Manufacturing method of fully-wrapped skin electrode based on spider web bionic structure and electrode

Abstract

The invention belongs to the technical field of flexible stretchable skin electrodes, and provides a manufacturing method of a fully-wrapped skin electrode based on a spider web bionic structure and spraying of the electrode and an adhesion material, so that a metal grid can keep good conformal adhesion capacity on the skin surface, and after a sacrificial layer is removed, electroplating is conducted through the surface layer of a conductive layer, and the surface layer of the conductive layer is electroplated. A self-supporting metal grid of a full-wrapping shell-core structure is formed, the problems that the self-supporting metal grid depends on substrate supporting and cannot be independently used are solved, the substrate is removed, and the breathability of the skin electrode is greatly improved; due to the existence of the excitation counter electrode, an electric field is only generated between the excitation electrode and the induction electrode and is not influenced by the substrate, and the problem that lines are influenced by substrate charges in the traditional electronic injection printing technology is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of flexible stretchable skin electrodes, and in particular relates to a method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure and an electrode. Background Art

[0002] Skin electrodes are interface devices attached to the skin surface, connecting a living organism to an external circuit. They maintain excellent conformal properties on human skin and can withstand mechanical deformations such as bending, twisting, and stretching. They can stably capture changes in surface or internal body signals under varying degrees of mechanical deformation, enabling high-precision skin sensing.

[0003] Traditional methods for fabricating skin electrodes fail to maintain conformal adhesion to the skin surface, often requiring a substrate for support and preventing standalone use. The presence of the substrate significantly impacts the breathability of the skin electrode, potentially causing skin discomfort and inflammation when worn long-term. Furthermore, due to the substrate's influence, the printed lines are affected by the substrate's charge, resulting in printing instability. Furthermore, metal meshes fabricated using current processes face challenges such as complex and costly manufacturing techniques (e.g., photolithography), insufficient precision (e.g., inkjet printing), insufficient mechanical strength and toughness (e.g., electrospray printing), and poor stretchability, particularly the inability to achieve large-scale stretching. Summary of the Invention

[0004] In order to solve the above problems, the present invention proposes a fully wrapped skin electrode manufacturing method and electrode based on a spider web bionic structure. The spraying of the adhesive material enables the metal grid to maintain good conformal adhesion on the skin surface. After removing the sacrificial layer, electroplating is performed on the surface of the conductive layer to form a fully wrapped self-supporting metal grid with a core-shell structure, which solves the problem of dependence on substrate support and inability to be used independently. The removal of the substrate greatly improves the air permeability of the skin electrode. The presence of the excitation and sensing electrodes enables the electric field to be generated only between the excitation electrode and the sensing electrode, and is not affected by the substrate, solving the problem that the lines of traditional electrospray printing technology are affected by the substrate charge.

[0005] In order to achieve the above objectives, in a first aspect, the present invention provides a method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure, which adopts the following technical solutions: A method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure, comprising: The sacrificial layer material is placed in deionized water to prepare a viscous liquid; the viscous liquid is spin-coated on a float glass sheet to prepare a glass plate with a sacrificial layer base; the glass plate with the sacrificial layer base is heated and solidified to obtain a sacrificial layer substrate; Printing a conductive layer on a sacrificial layer substrate using a paired electrode electrospray printing technique; sealing the edges of the conductive layer using a conductive paste; and heating and curing the sealed sample. The paired electrode electrospray printing technique includes connecting the positive electrode of a power supply to the excitation electrode to polarize the printing parameters and carry a positive charge. The skin electrode is placed close to the sacrificial layer substrate to cause the upper surface of the sacrificial layer substrate to carry a negative charge, thereby forming an electric field between the printing material and the sacrificial layer substrate. The conductive layer after edge sealing and heat curing is immersed in an electroplating solution to remove the sacrificial layer; the surface of the conductive layer after the sacrificial layer is removed is electroplated to form a self-supporting metal grid with a fully wrapped core-shell structure; and the fully wrapped self-supporting metal grid is cleaned; The adhesive material is sprayed onto the surface of the self-supporting metal grid to form an omnidirectional stretchable self-supporting metal grid with a spider web bionic structure adhesive effect.

[0006] Furthermore, preparing the viscous liquid includes: adding the sacrificial layer material to boiling deionized water, stirring until cooled, and degassing to remove bubbles.

[0007] Furthermore, preparing a glass plate with a sacrificial layer substrate includes: soaking a float glass sheet in alcohol for ultrasonic cleaning, and then drying the surface of the float glass sheet; adsorbing the glass sheet, pouring a prepared viscous liquid onto the glass surface, and coating a uniform sacrificial layer film on the glass sheet.

