order Araneae or the order Diptera of the class Insecta.

[0020] In a preferred embodiment of the present invention, the purification, drying, and hydrophobic treatment of the organism include:

[0021] Ultrasonically clean the organism with deionized water for 5 - 25 minutes, where the ultrasonic power is 50 - 90 W and the temperature is 21 - 27 °C.

[0022] Perform ultrasonic cleaning repeatedly 3 times, and finally use a nitrogen gas gun to dry it and place it on a hot plate or in an oven at 40 - 50 °C for 30 - 60 minutes to remove moisture.

[0023] Drop 1 - 5 ml of trimethylchlorosilane into the drying tower, seal it for 5 - 10 min, and then place the organism into the drying tower filled with trimethylchlorosilane for hydrophobic treatment for 10 - 20 min;

[0024] And / or, the step of pouring the PDMS curing agent mixed solution onto the organism on the PMMA substrate and curing it includes:

[0025] The treated organism is laid flat and fixed on the PMMA substrate, the PDMS curing agent mixed solution is poured onto the organism, and then it is placed in a vacuum environment below 10 Pa for vacuuming for 0.5 - 2 h; then it is placed on a horizontal static table and cured at room temperature for 20 - 28 h;

[0026] The step of separating the cured PDMS from the organism includes:

[0027] Separate the cured PDMS from the organism to obtain a PDMS micro - nano mold; put the PDMS micro - nano mold into deionized water and ultrasonically clean it for 0.5 - 2 h to remove the bristles remaining on the PDMS micro - nano mold during the demolding process. During the ultrasonic cleaning process, keep the structural surface facing down to make the bristles more easily detached from the PDMS micro - nano mold, where the ultrasonic power is 100 W - 300 W, the ultrasonic time is 30 - 60 min, and ultrasonically clean it repeatedly 3 times; dry the ultrasonically cleaned PDMS micro - nano mold with a nitrogen air gun and place it on a hot plate at 80 - 100 °C for 10 - 30 min to remove the moisture on the PDMS micro - nano mold, obtaining a biological vein micro - nano injection needle substrate.

[0028] In a preferred embodiment of the present invention, the polymer deposition method includes the following steps:

[0029] Place the biological vein micro - nano injection needle substrate into an oxygen plasma asher for oxygen plasma treatment, with a treatment power of 20 - 30 W and a treatment time of 15 - 30 s; place the oxygen plasma - treated biological vein micro - nano injection needle substrate in a parylene deposition chamber with the structural surface facing up; use 0.05 - 0.15 g of parylene for film growth, where the deposition pressure is 20 - 60 mTorr. Utilize the method of growing a parylene thin film to narrow the micro - nano channels of the biological vein micro - nano injection needle substrate, generate a parylene thin film on the surface of the micro - nano channels of the biological vein micro - nano injection needle substrate, and self - seal to obtain a needle nano - channel with a size below 100 nm.

[0030] In a preferred embodiment of the present invention, obtaining a needle cover plate by pouring the needle cover plate mold includes the following steps:

[0031] Spin - coat a layer of photoresist on the silicon wafer, where the low - speed spin - coating speed is 600 - 900 rpm and the high - speed spin - coating speed is 1500 - 5000 rpm;

[0032] Place the silicon wafer spin - coated with photoresist on a horizontal hot plate for pre - baking for 30 - 40 min, where the pre - baking temperature is 80 - 90 °C;

[0033] Place the pre - baked silicon wafer spin - coated with photoresist under the lithography machine, place the mask, and use an ultraviolet - light - transmissive mask to expose the photoresist, where the exposure time is 30 - 70 s;

[0034] After exposure, develop in an AZ series developer for 30 - 50 s to remove the exposed photoresist, and then place it in deionized water for rinsing for 30 - 50 s; obtain a photoresist step with a width of 50 μm;

[0035] Dry with a nitrogen gas gun, place it on a high - temperature hot plate at 150 - 200 °C for post - baking for 20 - 30 min, and the photoresist step gradually changes from a rectangular step shape to a semi - circular shape; then cool it to room temperature with the plate to obtain a needle - jet cover mold;

[0036] Drop 1 - 5 ml of trimethylchlorosilane (TMCS) into the drying tower and seal it for 5 - 10 min; place the needle - jet cover mold into the drying tower filled with trimethylchlorosilane atmosphere for 10 - 20 min for hydrophobic treatment, so that an anti - adhesion layer is formed on the surface of the needle - jet cover mold;

[0037] Pour a PDMS mixed solution with a ratio of 4:1 - 8:1 onto the needle - jet cover mold, and then place it in a vacuum environment for 1 - 2 h to enable the PDMS mixed solution to completely fill the pattern of the needle - jet cover mold;

[0038] Place the needle - jet cover mold poured with PDMS mixed solution on a horizontal table and let it stand for 10 - 20 min, and then bake it in an oven at 60 - 80 °C for 2 - 4 h to cure the PDMS mixed solution;

[0039] Separate the cured PDMS from the needle - jet cover mold, and then obtain a needle - jet cover with a connection channel.

[0040] In a preferred embodiment of the present invention, in step 3, align and bond the unbonded biological - vein needle - jet and the needle - jet cover that have been processed in step 2, seal the unbonded biological - vein needle - jet to form a micro - nano channel of the biological - vein needle - jet, and obtain a micro - nano needle - jet:

[0041] Before bonding the biological - vein needle - jet and the needle - jet cover, perform oxygen plasma treatment on them respectively, with a treatment power of 20 - 30 W and a treatment time of 10 - 30 s;

[0042] Insert a steel needle with a diameter of 60 μm after hydrophilic treatment into a short channel with a diameter of 50 μm between the bonded biological vein injection needle and the injection needle cover plate for interference fit to obtain a micro-nano injection needle.

[0043] In a preferred embodiment of the present invention, the hydrophobic treatment of the organism includes: dropping 1-5 ml of trimethylchlorosilane into a sealed drying tower, after volatilizing for 5-10 min, vertically placing the spider leg into the sealed drying tower with a trimethylchlorosilane atmosphere for atmosphere treatment for 10-20 min;

[0044] And / or, the photoresist is a positive photoresist, and the developer is a positive photoresist developer; or, the photoresist is a negative photoresist, and the developer is a negative photoresist developer;

[0045] And / or, the curing temperature of PDMS is 80 °C - 60 °C, and the curing time is 2 h - 4 h;

[0046] And / or, the ratio of the PDMS curing agent mixed solution is PDMS and curing agent with a ratio of 4:1 - 8:1.

[0047] In a preferred embodiment of the present invention, a method for manufacturing a micro-nano injection needle by casting deposition self-sealing, characterized in that: an injection needle is prepared by a method for manufacturing a micro-nano injection needle by casting deposition self-sealing.

