A method for manufacturing a micro-nano injection needle based on a stretchable material and the injection needle

Abstract

The present invention discloses a method for manufacturing a micro-nano injection needle based on a stretchable material, comprising: printing a photoresist on a first substrate to obtain a first line, obtaining the first substrate with nano-ridges through a stretching method, printing a photoresist on the first substrate with nano-ridges to obtain a second line, and curing and hardening the first substrate to obtain a micro-nano injection needle convex mold; pouring a polymer solution into the micro-nano injection needle convex mold to obtain a micro-nano injection needle bottom plate; merging and bonding the micro-nano injection needle bottom plate and a micro-nano injection needle cover plate to obtain a micro-nano injection needle. The present invention discloses a method for manufacturing a micro-nano injection needle based on a stretchable material and the injection needle. By using electrohydrodynamic printing, the stretching method and the pouring method to obtain a micro-nano injection needle substrate, and cooperating with oxygen plasma to seal the micro-nano channels of the injection needle, a complete micro-nano injection needle is obtained; by utilizing the stretchable characteristics of the thermoplastic material, the manufacturing cost of obtaining the micro-nano injection needle is reduced, and the method has the characteristics of simple process and easy implementation.

Description

Technical Field

[0001] The present invention relates to the field of microelectromechanics, and particularly to a method for manufacturing a micro-nano injection needle based on a stretchable material and the injection needle. Background Art

[0002] Micro-nano injection needles are widely used in high-precision manufacturing technologies such as electrohydrodynamic jet printing. Electrohydrodynamic jet printing technology has attracted much attention due to its high resolution, low cost, and wide ink compatibility, and has broad application prospects in the field of flexible electronic device manufacturing. However, micro-nano injection needles are extremely prone to clogging during the printing process and become consumables in printing experiments. Therefore, how to prepare nano-injection needles at low cost and quickly has become a key problem to be solved urgently.

[0003] In the prior art, methods for manufacturing micro-nano injection needles with low processing costs generally have the problems of difficult size control and complex processing steps. For example, in the stretching of a Sutter puller in traditional injection needle preparation technology, the size is difficult to control and it is easy to break. Moreover, in the prior art, the SU-8 photoresist crack method has poor size controllability and low repeatability. Summary of the Invention

[0004] The present invention overcomes the deficiencies of the prior art and provides a method for manufacturing a micro-nano injection needle based on a stretchable material and the injection needle. An electrohydrodynamic jet printing, stretching method, and casting method are used to obtain a micro-nano injection needle substrate, and an oxygen plasma is used to seal the micro-nano channels of the injection needle to obtain a complete micro-nano injection needle; by utilizing the stretchable characteristics of thermoplastic materials, the manufacturing cost of obtaining micro-nano injection needles is reduced, and it has the characteristics of simple process and easy implementation.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows: A method for manufacturing a micro-nano injection needle based on a stretchable material, comprising the following steps:

[0006] Step 1, obtaining a micro-nano injection needle bottom plate and a micro-nano injection needle cover plate;

[0007] Step 1a, obtaining a micro-nano injection needle bottom plate by casting a polymer solution onto a micro-nano injection needle convex mold;

[0008] The preparation method of the micro-nano injection needle convex mold comprises the following steps:

[0009] Step 1a1, printing a photoresist on a first substrate to obtain a first line, obtaining a first substrate with nano ridges by a stretching method, printing a photoresist on the first substrate with nano ridges to obtain a second line, obtaining a first substrate with micro-nano ridges, and curing and hardening the first substrate with micro-nano ridges to obtain a micro-nano injection needle convex mold;

[0010] Step 1a2, casting a polymer solution onto the micro-nano injection needle convex mold to obtain a micro-nano injection needle bottom plate;

[0011] Step 1b: Obtain the micro-nano needle cover plate by pouring a polymer solution into the micro-nano needle cover plate mold.

[0012] Step 2: Align and bond the micro-nano needle bottom plate and the micro-nano needle cover plate to obtain the micro-nano needle.

[0013] In a preferred embodiment of the present invention, Line 1 includes Micro Ridge 1.

[0014] Line 2 includes Micro Ridge 2 connected to Line 1 and an outer contour pattern surrounding Micro Ridge 1 and Micro Ridge 2.

[0015] The photoresist used for printing Line 1 and / or Line 2 is a positive photoresist or a negative photoresist.

[0016] In a preferred embodiment of the present invention, in Step 1a1, the stretching method includes:

[0017] Heat the substrate 1 printed with Line 1, and then stretch the heated substrate 1 to drive the stretching of Line 1 until Line 1 on the substrate 1 is stretched into a nano ridge.

[0018] In Step 1a1, curing and hardening the film includes the following steps:

[0019] Place the substrate 1 with micro-nano ridges on a horizontal hot plate for pre-baking, lithography, and hardening the film to obtain a micro-nano needle convex mold.

[0020] In a preferred embodiment of the present invention, obtaining the micro-nano needle bottom plate by pouring a polymer solution into the micro-nano needle convex mold includes the following steps:

[0021] Step 1a2.1: Seal, dry, and perform hydrophobic treatment on the micro-nano needle convex mold.

[0022] Step 1a2.2: Pour the polymer solution into the micro-nano needle convex mold.

[0023] Step 1a2.3: Place the micro-nano needle convex mold poured with the polymer solution in an oven for curing.

[0024] Step 1a2.4: Demold the micro-nano needle convex mold poured with the polymer solution after curing, and trim the outer shape to obtain the micro-nano needle bottom plate.

[0025] In a preferred embodiment of the present invention, in Step 1a2.1, place the micro-nano needle convex mold in a sealed drying tower with a trimethylsiloxane atmosphere of 1 - 5 ml for sealed drying, and the time for hydrophobic treatment is 10 - 20 min.

[0026] And / or, in step 1a2.2, the method for preparing the polymer solution is as follows: mix the PDMS base material and the curing agent in a ratio of 4:1 to 8:1, stir for 5 minutes to mix evenly, and then place it in a vacuum chamber to degas and remove air bubbles. The obtained polymer solution is the PDMS mixed solution;

[0027] And / or, in step 1a2.3, place the micro-nano syringe needle convex mold poured with the polymer solution in a vacuum chamber, keep the air pressure in the vacuum chamber below 10 Pa for 1 to 2 hours to eliminate the air bubbles in the polymer solution and fill the micro-nano syringe needle convex mold pattern, and then place it on a static table for 20 to 30 minutes; then place the micro-nano syringe needle convex mold poured with the polymer solution in an oven for curing, the oven temperature is 60 to 80 °C, and the baking time is 2 to 4 hours; then after cooling the cured micro-nano syringe needle convex mold poured with the polymer solution to room temperature, take it out for demolding, and use a coating tool to cut and trim the outer shape to obtain the micro-nano syringe needle bottom plate.

[0028] In a preferred embodiment of the present invention, the method for preparing the micro-nano syringe needle cover mold includes the following steps:

[0029] Print a photoresist on the washed substrate two by electrohydrodynamic printing, then place it on a horizontal hot plate and heat for 15 to 30 minutes, control the temperature at 60 to 100 °C, then perform photolithography for 5 to 10 minutes, and place it on the hot plate for hardening for 15 to 30 minutes, with a temperature of 60 to 100 °C, to obtain the micro-nano syringe needle cover mold.

[0030] In a preferred embodiment of the present invention, obtaining the micro-nano syringe needle cover by pouring a polymer solution into the micro-nano syringe needle cover mold includes the following steps:

[0031] Put the micro-nano syringe needle cover mold into a sealed drying tower with a trimethylsiloxane atmosphere of 1 to 5 ml for hydrophobic treatment for 10 to 20 minutes, pour the prepared polymer solution onto the micro-nano syringe needle cover mold, and then place the micro-nano syringe needle cover mold poured with the polymer solution in a vacuum chamber, with the air pressure in the vacuum chamber below 10 Pa for 1 to 2 hours, to remove the air bubbles in the polymer solution in the micro-nano syringe needle cover mold and fill the pouring cavity of the micro-nano syringe needle cover mold with the polymer solution; then place it on a static table for 20 to 30 minutes; then place it in an oven for curing, the oven temperature is 60 to 80 °C, and the baking time is 2 to 4 hours; then after cooling to room temperature, take it out for demolding, and use a coating tool to correct the outer shape to obtain the micro-nano syringe needle cover.