[0008] Furthermore, the sacrificial layer material includes but is not limited to hydroxypropyl methylcellulose, polyvinyl alcohol fiber and water-soluble epoxy resin; and the drying of the float glass surface includes but is not limited to vacuum defoaming, ultrasonic cleaning and nitrogen treatment.

[0009] Furthermore, when the sacrificial layer material is hydroxypropyl methylcellulose, the mass fraction of hydroxypropyl methylcellulose powder is 5wt%-10wt%, and the viscosity is 100mPa.s-600mPa.s; the spin coating speed is 1200r / min-1500r / min, the time is 30s-60s, 800rps / s; the heating curing temperature is 80℃-100℃, and the heating time is 3min.

[0010] Furthermore, as the applied voltage increases, the charges on the outer surface of the printing material continue to accumulate. When the electric field force exceeds the surface tension of the printing material, the positively charged printing material is ejected from the top of the Taylor cone, forming an extremely fine conical jet.

[0011] Furthermore, the viscosity of the printing material is 20,000 cps to 40,000 cps; the inner diameter of the printing nozzle is 10 μm to 30 μm, and the distance between the printing nozzle and the printing substrate is 20 μm to 40 μm; the power supply voltage is 800 V to 1200 V; the printing speed is 4 mm / s to 10 mm / s, and the printing air pressure is 100 kPa to 200 kPa; the curing temperature of the conductive layer is 120°C to 150°C, and the heating time is 10 minutes.

[0012] Furthermore, electroplating the surface of the conductive layer after removing the sacrificial layer includes: connecting the cathode of the DC power supply to the sample, connecting the anode of the DC power supply to the copper plate, and forming a copper shell on the upper surface of the conductive layer through an electrochemical reaction; then connecting the cathode of the DC power supply to the sample, connecting the anode of the DC power supply to the copper plate, and forming a copper shell on the upper surface of the conductive layer through an electrochemical reaction.

[0013] Furthermore, the configuration of the adhesive material includes: adding polydimethylsiloxane base material and curing agent into a paper cup in a preset proportion, and adding polyethylene glycol into the precursor; mixing the precursor evenly and degassing under vacuum; and the self-supporting metal grid adopts an ordered grid shape with serpentine lines.

[0014] In order to achieve the above objectives, in a second aspect, the present invention further provides a fully wrapped skin electrode based on a spider web bionic structure, which adopts the following technical solutions: A fully wrapped skin electrode based on a spider web bionic structure is obtained using the manufacturing method of a fully wrapped skin electrode based on a spider web bionic structure as described in the first aspect.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. In the present invention, first, a conductive layer is printed on a sacrificial layer substrate using an induced electrode electrospray printing technique; the conductive layer is sealed around the edges using a conductive paste; the sealed sample is heated and cured; wherein, the induced electrode electrospray printing technique includes connecting the positive electrode of a power supply at the excitation electrode so that the printing parameters are polarized and carry a positive charge, and the skin electrode is close to the sacrificial layer substrate so that the upper surface of the sacrificial layer substrate carries a negative charge, thereby forming an electric field between the printing material and the sacrificial layer substrate; then, the edge-sealed and heat-cured conductive layer is immersed in an electroplating solution to remove the sacrificial layer; the surface of the conductive layer after the sacrificial layer is removed is electroplated to form a self-supporting metal mesh with a fully encapsulated core-shell structure; the fully encapsulated self-supporting metal mesh is The grid is cleaned; finally, an adhesive material is sprayed onto the surface of the self-supporting metal grid to form an omnidirectional stretchable self-supporting metal grid with a spider web bionic structure adhesion effect; the spraying of the adhesive material enables the metal grid to maintain good conformal adhesion on the skin surface, and after removing the sacrificial layer, electroplating is performed on the surface of the conductive layer to form a self-supporting metal grid with a fully wrapped shell-core structure, which solves the problem of dependence on substrate support and inability to be used independently, and the removal of the substrate greatly improves the air permeability of the skin electrode; the presence of the excitation and sensing electrodes enables the electric field to be generated only between the excitation electrode and the sensing electrode, and is not affected by the substrate, solving the problem that the lines of the traditional electrospray printing technology are affected by the substrate charge.

[0016] 2. This invention leverages the outstanding advantages of high-resolution, high-stability electrospray printing technology using counter-electrode electrospray printing, overcoming the complex processes, low precision, low stability, and high production costs associated with existing technologies (such as screen printing, laser direct writing, and inkjet printing). Compared to traditional electric field printing, which is susceptible to substrate influence and can lead to jet deflection, counter-electrode electrospray generates the electric field only between the excitation and sensing electrodes, unaffected by the substrate. This solves the problem of conventional electrospray printing, where lines are affected by substrate charge and can lead to inaccurate lines, thereby improving printing consistency and achieving low-cost, efficient manufacturing of high-resolution, high-stability metal meshes.