[0048] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are:

[0049] A method for manufacturing a micro-nano injection needle by casting deposition self-sealing and an injection needle of the present invention obtain a micro-nano cross-scale injection needle nano-channel by replicating the micro-nano structure of biological bristle veins by the casting method; obtain an injection needle nano-channel by the polymer deposition method; and finally seal the micro-nano channel of the biological vein injection needle by oxygen plasma-assisted bonding method to obtain a complete micro-nano injection needle.

[0050] 1. By replicating the organism bristle structure by the casting method, a sub-micron pattern is obtained, and the sub-micron pattern is reduced to a nano-pattern below 100 nm by the polymer deposition method, thereby obtaining a self-sealing injection needle nano-channel; after obtaining the micro-nano channel, the sub-micron structure therein uses the deposition technology to reduce the sub-micron pores, and finally forms a self-sealing nano-channel. The end size of the organism bristle is at the sub-micron level. By using the thin film deposition technology, the sub-micron channel can be reduced and a self-sealing channel can be formed, killing two birds with one stone. The nano-channel has been self-sealed and changed from a channel to a channel.

[0051] 2. The injection needle cover plate is manufactured by the high-temperature post-baking method, and finally the micro-nano channel of the biological vein injection needle is sealed by the oxygen plasma-assisted bonding method to obtain a polymer micro-nano cross-scale injection needle.

[0052] 3. The production of micro-nano injection needles using the technology of the present invention simplifies the manufacturing process, reduces the production cost, and realizes the dual advantages of process simplicity and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The present invention will be further described below in conjunction with the drawings and embodiments.

[0054] Figure 1 is the manufacturing flow chart of the bio-vascular micro-nano injection needle substrate based on spider leg bristles in the preferred embodiment of the present invention;

[0055] Figure 2 is the manufacturing flow chart of obtaining the nano-channels of the bio-vascular injection needle in the preferred embodiment of the present invention;

[0056] Figure 3 is the preparation flow chart of the injection needle cover plate in the preferred embodiment of the present invention;

[0057] Figure 4 is the flow chart of aligning and bonding the bio-vascular injection needle and the injection needle cover plate in the preferred embodiment of the present invention;

[0058] Figure 5 is the structural diagram of the micro-nano injection needle in the preferred embodiment of the present invention;

[0059] Figure 6 is the microscope image of spider leg bristles in the third preferred embodiment of the present invention;

[0060] Figure 7 is the SEM image of the bio-vascular micro-nano injection needle substrate based on spider leg bristles in the third preferred embodiment of the present invention;

[0061] Figure 8 is the SEM image of the nano-channels of the bio-vascular injection needle obtained by the deposition method in the third preferred embodiment of the present invention;

[0062] Figure 9 is the SEM image of the micron photoresist steps obtained after lithography in the third preferred embodiment of the present invention;

[0063] Figure 10 is the SEM image of the photoresist obtained after post-baking at high temperature in the third preferred embodiment of the present invention.

[0064] In the figure: 1 - spider leg; 2 - PDMS solidified body; 3 - PDMS micro-nano mold; 4 - parylene film; 5 - silicon wafer; 6 - photoresist; 7 - mask; 8 - ultraviolet light; 9 - injection needle cover plate mold; 10 - PDMS curing agent mixed solution; 11 - steel needle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0065] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic manner, so they only show the components related to the present invention.

[0066] It should be noted that if there are directional indications (such as up, down, bottom, top, etc.) in the embodiments of the present invention, then such directional indications are only used to explain the relative positional relationship and movement conditions between components in a certain specific posture. If this specific posture changes, then such directional indications will also change accordingly. The terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Unless otherwise clearly specified and defined, the terms "set", "connected", and "connected" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0067] A method for manufacturing a micro-nano injection needle by casting deposition self-sealing method, comprising the following steps:

[0068] Step S1, prepare an unbonded biological vein injection needle and an injection needle cover plate, and enter step S2;

[0069] The preparation method of the unbonded biological vein injection needle comprises the following steps:

[0070] Step S1.1, replicate the micro-nano structure of biological bristle veins by casting method to manufacture a biological vein micro-nano injection needle substrate.

[0071] The acquisition steps of the biological vein micro-nano injection needle substrate include:

[0072] Step S1.1.1, obtain an organism with a micro-nano structure of biological bristle veins, and perform purification, drying, and hydrophobic treatment on the organism;

[0073] Step S1.1.2, lay the purified and dried organism flat on the PMMA substrate, pour the PDMS curing agent mixed solution 10 onto the organism on the PMMA substrate and cure it, separate the cured PDMS from the organism, and obtain a biological vein micro-nano injection needle substrate;

[0074] Step S1.2, deposit a polymer deposition layer on the inner wall of the micro-nano channel of the biological vein micro-nano injection needle substrate by polymer deposition method to form a biological vein injection needle nano-channel, and obtain an unbonded biological vein injection needle.

[0075] The preparation method of the needle spraying cover plate includes the following steps:

[0076] The needle spraying cover plate is obtained by pouring the needle spraying cover plate mold 9. The preparation method of the needle spraying cover plate mold 9 includes the following steps: The treated thermosetting photoresist 6 is exposed and developed by a lithography machine through a mask plate 7 to obtain the needle spraying cover plate mold 9. The step of obtaining the needle spraying cover plate by pouring the needle spraying cover plate mold 9 includes the following steps: Pour the PDMS curing agent mixed solution 10 into the needle spraying cover plate mold 9 and cure it; Separate the cured PDMS solid 2 from the PMMA substrate, and use the separated PDMS solid 2 as the needle spraying cover plate.

[0077] Step S2, perform oxygen plasma treatment on the unbonded biological vein needle and the needle spraying cover plate respectively, and enter step S3;

[0078] Step S3, align and bond the unbonded biological vein needle and the needle spraying cover plate after being treated in step S2, seal the unbonded biological vein needle, form a biological vein needle micro-nano channel, and obtain a micro-nano needle.

[0079] Specifically, the organism used is an organism in Araneae or Diptera of Insecta. The biological bristle vein micro-nano structure is the leg bristles of an organism in Araneae or Diptera of Insecta. Organisms in Araneae are, for example, spiders, and organisms in Diptera of Insecta are, for example, mosquitoes and flies.

[0080] Specifically, the photoresist 6 can be a positive photoresist or a negative photoresist. When a positive photoresist is used, a positive photoresist developer is selected. When a negative photoresist is used, a negative photoresist developer is used. The selection of the photoresist 6 is not elaborated here one by one. As long as it can basically meet the requirements of photolithography, exposure, and development of the photoresist 6 in this embodiment. Embodiment 1

[0081] As Figures 1-4 shown, in this embodiment, the organism used is an organism in Araneae. The biological bristle vein micro-nano structure is the leg with bristles in Araneae.