[0032] In a preferred embodiment of the present invention, in step 2, the micro-nano syringe needle bottom plate and the micro-nano syringe needle cover are aligned and bonded to obtain the micro-nano syringe needle, including the following steps:

[0033] The micro-nano injection needle bottom plate and the micro-nano injection needle cover plate are respectively treated with oxygen plasma, with a treatment power of 15 - 25 W and a treatment time of 20 - 30 s;

[0034] Align and bond the treated micro-nano injection needle bottom plate and the micro-nano injection needle cover plate to seal the micro-nano channels on the micro-nano injection needle bottom plate.

[0035] In a preferred embodiment of the present invention, the micron ridge two includes micron ridges with a printing width of 30 - 50 μm and 70 - 100 μm after the nano ridge;

[0036] And / or, in step 1a1, the pre-baking time in the curing and hardening film is 15 - 30 min, the pre-baking temperature is 60 - 100 °C, the photolithography time is 5 - 10 min, the hardening time for placing on the hot plate for hardening the film is 15 - 30 min, and the hardening temperature is 60 - 100 °C;

[0037] And / or, in step 1a1, the heating temperature of the first substrate is 110 - 130 °C, the tensile force for stretching is 5 - 30 N, the stretching time is 8 - 15 s, and the nano ridge is a nano ridge below 100 nm;

[0038] And / or, in step 1a1, when the first substrate is at room temperature, the tensile force for stretching is 5 - 30 N, the stretching time is 8 - 15 s, and the nano ridge is a nano ridge below 100 nm;

[0039] And / or, during the stretching process in step 1a1, the relative direction of stretching can be adjusted according to the required nano ridge size; among them, the force trajectories between the relative directions of several stretches can adopt intersecting force trajectories for adjusting the nano ridge size;

[0040] And / or, the first substrate and / or the second substrate is one of PMMA film, PET film, PVP film, sealing film, PDMS film, PC film, PP film, PE film, PVC film, PS film, SERS thin film, hydrogel film;

[0041] And / or, the photoresist used for printing line one and / or line two is BN photoresist;

[0042] And / or, the photoresist used for printing line one and / or line two can be replaced by one of PDMS, PEO, hydrogel, liquid metal, rubber, graphene;

[0043] And / or, in step 2, insert the steel needle into the microchannel of the micro-nano channel formed by sealing the bonded micro-nano injection needle bottom plate and the micro-nano injection needle cover plate for interference fit to obtain the micro-nano injection needle;

[0044] And / or, the parameter requirements of the photoresist of the first line include: the viscosity range includes 5 to 5000 cP; the surface tension range includes: 20 to 45 mN / m.

[0045] In a preferred embodiment of the present invention, a micro-nano injection needle is prepared by a micro-nano injection needle manufacturing method based on a stretching material.

[0046] The present invention solves the defects existing in the technical background, and the beneficial technical effects of the present invention are:

[0047] A micro-nano injection needle manufacturing method and injection needle based on a stretching material obtain a micro-nano injection needle substrate by electrohydrodynamic printing, stretching method and casting method, and cooperate with oxygen plasma to seal the micro-nano channels of the injection needle to obtain a complete micro-nano injection needle; by utilizing the stretchable characteristics of thermoplastic materials, the manufacturing cost of obtaining micro-nano injection needles is reduced, and it has the characteristics of simple process and easy implementation. Brief Description of the Drawings

[0048] The present invention will be further described below in conjunction with the drawings and embodiments.

[0049] Figure 1 It is a manufacturing flow chart of the convex mold of the micro-nano injection needle in the preferred embodiment of the present invention.

[0050] Figure 2 It is a manufacturing flow chart of the micro-nano injection needle in the preferred embodiment of the present invention;

[0051] Figure 3 It is a manufacturing flow chart of the cover mold of the micro-nano injection needle in the preferred embodiment of the present invention;

[0052] Figure 4 It is a manufacturing flow chart of the cover of the micro-nano injection needle in the preferred embodiment of the present invention;

[0053] Figure 5 It is a bonding and encapsulation flow chart of the micro-nano injection needle in the preferred embodiment of the present invention;

[0054] Figure 6 It is an optical microscope of the convex mold of the micro-nano injection needle in the preferred embodiment of the present invention Figure 1 ;

[0055] Figure 7 It is an optical microscope of the convex mold of the micro-nano injection needle in the preferred embodiment of the present invention Figure 2 ;

[0056] Figure 8 It is a partial optical microscope image of the micro-nano injection needle in the preferred embodiment of the present invention;

[0057] Figure 9It is a picture of gradually stretching the first printed line (micron line) in the preferred embodiment of the present invention by the stretching method to make the first printed line thinner to form the first micron ridge;

[0058] Figure 10 It is the lateral stretching in the preferred embodiment of the present invention to make the line thicker. The left side is the printed line and the right side is the line after being laterally widened.

[0059] In the figure: 1, the first micron ridge; 21, the first substrate; 22 - the second substrate; 3, the printing steel needle; 4, the nano ridge; 5, the second micron ridge; 7, the plastic conical needle head; 8, the polymer solution; 9, the steel needle. Specific embodiments

[0060] Now, the present invention will be further described in 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.

[0061] It should be noted that if there are directional indications (such as up, down, bottom, top, etc.) in the embodiments of the present invention, the directional indications are only used to explain the relative position relationship and movement situation between components in a specific posture. If the specific posture changes, the 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 indicating 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 limited, the terms "set", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

[0062] As Figures 1 - 5 shown, a method for manufacturing a micro - nano injection needle based on a stretched material includes the following steps:

[0063] Step 1, obtaining a micro - nano injection needle bottom plate and a micro - nano injection needle cover plate;

[0064] Step 1a, obtaining the micro - nano injection needle bottom plate by pouring the polymer solution 8 into the micro - nano injection needle convex mold;

[0065] Among them, the preparation method of the micro - nano injection needle convex mold includes the following steps:

[0066] Step 1a1: Print photoresist on substrate 1 - 21 to obtain Line 1, and obtain substrate 1 - 21 with nano - ridges 4 through the stretching method. Specifically, Line 1 includes micro - ridge 1. The stretching method uses the heat - stretching method, which includes: heating substrate 1 - 21 printed with Line 1, and then stretching the heated substrate 1 - 21 to drive the stretching of Line 1 until Line 1 on substrate 1 - 21 is stretched into nano - ridge 4. Further, the heating temperature of substrate 1 - 21 is 110 - 130 °C, the stretching force is 5 - 30 N, the stretching time is 8 - 15 s, and nano - ridge 4 is a nano - ridge with a size below 100 nm. However, it is not limited to this. In other embodiments, the stretching method includes: when substrate 1 - 21 is at room temperature, the stretching force is 2 - 50 N, the stretching time is 2 - 10 s, and nano - ridge 4 is a nano - ridge with a size below 100 nm. Further, in the present invention, by selecting different stretching materials as the preparation materials for substrate 1 - 21, the heat - stretching method or the room - temperature stretching method in the stretching method is correspondingly adopted. The stretching materials include: thermoplastics (which can be stretched by heating, such as PMMA, PET, etc.), characteristics: softening after heating, plastically stretchable (irreversible deformation), and shaping after cooling. Or, the stretching materials include: elastomers (which can be elastically stretched at room temperature, such as PDMS, rubber, TPE / TPU, etc.); characteristics: reversibly stretchable at room temperature (elastic deformation), with strong resilience. Or, the stretching materials include: flexible thermoplastics (which can be plastically stretched at room temperature, such as LDPE food wrap, PVC sealing film, PC film, etc.); characteristics: can be extended and stretched at room temperature, but it is irreversible plastic deformation (no resilience). Even further, the photoresist itself has a certain viscosity; the adhesion strength of the substrate is improved by performing oxygen plasma treatment on substrate 1 - 21, thereby improving the bonding force between the substrate and the printing material; the surface tension mainly affects the width of the line. For example, it can be in a spread - out shape or a three - dimensional cylindrical shape; so for the actual experiment itself, the photoresist can form nano - ridge 4 under the stretching of the stretching method. And the parameter requirements of the photoresist of Line 1 in the present invention include: the viscosity range is 5 - 5000 cP; the surface tension range is 20 - 45 mN / m.

