Preparation method for preparing electrode access on acupuncture needle and application

Abstract

The invention discloses a preparation method for preparing an electrode path on an acupuncture needle and application, and belongs to the field of micro-nano manufacturing. Compared with other preparation methods in the prior art, the method has the advantages that the operation is repeated, the process equipment is simple, the production cost is low, and the patterning on the taper edge with the minimum curvature radius is different from the traditional standard planar micro-nano processing technology, for example, the patterning can only be carried out on the plane by using the traditional photoetching; and operation cannot be performed on the surface of the acupuncture needle with the extremely small curvature radius. According to the invention, digitization, standardization, intelligentization and visualization can be realized in acupuncture. The acupuncture needle can be used for measuring various ion concentrations, temperatures, tissue impedance and the like.

Description

Technical Field

[0001] The invention relates to a method for preparing an electrode path on an acupuncture needle, and belongs to the field of micro-nano manufacturing. Background Art

[0002] In the field of micro-nano manufacturing, flexible photolithography for curvature edges is a challenging but critical technology. With the rapid development of micro-nano processing technology, biomedical devices and sensors, the demand for fine pattern preparation on curvature edges is increasing. However, traditional photolithography technology is often limited by hard substrates, making it difficult to achieve high-precision pattern transfer on curvature edges. Therefore, the development of flexible photolithography technology suitable for curvature edges has become one of the hot topics in current research. Traditional photolithography technology is usually based on rigid substrates such as silicon wafers. Its pattern preparation process requires covering a photoresist layer on a flat substrate surface, and using a light source to project the desired pattern onto the photoresist through a mask, and then achieving pattern transfer through steps such as development. However, on curvature edges or uneven surfaces, such as coating photoresist and pattern transfer processes on invasive acupuncture needles, there are great challenges, and problems such as light fatigue and distortion are prone to occur, resulting in the prepared pattern not meeting the requirements. In response to this challenge, researchers have proposed a new technical solution for flexible photolithography on tapered edges with extremely small curvature radii in recent years. This technology uses the characteristics of flexible substrates, combined with advanced photolithography equipment and materials, to adjust the properties of photoresist and the preparation process to accurately prepare micro-nano patterns on the edge of the curvature. Specifically, by optimizing the adhesion and plasticity of the photoresist, it can completely cover the surface of the edge of the curvature, and use a high-resolution photolithography exposure system to achieve accurate projection and transfer of the pattern. Summary of the invention

[0003] The purpose of the present invention is to prepare a multi-channel electrode path on an acupuncture needle by a flexible photolithography mask. The method is simple to operate, the process equipment is simple, and the production cost is low. The present invention can realize digitization, standardization, intelligence and visualization in acupuncture. The acupuncture needle can be used to measure multiple ion concentrations or temperatures.

[0004] In order to solve the technical problem of the present invention, a technical solution is proposed: a method for preparing an electrode path on an acupuncture needle, comprising the following steps:

[0005] The surface of the silicon wafer is treated, and then a Ni sacrificial layer and a Cr metal layer are successively evaporated on the surface of the silicon wafer, and then a photoresist is spin-coated, and a pattern is formed on the main substrate silicon wafer using a common photolithography process to prepare a master template;

[0006] Then, a light-transmitting elastomer polydimethylsiloxane (PDMS) is applied to the master template. The cured PDMS has completed the pattern transfer. The Ni metal is etched using a Ni etchant, and the PDMS wrapped with patterned Cr is peeled off from the master template to obtain a flexible mask with patterned Cr metal wrapped.

[0007] A layer of insulating material, a layer of metal layer and a layer of photoresist are prepared on the acupuncture needle in sequence, and a flexible mask wrapped with Cr metal is conformally contacted and attached to the photoresist surface of the acupuncture needle. An ultraviolet lamp is used to shield the ultraviolet light through the metal layer Cr wrapped by the elastic polymer in the flexible mask, and then it is placed in a developer to form a pattern.