[0017] 3. The present invention's suspended electroplating can form a self-supporting metal grid that fully encapsulates the core-shell structure. The electroplating process offers advantages such as uniform coating, high conductivity, wear resistance, and corrosion resistance. Furthermore, the dense and controllable thickness of the electroplated layer significantly enhances the electrode's bending resistance and long-term stability.

[0018] 4. The self-supporting metal mesh fabricated by this invention utilizes a core-shell design with a copper shell fully encasing silver conductors, effectively improving the material's toughness and avoiding the fragility of traditional silver meshes. This structure is resistant to cracking and damage during deformation, can be repeatedly stretched and bent without any performance degradation, and can achieve uniform adhesion to any curved surface.

[0019] 5. To address the problem of poor adhesion between the electrode material and the substrate, which easily falls off when bent and attached, and easily causes device failure, the present invention uses PPA with excellent wet adhesion performance and good physical compatibility. PPA can be slowly removed without pain or residue; PPA droplets mainly exist at the nodes, which enhances the adhesion between the electronic skin and human skin and reduces the influence of hair.

[0020] 6. Traditional metal mesh flexible electrodes require a flexible substrate as a medium during use, which greatly affects the breathability of the flexible electrodes. Long-term wear may cause skin discomfort, inflammation, and other phenomena, which can easily lead to physiological or psychological effects. The omnidirectional stretchable self-supporting metal mesh prepared by this invention completely eliminates the influence of the substrate, has high porosity and good breathability, and improves wearing comfort. In addition, it maintains the good electromechanical properties of the flexible substrate electronic skin, and has universal applicability in the fields of electronic skin, flexible sensors, etc.

[0021] 7. The present invention arranges serpentine lines to form a tortuous and orderly grid shape, which can achieve large-scale stretching through shape changes. When stretched by external forces, it can adapt to deformation through shape changes to ensure the stability of functions such as conductivity. The prepared metal grid has a large range of stretchability while having excellent photoelectric properties and excellent mechanical stability, and has good performance repeatability.

[0022] 8. The samples prepared by the present invention have high-precision characteristics because they are completely free from the limitations of the substrate; therefore, this type of electrode is not only ultra-light, but also difficult to detect when attached to the skin surface, providing an ideal lightweight solution for the manufacture of skin electronics and portable electronic devices; it is ultra-thin and lightweight, and can be worn without feeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The drawings constituting a part of the specification of this embodiment are used to provide a further understanding of this embodiment. The schematic embodiments and descriptions of this embodiment are used to explain this embodiment and do not constitute an improper limitation on this embodiment.

[0024] Figure 1 Schematic diagram of the omnidirectional stretchable self-supporting metal grid of the present invention; Figure 2 Schematic diagram of the self-supporting metal grid skin electrode of the present invention; Figure 3 The printer platform of the present invention; Figure 4 This is a flow chart of the preparation of a self-supporting metal grid flexible transparent electrode according to the present invention; Figure 5 This is a schematic diagram of the electrospray printing principle of the excitation counter electrode of the present invention; Figure 6Schematic diagram of the transparent electrode prepared according to the present invention. DETAILED DESCRIPTION

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0026] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present application belongs.

[0027] Example 1: A skin electrode is an interface device attached to the surface of the skin and used to connect a biological body to an external circuit. Its core function is to establish an interactive channel between human physiological signals and electronic devices. Therefore, skin electrodes must meet the following conditions: maintain good conformal ability on human skin; be able to withstand mechanical deformation such as bending, twisting, and stretching; and be able to stably capture changes in signals on the surface or inside the body under varying degrees of mechanical deformation to achieve high-precision skin sensing. Currently, skin electrodes have shown great application potential in wearable electronics, non-invasive medical systems, skin repair, human-computer interaction, prosthetics, and biomedicine. However, skin electrodes have difficulty in achieving high precision, low cost, breathability, and adhesion at the same time.