[0082] Therefore, a method for manufacturing a micro-nano needle by the pouring deposition self-sealing method includes the following steps:

[0083] Step S1, prepare an unbonded biological vein needle and a needle spraying cover plate, and enter step S2;

[0084] The preparation method of the unbonded biological vein needle includes the following steps:

[0085] Step S1.1, use the pouring method to replicate the biological bristle vein micro-nano structure to manufacture a biological vein micro-nano needle substrate;

[0086] like Figure 1 As shown, the steps for obtaining the biological vascular micro-nano spray needle substrate include:

[0087] Step S1.1.1, obtaining an organism having a biological bristle venation micro-nano structure, and purifying, drying, and hydrophobicizing the organism.

[0088] Among them, the purification, drying and hydrophobic treatment of organisms include:

[0089] like Figure 1 As shown in 1a, the spider leg 1 is ultrasonically cleaned with deionized water for 5 minutes, wherein the ultrasonic power is 50W and the temperature is 21°C; after cleaning and purification, it is blown dry with a nitrogen air gun, ultrasonic cleaning is repeated 3 times, and finally, it is blown dry with a nitrogen air gun and placed in a 40°C oven for 30 minutes to remove moisture, but it is not limited to this. In other embodiments, a hot plate can be used instead of an oven. 1 ml of trimethylchlorosilane (TMCS) is dripped into the drying tower, and after sealing and volatilization for 5 minutes, the spider leg 1 is vertically placed in a sealed drying tower with a trimethylchlorosilane atmosphere for 10 minutes of atmosphere treatment.

[0090] Step S1.1.2, as Figure 1 As shown in Figure 1b, the purified and dried organisms are spread flat on PMMA (

[0091] On a polymethyl methacrylate) substrate, a PDMS curing agent mixed solution 10 is poured onto the organism of the PMMA substrate and cured to form a PDMS cured body 2, and the PDMS cured body 2 is cut according to actual needs, and the PDMS cured body 2 is separated from the spider leg 1 to obtain a biological venous micro-nano spray needle substrate. The PDMS curing agent mixed solution 10 is a PDMS and curing agent in a ratio of 4:1. Further, after collecting the spider leg 1, the leg bristles are messy before cleaning. After repeated ultrasonic cleaning, some fragile hairs have fallen off, and most of the remaining bristles are regular. After obtaining the PDMS cured body 2, the nanochannel end is cut, and the port can obtain an array-distributed spray needle port. Furthermore, in order to improve the stability of cutting, the present invention uses a relatively sharp coating knife in the prior art to avoid deformation of the channel caused by a blunt tool. Moreover, when cutting, cut from the back of the channel instead of the front. Cutting from the front of the channel is likely to cause channel deformation.

[0092] Among them, the steps of pouring the PDMS curing agent mixed solution 10 onto the organism on the PMMA substrate and curing it include: the treated spider leg 1 is laid and fixed on the PMMA substrate, the PDMS curing agent mixed solution 10 is poured onto the spider leg 1, and then it is placed in a vacuum environment below 10 Pa and evacuated for 0.5 h; then it is placed on a horizontal static table and cured at room temperature for 20 h.

[0093] Among them, the steps of separating the cured PDMS from the organism include: the cured PDMS forms a PDMS cured body 2 and separates from the spider leg 1 to obtain a PDMS micro-nano mold 3; the PDMS micro-nano mold 3 is placed in deionized water and ultrasonically cleaned for 0.5 h to remove the setae remaining on the PDMS micro-nano mold 3 during the demolding process. During the ultrasonic cleaning process, the structural surface should be kept facing downwards to make the setae easier to detach from the PDMS micro-nano mold 3. Among them, the ultrasonic power is 100 W and the ultrasonic time is 30 min; the ultrasonically cleaned PDMS micro-nano mold 3 is dried with a nitrogen gas gun and placed on a hot plate at 80 °C for 10 min to remove the moisture on the PDMS micro-nano mold 3, obtaining a biological vein micro-nano injection needle substrate.

[0094] Step S1.2, as Figure 2 shown, a polymer deposition layer is deposited on the inner wall of the micro-nano channels of the biological vein micro-nano injection needle substrate by the polymer deposition method to form biological vein injection needle nano-channels, obtaining an unbonded biological vein injection needle. Among them, the polymer deposition method for growing the parylene film 4 includes the following steps: as Figure 2 shown in 2a, the biological vein micro-nano injection needle substrate is placed in an oxygen plasma asher for oxygen plasma treatment, the treatment power is 20 W, and the treatment time is 15 s; as Figure 2 shown in 2b, the oxygen plasma-treated biological vein micro-nano injection needle substrate is placed in a parylene deposition chamber with the structural surface facing upwards; 0.05 g of parylene is used for film growth. Among them, the deposition pressure is 20 mTorr. The nano-channels of the biological vein micro-nano injection needle substrate are reduced by growing the parylene film 4, and a parylene film 4 is generated on the surface of the nano-channels of the biological vein micro-nano injection needle substrate. As Figure 2 shown in 2c, injection needle nano-channels below 100 nm are obtained.

[0095] Specifically, the end size of the spider leg 1 is approximately around 200 nm. Structures with a size of 100 nm and below are called nanostructures. Above 100 nm and below 1 μm are submicrons. After obtaining the micro-nano channels, the submicron structures therein use deposition technology to reduce the submicron pores, and finally form self-enclosed nanochannels. The bristle end size of the spider leg 1 is at the submicron level. By simply using thin film deposition technology, the submicron channels can be reduced and self-enclosed channels can be formed, killing two birds with one stone. Therefore, there is no need to additionally stretch and reduce to obtain nanochannels. After deposition, the nanochannels are already self-enclosed and change from channels to channels. However, the micron channel size is relatively too large to complete self-enclosure. Therefore, the micron channels remain channels after being treated by the polymer deposition method. Further, after deposition, the micro-nano channels and other planes (any exposed surface) will be deposited with parylene film 4. Finally, in the reduced micro-nano channels, the submicron channels form self-enclosed nanochannels.

[0096] As Figure 3 shown, the preparation method of the needle nozzle cover plate includes the following steps:

[0097] The needle nozzle cover plate is obtained by pouring the needle nozzle cover plate mold 9.