[0008] Preferably, the method comprises the following steps:

[0009] First, the surface of the silicon wafer is treated with an oxygen plasma cleaning machine, and then a Ni sacrificial layer and a Cr metal layer are successively evaporated on the surface of the silicon wafer; then SU-8 photoresist is spin-coated at a rotation speed of 1000rmp, and after pre-baking and curing, it is contact-covered on the surface of the silicon wafer with a traditional optical mask, and after irradiation with an ultraviolet lamp with a wavelength of 365nm, the silicon wafer with photoresist is immersed in AR 300-26 developer for 2min, and the surface is immediately rinsed with deionized water and blown dry with nitrogen; the silicon wafer is immersed in Cr etching solution for 2min and then taken out, and the surface is immediately rinsed with deionized water and blown dry with nitrogen, and then a plasma stripper is used to remove excess photoresist; at this time, a patterned Cr metal layer has been formed;

[0010] On the patterned Cr surface, PDMS was spin-coated at a speed of 3500 rpm for 30 seconds, and then the spin-coated silicon wafer was placed on a CNC heating table and heated at 80°C for 1 hour to complete the curing of PDMS; the cured PDMS has completed the pattern transfer, and the Ni metal is etched using a Ni etchant to peel off the PDMS wrapped with patterned Cr from the silicon wafer; the designed CAD circuit pattern includes a three-electrode system, a counter electrode, a reference electrode, and a working electrode; there are three working electrodes that can measure Na, K, and Ca ions, which are the three left paths, the tip rectangular part is the working sensing electrode part, and the conductive path connects the sensing electrode; the fourth path is the reference electrode; the fifth path is the counter electrode; the five paths are arranged in a gradient;

[0011] A 200-micron acupuncture needle was sanded for 5 minutes and ultrasonically cleaned; a polyurethane acrylate photocurable resin solution was evenly sprayed on the surface of the acupuncture needle by spraying, and then quickly cured by ultraviolet light to complete the preparation of the insulating layer; the insulated acupuncture needle was placed in a sputtering gold spraying instrument, and the sputtering was repeated 10 times to complete the preparation of the Au metal layer; finally, a photoresist was sprayed on the metal layer by spraying and cured;

[0012] A long strip of PDMS flexible mask with a width equal to the circumference of the surface of the acupuncture needle is tightly attached to the surface of the acupuncture needle under a microscope, and a UV lamp with a wavelength of 365nm is used to uniformly rotate and irradiate the acupuncture needle to complete the exposure on the acupuncture needle. The acupuncture needle is then placed in the developer AR 300-26 developer for 1 minute, and the surface is immediately rinsed with deionized water after being taken out; the metal layer not attached by the photoresist is etched with a gold etchant; after the etching is completed, the surface is immediately rinsed with deionized water, and then a microwave plasma stripper is used to remove all the remaining photoresist, completing the preparation of micron-scale needle patterning with multiple electrode channels.

[0013] Preferably, the insulating material is one selected from nitrocellulose, unsaturated polyester resin, polyacid acrylate resin, epoxy acrylate resin, polyurethane acrylate resin, and cationic curing base resin.

[0014] Preferably, the metal layer is deposited by one of vacuum evaporation, sputtering, electroplating and chemical vapor deposition.

[0015] Preferably, in the flexible photomask, the pattern thickness of the patterned surface is in the range of 1 μm to 100 μm.

[0016] Preferably, in the flexible photomask, the width of the electrode path is in the range of 1 nm to 10 μm.

[0017] Preferably, the acupuncture needle has a diameter in the range of 50 μm to 400 μm.

[0018] In order to solve the technical problem of the present invention, another technical solution is proposed: the use of acupuncture needles with multiple electrode channels prepared by any method can realize digitization, standardization, intelligence and visualization in acupuncture.

[0019] Preferably, the acupuncture needle is used to measure multiple ion concentrations or temperatures, and can also measure ion concentrations at different depths.

[0020] Preferably, the ultraviolet irradiation wavelength of the conventional photolithography process is 365 nm, the main substrate uses a silicon wafer, and the photoresist uses SU-8 photoresist.

[0021] Preferably, the light-transmitting elastomer is a 10:1 mixture of PDMS, a PDMS precursor of Sylgard 184 and a cross-linking agent, which is cut into rectangles of 8 cm*1 mm after polymerization.