[0028] Currently, materials used to fabricate skin electrodes are primarily categorized into carbon-based materials (e.g., carbon nanotubes, graphene), conductive polymers (e.g., PEDOT:PSS), metals (e.g., Cu, Ag, Au), and composite materials (e.g., Ag / PDMS, Al / Ga-doped ZnO). While carbon-based materials offer excellent conductivity and mechanical properties, they are expensive to prepare and prone to agglomeration, impacting film / line uniformity. Conductive polymers, while highly transparent and flexible, suffer from low conductivity and poor environmental stability (e.g., PEDOT:PSS is susceptible to hygroscopic degradation). Metals, owing to their excellent conductivity and signal transmission capabilities, mechanical strength, and structural stability, are a common choice for traditional skin electrodes. However, their poor flexibility prevents them from maintaining good conformability to human skin, and some precious metals are expensive. Composite materials can combine the properties of multiple materials, but their fabrication process is complex. In addition to material factors, structural design is also crucial for the performance of skin electrodes. Currently, the main structures include thin films, fibers, and metal meshes. The film structure has a better adhesion effect, but it is difficult to balance conductivity and breathability; the fiber structure, as a disordered conductive network, has a certain breathability, but is mostly prepared by electrospinning, with a large contact resistance, and the uncontrollable structure leads to poor repeatability and consistency, and poor mechanical stability; the metal mesh, as a conductive network with designable structure and adjustable performance, has outstanding performance in terms of performance balance due to its unique structural design advantages, especially in solving the contradiction between the breathability and conductivity of traditional skin electrodes. By optimizing the grid line width, period and through structural design, ultra-low square resistance and strong breathability can be achieved, with a certain degree of stretchability. Therefore, metal meshes show great application potential in the field of skin electrodes.

[0029] However, metal mesh-based skin electrodes still face several challenges. First, metal meshes fabricated using current processes face complex and costly manufacturing techniques (e.g., photolithography), limited precision (e.g., inkjet printing), insufficient mechanical strength and toughness (e.g., electrospray printing), and poor stretchability, particularly inability to achieve large-scale stretching. Second, metal meshes lack conformal adhesion to the skin surface and often require a substrate for support, preventing standalone use. The presence of a substrate significantly impacts the breathability of skin electrodes, potentially causing skin discomfort and inflammation with long-term wear. Furthermore, the substrate makes it difficult to achieve conformal adhesion on non-developable surfaces, and the electrode material exhibits poor adhesion to the substrate, leading to device failure due to detachment during bending. To completely overcome the negative impact of the substrate, current approaches primarily utilize fiber adhesive pads and spray-on skin-friendly coatings as alternatives. While fiber adhesive pads offer some breathability, fabricating high-precision metal meshes on fiber surfaces is difficult and results in poor durability. Skin-friendly coatings, while offering good biocompatibility, adhesion, and some breathability, suffer from poor environmental stability and uncontrollable coating thickness, leading to skin discomfort. In summary, metal mesh skin electrodes face the following unresolved problems: it is impossible to achieve efficient and low-cost manufacturing of high-stretchability, high-performance metal meshes; it is impossible to completely get rid of the influence of the substrate, and the adhesion effect is poor.

[0030] In order to solve at least one of the above problems, Figure 1 As shown, this embodiment provides a method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure, and prepares a serpentine self-supporting metal mesh skin electrode with a fully wrapped shell-core structure, which has good mechanical properties and can take into account high air permeability and conductivity. A bionic adhesion strategy is proposed based on the spider web structure to solve the problem that the self-supporting metal mesh cannot be conformally adhered to the skin. The electrospray printing of the excitation and sensing electrodes generates an electric field between the excitation electrode and the sensing electrode, which is not affected by the substrate, thereby improving the stability of the printing. The diversity of the conductive slurry and the simplified preparation process can achieve rapid manufacturing of high-precision metal meshes; the suspended electroplating technology deposits a dense metal shell on the surface of the metal mesh, which completely wraps the low-toughness metal mesh prepared by the metal slurry to form a shell-core structure, thereby improving the overall rigidity and toughness of the self-supporting mesh; spraying tiny adhesive droplets on the surface of the fully wrapped serpentine self-supporting metal mesh can make it completely free from the influence of the substrate and have good conformal and shape-keeping capabilities with human skin, allowing stretching and deformation. The method includes: S1. Preparation of sacrificial layer: S1.1. Prepare sacrificial layer solution: A certain proportion of hydroxypropyl methylcellulose (HPMC) powder is placed in boiling deionized water and stirred until cooled, and then degassed in a vacuum drying oven to prepare a viscous liquid.

[0031] Alternatively, use a precision electronic scale to weigh a certain amount of deionized water into a beaker. Heat the water to boiling in a heating oven, then weigh a certain amount of HPMC powder. Add the weighed HPMC powder to the boiling deionized water and stir with a glass rod until cooled to prevent stratification caused by water precipitation. Degas the mixture in a vacuum drying oven to remove bubbles.