[0067] Then, print photoresist on substrate 1 - 21 with nano - ridges 4 to obtain Line 2. Specifically, Line 2 includes micro - ridge 2 - 5 connected to Line 1 and an outer - contour pattern surrounding micro - ridge 1 and micro - ridge 2 - 5; obtain substrate 1 - 21 with micro - nano - ridges. More specifically, micro - ridge 2 - 5 includes micro - ridges printed after nano - ridge 4 with a width of 30 - 50 μm and 70 - 100 μm.

[0068] Then, the substrate 21 with micro-nano ridges is cured and hardened to obtain a micro-nano injection needle convex mold. Specifically, the curing and hardening process includes the following steps: placing the substrate 21 with micro-nano ridges on a horizontal hot plate for pre-baking, photolithography, and hardening to obtain a micro-nano injection needle convex mold. Further, in the curing and hardening process, the pre-baking time is 15 - 30 min, the pre-baking temperature is 60 - 100 °C, the photolithography time is 5 - 10 min, the hardening time of placing on the hot plate is 15 - 30 min, and the hardening temperature is 60 - 100 °C. Hardening can improve the adhesion between the photoresist and the substrate 21.

[0069] Step 1a2, pouring a polymer solution 8 into the micro-nano injection needle convex mold to obtain a micro-nano injection needle bottom plate; it includes the following steps:

[0070] Step 1a2.1, performing sealing drying and hydrophobic treatment on the micro-nano injection needle convex mold. Specifically, in step 1a2.1, the micro-nano injection needle convex mold is placed in a sealed drying tower with an atmosphere of 1 - 5 ml trimethylchlorosilane (TMCS) for sealing drying, and the hydrophobic treatment time is 10 - 20 min.

[0071] Step 1a2.2, pouring the polymer solution 8 into the micro-nano injection needle convex mold.

[0072] Step 1a2.3, placing the micro-nano injection needle convex mold with the poured polymer solution 8 in an oven for curing. Specifically, in step 1a2.3, the micro-nano injection needle convex mold with the poured polymer solution 8 is placed in a vacuum chamber, keeping the air pressure in the vacuum chamber below 10 Pa for 1 - 2 h to remove the bubbles in the polymer solution 8 and fill the micro-nano injection needle convex mold pattern, and then placed on a static table for 20 - 30 min; then the micro-nano injection needle convex mold with the poured polymer solution 8 is placed in an oven for curing, the oven temperature is 60 - 80 °C, and the baking time is 2 - 4 h.

[0073] Step 1a2.4, demolding the cured micro-nano injection needle convex mold with the poured polymer solution 8 and trimming its outer shape to obtain a micro-nano injection needle bottom plate. Specifically, after cooling the cured micro-nano injection needle convex mold with the poured polymer solution 8 to room temperature, it is taken out for demolding, and a coating tool is used to cut and trim the outer shape to obtain a micro-nano injection needle bottom plate.

[0074] Step 1b, obtaining a micro-nano injection needle cover plate by pouring a polymer solution 8 into the micro-nano injection needle cover plate mold.

[0075] Among them, the preparation method of the micro-nano injection needle cover plate mold includes the following steps:

[0076] The photoresist is printed on the cleaned substrate 22 by electrohydrodynamic printing, and then placed on a horizontal hot plate and heated for 15 - 30 min at a controlled temperature of 60 - 100 °C. Then, photolithography is performed for 5 - 10 min, and it is placed on the hot plate for hard baking for 15 - 30 min at a temperature of 60 - 100 °C to obtain the micro-nano injection needle cover mold. Hard baking can improve the adhesion between the photoresist and the substrate 22.

[0077] The micro-nano injection needle cover is obtained by pouring the polymer solution 8 into the micro-nano injection needle cover mold, including the following steps:

[0078] The micro-nano injection needle cover mold is placed in a sealed drying tower with a trimethylsiloxane atmosphere of 1 - 5 ml for hydrophobic treatment for 10 - 20 min. The prepared polymer solution 8 is poured onto the micro-nano injection needle cover mold, and then the micro-nano injection needle cover mold with the polymer solution 8 poured on it is placed in a vacuum chamber with a pressure below 10 Pa for 1 - 2 h to remove the air bubbles in the polymer solution 8 in the micro-nano injection needle cover mold and fill the pouring cavity of the micro-nano injection needle cover mold with the polymer solution 8. Subsequently, it is placed on a static table for 20 - 30 min; then it is placed in an oven for curing, the oven temperature is 60 - 80 °C, and the baking time is 2 - 4 h; then after cooling to room temperature, it is taken out for demolding, and the outer shape is corrected with a coating tool to obtain the micro-nano injection needle cover.

[0079] Step 2, the micro-nano injection needle bottom plate and the micro-nano injection needle cover are aligned and bonded; the micro-nano injection needle is obtained. Specifically, it includes the following steps:

[0080] The micro-nano injection needle bottom plate and the micro-nano injection needle cover are respectively treated with oxygen plasma, the treatment power is 15 - 25 W, and the treatment time is 20 - 30 s;

[0081] The treated micro-nano injection needle bottom plate and the micro-nano injection needle cover are aligned and bonded to seal the micro-nano channels on the micro-nano injection needle bottom plate.

[0082] More specifically, the substrate 21 and / or the substrate 22 is one of PMMA film, PET film, PVP film, sealing film, PDMS film, PC film, PP film, PE film, PVC film, PS film, SERS thin film, hydrogel film.

[0083] More specifically, the photoresist used for printing the first line and / or the second line is BN photoresist.

[0084] More specifically, the photoresist used for printing the first line and / or the second line can be replaced by one of PDMS, PEO, hydrogel, liquid metal, rubber, graphene.

[0085] In the present invention, the biggest feature lies in its strong inclusiveness and flexibility. As long as the substrate material has strong plasticity and can be infinitely stretched, a pattern of the target scale can be obtained. However, since the substrate will break when stretched to the limit, the size also depends on the choice of the substrate. In the present invention, most of the printing is at the sub-micron level, which is convenient for quickly obtaining nano-scale lines. Example 1

[0086] As Figures 1 - 5 shown, a method for manufacturing a micro-nano injection needle based on a stretchable material includes the following steps:

[0087] Step 1: Obtain a micro-nano injection needle bottom plate and a micro-nano injection needle cover plate;

[0088] Step 1a: Obtain the micro-nano injection needle bottom plate by pouring a polymer solution 8 into a micro-nano injection needle convex mold;

[0089] Among them, the preparation method of the micro-nano injection needle convex mold includes the following steps:

[0090] Step 1a1: Print a photoresist on the substrate 1 21 to obtain a line 1, and obtain the substrate 1 21 with a nano-ridge 4 by the stretching method. Print a photoresist on the substrate 1 21 with a nano-ridge 4 to obtain a line 2. Cure and harden the substrate 1 21 with a micro-nano ridge to obtain a micro-nano injection needle convex mold.

[0091] Specifically, the substrate 1 21 is a PMMA substrate. Before printing the photoresist on the PMMA substrate to obtain the line 1, the substrate 1 21 is ultrasonically cleaned in deionized water for 15 min, where the ultrasonic power is 70 W. In this embodiment, the deionized water used is anhydrous ethanol. Finally, the substrate 1 21 is dried with a nitrogen gas gun and placed on a hot plate at 80 °C to dry the substrate 1 21 and remove the excess moisture on the surface of the substrate 1 21. And place it on a hot plate at 80 °C to dry and remove the moisture. When printing the photoresist to obtain the line 1, the cleaned PMMA substrate is placed on the printing table, and the printing needle 3 of the printing mechanism is used to print the line 1 on the PMMA substrate. The line 1 includes a micro-ridge 1, and the arrangement structure of the micro-ridge 1 is an array of BN photoresist with a micro-ridge 1 of 1-2 um.