[0098] Among them, as Figure 3 shown in 3a, the preparation method of the needle nozzle cover plate mold 9 includes the following steps: The steps of obtaining the needle nozzle cover plate by pouring the needle nozzle cover plate mold 9 include: spin-coating a layer of photoresist 6 on the silicon wafer 5. The photoresist 6 used is AZ703 photoresist, where the low-speed spin-coating speed is 600 rpm and the high-speed spin-coating speed is 1500 rpm. Place the silicon wafer 5 spin-coated with photoresist 6 on a horizontal hot plate for pre-baking for 30 min, where the pre-baking temperature is 80 °C. The heat-cured photoresist 6 after treatment is exposed and developed by a mask 7 using a lithography machine. Specifically, place the pre-baked silicon wafer 5 spin-coated with photoresist 6 under the lithography machine, place the mask 7, and the ultraviolet light 8 passes through the mask 7 to expose the photoresist 6, where the exposure time is 30 s. After exposure, develop in a developer (AZ series developer) for 30 s. As Figure 3 shown in 3b, remove the exposed photoresist 6, and then place it in deionized water for rinsing for 30 s. Obtain a photoresist step with a width of 5 μm. Dry it with a nitrogen gas gun and place it on a high-temperature hot plate at 150 °C for post-baking for 20 min. The photoresist step gradually changes from a rectangular step shape to a semi-circular shape. As Figure 3 shown in 3c, then cool it to room temperature with the plate to obtain the needle nozzle cover plate mold 9.

[0099] The steps for obtaining the needle tip cover plate by casting the needle tip cover plate mold 9 are as follows: Pour the PDMS curing agent mixed solution 10 into the needle tip cover plate mold 9 and cure it; Separate the cured PDMS solid 2 from the PMMA substrate, and use the separated PDMS solid 2 as the needle tip cover plate. Specifically, 1 ml of trimethylchlorosilane (TMCS) is dropped into the drying tower and sealed for 5 min; The needle tip cover plate mold 9 is placed in the drying tower filled with TMCS atmosphere for 10 min for hydrophobic treatment, so that an anti-adhesion layer is formed on the surface of the needle tip cover plate mold 9; As Figure 3 shown in 3d, pour the PDMS mixed solution onto the needle tip cover plate mold 9. The PDMS curing agent mixed solution 10 is a mixture of PDMS and curing agent with a ratio of 4:1. Immediately place it in a vacuum environment for 1 h to enable the PDMS mixed solution to completely fill the pattern of the needle tip cover plate mold 9; Place the needle tip cover plate mold 9 poured with the PDMS mixed solution on a horizontal table and let it stand for 10 min, and then bake it in an oven at 60 °C for 2 h to cure the PDMS mixed solution; As Figure 3 shown in 3e, separate the cured PDMS from the needle tip cover plate mold 9, and immediately obtain the needle tip cover plate with a connection channel.

[0100] Step S2, as Figure 4 shown in 4f, perform oxygen plasma treatment on the unbonded biological vein needle and the needle tip cover plate respectively. The treatment power of the oxygen plasma treatment is 20 W and the treatment time is 10 s; Proceed to step S3;

[0101] Step S3, as Figure 4 shown in 4g, align and bond the unbonded biological vein needle and the needle tip cover plate after being treated in step S2, and seal the unbonded biological vein needle to form a biological vein needle micro-nano channel, thereby obtaining a micro-nano needle. Example 2

[0102] As Figures 1-4 shown, in this example, the organism used is a creature in the order Araneae, and the micro-nano structure of the biological bristle veins is the legs with bristles in the order Araneae.

[0103] Therefore, a method for manufacturing a micro-nano needle by the casting deposition self-sealing method includes the following steps:

[0104] Step S1, prepare an unbonded biological vein needle and a needle tip cover plate, and proceed to step S2;

[0105] As Figure 1 shown, the method for preparing the unbonded biological vein needle includes the following steps:

[0106] Step S1.1, using a casting method to replicate the biological bristle vascular micro-nano structure to manufacture a biological vascular micro-nano spray needle substrate;

[0107] The steps for obtaining the biological vascular micro-nano spray needle substrate include:

[0108] Step S1.1.1, obtaining an organism having a biological bristle venation micro-nano structure, and purifying, drying, and hydrophobicizing the organism.

[0109] Among them, the purification, drying and hydrophobic treatment of organisms include:

[0110] like Figure 1 As shown in 1a, the spider leg 1 is ultrasonically cleaned with deionized water for 25 minutes, the ultrasonic power is 90W, and the temperature is 27°C; the ultrasonic cleaning is repeated 3 times, and finally, a nitrogen air gun is used to blow dry and placed in a 50°C oven for 60 minutes to remove moisture, but it is not limited to this. In other embodiments, a hot plate can be used instead of an oven. 5 ml of trimethylchlorosilane (TMCS) is dripped into the drying tower, and after sealing and volatilizing for 10 minutes, the spider leg 1 is vertically placed in a sealed drying tower with a trimethylchlorosilane atmosphere for 20 minutes.

[0111] Step S1.1.2, as Figure 1 As shown in 1b, the purified and dried organism is laid flat on the PMMA substrate, and the PDMS curing agent mixed solution 10 is poured onto the organism of the PMMA substrate and cured to form a PDMS solidified body 2. The PDMS solidified body 2 is cut according to actual needs, and the PDMS solidified body 2 is separated from the spider leg 1 to obtain a biological venous micro-nano spray needle substrate. The PDMS curing agent mixed solution 10 is a PDMS and curing agent in a ratio of 8:1. Further, after collecting the spider leg 1, the leg bristles are messy before cleaning. After repeated ultrasonic cleaning, some fragile hairs have fallen off, and most of the remaining bristles are regular. After obtaining the PDMS solidified body 2, the nanochannel end is cut, and the port can obtain an array-distributed spray needle port. Furthermore, in order to improve the cutting stability, the present invention uses a relatively sharp coating knife in the prior art to avoid deformation of the channel caused by a blunt tool. Moreover, when cutting, cut from the back of the channel instead of the front, and cutting from the front of the channel is likely to cause channel deformation.

[0112] Among them, the steps of pouring the PDMS curing agent mixed solution 10 onto the organism on the PMMA substrate and curing it include: the processed spider leg 1 is laid and fixed on the PMMA substrate, the PDMS curing agent mixed solution 10 is poured onto the spider leg 1, and then it is placed in a vacuum environment below 10 Pa for vacuum pumping for 2 h; then it is placed on a horizontal static table and cured at room temperature for 28 h. The PDMS curing agent mixed solution 10 is PDMS and curing agent with a ratio of 8:1.

[0113] Among them, the steps of separating the cured PDMS from the organism include: separating the cured PDMS from the spider leg 1 to obtain the PDMS micro-nano mold 3; putting the PDMS micro-nano mold 3 into deionized water and ultrasonically cleaning it for 2 h to remove the setae remaining on the PDMS micro-nano mold 3 during the demolding process. During the ultrasonic cleaning process, the structural surface should be kept facing down to make the setae easier to detach from the PDMS micro-nano mold 3, where the ultrasonic power is 300 W and the ultrasonic time is 60 min; the ultrasonically cleaned PDMS micro-nano mold 3 is dried with a nitrogen gas gun and placed on a hot plate at 100 °C for 30 min to remove the moisture on the PDMS micro-nano mold 3, obtaining the biological vein micro-nano injection needle substrate.