[0032] S1.2, Spin coating: A clean float glass sheet is placed in a spin coater for spin coating to manufacture a glass plate with a sacrificial layer substrate.

[0033] Alternatively, the float glass can be pre-cleaned by soaking it in alcohol and ultrasonically cleaning it. The surface of the float glass can then be dried with nitrogen. A coating machine can be used to absorb the glass plate and pour the prepared viscous liquid onto the glass surface, coating the glass with a uniform sacrificial layer to facilitate subsequent metal grid removal.

[0034] S1.3, curing: The spin-coated sample is placed on a hot plate for curing to form the final sacrificial layer substrate.

[0035] In this embodiment, the mass fraction of hydroxypropyl methylcellulose (HPMC) powder can be 5wt%-10wt%, and the viscosity can be 100mPa.s-600mPa.s. Materials for the sacrificial layer include, but are not limited to, hydroxypropyl methylcellulose, polyvinyl alcohol (PVA) fibers, and water-soluble epoxy resins. Cleaning methods for pre-treating the glass sheet include, but are not limited to, vacuum defoaming, ultrasonic cleaning, and nitrogen treatment. Spin-coated substrates include, but are not limited to, glass, quartz, and polyethylene terephthalate (PET). The speed of the coating machine can be 1200r / min-1500r / min, the heating time can be 30s-60s, and the heating time can be 800rps / s. The temperature of the heating plate can be 80°C-100°C, and the heating time can be 3 minutes.

[0036] S2. Printing high-precision conductive layer: S2.1, Printing: A high-precision conductive layer is printed on a sacrificial layer substrate using an electrospray printing technique using an inductive counter electrode to obtain a metal grid, such as a silver grid.

[0037] Optionally, a large stretch printing structure is designed according to demand, converted into processing code using data pre-processing software and input into the printer. The sacrificial layer substrate cured in step S1 is placed as a substrate on a three-axis linkage printing platform, preset printing parameters are selected, and printing is performed according to a pre-edited program to complete the printing of the conductive layer structure. The excitation electrode electrospray printing technology connects the positive pole of the power supply to the excitation electrode, so that the printing parameters in the nozzle are polarized and carry a positive charge. When the nozzle is close to the substrate, the surface of the substrate is negatively charged due to the effect of electrostatic induction, thereby forming an electric field between the printing parameters and the substrate. Under the combined action of electric field force, viscosity, surface tension, etc., the printed material forms a Taylor cone at the nozzle. As the applied voltage increases, the charge on the outer surface of the material continues to accumulate. When the electric field force exceeds the surface tension of the material, the positively charged material is ejected from the top of the Taylor cone to form an extremely fine cone jet. The presence of the excitation electrode ensures that the electric field is only generated between the excitation electrode and the sensing electrode, and is not affected by the substrate. This can solve the problem that the lines of traditional electrospray printing technology are affected by the charge of the substrate, resulting in line inaccuracy, and improve the stability of printing.

[0038] In some embodiments, the printing material is a highly viscous material containing nanosilver particles.

[0039] S2.2, Edge Banding: Conductive paste is used to seal the edges around the high-precision conductive layer.

[0040] Optionally, a scraper is used to seal the edges of the conductive layer so that the printed silver grid has a certain supporting capacity, providing favorable conditions for suspension electroplating.

[0041] S2.3, curing: The edge-sealed sample is placed on a heating plate for heating and curing to sinter and solidify the silver grid.

[0042] Optionally, the viscosity of the printed conductive layer material is 20,000 cps to 40,000 cps. The electrospray printer for the inductively coupled electrode includes at least a print head module, a feed module, a motion module, a power supply module, and a heating module. When printing the conductive layer structure, the inner diameter of the print head is 10 μm to 30 μm, the distance between the print head and the printing substrate is 20 μm to 40 μm, the power supply voltage is 800 V to 1200 V, the printing speed is 4 mm / s to 10 mm / s, and the printing pressure is 100 kPa to 200 kPa. The curing temperature of the conductive layer is 120°C to 150°C, and the heating time is 10 minutes.

[0043] S3, Suspension Plating: S3.1. Prepare electroplating solution: Copper sulfate pentahydrate, copper chloride dihydrate, potassium sulfate, sodium sulfate, activated carbon, and brightener are mixed to prepare an electroplating solution. Alternatively, deionized water, copper sulfate pentahydrate, copper chloride dihydrate, potassium sulfate, sodium sulfate, activated carbon, and brightener are placed in a water tank and stirred uniformly to form an electroplating solution.