[0092] Specifically, in the step of obtaining the substrate 21 with the nano-ridges 4 by the stretching method, the stretching method specifically includes: placing the substrate 21 printed with the first line on a stretcher, heating the heating pad to 110 °C, and placing the heated heating pad under the substrate 21 (i.e., the PMMA substrate) printed with the first line (i.e., the BN photoresist micro-ridge), heating the substrate 21 printed with the first line, the heating temperature of the substrate 21 is 110 °C, and then using the stretcher to stretch the heated substrate 21, thereby driving the first line to stretch, the stretching force is 5 N, and the stretching time is 8 s, until the first line on the substrate 21 is stretched into the nano-ridges 4. Further, the nano-ridges 4 are nano-ridges below 100 nm.

[0093] Specifically, the second line includes the second micro-ridge 5 connected to the first line, and the outer contour pattern surrounding the first micro-ridge 1 and the second micro-ridge 5; obtaining the substrate 21 with micro-nano ridges. Among them, the second micro-ridge 5 includes a micro-ridge printed after the nano-ridges 4 with a width of 30 μm, 70 μm, and 30 μm. Further, in this embodiment, an electrohydrodynamic printing method is used to print a 30-μm BN photoresist micro-ridge on the basis of the array nano-ridges; the printing parameters are a voltage of 1500 V and a working distance of 450 μm. An electrohydrodynamic printing method is used to print a 70-μm BN photoresist micro-ridge on the basis of the 30-μm BN photoresist micro-ridge; the printing parameters for the 70-μm BN photoresist micro-ridge are a voltage of 2100 V and a working distance of 600 μm. An electrohydrodynamic printing method is used to print a 30-μm BN photoresist micro-ridge on the basis of the 70-μm BN photoresist micro-ridge. The parameters are a voltage of 1500 V and a working distance of 450 μm. The printing method of the outer contour pattern includes: using a plastic tapered needle 7 to print the outer contour pattern on the clean substrate 21, and the printing parameters of the outer contour pattern include: a printing voltage of 2000 V, a moving speed of 50 mm / min, and a printing working distance of 300 μm.

[0094] Specifically, curing and hardening the film includes the following steps: placing the substrate 21 with micro-nano ridges on a horizontal hot plate for pre-baking, the pre-baking time in curing and hardening the film is 15 min, and the pre-baking temperature is 60 °C; then lithography, the lithography time is 5 min; then placing it on the hot plate for hardening the film, the hardening time of the film is 15 min, and the hardening temperature is 60 °C. Hardening the film can improve the adhesion between the photoresist and the substrate 21; then obtaining the micro-nano injection needle convex mold.

[0095] Step 1a2, pouring the polymer solution 8 into the micro-nano injection needle convex mold to obtain the micro-nano injection needle bottom plate; including the following steps:

[0096] Step 1a2.1: Seal and dry the micro-nano injection needle convex mold and perform hydrophobic treatment. Specifically, in Step 1a2.1, place the micro-nano injection needle convex mold into a sealed drying tower with an atmosphere of 1 ml trimethylchlorosilane (TMCS) for sealing and drying, and the hydrophobic treatment time is 10 min.

[0097] Step 1a2.2: Pour the polymer solution 8 into the micro-nano injection needle convex mold. Specifically, the preparation method of the polymer solution 8 is as follows: Mix the PDMS base material and the curing agent in a ratio of 4:1, stir for 5 min to mix evenly, and then place it in a vacuum box for degassing to remove air bubbles. The obtained polymer solution 8 is a PDMS mixed solution.

[0098] Step 1a2.3: Place the micro-nano injection needle convex mold poured with the polymer solution 8 into an oven for curing. Specifically, in Step 1a2.3, first place the micro-nano injection needle convex mold poured with the polymer solution 8 in a vacuum box, keep the air pressure in the vacuum box below 10 Pa for 1 h to eliminate the polymer solution 8, in this embodiment, eliminate the air bubbles in the PDMS mixed solution, and fill the micro-nano injection needle convex mold pattern, and then place it on a static table for 20 min; then place the micro-nano injection needle convex mold poured with the polymer solution 8 in an oven for curing, the oven temperature is 60 °C, and the baking time is 2 h.

[0099] Step 1a2.4: Demold the cured micro-nano injection needle convex mold poured with the polymer solution 8 and trim the outer shape to obtain a micro-nano injection needle bottom plate. Specifically, after cooling the cured micro-nano injection needle convex mold poured with the polymer solution 8 to room temperature, take it out for demolding, and use a coating tool to cut and trim the outer shape to obtain a micro-nano injection needle bottom plate.

[0100] Step 1b: Obtain a micro-nano injection needle cover plate by pouring the polymer solution 8 into the micro-nano injection needle cover plate mold.

[0101] Among them, the preparation method of the micro-nano injection needle cover plate mold includes the following steps:

[0102] Obtain the second substrate 22. In this embodiment, the second substrate 22 is a PMMA substrate. Place the second substrate 22 in absolute ethanol and ultrasonically clean it for 30 min, with an ultrasonic power of 100 W; then ultrasonically clean it in deionized water for 30 min, with an ultrasonic power of 100 W; finally, dry it with a nitrogen gas gun and place it on a hot plate at 80 °C to dry, removing the excess water on the second substrate 22. Place the cleaned second substrate 22 on the printing table, and print a photoresist on the second substrate 22 by electrohydrodynamic printing. When printing, use a plastic conical needle 7 to print a BN photoresist micro-nano needle cover mold, with printing parameters of a voltage of 2000 V, a printing moving speed of 50 mm / min, and a printing working distance of 300 μm. Then place the second substrate 22 printed with BN photoresist on a horizontal hot plate and heat it for 15 min, with a heating temperature of 60 °C, then perform photolithography for 5 min, and place it on the hot plate for post-baking for 15 min, at a temperature of 60 °C, to obtain a micro-nano needle cover mold. Post-baking can improve the adhesion of the photoresist to the second substrate 22.

[0103] Obtain a micro-nano needle cover by pouring a polymer solution 8 into the micro-nano needle cover mold, including the following steps:

[0104] Place 1 ml in a sealed drying tower with a trimethylsiloxane atmosphere. After volatilizing for 5 min, vertically place the micro-nano needle cover mold into a sealed drying tower with a trimethylsiloxane atmosphere for atmosphere treatment for 10 min. Pour the prepared polymer solution 8 onto the micro-nano needle cover mold, and then place the micro-nano needle cover mold poured with the polymer solution 8 in a vacuum chamber. The air pressure in the vacuum chamber is below 10 Pa and lasts for 1 - 2 h to remove the bubbles in the polymer solution 8 in the micro-nano needle cover mold and fill the casting cavity of the micro-nano needle cover mold with the polymer solution 8; then place it on a static table for 20 min; then place it in an oven for curing, with an oven temperature of 60 °C and a baking time of 2 h; then cool it to room temperature, take it out for demolding, and use a coating tool to correct the shape to obtain a micro-nano needle cover.

[0105] Step 2: Align and bond the micro-nano needle bottom plate and the micro-nano needle cover; obtain a micro-nano needle. Specifically, it includes the following steps:

[0106] Perform oxygen plasma treatment on the micro-nano needle bottom plate and the micro-nano needle cover respectively, with a treatment power of 15 W and a treatment time of 20 s;

[0107] Align and bond the treated micro-nano needle bottom plate and the micro-nano needle cover to seal the micro-nano channels on the micro-nano needle bottom plate. Embodiment 2

[0108] As Figures 1 - 5 shown, a method for manufacturing a micro-nano needle based on a stretchable material includes the following steps:

[0109] Step 1: Obtain a micro-nano injection needle bottom plate and a micro-nano injection needle cover plate.

[0110] Step 1a: Obtain the micro-nano injection needle bottom plate by pouring a polymer solution 8 into a micro-nano injection needle convex mold.

[0111] Among them, the preparation method of the micro-nano injection needle convex mold includes the following steps:

[0112] Step 1a1: Print a photoresist on a substrate 21 to obtain a first line, and obtain the substrate 21 with nano ridges 4 through a stretching method. Print a photoresist on the substrate 21 with nano ridges 4 to obtain a second line. Cure and harden the substrate 21 with micro-nano ridges to obtain the micro-nano injection needle convex mold.