[0022] Preferably, the light-transmitting elastomer can be prepared by spin coating at a rate of 3500 rpm for 30 seconds, and polymerized in a heating device at 80° C. for 1 hour.

[0023] Preferably, the insulating material is polyurethane acrylate photocurable resin (PUA).

[0024] Preferably, the metal layer material is Au.

[0025] Preferably, the metal layer is prepared using a gold sputtering instrument, current is applied after vacuum, and the sputtering process is repeated 10 times.

[0026] The method of being able to prepare a multi-channel electrode pathway on an acupuncture needle can also be extended to other cylindrical or conical objects with a very small radius of curvature.

[0027] The present invention provides a micron-scale needle with multiple electrode channels, including materials corresponding to specific processing methods, and preparing several electrode paths with conductive properties by controlling parameters of instruments such as photolithography, spin coating, evaporation, sputtering, etc. The width of the conductive path can be adjusted in the range of tens of nanometers to tens of micrometers.

[0028] After patterning on the main substrate using a traditional photomask, a flexible photolithography mask is prepared using a light-transmitting elastomer. An insulating layer, a metal layer, and a photoresist layer are sequentially formed on the surface of the acupuncture needles, respectively to insulate the acupuncture needles, obtain a conductive layer for the conductive path, and etch using the photoresist properties. After the flexible mask is tightly wrapped around the acupuncture needles, ultraviolet lithography is used to obtain several conductive paths with conductivity.

[0029] The material of the main substrate is a rigid substrate, and the preferred material is a silicon wafer.

[0030] The insulating layer material is epoxy resin. The preferred material is polyurethane acrylate photocurable resin. The conductive layer is a metal layer. The preferred material is Au.

[0031] Among them, the main substrate material, insulating layer, metal layer, photoresist, acupuncture needles, etc. are all synthesized using mature existing technologies or purchased commercially.

[0032] The photolithography condition was to use ultraviolet light with a wavelength of 365 nm for 20 seconds.

[0033] The spin coating parameters are 3500 rpm and the spin coating time is 30 s.

[0034] The sputtering was repeated 10 times.

[0035] The light-transmitting elastomer polymerization can be carried out by a CNC heating stage and a vacuum oven at 80°C for 1 hour.

[0036] An acupuncture needle with multiple electrode channels can be used for acupuncture treatment in acupuncture, but the method is not limited to acupuncture needles. The method can also be used for conical or cylindrical objects with a very small curvature radius, such as optical fibers and invasive medical needles.

[0037] Beneficial effects of the present invention:

[0038] 1. The embodiment of the present invention prepares a micron-sized needle with multiple electrode channels. Compared with other preparation methods in the prior art, this method is simple to operate, has simple process equipment, and has low production cost. A multi-channel electrode path is prepared on an acupuncture needle with a very small radius of curvature through a flexible photolithography mask. A pattern is formed on a main substrate through a traditional photolithography process to prepare a master template. Subsequently, a light-transmitting elastomer is applied to the main substrate, and then the light-transmitting elastomer is polymerized and peeled off from the main template to obtain a patterned flexible mask. A layer of insulating material, a layer of metal layer, and a layer of photoresist are prepared on the acupuncture needle in sequence, and a flexible mask is wrapped around the photoresist surface of the acupuncture needle, and rotated at a uniform speed under an ultraviolet lamp. The light-transmitting layer and the opaque layer of the flexible mask are used to achieve the solubility difference between the exposed area and the unexposed area in the photoresist layer. After it is placed in a developer, a pattern is formed. After a metal layer is formed on the surface, the excess photoresist and the metal layer on the surface of the photoresist are removed, thereby obtaining an acupuncture needle with multiple electrode channels.

[0039] 2. The embodiment of the present invention prepares a micron-scale needle with multiple electrode channels, which can realize digitization, standardization, intelligence and visualization in acupuncture.

[0040] 3. The embodiment of the present invention prepares an acupuncture needle with multiple electrode channels, which can be used not only in acupuncture needles, but also in various invasive medical probes to achieve accurate identification and treatment.