[0044] S3.2. Soaking: The high-precision conductive layer prepared in step S2 is immersed in an electroplating solution to remove the sacrificial layer. Specifically, the sample cured in step S2 is placed in the prepared electroplating solution and immersed to remove the sacrificial layer film.

[0045] S3.3, Electroplating: The surface of the conductive layer is electroplated to form a self-supporting metal grid that fully encapsulates the core-shell structure. Specifically, the cathode of a DC power supply is connected to the sample, and the anode of the DC power supply is connected to a copper plate. A copper shell is formed on the upper surface of the conductive layer through an electrochemical reaction. Then, the cathode of the DC power supply is connected to the sample, and the anode of the DC power supply is connected to the copper plate. A copper shell is formed on the upper surface of the conductive layer through an electrochemical reaction.

[0046] S3.4, post-processing: The fully wrapped self-supporting metal grid is removed and placed in a cleaning solution for cleaning, and then dried. Specifically, the electroplated sample is placed in a cleaning solution for cleaning to remove residual electroplating solution and sacrificial layer on the surface.

[0047] Optionally, the equipment required for electroplating mainly includes anode (copper plate), cathode (part to be plated), electroplating power supply, electroplating tank, electroplating solution and liquid circulation device; cleaning solutions include but are not limited to deionized water, alcohol solution, etc.; drying methods include natural drying, hair dryer drying and nitrogen drying, etc.

[0048] S4. Spraying biomimetic adhesive: S4.1. Prepare biomimetic adhesive: A certain proportion of polydimethylsiloxane (PDMS) base material, curing agent and PEG oligomer were uniformly mixed and then degassed in a vacuum drying oven to prepare the biomimetic adhesive material.

[0049] Alternatively, a biomimetic adhesive material, polyphthalamide (PPA), is prepared by adding a PDMS base material and a curing agent in a predetermined ratio into a paper cup, and then weighing a predetermined amount of PEG oligomer into the precursor. The precursor is mixed thoroughly and degassed under vacuum.

[0050] S4.2, spraying biomimetic adhesive: The adhesive material is sprayed onto the surface of the self-supporting metal grid using an atomizer to form an omnidirectional stretchable self-supporting metal grid with bionic adhesion effect.

[0051] Optionally, the configured biomimetic adhesive material is atomized using an atomizer and sprayed onto the surface of the self-supporting metal mesh. PPA is coated on the intersections and line surfaces of the fully wrapped self-supporting metal network, acting as an adhesive droplet similar to that on spider silk. This material can fill the wrinkles of the skin, increase the contact area with the skin, and enable the self-supporting metal mesh to better adhere to the skin surface.

[0052] The biomimetic adhesive may be polyphthalamide or epoxy resin.

[0053] Example 2: This embodiment provides a method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure. Figure 1 As shown in the figure, it is a schematic diagram of an omnidirectional stretchable self-supporting metal grid, including a metal copper shell and nano silver paste. Figure 2 Figure 2 shows a schematic diagram of an omnidirectional, stretchable, self-supporting metal mesh on skin based on biomimetic adhesion, including a biomimetic adhesive and a self-supporting metal mesh. The parameters of the transparent electrode to be fabricated in this embodiment are: a line width of 700nm, a radius of 300μm, a glass needle inner diameter of 15μm, and copper as the plated metal.

[0054] Taking the transparent electrode described in the embodiment as an example, the specific process of preparation based on the proposed method is described in detail: S1. Spin coating sacrificial layer solution.

[0055] The sacrificial layer solution is prepared from hydroxypropyl methylcellulose (HPMC) and deionized water, and the sample is degassed in a vacuum drying oven. Spin coating is performed using a spin coater. HPMC is chosen because it will not damage the conductive layer on the surface due to expansion or contraction, ensuring the integrity of the conductive layer's overall structure during the transfer process, laying the foundation for the manufacture of electronic skin. Specific process: S1.1. Prepare the materials. Optionally, use a precision electronic scale to weigh 76g of deionized water into a beaker. Heat to boiling at 100°C. Weigh 4g (5wt%) of 100% viscosity hydroxypropyl methylcellulose powder. Add the weighed HPMC powder to the boiling deionized water and stir with a glass rod until cooled to prevent separation due to water precipitation.

[0056] S1.2 Vacuum defoaming: Place the beaker containing the prepared solution in a vacuum drying oven for defoaming for 30 minutes to completely remove any bubbles in the solution.

[0057] S1.3, Pretreatment. The spin coating substrate is a float glass of 100mm×100mm×1.1mm. The float glass is soaked in alcohol and ultrasonically cleaned for 3 minutes. Then the surface of the float glass is blown dry with nitrogen to clean the glass. S1.4. Spin coating. Use a spin coater to adsorb the glass plate and pour the prepared cellulose solution onto the sample surface. Set the spin coater speed to 1900 rpm, time to 30 s, and 800 rpm to form a uniform sacrificial layer film.