[0113] Specifically, the substrate 21 is a PMMA substrate. Before printing the photoresist on the PMMA substrate to obtain the first line, first ultrasonically clean the substrate 21 in deionized water for 30 minutes, where the ultrasonic power is 120 W; in this embodiment, the deionized water used is anhydrous ethanol; finally, dry the substrate 21 with a nitrogen gas gun and place it on a hot plate at 80 - 100 °C to dry the substrate 21 and remove the excess moisture on the surface of the substrate 21. When printing the photoresist to obtain the first line, place the cleaned PMMA substrate on the printing table, and use the printing needle 3 of the printing mechanism to print the first line on the PMMA substrate. The first line includes a first micron ridge 1, and the arrangement structure of the first micron ridge 1 is an array of 2-μm BN photoresist micron ridges 1.

[0114] Specifically, in the step of obtaining the substrate 21 with nano ridges 4 through the stretching method, the stretching method specifically includes: Place the substrate 21 printed with the first line on a stretcher, heat the heating pad to 130 °C, and place the heated heating pad under the substrate 21 (i.e., the PMMA substrate) printed with the first line (i.e., the BN photoresist micron ridge) to heat the substrate 21 printed with the first line. The heating temperature of the substrate 21 is 130 °C, and then use the stretcher to stretch the heated substrate 21, thereby driving the first line to stretch. The stretching force is 30 N, and the stretching time is 15 s until the first line on the substrate 21 is stretched into nano ridges 4. Further, the nano ridges 4 are nano ridges below 100 nm.

[0115] Specifically, the second line includes a micro-ridge two 5 connected to the first line, and an outer contour pattern circumferentially arranged around the first micro-ridge 1 and the second micro-ridge 5; a first substrate 21 with micro-nano ridges is obtained. Among them, the second micro-ridge 5 includes micro-ridges with printing widths of 50 μm, 100 μm, and 50 μm after the nano-ridge 4. Further, in this embodiment, a 50-μm BN photoresist micro-ridge is printed on the basis of the array nano-ridge by electrohydrodynamic printing; the printing parameters are a voltage of 2500 V and a working distance of 700 μm. A 100-μm BN photoresist micro-ridge is printed on the basis of the 50-μm BN photoresist micro-ridge by electrohydrodynamic printing; the printing parameters for the 100-μm BN photoresist micro-ridge are a voltage of 2600 V and a working distance of 900 μm. A 50-μm BN photoresist micro-ridge is printed on the basis of the 100-μm BN photoresist micro-ridge by electrohydrodynamic printing. The parameters are a voltage of 2500 V and a working distance of 700 μm. The printing method of the outer contour pattern includes: using a plastic tapered needle 7 to print the outer contour pattern on a clean first substrate 21, and the printing parameters of the outer contour pattern include: a printing voltage of 2500 V, a moving speed of 100 mm / min, and a printing working distance of 500 μm.

[0116] Specifically, curing and hardening the film includes the following steps: placing the first substrate 21 with micro-nano ridges on a horizontal hot plate for pre-baking, the pre-baking time in curing and hardening the film is 30 min, and the pre-baking temperature is 100 °C; then performing photolithography, the photolithography time is 10 min; then placing it on the hot plate for hardening the film, the hardening time of the film is 30 min, and the hardening temperature is 100 °C. Hardening the film can improve the adhesion between the photoresist and the first substrate 21; then a micro-nano needle ejection convex mold is obtained.

[0117] Step 1a2, pouring a polymer solution 8 into the micro-nano needle ejection convex mold to obtain a micro-nano needle bottom plate; including the following steps:

[0118] Step 1a2.1, performing sealing drying and hydrophobic treatment on the micro-nano needle ejection convex mold. Specifically, in step 1a2.1, the micro-nano needle ejection convex mold is placed in a sealed drying tower with an atmosphere of 5 ml trimethylchlorosilane (TMCS) for sealing drying, and the hydrophobic treatment time is 20 min.

[0119] Step 1a2.2, pouring the polymer solution 8 into the micro-nano needle ejection convex mold. Specifically, the preparation method of the polymer solution 8 is: mixing PDMS base material and curing agent in a ratio of 4:1 to 8:1, stirring for 5 to 10 min to mix evenly, and then placing it in a vacuum box for degassing to remove bubbles. The obtained polymer solution 8 is a PDMS mixed solution.

[0120] Step 1a2.3: The micro-nano needle convex mold poured with the polymer solution 8 is placed in an oven for curing. Specifically, in Step 1a2.3, the micro-nano needle convex mold poured with the polymer solution 8 is first placed in a vacuum chamber, and the air pressure in the vacuum chamber is maintained below 10 Pa for 2 h to eliminate the polymer solution 8. In this embodiment, the bubbles in the PDMS mixed solution are eliminated, and the pattern of the micro-nano needle convex mold is filled. Then, it is placed on a static table for 30 min. Then, the micro-nano needle convex mold poured with the polymer solution 8 is placed in an oven for curing. The oven temperature is 80 °C, and the baking time is 4 h.

[0121] Step 1a2.4: Demold the cured micro-nano needle convex mold poured with the polymer solution 8 and trim its outer shape to obtain the micro-nano needle bottom plate. Specifically, after the cured micro-nano needle convex mold poured with the polymer solution 8 is cooled to room temperature, it is taken out for demolding, and a coating tool is used to cut and trim the outer shape to obtain the micro-nano needle bottom plate.

[0122] Step 1b: The micro-nano needle cover plate is obtained by pouring the polymer solution 8 into the micro-nano needle cover plate mold.

[0123] Among them, the preparation method of the micro-nano needle cover plate mold includes the following steps:

[0124] Obtain the substrate two 22. In this embodiment, the substrate two 22 is a PMMA substrate. The substrate two 22 is placed in absolute ethanol and ultrasonically cleaned for 30 min, with an ultrasonic power of 100 W. Then, it is ultrasonically cleaned in deionized water for 30 min, with an ultrasonic power of 100 W. Finally, it is dried with a nitrogen gas gun and placed on a hot plate at 100 °C to dry, removing the excess water on the substrate two 22. The cleaned substrate two 22 is placed on a printing table, and a BN photoresist is printed on the substrate two 22 by electrohydrodynamic printing. When printing, a plastic conical needle 7 is used to print the BN photoresist micro-nano needle cover plate mold. The printing parameters are a voltage of 2500 V, a printing moving speed of 100 mm / min, and a printing working distance of 500 μm. Then, the substrate two 22 printed with the BN photoresist is placed on a horizontal hot plate and heated for 30 min at a heating temperature of 100 °C, then lithographed for 10 min, and placed on the hot plate for hard baking for 30 min at a temperature of 100 °C to obtain the micro-nano needle cover plate mold. Hard baking can improve the adhesion between the photoresist and the substrate two 22.

[0125] Obtaining the micro-nano needle cover plate by pouring the polymer solution 8 into the micro-nano needle cover plate mold includes the following steps:

[0126] In a sealed and dry tower with a 5 ml trimethylsiloxane atmosphere, after volatilizing for 10 min, the micro-nano syringe needle cover mold is vertically placed into the sealed and dry tower with a trimethylsiloxane atmosphere for atmosphere treatment for 20 min. The prepared polymer solution 8 is poured onto the micro-nano syringe needle cover mold, and then the micro-nano syringe needle cover mold with the polymer solution 8 poured thereon is placed in a vacuum chamber. The air pressure in the vacuum chamber is below 10 Pa for 2 h to remove the air bubbles in the polymer solution 8 in the micro-nano syringe needle cover mold, and the polymer solution 8 fills the casting cavity of the micro-nano syringe needle cover mold; then it is placed on a stationary table for 30 min; then it is placed in an oven for curing. The oven temperature is 80 °C and the baking time is 4 h; then after cooling to room temperature, it is taken out for demolding, and the outer shape is corrected with a coating tool to obtain a micro-nano syringe needle cover.