[0041] 4. Exposure is completed by rotating the acupuncture needle at a constant speed. This operation can make the photoresist on the entire surface of the acupuncture needle more uniform under ultraviolet light exposure. The designed CAD circuit pattern can also be further expanded to measure multiple ion concentration sensing electrodes and temperature sensing electrodes, and the gradient configuration can measure ion concentrations at different depths. The acupuncture needle is used to measure multiple ion concentrations or temperatures, and can also measure ion concentrations at different depths. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1This is a SEM image of the electrode pathway on the acupuncture needle obtained in Example 1 of the present invention.

[0043] Figure 2 It is a CAD drawing used for preparing a flexible mask in an embodiment of the present invention.

[0044] Figure 3 The Na ion solutions of different concentrations measured in Example 1 of the present invention are

[0045] Figure 4 The K ion solutions of different concentrations measured in Example 1 of the present invention are

[0046] Figure 5 The mask pattern used to prepare the flexible mask in Example 3 of the present invention

[0047] Figure 6 This is a conceptual diagram of the acupuncture needle with multiple electrode channels of the present invention. DETAILED DESCRIPTION

[0048] The present invention is further described below in conjunction with the examples. The following examples are only used to more clearly illustrate the performance of the present invention, and are not limited to the following examples.

[0049] Embodiment 1:

[0050] Preparation of an acupuncture needle with multiple electrode channels

[0051] First, the silicon wafer surface is treated with an oxygen plasma cleaner, and then a Ni sacrificial layer and a Cr metal layer are successively evaporated on the silicon wafer surface. Then, SU-8 positive photoresist is spin-coated at a rotation speed of 3000rmp. After pre-baking and curing, a traditional optical mask (the substrate is glass, and Cr metal is embedded in the glass, and the pattern is the same as the Cr metal) is used. Figure 2 Consistent, Figure 2 All lines in the figure are shielded parts, and the rest are transparent parts) are covered on the surface of the silicon wafer in a contact manner. After being irradiated by a UV lamp with a wavelength of 365nm, the silicon wafer with photoresist is immersed in AR 300-26 developer for 2 minutes. After being taken out, the surface is immediately rinsed with deionized water and blown dry with nitrogen. The silicon wafer is immersed in Cr etching solution for 2 minutes and then taken out. The surface is immediately rinsed with deionized water and blown dry with nitrogen. Then, a plasma stripper is used to remove the excess SU-8 photoresist. At this time, a patterned Cr metal layer has been formed.

[0052] On the patterned Cr surface, PDMS was spin-coated at a speed of 3500 rpm (PDMS was a 10:1 mixture of PDMS precursor and cross-linking agent of Sylgard 184 from Corning, which was stirred and evacuated before spin-coating) for 30 seconds. The spin-coated silicon wafer was then placed on a CNC heating table and heated at 80°C for 1 hour to complete the curing of PDMS. The cured PDMS has completed the pattern transfer. The Ni metal is etched with a Ni etchant to peel off the PDMS wrapped with patterned Cr from the silicon wafer. The Cr metal of the flexible mask is located at Figure 2 The line part, the rest is the Cr-free metal light-transmitting part.

[0053] The designed CAD circuit pattern is as follows Figure 2 As shown, the left side is the temperature sensing circuit, and the right side is the three-electrode system (counter electrode, reference electrode and working electrode). There are three working electrodes, which can measure Na, K and Ca ions. They are the three paths on the left. The tip rectangular part is the working sensing electrode part, and the conductive path connects the sensing electrode; the fourth path is the reference electrode; and the fifth path is the counter electrode. The five paths are arranged in a gradient. The pattern thickness of the patterned surface is 5μm; the width of the electrode path is 20μm. The pattern can also be further expanded to measure multiple ion concentration sensing electrodes, and the gradient configuration can measure ion concentrations at different depths.