[0114] Step S1.2, as Figure 2 shown, the polymer deposition method is used to deposit a polymer deposition layer on the inner wall of the micro-nano channels of the biological vein micro-nano injection needle substrate to form biological vein injection needle nano-channels, obtaining an unbonded biological vein injection needle. Among them, as Figure 2 shown in 2a, the polymer deposition method for growing the parylene film 4 includes the following steps: placing the biological vein micro-nano injection needle substrate into an oxygen plasma asher for oxygen plasma treatment, with a treatment power of 30 W and a treatment time of 30 s; as Figure 2 shown in 2b, placing the oxygen plasma-treated biological vein micro-nano injection needle substrate in the parylene deposition chamber with the structural surface facing up; using 0.15 g of parylene for film growth, where the deposition pressure is 60 mTorr, and using the growth of the parylene film 4 to narrow the nano-channels of the biological vein micro-nano injection needle substrate, generating a parylene film 4 on the surface of the nano-channels of the biological vein micro-nano injection needle substrate, obtaining injection needle nano-channels below 100 nm.

[0115] Specifically, the end size of the spider leg 1 is approximately around 200 nm. Structures with a size of 100 nm and below are called nanostructures. Those with a size above 100 nm and below 1 μm are sub-micrometers. After obtaining the micro-nano channels, the sub-micron structures therein use deposition technology to reduce the sub-micron pores, and finally form self-enclosed nanochannels. The bristle end size of the spider leg 1 is at the sub-micron level. By simply using thin-film deposition technology, the sub-micron channels can be reduced and self-enclosed channels can be formed, achieving two goals with one action. Therefore, there is no need to obtain nanochannels by additional stretching and reduction. After deposition, the nanochannels are already self-enclosed and change from channels to channels. However, the size of the microchannels is relatively too large to be self-enclosed. Therefore, the microchannels remain channels after being treated by the polymer deposition method. Further, after deposition, the micro-nano channels and other planes (any exposed surface) will be deposited with Parylene film 4. Finally, for the reduced micro-nano channels, the sub-micron channels therein form self-enclosed nanochannels.

[0116] As Figure 3 shown, the preparation method of the needle nozzle cover plate includes the following steps:

[0117] By pouring the needle nozzle cover plate mold 9, the needle nozzle cover plate is obtained.

[0118] Among them, as Figure 3 shown in Figure 3a, the preparation method of the needle nozzle cover plate mold 9 includes the following steps: Spin-coat a layer of photoresist 6 on the silicon wafer 5. The photoresist 6 used is AZ703 photoresist, but it is not limited to this. In other embodiments, other types of positive photoresists in the prior art can be selected according to actual usage requirements. The selection of the photoresist 6 will not be elaborated here one by one. As long as it can basically meet the requirements of photolithography, exposure, and development in this embodiment. Among them, the low-speed spin-coating speed of the photoresist 6 is 900 rpm, and the high-speed spin-coating speed is 5000 rpm. Place the silicon wafer 5 spin-coated with the photoresist 6 on a horizontal hot plate for pre-baking for 40 min, where the pre-baking temperature is 90 °C. The heat-cured photoresist 6 after treatment is exposed and developed by a mask aligner through a mask 7. Specifically, place the silicon wafer 5 spin-coated with the photoresist 6 after pre-baking under the mask aligner, place the mask 7, and the ultraviolet light 8 passes through the mask 7 to expose the photoresist 6, where the exposure time is 70 s. After exposure, develop in a developer (AZ series developer) for 50 s. As Figure 3 shown in Figure 3b, remove the exposed photoresist 6, and then place it in deionized water for rinsing for 50 s to obtain a photoresist step with a width of 50 μm. Dry it with a nitrogen gas gun and place it on a high-temperature hot plate at 200 °C for post-baking for 30 min. The photoresist step gradually changes from a rectangular step shape to a semi-circular shape. As Figure 3 shown in Figure 3c, then cool it to room temperature with the plate to obtain the needle nozzle cover plate mold 9.

[0119] The method of obtaining the needle cover plate by casting the needle cover plate mold 9 includes the following steps: pouring the PDMS curing agent mixed solution 10 into the needle cover plate mold 9 and curing it; separating the cured PDMS solid 2 from the PMMA substrate, and using the separated PDMS solid 2 as the needle cover plate. Specifically, 5 ml of trimethylchlorosilane (TMCS) is dropped into the drying tower and sealed for 10 min; the needle cover plate mold 9 is placed in the drying tower filled with TMCS atmosphere for 20 min for hydrophobic treatment, so that an anti-adhesion layer is formed on the surface of the needle cover plate mold 9; as Figure 3 As shown in 3D in the figure, pour the PDMS mixed solution onto the needle cover plate mold 9. The PDMS curing agent mixed solution 10 is a mixture of PDMS and curing agent with a ratio of 8:1. Then place it in a vacuum environment for 2 h to enable the PDMS mixed solution to completely fill the pattern of the needle cover plate mold 9; place the needle cover plate mold 9 poured with the PDMS mixed solution on a horizontal table and let it stand for 20 min, and then bake it in an oven at 80 °C for 4 h to cure the PDMS mixed solution; separate the cured PDMS from the needle cover plate mold 9, and then obtain the needle cover plate with a connection channel. The PDMS curing agent mixed solution 10 is a mixture of PDMS and curing agent with a ratio of 4:1 to 8:1.

[0120] Step S2, as Figure 4 As shown in 4F in the figure, perform oxygen plasma treatment on the unbonded biological vein needle and the needle cover plate respectively. The treatment power of the oxygen plasma treatment is 30 W and the treatment time is 30 s; enter step S3;

[0121] Step S3, as Figure 4 As shown in 4G in the figure, align and bond the unbonded biological vein needle and the needle cover plate after being treated in step S2, seal the unbonded biological vein needle, form a biological vein needle micro-nano channel, and obtain a micro-nano needle. Example 3

[0122] As Figures 1-10 shown, in this embodiment, the organism used is a biological species in the order Araneae, and the micro-nano structure of the biological bristle veins is the legs with bristles in the order Araneae.

[0123] Therefore, a method for manufacturing a micro-nano needle by the casting deposition self-sealing method includes the following steps:

[0124] Step S1, prepare an unbonded biological vein needle and a needle cover plate, and enter step S2;

[0125] As Figure 1 shown, the method for preparing the unbonded biological vein needle includes the following steps:

[0126] Step S1.1, using a casting method to replicate the biological bristle vascular micro-nano structure to manufacture a biological vascular micro-nano spray needle substrate;

[0127] The steps for obtaining the biological vascular micro-nano spray needle substrate include:

[0128] Step S1.1.1, obtaining an organism having a biological bristle venation micro-nano structure, and purifying, drying, and hydrophobicizing the organism.