[0127] Step 2, align and bond the micro-nano syringe needle bottom plate and the micro-nano syringe needle cover; obtain a micro-nano syringe needle. Specifically, it includes the following steps:

[0128] The micro-nano syringe needle bottom plate and the micro-nano syringe needle cover are respectively treated with oxygen plasma. The treatment power is 25 W and the treatment time is 30 s;

[0129] Align and bond the treated micro-nano syringe needle bottom plate and the micro-nano syringe needle cover to seal the micro-nano channels on the micro-nano syringe needle bottom plate. Example 3

[0130] As Figures 1 - 5 shown, a method for manufacturing a micro-nano syringe needle based on a stretchable material includes the following steps:

[0131] Step 1, obtain a micro-nano syringe needle bottom plate and a micro-nano syringe needle cover;

[0132] Step 1a, obtain a micro-nano syringe needle bottom plate by pouring a polymer solution 8 into a micro-nano syringe needle convex mold;

[0133] Among them, as Figure 1 、 Figure 2 shown, the preparation method of the micro-nano syringe needle convex mold includes the following steps:

[0134] Step 1a1, print a photoresist on the substrate 1 21 to obtain a line 1, and obtain the substrate 1 21 with a nano-ridge 4 by the stretching method. Print a photoresist on the substrate 1 21 with a nano-ridge 4 to obtain a line 2. Cure and harden the substrate 1 21 with a micro-nano ridge to obtain a micro-nano syringe needle convex mold.

[0135] Specifically, the substrate 21 is a PMMA substrate. Before printing the photoresist on the PMMA substrate to obtain the line 1, the substrate 21 is ultrasonically cleaned in deionized water for 22 minutes, with the ultrasonic power being 95 W. In this embodiment, the deionized water used is anhydrous ethanol. Finally, the substrate 21 is dried with a nitrogen gas gun and placed on a hot plate at 90 °C to dry the substrate 21 and remove the excess moisture on the surface of the substrate 21. When printing the photoresist to obtain the line 1, the cleaned PMMA substrate is placed on the printing table, and the printing needle 3 of the printing mechanism is used to print the line 1 (such as Figure 1 1a in). The line 1 includes the micro-ridge 1, and the arrangement structure of the micro-ridge 1 is an array of BN photoresist with a size of 1 - 2 μm. In this embodiment, it is an array of BN photoresist with a size of 1.5 μm for the micro-ridge 1.

[0136] Among them, as Figure 9 shows, after printing the line 1 (micro-line), the printed line is gradually stretched by the heating and stretching method to make the line thinner to form the micro-ridge 1. The first one in the order of the arrow direction is the original image, the second one is stretched by 50%, the third one is stretched by 100%, and the fourth one is stretched by 150%. The size of the fourth one is about 1 μm, and the unclear part in the local area is about sub-micron. Since single nanoscale single lines cannot be photographed under a microscope unless they are in an array. Figure 6 、 Figure 7 shows the optical microscope image of the micro-nano injection needle convex mold; among them, Figure 6 is Figure 7 the enlarged schematic diagram of the end part. In addition, Figure 10 shows that the line becomes thicker through horizontal stretching. The left side is the printed line, and the right side is the line after being horizontally widened.

[0137] Specifically, in the step of obtaining the substrate 21 with the nano-ridge 4 by the stretching method, the stretching method specifically includes: placing the substrate 21 printed with the line 1 on the stretcher, heating the heating pad to 120 °C, and placing the heated heating pad under the substrate 21 (i.e., the PMMA substrate) printed with the line 1 (i.e., the BN photoresist micro-ridge) to heat the substrate 21 printed with the line 1. The heating temperature of the substrate 21 is 120 °C, and then the stretcher is used to stretch the heated substrate 21, thereby driving the line 1 to stretch. The stretching force is 17 N, and the stretching time is 12 s until the line 1 on the substrate 21 is stretched into the nano-ridge 4. Further, the nano-ridge 4 is a nano-ridge below 100 nm (as shown in Figure 1 1b).

[0138] Specifically, the second line includes a micron ridge two 5 connected to the first line, and an outer contour pattern surrounding the micron ridge one 1 and the micron ridge two 5; a first substrate 21 with micro-nano ridges is obtained. Among them, the micron ridge two 5 includes a printed width after the nano ridge 4, including three micron ridges printed successively of 40 μm (such as Figure 1 in 1c), 85 μm (such as Figure 1 in 1d), and 40 μm (such as Figure 1 in 1e). Further, in this embodiment, a 40-μm BN photoresist micron ridge is printed on the basis of the array nano ridge by electrohydrodynamic printing; the printing parameters are a voltage of 2000 V and a working distance of 600 μm. A 85-μm BN photoresist micron ridge is printed on the basis of the 40-μm BN photoresist micron ridge by electrohydrodynamic printing; the printing parameters of the 85-μm BN photoresist micron ridge are a voltage of 2400 V and a working distance of 750 μm. A 40-μm BN photoresist micron ridge is printed on the basis of the 85-μm BN photoresist micron ridge by electrohydrodynamic printing. The parameters are a voltage of 2000 V and a working distance of 600 μm. The printing method of the outer contour pattern includes: using a plastic tapered needle 7 to print the outer contour pattern (such as Figure 1 in 1f) on a clean first substrate 21. The printing parameters of the outer contour pattern include: a printing voltage of 2000 V, a moving speed of 75 mm / min, and a printing working distance of 400 μm.

[0139] Specifically, curing and hardening the film includes the following steps: placing the first substrate 21 with micro-nano ridges on a horizontal hot plate for pre-baking. The pre-baking time in curing and hardening the film is 22 min, and the pre-baking temperature is 80 °C; then performing photolithography, and the photolithography time is 7.5 min; then placing it on the hot plate for hardening the film, the hardening time of the film is 22 min, and the hardening temperature is 80 °C. Hardening the film can improve the adhesion between the photoresist and the first substrate 21; then a micro-nano spray needle convex mold is obtained.

[0140] Step 1a2, pouring a polymer solution 8 into the micro-nano spray needle convex mold to obtain a micro-nano spray needle bottom plate; including the following steps:

[0141] Step 1a2.1, performing sealing drying and hydrophobic treatment on the micro-nano spray needle convex mold. Specifically, in step 1a2.1, the micro-nano spray needle convex mold is placed in a sealed drying tower with an atmosphere of 3 ml trimethylchlorosilane (TMCS) for sealing drying, and the hydrophobic treatment time is 15 min.

[0142] Step 1a2.2, pour the polymer solution 8 into the micro-nano ejector pin convex mold. Specifically, the preparation method of the polymer solution 8 is as follows: mix the PDMS base material and the curing agent in a ratio of 6:1, stir for 7.5 min to mix evenly, and then place it in a vacuum chamber for degassing to remove air bubbles. The obtained polymer solution 8 is a PDMS mixed solution.

[0143] Step 1a2.3, place the micro-nano ejector pin convex mold poured with the polymer solution 8 in an oven for curing (such as Figure 2 in 2a). Specifically, in Step 1a2.3, first place the micro-nano ejector pin convex mold poured with the polymer solution 8 in a vacuum chamber, keep the air pressure in the vacuum chamber below 10 Pa, and continue for 1.5 h to eliminate the polymer solution 8. In this embodiment, it is to eliminate the air bubbles in the PDMS mixed solution and fill the micro-nano ejector pin convex mold pattern, and then place it on the static table for 25 min; then place the micro-nano ejector pin convex mold poured with the polymer solution 8 in an oven for curing. The oven temperature is 70 °C and the baking time is 3 h.

[0144] Step 1a2.4, demold the cured micro-nano ejector pin convex mold poured with the polymer solution 8, and trim the outer shape to obtain the micro-nano ejector pin bottom plate. Specifically, after cooling the cured micro-nano ejector pin convex mold poured with the polymer solution 8 to room temperature, take it out for demolding, and use a coating tool to cut and trim the outer shape to obtain the micro-nano ejector pin bottom plate (such as Figure 2 in 2b).

[0145] Step 1b, obtain the micro-nano ejector pin cover plate by pouring the polymer solution 8 into the micro-nano ejector pin cover plate mold.