[0054] Acupuncture needles with a diameter of 300 microns were sanded for 5 minutes (acupuncture needles are commonly sold on the market, with a diameter of 300 microns), and then ultrasonically cleaned. Polyurethane acrylate photocurable resin solution (Yisheng LCD photosensitive resin) was evenly sprayed on the surface of the acupuncture needles by spraying, and then quickly cured by ultraviolet light to complete the preparation of the insulating layer. The insulated acupuncture needles were placed in a sputtering gold spraying instrument, and the sputtering was repeated 10 times to complete the preparation of the Au metal layer. Finally, the photoresist was sprayed on the metal layer by spraying and cured.

[0055] Since the diameter of the acupuncture needle is 300 microns, the length is 12 cm, and the cross-sectional circumference of the needle is about 1 mm, the prepared flexible PDMS mask is cut into a rectangle of 8 cm × 1 mm. The long strip of PDMS flexible mask is tightly attached to the surface of the acupuncture needle under a microscope, and the acupuncture needle is irradiated with a 365 nm ultraviolet lamp at a uniform speed (speed range is 10 rpm / min-100 rpm / min) to complete the exposure on the acupuncture needle (the uniform rotation uses the self-built x, y, z and r axis four-axis mechanical system, and the acupuncture needle is inserted into the r axis system for rotation). The exposure is completed by irradiating the acupuncture needle with uniform rotation. This operation can make the photoresist on the entire surface of the acupuncture needle more uniform under ultraviolet light exposure. Then the acupuncture needle is placed in the developer AR 300-26 developer for 1 minute, and the surface is immediately rinsed with deionized water after being taken out. Use gold etchant (complexing agent composed of potassium iodide and iodine) to etch the metal layer that is not attached to the photoresist. After etching is completed, rinse the surface immediately with deionized water, and then use a microwave plasma stripper to remove all remaining photoresist.

[0056] Finally, a layer of urethane acrylate photocurable resin solution (Yisheng LCD photosensitive resin) was sprayed in a gradient form and cured to insulate the circuit channel. Only three electrodes (working electrode, counter electrode and reference electrode) were exposed on the entire surface of the acupuncture needle to contact the object being measured. The preparation of micron-scale needles with multiple electrode channels was completed. The preparation of the ion-selective membrane was completed by coating and curing the ion-selective solution under a microscope.

[0057] Through wiring, the circuit is connected to the PCB board and connected to the computer. Place the acupuncture needles in Na and K ion solutions of different concentrations to measure the solution ion concentration. Prepare Na ion concentrations of 10mM, 20mM, 40mM, 80mM, and 160mM and K ion concentrations of 1mM, 2mM, 4mM, 8mM, 16mM, and 32mM in different beakers, then immerse the acupuncture needles and wait for stabilization. Use an electrochemical workstation to give current and measure voltage changes. The measured solution ion concentration is consistent with the actual calculated solution concentration. This sensor integration on the acupuncture needle is expected to contribute to the exploration of the fundamental mechanism behind traditional Chinese medicine acupuncture.

[0058] Embodiment 2:

[0059] Preparation of an acupuncture needle with multiple electrode channels

[0060] SU-8 photoresist was spin-coated on the surface of a clean silicon wafer at a rotation speed of 1000 rpm. After pre-baking and curing, it was contact-covered on the surface of the silicon wafer with a traditional optical mask. After irradiation with a UV lamp with a wavelength of 365 nm, the silicon wafer with photoresist was immersed in AR 300-26 developer for 2 minutes. After taking it out, the surface was immediately rinsed with deionized water.

[0061] On the surface of the patterned silicon wafer, PDMS was spin-coated at a speed of 3500 rpm for 30 seconds, and then the spin-coated silicon wafer was placed on a CNC heating table and heated at 80°C for 1 hour to complete the curing of PDMS. The cured PDMS has completed the pattern transfer, and the PDMS is peeled off from the silicon wafer. (The pattern is consistent with the pattern in Example 1)

[0062] The 200-micron acupuncture needle was placed in a polyurethane acrylate photocurable resin solution by dip coating, and then quickly cured by ultraviolet light to complete the preparation of the insulation layer. The insulated acupuncture needle was placed in a sputtering gold spraying instrument and sputtering was repeated 10 times to complete the preparation of the metal layer. Finally, the photoresist was applied to the metal layer by dip coating and cured.