[0058] S1.5. Curing: Heat the spin-coated glass plate on a hot plate at 80° C. for 3 minutes to cure the sacrificial layer film.

[0059] S2. Print high-precision conductive layer.

[0060] A high-precision conductive layer structure was printed using an electrospray printer with an excitation counter electrode, with a pattern area of ​​80mm×80mm, a line width of 700nm, and a grid radius of 300μm. Printing was also performed using an electrospray deposition micro-nano printer driven by an excitation counter electrode electric field. Specific process: S2.1 Preprocessing: Use CAD drawing software to draw the designed grid structure, and then use relevant slicing software to convert it into program code and input it into the printer, such as Autodesk ArtCAM Premium slicing software or other software.

[0061] S2.2, Printing. Place the float glass with the sacrificial layer spin-coated in step S2 on the printing platform. Figure 4 As shown, printing is performed on the substrate according to the program code, the printing speed is 10 mm / s, the voltage is 800 V, the inner diameter of the print nozzle is a glass nozzle, the distance from the print nozzle to the substrate is 20 μm, the printing pressure is 150 kPa, and the printing of the conductive layer structure is completed.

[0062] S2.3, Edge sealing: Use a hook to apply a thin layer of conductive paste around the conductive layer.

[0063] S2.5. Curing. Place the edge-sealed sample on a hot plate at 120°C for 15 minutes. This sintering process evaporates most of the non-metallic substances in the conductive layer, including the binder and solvent, leaving a small amount of non-metallic substances that act as a binder.

[0064] S3, suspension electroplating.

[0065] The metal plated in this example is copper (Cu), and conventional chemical reagents can be used for copper sulfate pentahydrate (CuSO4·5H2O), copper chloride dihydrate (CuCl2·2H2O), sodium sulfate (Na2SO4), potassium sulfate (K2SO4), activated carbon (C), and brightener. Suspension electroplating is the process of depositing metals or alloys on the surface of conductive materials using the principle of electrolysis. The suspension electroplating equipment uses a self-built precision micro-electroplating system, which mainly includes: an electroplating cell, an electroplating DC power supply, an anode copper plate, a liquid circulation device, etc. Specific process: S3.1. Prepare the materials. Use a precision electronic scale to weigh an appropriate amount of deionized water into a beaker. Heat the beaker to 30°C on a hot plate. Add copper sulfate pentahydrate (150 g / L), copper chloride dihydrate (90 g / L), potassium sulfate (120 g / L), sodium sulfate (70 g / L), activated carbon (2.0 g / L), and brightener (3.0 g / L) to the heated deionized water and stir thoroughly to dissolve the particles.

[0066] S3.2. Soak. Soak the sample in the de-plating solution for 10 minutes to remove the sacrificial layer and suspend the conductive layer circuit.

[0067] S3.3. Electroplating. Place the sample cured in step S2 into the prepared electroplating solution. Connect the cathode of a DC power supply to the sample, and the anode of the DC power supply to the copper plate. An electrochemical reaction forms a dense copper shell on the upper surface of the conductive layer, forming a fully encapsulated core-shell skin electrode. Electroplating is performed using a constant voltage of 1.5V for 1 minute.

[0068] S3.4 Post-processing: Rinse the sample in deionized water to remove any residual plating solution and sacrificial layer on the surface of the self-supporting metal grid, and then blow dry with nitrogen.

[0069] S4. Spraying biomimetic adhesive on the surface of self-supporting metal grid: Polyphthalamide (PPA) has excellent adhesion and good biocompatibility, and PPA can be removed slowly without pain or residue. Specific process: S4.1. Weighing and Preparation: Use a precision electronic scale to add the PDMS base and curing agent in a ratio of 10:1 into a paper cup and stir thoroughly. Then weigh 4.5% of the PEG oligomer and add it to the precursor to mix thoroughly.

[0070] S4.2 Vacuum defoaming: Place in a vacuum drying oven for defoaming for 30 minutes.

[0071] S4.3. Spraying. Use an atomizer to materialize the biomimetic adhesive material prepared in Step 4 and spray it onto the surface of the self-supporting metal mesh. PPA is applied to the intersections of the mesh, acting like an adhesive droplet on spider silk. This material can fill skin wrinkles, increase the contact area with the skin, and better adhere the self-supporting metal mesh to the skin surface.

[0072] S4.4. Adhesion. Adhere a self-supporting metal mesh containing an adhesive material to the skin surface.