[0146] Among them, the preparation method of the micro-nano ejector pin cover plate mold includes the following steps:

[0147] Obtain the substrate two 22. In this embodiment, the substrate two 22 is a PMMA substrate. Put the substrate two 22 into absolute ethanol and ultrasonically clean it for 30 min, with an ultrasonic power of 100 W; then ultrasonically clean it in deionized water for 30 min, with an ultrasonic power of 100 W; finally, dry it with a nitrogen gas gun and place it on a hot plate at 90 °C to dry, removing the excess moisture on the substrate two 22. Place the cleaned substrate two 22 on the printing table, and print the photoresist on the substrate two 22 by electrohydrodynamic printing. When printing, use a plastic conical needle 7 to print the BN photoresist micro-nano ejector pin cover plate mold, and the printing parameters are a voltage of 2000 V, a printing moving speed of 75 mm / min, and a printing working distance of 400 μm. Then place the substrate two 22 printed with BN photoresist on a horizontal hot plate and heat it for 22 min, with a heating temperature of 80 °C, then perform photolithography for 7.5 min, and place it on the hot plate for hardening for 22 min, at a temperature of 80 °C, to obtain the micro-nano ejector pin cover plate mold (such asFigure 3 in 3a). Hard baking can improve the adhesion between the photoresist and the substrate 22.

[0148] The micro-nano needle cover plate is obtained by pouring a polymer solution 8 into the micro-nano needle cover plate mold, including the following steps:

[0149] Place it in a sealed drying tower with a trimethylsiloxane atmosphere for 3 ml. After volatilizing for 7.5 min, vertically place the micro-nano needle cover plate mold into a sealed drying tower with a trimethylsiloxane atmosphere for atmosphere treatment for 15 min. Pour the prepared polymer solution 8 onto the micro-nano needle cover plate mold, and then place the micro-nano needle cover plate mold poured with the polymer solution 8 in a vacuum box. The air pressure in the vacuum box is below 10 Pa for 1.5 h to remove the air bubbles in the polymer solution 8 in the micro-nano needle cover plate mold, and the polymer solution 8 fills the pouring cavity of the micro-nano needle cover plate mold (such as Figure 4 in 4a); then place it on a static table for 25 min; then place it in an oven for curing. The oven temperature is 70 °C and the baking time is 3 h; then after cooling to room temperature, take it out for demolding and use a coating tool to correct the shape to obtain the micro-nano needle cover plate (such as Figure 4 in 4b).

[0150] Step 2, align and bond the micro-nano needle bottom plate and the micro-nano needle cover plate; obtain the micro-nano needle. Specifically, it includes the following steps:

[0151] Perform oxygen plasma treatment on the micro-nano needle bottom plate and the micro-nano needle cover plate respectively (such as Figure 5 in 5a), the treatment power is 20 W and the treatment time is 25 s;

[0152] Align and bond the treated micro-nano needle bottom plate and the micro-nano needle cover plate (such as Figure 5 in 5b) to seal the micro-nano channels on the micro-nano needle bottom plate. Example 4

[0153] On the basis of Example 1, the viscosity range of the photoresist for printing Line 1, Line 2 and the outer contour pattern includes 5 cP; the surface tension range includes: 20 mN / m. Example 5

[0154] On the basis of Example 2, the viscosity range of the photoresist for printing Line 1, Line 2 and the outer contour pattern includes 5000 cP; the surface tension range includes: 45 mN / m. Example 6

[0155] On the basis of Example 3, the viscosity range of the photoresist for printing Line 1, Line 2 and the outer contour pattern includes 2500 cP; the surface tension range includes: 40 mN / m. Example VII

[0156] Based on Example III, the viscosity range of the photoresist for printing Line 1, Line 2, and the outer contour pattern includes 300 cP; the surface tension range includes: 25 mN / m. Example VIII

[0157] Based on Example III, the viscosity range of the photoresist for printing Line 1, Line 2, and the outer contour pattern includes 400 cP; the surface tension range includes: 30 mN / m. Example IX

[0158] Based on Example I, in Step 2, insert the 50-μm steel needle 9 after hydrophilic treatment into the microchannel of the micro-nano injection needle formed by sealing the bonded micro-nano injection needle bottom plate and the micro-nano injection needle cover plate for interference fit (such as Figure 5 5c in), to obtain the micro-nano injection needle. Example X

[0159] Based on Example II, in Step 2, insert the 60-μm steel needle 9 after hydrophilic treatment into the microchannel of the micro-nano injection needle formed by sealing the bonded micro-nano injection needle bottom plate and the micro-nano injection needle cover plate for interference fit to obtain the micro-nano injection needle. Example XI

[0160] Based on Example III, in Step 2, insert the 55-μm steel needle 9 after hydrophilic treatment into the microchannel of the micro-nano injection needle formed by sealing the bonded micro-nano injection needle bottom plate and the micro-nano injection needle cover plate for interference fit to obtain the micro-nano injection needle. Example XII

[0161] As Figures 1 - 5 shown, a micro-nano injection needle is prepared by using a method for manufacturing a micro-nano injection needle based on a stretching material in Example XI. Example XIII

[0162] Based on Example III, in Step 1a1, print photoresist on the substrate 1 21 to obtain Line 1, and obtain the substrate 1 21 with nano-ridges 4 by the stretching method. Print photoresist on the substrate 1 21 with nano-ridges 4 to obtain Line 2. Cure and harden the substrate 1 21 with micro-nano ridges to obtain the micro-nano injection needle convex mold.

[0163] Specifically, the first substrate 21 is a PC substrate. Before printing the photoresist on the first substrate 21 to obtain the first line, the first substrate 21 is ultrasonically cleaned in deionized water for 22 minutes, with an ultrasonic power of 95 W; and then dried with a nitrogen gas gun. When printing the photoresist to obtain the first line, the cleaned first substrate 21 is placed on the printing table, and the printing needle 3 of the printing mechanism is used to print the first line on the first substrate 21. The first line includes the first micron ridge 1, and the arrangement structure of the first micron ridge 1 is an array of BN photoresist with a size of 1 - 2 μm. In this embodiment, it is an array of BN photoresist with a size of 1.5 μm for the first micron ridge 1.

[0164] Among them, the stretching method uses the normal-temperature stretching method, including: when the first substrate 21 is in the normal-temperature state, the stretching force is 2 N, the stretching time is 2 s, and the nano ridge 4 is a nano ridge with a size of less than 100 nm. Example 14

[0165] Based on Example 13, the stretching method uses the normal-temperature stretching method, including: when the first substrate 21 is in the normal-temperature state, the stretching force is 50 N, the stretching time is 10 s, and the nano ridge 4 is a nano ridge with a size of less than 100 nm. Example 15

[0166] Based on Example 13, the stretching method uses the normal-temperature stretching method, including: when the first substrate 21 is in the normal-temperature state, the stretching force is 25 N, the stretching time is 6 s, and the nano ridge 4 is a nano ridge with a size of less than 100 nm.

[0167] Working principle:

[0168] The present invention provides a method for manufacturing a micro-nano injection needle based on a stretched material and an injection needle. The electrohydrodynamic printing, stretching method, and casting method are used to obtain the micro-nano injection needle substrate, and the micro-nano channels of the injection needle are sealed with oxygen plasma to obtain a complete micro-nano injection needle; by utilizing the stretchable characteristics of the thermoplastic material, the manufacturing cost of obtaining the micro-nano injection needle is reduced, and it has the characteristics of simple process and easy implementation.

[0169] The present invention directly obtains the micro-nano injection needle convex mold by using two processes of stretching and printing; finally, the micro-nano injection needle is obtained by casting and replicating the micro-nano injection needle convex mold pattern, and bonding is performed.

[0170] The present invention obtains a micron pattern by printing any material with high ductility onto a thermoplastic or flexible substrate, and obtains a nano pattern by stretching and shrinking the micron pattern; then, the injection needle profile is printed again using the printing technology to complete the manufacturing of the micro-nano injection needle convex mold.

[0171] The steps of the present invention are simple, the process is environmentally friendly, the cost is low, the efficiency is high, there are no dangerous experimental links, and the requirements for experimental equipment and experimental environment are low. It belongs to a flexible and simple micro-nano manufacturing technology.

[0172] Although the present invention is a manufacturing method based on thermoplastic materials, if lines are printed on a flexible substrate, it is still possible to reduce micron lines to nano lines depending on the high elasticity of the flexible substrate, with high selectivity and flexible controllability.