[0063] Under a microscope, a long strip of PDMS flexible mask with a width of about the circumference of the surface of the acupuncture needle is tightly attached to the surface of the acupuncture needle, and a 365nm ultraviolet lamp is used to rotate and irradiate the acupuncture needle at a uniform speed to complete the exposure on the acupuncture needle. The acupuncture needle is placed in the developer AR 300-26 developer for 1 minute, and the surface is immediately rinsed with deionized water after being taken out. The metal layer not attached by the photoresist is etched with a gold etchant (a complexing agent composed of potassium iodide and iodine). After etching, the surface is immediately rinsed with deionized water, and then a microwave plasma stripper is used to remove all the remaining photoresist, completing the preparation of a micron-scale needle with multiple electrode channels.

[0064] Compared with Example 1, the light transmittance of the flexible mask under ultraviolet light is solely dependent on the thickness of the PDMS film, which is prone to exposure problems. For example, overexposure will cause excessive crosslinking of the photoresist, which will be difficult to completely dissolve during the development process, and there will be residual glue; while underexposure will be the opposite, resulting in insufficient crosslinking of the photoresist and complete dissolution during the development process. The light transmittance of the flexible mask in Example 1 depends on the Cr metal wrapped by the PDMS, which can directly block the irradiation of ultraviolet light and has the advantage of conformal contact with the photoresist.

[0065] Embodiment 3:

[0066] All the operation steps of Example 3 are basically the same as those of Example 1, except that the pattern of the conventional optical mask is different from that of Example 1. The mask pattern in this embodiment is Figure 5 The interdigitated electrodes and Figure 2 After the patterning of the acupuncture needle surface is completed, there is no need to make ion selective membranes and other sensors. The electrical impedance and tissue temperature of different tissues of the human body can be directly measured through the circuit to determine the tissue location and temperature changes of the acupuncture needle insertion.

[0067] Comparative Example 1

[0068] The implementation steps of Comparative Example 1 are basically the same as those of Example 1, except that when the PDMS flexible mask is replaced with a thermoplastic polyester elastomer, due to the high hardness of the thermoplastic polyester elastomer and the large curvature of the acupuncture needle, the flexible mask cannot be conformally attached to the surface of the acupuncture needle, resulting in the inability to carry out subsequent steps.

[0069] Comparative Example 2

[0070] The implementation steps of Comparative Example 2 are basically the same as those of Example 1, except that when the first sacrificial layer on the silicon wafer is replaced by polyvinyl alcohol hydrogel from Ni metal, the temperature in the vacuum evaporation equipment is too high, causing the PVA water-soluble film to denature and be unable to be dissolved and peeled off in the aqueous solution, resulting in the inability to carry out subsequent steps.

[0071] The embodiment provided by the present invention provides a micron-sized needle with multiple electrode channels. Compared with other preparation methods in the prior art, this method is simple to operate, has simple process equipment, and has low production cost. It can realize digitization, standardization, intelligence, and visualization in acupuncture. It can be applied not only to acupuncture needles, but also to various invasive medical probes to achieve accurate identification and treatment.

[0072] The above description is only a preferred embodiment of the present invention. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the creative concept of the present invention, and these should also be regarded as within the scope of protection of the present invention.

Claims

1. A method for preparing an electrode pathway on an acupuncture needle, It is characterized in that The following steps are involved: The surface of the silicon wafer is treated, and then a Ni sacrificial layer and a Cr metal layer are successively evaporated on the surface of the silicon wafer, and then a photoresist is spin-coated, and a pattern is formed on the main substrate silicon wafer using a common photolithography process to prepare a master template; Then, a light-transmitting elastomer polydimethylsiloxane (PDMS) is applied to the master template. The cured PDMS has completed the pattern transfer. The Ni metal is etched using a Ni etchant, and the PDMS wrapped with patterned Cr is peeled off from the master template to obtain a flexible mask with patterned Cr metal wrapped. A layer of insulating material, a layer of metal layer and a layer of photoresist are prepared on the acupuncture needle in sequence, and a flexible mask wrapped with Cr metal is conformally contacted and attached to the photoresist surface of the acupuncture needle. An ultraviolet lamp is used to shield the ultraviolet light through the metal layer Cr wrapped by the elastic polymer in the flexible mask, and then it is placed in a developer to form a pattern.