[0129] Among them, the purification, drying and hydrophobic treatment of organisms include:

[0130] like Figure 1 As shown in 1a, the spider leg 1 is ultrasonically cleaned with deionized water for 15 minutes, the ultrasonic power is 70W, and the temperature is 24°C; the ultrasonic cleaning is repeated 3 times, and finally, a nitrogen air gun is used to blow dry and placed in a 45°C oven for 45 minutes to remove moisture, but it is not limited to this. In other embodiments, a hot plate can be used instead of an oven. 3 ml of trimethylchlorosilane (TMCS) is dripped into the drying tower, and after sealing and volatilization for 7 minutes, the spider leg 1 is vertically placed in a sealed drying tower with a trimethylchlorosilane atmosphere for 15 minutes.

[0131] Step S1.1.2, as Figure 1 As shown in 1b, the purified and dried organism is laid flat on a PMMA substrate, and the PDMS curing agent mixed solution 10 is poured onto the organism on the PMMA substrate and cured to form a PDMS solidified body 2. The PDMS solidified body 2 is cut according to actual needs, and the PDMS of the PDMS solidified body 2 is separated from the spider leg 1 to obtain a biological venous micro-nano spray needle substrate. The PDMS curing agent mixed solution 10 is a 6:1 ratio of PDMS and curing agent. Further, after collecting the spider leg 1, the leg bristles are messy before cleaning. After repeated ultrasonic cleaning, some fragile hairs have fallen off, and most of the remaining bristles are regular. After obtaining the PDMS solidified body 2, the nanochannel end is cut, and the port can obtain an array-distributed spray needle port. Furthermore, in order to improve the cutting stability, the present invention uses a relatively sharp coating knife in the prior art to avoid deformation of the channel caused by a blunt tool. Moreover, when cutting, cut from the back of the channel instead of the front, and cutting from the front of the channel is likely to cause channel deformation.

[0132] Among them, the steps of pouring the PDMS curing agent mixed solution 10 onto the organism of the PMMA substrate and curing it include: the treated spider leg 1 is flatly fixed on the PMMA substrate, the PDMS curing agent mixed solution 10 is poured onto the spider leg 1, and then placed in a vacuum environment below 10Pa and evacuated for 1.2 hours; then placed on a horizontal stationary table and cured at room temperature for 24 hours.

[0133] Among them, the steps of separating the cured PDMS from the organism include: separating the cured PDMS from the spider leg 1 to obtain the PDMS micro-nano mold 3; putting the PDMS micro-nano mold 3 into deionized water and ultrasonically cleaning it for 1.2 h to remove the setae remaining on the PDMS micro-nano mold 3 during the demolding process. During the ultrasonic cleaning process, keep the structural surface facing downwards to make the setae more likely to detach from the PDMS micro-nano mold 3. Among them, the ultrasonic power is 200 W and the ultrasonic time is 45 min; drying the ultrasonically cleaned PDMS micro-nano mold 3 with a nitrogen gas gun and placing it on a hot plate at 90 °C for 20 min to remove the moisture on the PDMS micro-nano mold 3, thereby obtaining the biological vein micro-nano injection needle substrate.

[0134] Step S1.2, as Figure 2 shown, a polymer deposition layer is deposited on the inner wall of the micro-nano channels of the biological vein micro-nano injection needle substrate by the polymer deposition method to form biological vein injection needle nano-channels, thereby obtaining an unbonded biological vein injection needle. Among them, as Figure 2 shown in 2a, the polymer deposition method for growing the parylene film 4 includes the following steps: placing the biological vein micro-nano injection needle substrate into an oxygen plasma asher for oxygen plasma treatment, with a treatment power of 25 W and a treatment time of 25 s; as Figure 2 shown in 2b, placing the oxygen plasma-treated biological vein micro-nano injection needle substrate in a parylene deposition chamber with the structural surface facing upwards; using 0.1 g of parylene for film growth. Among them, the deposition pressure is 45 mTorr. The nano-channels of the biological vein micro-nano injection needle substrate are reduced by growing the parylene film 4, and a parylene film 4 is generated on the surface of the nano-channels of the biological vein micro-nano injection needle substrate to obtain injection needle nano-channels with a size below 100 nm.

[0135] Specifically, the end size of the spider leg 1 is approximately around 200 nm. Structures with a size of 100 nm and below are called nano-structures. Structures with a size above 100 nm and below 1 μm are sub-microns. After obtaining the micro-nano channels, the sub-micron structures therein are reduced by deposition technology to finally form self-enclosed nano-channels. The end size of the setae of the spider leg 1 is at the sub-micron level. Only by using the thin film deposition technology can the sub-micron channels be reduced and self-enclosed channels be formed, killing two birds with one stone. Therefore, there is no need to additionally stretch and reduce to obtain nano-channels. After deposition, the nano-channels are already self-enclosed and change from channels to channels. However, the micron channels are relatively too large in size and cannot be self-enclosed; therefore, the micron channels remain channels after being treated by the polymer deposition method. Further, after deposition, the micro-nano channels and other planes (any exposed surfaces) will be deposited with the parylene film 4; finally, the reduced micro-nano channels, and the sub-micron channels therein form self-enclosed nano-channels.

[0136] As Figure 3 shown, the preparation method of the needle spray cover plate comprises the following steps:

[0137] The needle spray cover plate is obtained by pouring the needle spray cover plate mold 9.

[0138] Among them, as Figure 3 shown in Fig. 3a, the preparation method of the needle spray cover plate mold 9 comprises the following steps: Spin-coat a layer of photoresist 6 on the silicon wafer 5. The photoresist 6 is AZ703 photoresist, but not limited thereto. In other embodiments, other types of positive photoresists and corresponding developers in the prior art can be selected according to actual usage requirements. The selection of the photoresist 6 will not be elaborated here one by one. As long as it can basically meet the requirements of photolithography, exposure, and development of the photoresist 6 in this embodiment. Among them, the low-speed spin-coating speed of the photoresist 6 is 750 rpm, and the high-speed spin-coating speed is 3500 rpm; Place the silicon wafer 5 spin-coated with the photoresist 6 on a horizontal hot plate and pre-bake for 35 min, where the pre-bake temperature is 85°C. The heat-cured photoresist 6 after treatment is exposed and developed by a mask aligner through a mask 7. Specifically, place the silicon wafer 5 spin-coated with the photoresist 6 after pre-baking under the mask aligner, place the mask 7, and the ultraviolet light 8 passes through the mask 7 to expose the photoresist 6, where the exposure time is 50 s; After exposure, develop in a developer (AZ series developer) for 40 s. As Figure 3 shown in Fig. 3b, remove the exposed photoresist 6, and then place it in deionized water and rinse for 40 s; Obtain a photoresist step with a width of 50 μm; Dry it with a nitrogen gas gun, and place it on a high-temperature hot plate at 175°C and post-bake for 25 min. The photoresist step gradually changes from a rectangular step shape to a semi-circular shape. As Figure 3 shown in Fig. 3c, then cool it to room temperature with the plate to obtain the needle spray cover plate mold 9.