[0073] The above description is merely a preferred embodiment of this embodiment and is not intended to limit this embodiment. Those skilled in the art will readily appreciate that this embodiment may be modified and varied in various ways. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this embodiment shall be within the scope of protection of this embodiment.

Claims

1. A method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure, characterized in that: include: The sacrificial layer material is placed in deionized water to prepare a viscous liquid; Spin-coating a viscous liquid onto a float glass sheet to prepare a glass sheet having a sacrificial layer substrate; heating and curing the glass plate with the sacrificial layer base to obtain a sacrificial layer substrate; Printing a conductive layer on a sacrificial layer substrate using an electrospray printing technique using an inductive counter electrode; Using conductive paste to seal the edges of the conductive layer; The edge-sealed sample is heated and cured; wherein, the excitation electrode electrospray printing technology includes connecting the positive pole of the power supply to the excitation electrode so that the printing parameters are polarized and have a positive charge, and the skin electrode is close to the sacrificial layer substrate so that the upper surface of the sacrificial layer substrate has a negative charge, thereby forming an electric field between the printing material and the sacrificial layer substrate; The conductive layer after edge sealing and heat curing is immersed in an electroplating solution to remove the sacrificial layer; the surface of the conductive layer after the sacrificial layer is removed is electroplated to form a self-supporting metal grid with a fully wrapped core-shell structure; and the fully wrapped self-supporting metal grid is cleaned; The adhesive material is sprayed onto the surface of the self-supporting metal grid to form an omnidirectional stretchable self-supporting metal grid with a spider web bionic structure adhesive effect.

2. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 1, characterized in that: The viscous liquid is prepared by adding the sacrificial layer material to boiling deionized water, stirring until cooled, and degassing to remove air bubbles.

3. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 2, characterized in that: The preparation of a glass plate with a sacrificial layer substrate includes: immersing a float glass sheet in alcohol for ultrasonic cleaning, and then drying the surface of the float glass sheet; adsorbing the glass sheet, pouring a prepared viscous liquid onto the glass surface, and coating a uniform sacrificial layer film on the glass sheet.

4. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 3, characterized in that: The sacrificial layer material includes but is not limited to hydroxypropyl methylcellulose, polyvinyl alcohol fiber and water-soluble epoxy resin; the blowing-drying of the float glass surface includes but is not limited to vacuum defoaming, ultrasonic cleaning and nitrogen treatment.

5. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 4, characterized in that: When the sacrificial layer material is hydroxypropyl methylcellulose, the mass fraction of hydroxypropyl methylcellulose powder is 5wt%-10wt%, and the viscosity is 100mPa.s-600mPa.s; the spin coating speed is 1200r / min-1500r / min, the time is 30s-60s, 800rps / s; the heating curing temperature is 80℃-100℃, and the heating time is 3min.

6. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 1, characterized in that: As the applied voltage increases, the charge on the outer surface of the printing material continues to accumulate. When the electric field force exceeds the surface tension of the printing material, the positively charged printing material is ejected from the top of the Taylor cone to form an extremely fine conical jet.

7. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 6, characterized in that: The viscosity of the printing material is 20,000 cps to 40,000 cps; the inner diameter of the printing nozzle is 10 μm to 30 μm, and the distance between the printing nozzle and the printing substrate is 20 μm to 40 μm; the power supply voltage is 800 V to 1200 V; the printing speed is 4 mm / s to 10 mm / s, and the printing air pressure is 100 kPa to 200 kPa; the curing temperature of the conductive layer is 120°C to 150°C, and the heating time is 10 minutes.

8. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 1, characterized in that: Electroplating the surface of the conductive layer after removing the sacrificial layer includes: connecting the cathode of the DC power supply to the sample, connecting the anode of the DC power supply to the copper plate, and forming a copper shell on the upper surface of the conductive layer through an electrochemical reaction; then connecting the cathode of the DC power supply to the sample, connecting the anode of the DC power supply to the copper plate, and forming a copper shell on the upper surface of the conductive layer through an electrochemical reaction.

9. The method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure according to claim 1, wherein: The configuration of the adhesive material includes: adding polydimethylsiloxane base material and curing agent into a paper cup according to a preset ratio, adding polyethylene glycol into the precursor; mixing the precursor evenly and degassing under vacuum; and the self-supporting metal grid adopts an ordered grid shape with serpentine lines.

10. A fully enclosed skin electrode based on a spider web bionic structure, characterized by: The skin electrode is obtained using the method for manufacturing a fully wrapped skin electrode based on a spider web bionic structure as described in any one of claims 1 to 9.

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