2. The method for preparing an electrode path on an acupuncture needle according to claim 1, Features: The following steps are involved: First, the surface of the silicon wafer is treated with an oxygen plasma cleaning machine, and then a Ni sacrificial layer and a Cr metal layer are successively evaporated on the surface of the silicon wafer; then SU-8 photoresist is spin-coated at a rotation speed of 1000rmp, and after pre-baking and curing, it is contact-covered on the surface of the silicon wafer with a traditional optical mask, and after irradiation with an ultraviolet lamp with a wavelength of 365nm, the silicon wafer with photoresist is immersed in AR300-26 developer for 2min, and the surface is immediately rinsed with deionized water and blown dry with nitrogen after being taken out; the silicon wafer is immersed in Cr etching solution for 2min and then taken out, and the surface is immediately rinsed with deionized water and blown dry with nitrogen, and then a plasma stripper is used to remove excess photoresist; at this time, a patterned Cr metal layer has been formed; On the patterned Cr surface, PDMS was spin-coated at a speed of 3500 rpm for 30 seconds, and then the spin-coated silicon wafer was placed on a CNC heating table and heated at 80°C for 1 hour to complete the curing of PDMS; the cured PDMS had completed the pattern transfer, and the Ni metal was etched using a Ni etchant to peel off the PDMS wrapped with patterned Cr from the silicon wafer; A 200-micron acupuncture needle was sanded for 5 min and cleaned ultrasonically; The polyurethane acrylate photocurable resin solution is evenly sprayed on the surface of the acupuncture needle by spraying, and then quickly cured by ultraviolet light to complete the preparation of the insulation layer; the insulated acupuncture needle is placed in a sputtering gold spraying instrument, and the sputtering is repeated 10 times to complete the preparation of the Au metal layer; finally, the photoresist is sprayed on the metal layer by spraying and cured; A long strip of PDMS flexible mask wrapped with patterned Cr with a width equal to the circumference of the surface of the acupuncture needle is tightly attached to the surface of the acupuncture needle under a microscope, and a UV lamp with a wavelength of 365nm is used to uniformly rotate and irradiate the acupuncture needle to complete the exposure on the acupuncture needle. The acupuncture needle is then placed in the developer AR 300-26 developer for 1 minute, and the surface is immediately rinsed with deionized water after being taken out; the metal layer not attached by the photoresist is etched with a gold etchant; after the etching is completed, the surface is immediately rinsed with deionized water, and then a microwave plasma stripper is used to remove all the remaining photoresist, completing the preparation of micron-scale needle patterning with multiple electrode channels.

3. The method for preparing an electrode path on an acupuncture needle according to claim 1, Features: The insulating material is one selected from nitrocellulose, unsaturated polyester resin, polyacid acrylate resin, epoxy acrylate resin, polyurethane acrylate resin, and cationic curing base resin.

4. The method for preparing an electrode path on an acupuncture needle according to claim 1, Features: The metal layer is deposited by one of vacuum evaporation, sputtering, electroplating and chemical vapor deposition.

5. A method for preparing an electrode path on an acupuncture needle according to claim 1, Features: The pattern thickness of the patterned surface of the flexible photomask is in the range of 1 μm to 100 μm.

6. A method for preparing an electrode path on an acupuncture needle according to claim 1, Features: In the flexible photomask, the width of the electrode path is in the range of 1 nm to 10 μm.

7. A method for preparing an electrode path on an acupuncture needle according to claim 1, Features: The diameter of the acupuncture needle is in the range of 50 μm to 400 μm.

8. Use of an acupuncture needle with multiple electrode channels prepared according to any one of claims 1 to 7, Features: It can realize digitization, standardization, intelligence and visualization in acupuncture.

9. Use of an acupuncture needle with multiple electrode channels prepared according to any one of claims 1 to 7, Features: The acupuncture needle can be used to measure multiple ion concentrations or temperatures, and can also measure ion concentrations at different depths.

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