[0139] Obtaining the needle tip cover plate through pouring into the needle tip cover plate mold 9 includes the following steps: Pour the PDMS curing agent mixed solution 10 into the needle tip cover plate mold 9 and cure it; Separate the cured PDMS solid 2 from the PMMA substrate, and use the separated PDMS solid 2 as the needle tip cover plate. Specifically, drip 3 ml of trimethylchlorosilane (TMCS) into the drying tower and seal it for 7.5 min; Place the needle tip cover plate mold 9 into the drying tower filled with TMCS atmosphere for 15 min for hydrophobic treatment, so that an anti-adhesion layer is formed on the surface of the needle tip cover plate mold 9; Pour the PDMS mixed solution onto the needle tip cover plate mold 9, and the PDMS curing agent mixed solution 10 is PDMS and curing agent with a ratio of 6:1. Immediately place it in a vacuum environment for 1.5 h to enable the PDMS mixed solution to completely fill the needle tip cover plate mold 9; Place the needle tip cover plate mold 9 poured with the PDMS mixed solution on a horizontal platform and let it stand for 15 min, then bake it in an oven at 70 °C for 3 h to cure the PDMS mixed solution; Separate the cured PDMS from the needle tip cover plate mold 9, and immediately obtain the needle tip cover plate with a connection channel.

[0140] Step S2, as Figure 4 shown in 4f, perform oxygen plasma treatment on the unbonded biological vein needle tip and the needle tip cover plate respectively. The treatment power of the oxygen plasma treatment is 25 W and the treatment time is 20 s; Proceed to step S3;

[0141] Step S3, as Figure 4 shown in 4g, align and bond the unbonded biological vein needle tip and the needle tip cover plate after being processed in step S2, seal the unbonded biological vein needle tip, form a biological vein needle tip micro-nano channel, and obtain a micro-nano needle tip. Example 4

[0142] Based on Example 3, the PDMS curing temperature is 80 °C and the curing time is 2 h. Example 5

[0143] Based on Example 3, the PDMS curing temperature is 75 °C and the curing time is 2.5 h. Example 6

[0144] Based on Example 3, the PDMS curing temperature is 65 °C and the curing time is 3.5 h. Example 7

[0145] Based on Example 3, the PDMS curing temperature is 60 °C and the curing time is 4 h. Example 8

[0146] Based on Example 3, as Figure 5As shown in the figure, in step S3, the steel needle 11 with a diameter of 60 μm after hydrophilic treatment is inserted into the short channel with a diameter of 50 μm between the bonded biological vein injection needle and the injection needle cover plate for interference fit to obtain a micro-nano injection needle. Example Nine

[0147] An injection needle is prepared by using the method for manufacturing a micro-nano injection needle by the casting deposition self-sealing method of Example Eight. Example Ten

[0148] On the basis of Example Three, the photoresist 6 used is SU-8 photoresist, and the developer used is SU-8 developer. However, it is not limited to this. In other embodiments, other types of negative photoresists in the prior art and corresponding developers can be selected according to actual usage requirements. The selection of the photoresist 6 will not be elaborated one by one here. As long as it can basically meet the requirements of photolithography, exposure, and development of the photoresist 6 in this embodiment. Further, when using a negative photoresist, the black and white parts of the mask 7 are opposite to Figure 3 that in 3a; that is, if the same pattern is to be obtained for positive and negative photoresists, the black and white parts (i.e., the light-transmitting and light-blocking areas) of the mask 7 are opposite.

[0149] Working principle:

[0150] A method for manufacturing a micro-nano injection needle by the casting deposition self-sealing method and an injection needle of the present invention obtain a micro-nano cross-scale injection needle nano-channel by replicating the micro-nano structure of biological bristle veins by the casting method; obtain the injection needle nano-channel by the polymer deposition method; and finally use the oxygen plasma-assisted bonding method to seal the micro-nano channel of the biological vein injection needle to obtain a complete micro-nano injection needle.

[0151] The sub-micron pattern is obtained by replicating the bristle structure of the spider leg 1 by the casting method, and the sub-micron pattern is reduced to a nano-pattern below 100 nm by the polymer deposition method, thereby obtaining the injection needle nano-channel; the injection needle cover plate is manufactured by the high-temperature post-baking method, and finally the oxygen plasma-assisted bonding method is used to seal the micro-nano channel of the biological vein injection needle to obtain a polymer micro-nano cross-scale injection needle. Using the technology of the present invention to produce micro-nano injection needles simplifies the manufacturing process, reduces the production cost, and realizes the dual advantages of process simplicity and economic benefits.

[0152] The above specific embodiments are specific supports for the proposed solution idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any equivalent change or equivalent modification made on the basis of this technical solution according to the technical idea proposed by the present invention still belongs to the protection scope of the technical solution of the present invention.

Claims

1. A method for manufacturing micro-nano injection needles by casting deposition self-sealing method, characterized in that, It includes the following steps: Step S1, prepare an unbonded biological vein injection needle and an injection needle cover plate, and enter step S2; The preparation method of the unbonded biological vein injection needle includes the following steps: Step S1.1, replicate the micro-nano structure of biological bristle veins by the casting method to manufacture a biological vein micro-nano injection needle substrate: The acquisition steps of the biological vein micro-nano injection needle substrate include: Step S1.1.1, obtain an organism with a micro-nano structure of biological bristle veins, and perform purification, drying, and hydrophobic treatment on the organism; Step S1.1.2, lay the purified and dried organism flat on a PMMA substrate, pour a PDMS curing agent mixed solution onto the organism on the PMMA substrate and cure it, separate the cured PDMS from the organism, and obtain a biological vein micro-nano injection needle substrate; Step S1.2, deposit a polymer deposition layer on the inner wall of the micro-nano channels of the biological vein micro-nano injection needle substrate by the polymer deposition method to form a biological vein injection needle nano-channel, and obtain an unbonded biological vein injection needle; The polymer deposition method includes the following steps: Place the biological vein micro-nano injection needle substrate into an oxygen plasma asher for oxygen plasma treatment, with a treatment power of 20 - 30 W and a treatment time of 15 - 30 s; place the oxygen plasma-treated biological vein micro-nano injection needle substrate in a parylene deposition chamber with the structural surface facing up; use 0.05 - 0.15 g of parylene for film growth, where the deposition pressure is 20 - 60 mTorr, and use the method of growing a parylene thin film to narrow the micro-nano channels of the biological vein micro-nano injection needle substrate, generate a parylene thin film on the surface of the micro-nano channels of the biological vein micro-nano injection needle substrate, and self-seal to obtain a needle nano-channel with a diameter of less than 100 nm; The preparation method of the injection needle cover plate includes the following steps: Obtain an injection needle cover plate by casting the injection needle cover plate mold, Step S2, perform oxygen plasma treatment on the unbonded biological vein injection needle and the injection needle cover plate respectively, and enter step S3; Step S3, align and bond the unbonded biological vein injection needle and the injection needle cover plate after being processed in step S2, seal the unbonded biological vein injection needle, form a biological vein injection needle micro-nano channel, and obtain a micro-nano injection needle.