[0173] 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 changes or equivalent modifications made on the basis of this technical solution according to the technical idea proposed by the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A method for manufacturing a micro-nano injection needle based on a stretchable material, characterized in that, It includes the following steps: Step 1: Obtain a micro-nano injection needle bottom plate and a micro-nano injection needle cover plate; Step 1a: Obtain the micro-nano injection needle bottom plate by pouring a polymer solution into a micro-nano injection needle convex mold; The preparation method of the micro-nano injection needle convex mold includes the following steps: Step 1a1: Print a photoresist on a first substrate to obtain a first line. Obtain a first substrate with nano ridges by the stretching method. Then print a photoresist on the first substrate with nano ridges to obtain a second line, and obtain a first substrate with micro-nano ridges. Then cure and harden the first substrate with micro-nano ridges to obtain the micro-nano injection needle convex mold; The stretching method includes: Heat the first substrate printed with the first line, and then stretch the heated first substrate to drive the first line to stretch until the first line on the first substrate is stretched into nano ridges; In Step 1a1, curing and hardening includes the following steps: Place the first substrate with micro-nano ridges on a horizontal hot plate for pre-baking, lithography, and hardening to obtain the micro-nano injection needle convex mold; Step 1a2: Obtain the micro-nano injection needle bottom plate by pouring a polymer solution into the micro-nano injection needle convex mold; Step 1b: Obtain the micro-nano injection needle cover plate by pouring a polymer solution into a micro-nano injection needle cover plate mold; Step 2: Align and bond the micro-nano injection needle bottom plate and the micro-nano injection needle cover plate to obtain a micro-nano injection needle.

2. The method for manufacturing a micro-nano injection needle based on a stretchable material according to claim 1, wherein: The first line includes a first micro-ridge; The second line includes a second micro-ridge connected to the first line and an outer contour pattern surrounding the first micro-ridge and the second micro-ridge; The photoresist used for printing the first line and / or the second line is a positive photoresist or a negative photoresist.

3. The method for manufacturing a micro-nano injection needle based on a stretchable material according to claim 2, characterized in that: Obtaining the micro-nano injection needle bottom plate by pouring a polymer solution into the micro-nano injection needle convex mold includes the following steps: Step 1a2.1: Seal and dry the micro-nano injection needle convex mold and perform hydrophobic treatment; Step 1a2.2: Pour the polymer solution into the micro-nano injection needle convex mold; Step 1a2.3: Place the micro-nano injection needle convex mold poured with the polymer solution in an oven for curing; Step 1a2.4: Demold the cured micro-nano injection needle convex mold poured with the polymer solution and trim the outer shape to obtain the micro-nano injection needle bottom plate.

4. A method for manufacturing a micro-nano injection needle based on a stretching material according to claim 3, characterized in that: In Step 1a2.1, place the micro-nano injection needle convex mold in a sealed drying tower with a 1 - 5 ml trimethylsiloxane atmosphere for sealed drying, and the hydrophobic treatment time is 10 - 20 min; In Step 1a2.2, the preparation method of the polymer solution is: Mix PDMS base material and curing agent in a ratio of 4:1 - 8:1, stir for 5 min to mix evenly, and then place it in a vacuum box for degassing to remove bubbles. The obtained polymer solution is a PDMS mixed solution; In Step 1a2.3, place the micro-nano needle convex mold poured with the polymer solution in a vacuum chamber, keep the air pressure in the vacuum chamber below 10 Pa for 1 - 2 h to eliminate the bubbles in the polymer solution and fill the micro-nano needle convex mold pattern, and then place it on a static table for 20 - 30 min; then place the micro-nano needle convex mold poured with the polymer solution in an oven for curing, with the oven temperature at 60 - 80 °C and the baking time of 2 - 4 h; then after cooling the cured micro-nano needle convex mold poured with the polymer solution to room temperature, take it out for demolding, and use a coating tool to cut and trim the outer shape to obtain the micro-nano needle bottom plate.

5. A method for manufacturing a micro-nano needle based on a stretching material according to claim 4, characterized in that: A method for preparing a micro-nano needle cover mold includes the following steps: Print a photoresist on the washed Substrate 2 by electrohydrodynamic printing, then place it on a horizontal hot plate and heat for 15 - 30 min, control the temperature at 60 - 100 °C, then perform photolithography for 5 - 10 min, and place it on the hot plate for hardening for 15 - 30 min at a temperature of 60 - 100 °C to obtain the micro-nano needle cover mold.

6. A method for manufacturing a micro-nano needle based on a stretching material according to claim 5, characterized in that: Obtaining the micro-nano needle cover by pouring a polymer solution into the micro-nano needle cover mold includes the following steps: Put the micro-nano needle cover mold into a sealed drying tower with a 1 - 5 ml trimethylsiloxane atmosphere for hydrophobic treatment for 10 - 20 min, pour the prepared polymer solution onto the micro-nano needle cover mold, then place the micro-nano needle cover mold poured with the polymer solution in a vacuum chamber, with the air pressure in the vacuum chamber below 10 Pa for 1 - 2 h to remove the bubbles in the polymer solution in the micro-nano needle cover mold and fill the pouring cavity of the micro-nano needle cover mold with the polymer solution; then place it on a static table for 20 - 30 min; then place it in an oven for curing, with the oven temperature at 60 - 80 °C and the baking time of 2 - 4 h; then after cooling to room temperature, take it out for demolding, and use a coating tool to correct the outer shape to obtain the micro-nano needle cover.

7. A method for manufacturing a micro-nano injection needle based on a stretching material according to claim 6, characterized in that: In Step 2, the micro-nano needle bottom plate and the micro-nano needle cover are aligned and bonded to obtain the micro-nano needle, including the following steps: Respectively perform oxygen plasma treatment on the micro-nano needle bottom plate and the micro-nano needle cover, with the treatment power at 15 - 25 W and the treatment time of 20 - 30 s; Align and bond the treated micro-nano needle bottom plate and the micro-nano needle cover to seal the micro-nano channels on the micro-nano needle bottom plate.

8. A method for manufacturing a micro-nano injection needle based on a stretchable material according to claim 7, characterized in that: The micro-ridge 2 includes printing micro-ridges with a width of 30 - 50 μm and 70 - 100 μm after the nano-ridge.

9. A method for manufacturing a micro-nano injection needle based on a stretchable material according to claim 8, characterized in that: In Step 1a1, the pre-baking time in the curing hardening film is 15 - 30 min, the pre-baking temperature is 60 - 100 °C, the photolithography time is 5 - 10 min, and the hardening time when placed on the hot plate for hardening is 15 - 30 min, and the hardening temperature is 60 - 100 °C.

10. A method for manufacturing a micro-nano injection needle based on a stretching material according to claim 9, characterized in that: In step 1a1, the heating temperature of the first substrate is 110~130°C, the tensile force for stretching is 5~30 N, the stretching time is 8~15 s, and the nanoridges are nanoridges below 100 nm.

11. A method for manufacturing a micro-nano injection needle based on a stretching material according to claim 10, characterized in that: In step 1a1, during the stretching process, the relative stretching direction is adjusted according to the required nanoridge size; among them, the force trajectories between the relative directions of several stretches adopt intersecting force trajectories for adjusting the nanoridge size.

12. A method for manufacturing a micro-nano injection needle based on a stretchable material according to claim 11, characterized in that: The first substrate and / or the second substrate is one of PMMA film and PC film.

13. A manufacturing method of a micro-nano injection needle based on a stretching material according to claim 12, characterized in that: The photoresist used for printing the first line and / or the second line is BN photoresist.

14. A method for manufacturing a micro-nano injection needle based on a stretching material according to claim 13, characterized in that: In step 2, a steel needle is inserted into the microchannel of the micro-nano injection needle formed by sealing the micro-nano injection needle bottom plate and the micro-nano injection needle cover plate after bonding for interference fit to obtain a micro-nano injection needle.

15. A method for manufacturing a micro-nano injection needle based on a stretching material according to claim 14, characterized in that: The parameter requirements of the photoresist for the first line include: viscosity range: 5~5000 cP; surface tension range: 20~45 mN / m.

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