2. The method for manufacturing a micro-nano injection needle by the casting deposition self-sealing method according to claim 1, characterized in that: The preparation method of the injection needle cover plate mold includes the following steps: expose and develop the processed thermosetting photoresist through a mask using a lithography machine to obtain an injection needle cover plate mold; Obtaining an injection needle cover plate by casting the injection needle cover plate mold includes the following steps: pour a PDMS curing agent mixed solution into the injection needle cover plate mold and cure it, separate the cured PDMS solid from the PMMA substrate, and use the separated PDMS solid as the injection needle cover plate.

3. The method for manufacturing a micro-nano injection needle by the casting deposition self-sealing method according to claim 2, characterized in that: The organism used is an organism in the Araneae or Diptera of the Insecta class, and the micro-nano structure of the biological bristle veins is the leg bristles of an organism in the Araneae or Diptera of the Insecta class.

4. The method for manufacturing a micro-nano injection needle by the casting deposition self-sealing method according to claim 3, characterized in that: The purification, drying, and hydrophobic treatment of the organism include: Ultrasonically clean the organism with deionized water for 5 - 25 min, where the ultrasonic power is 50 - 90 W and the temperature is 21 - 27 °C; Repeat ultrasonic cleaning for 3 times, and finally use a nitrogen air gun to blow dry and place on a 40-50℃ hot plate or oven for 30-60 min to remove moisture; Drop 1-5 ml of trimethylsilyl chloride into the drying tower, seal it for 5-10 minutes, then place the organism into the drying tower filled with trimethylsilyl chloride and perform hydrophobic treatment for 10-20 minutes; And / or, the step of pouring the PDMS curing agent mixed solution onto the organism on the PMMA substrate and curing the mixture comprises: The treated organism is fixed flat on a PMMA substrate, and the PDMS curing agent mixed solution is poured onto the organism, which is then placed in a vacuum environment below 10Pa for 0.5 to 2 hours; then placed on a horizontal stationary table and cured at room temperature for 20 to 28 hours; The steps to separate the cured PDMS from the organism include: The solidified PDMS is separated from the organism to obtain a PDMS micro-nano mold; the PDMS micro-nano mold is placed in deionized water for ultrasonic cleaning for 0.5 to 2 hours to remove the bristles remaining on the PDMS micro-nano mold during the demolding process. During the ultrasonic cleaning process, the structure should be kept facing downward to make it easier for the bristles to detach from the PDMS micro-nano mold. The ultrasonic power is 100W to 300W, the ultrasonic time is 30 to 60 minutes, and the ultrasonic treatment is repeated 3 times; the PDMS micro-nano mold after ultrasonic cleaning is blown dry with a nitrogen air gun and placed on a hot plate at 80 to 100°C for 10 to 30 minutes to remove moisture from the PDMS micro-nano mold to obtain a biological vascular micro-nano spray needle substrate.

5. The method for manufacturing micro-nano spray needles by a casting deposition self-sealing method according to claim 4, characterized in that: The steps of obtaining the nozzle cover plate by pouring the nozzle cover plate mold include: Spin-coat a layer of photoresist on the silicon wafer, wherein the low-speed spin-coating speed is 600~900rpm and the high-speed spin-coating speed is 1500~5000rpm; Place the silicon wafer with the photoresist spin-coated on a horizontal hot plate and pre-bake for 30-40 minutes at a temperature of 80-90°C. The silicon wafer with the photoresist spun on it after pre-baking is placed under the photolithography machine, and the mask is placed. The photoresist is exposed to ultraviolet light through the mask, and the exposure time is 30-70s. After exposure, develop in AZ series developer for 30-50 seconds to remove the exposed photoresist, and then rinse in deionized water for 30-50 seconds to obtain a photoresist step with a width of 50 μm; Blow dry with a nitrogen air gun, place on a high-temperature hot plate at 150-200°C and bake for 20-30 minutes, the photoresist step gradually changes from a rectangular step to a semicircular shape; then cool to room temperature with the plate to obtain a needle cover plate mold; 1-5 ml of trimethylchlorosilane is dripped into the drying tower and sealed for 5-10 minutes; the spray needle cover plate mold is placed in the drying tower filled with trimethylchlorosilane atmosphere for 10-20 minutes for hydrophobic treatment, so that an anti-adhesion layer is formed on the surface of the spray needle cover plate mold; Pour the PDMS mixed solution with a ratio of 4:1 to 8:1 onto the needle cover mold, and then place it in a vacuum environment for 1 to 2 hours to allow the PDMS mixed solution to completely fill the patterns of the needle cover mold; Place the needle cover mold poured with the PDMS mixed solution on a horizontal table and let it stand for 10 to 20 minutes, and then bake it in an oven at 60 to 80 °C for 2 to 4 hours to cure the PDMS mixed solution; Separate the cured PDMS from the needle cover mold, and then obtain a needle cover with a connection channel.

6. A method for manufacturing a micro-nano needle by casting deposition self-sealing method according to claim 5, characterized in that: In step S3, align and bond the unbonded biological vein needles and the needle cover after being processed in step S2 to seal the unbonded biological vein needles, form a micro-nano channel of the biological vein needle, and obtain a micro-nano needle: Before bonding the biological vein needle and the needle cover, the treatment power of oxygen plasma treatment is 20 to 30 W, and the treatment time is 10 to 30 s; Insert a steel needle with a diameter of 60 μm after hydrophilic treatment into the short channel with a diameter of 50 μm between the bonded biological vein needle and the needle cover for interference fit to obtain a micro-nano needle.

7. A method for manufacturing a micro-nano needle by casting deposition self-sealing method according to claim 6, characterized in that: The hydrophobic treatment of the organism includes: dropping 1 to 5 ml of trimethylchlorosilane into a sealed drying tower. After volatilizing for 5 to 10 minutes, vertically place the spider leg into the sealed drying tower with a trimethylchlorosilane atmosphere for atmosphere treatment for 10 to 20 minutes; The photoresist uses a positive photoresist, and the developer uses a positive resist developer; or, the photoresist uses a negative photoresist, and the developer uses a negative resist developer; The curing temperature of PDMS is 60 °C to 80 °C, and the curing time is 2 h to 4 h; The ratio of the PDMS curing agent mixed solution is PDMS and curing agent with a ratio of 4:1 to 8:

1.

8. A micro-nano injection needle manufactured by a casting deposition self-sealing method, characterized in that: A needle is prepared by using the method for manufacturing a micro-nano needle by casting deposition self-sealing method described in any one of claims 1-7.

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