Transparent elastic electronic skin for wearable optoelectronic devices and method of making the same

Abstract

The present disclosure provides a transparent elastic electronic skin of a wearable optoelectronic device and a preparation method thereof. The method comprises the following steps: obtaining an electrode patterned carrier; electrospinning an elastic polymer spinning solution on an electrode pattern layer of the electrode patterned carrier to obtain an elastic fiber membrane-electrode patterned carrier; immersing the elastic fiber membrane-electrode patterned carrier in water or an ethanol solution to obtain a conductive elastic fiber precursor membrane A; performing spin coating on the conductive elastic fiber precursor membrane A, and then drying and curing to obtain a conductive elastic fiber precursor membrane B; and performing selective wetting operation on the electrode pattern layer of the conductive elastic fiber precursor membrane B by using a liquid conductive metal to obtain the transparent elastic electronic skin of the wearable optoelectronic device. The transparent elastic electronic skin prepared by the method has high light transmittance, high mechanical elasticity, excellent air and moisture permeability, stable conductivity and suitable adhesion, so as to better meet the long-term dynamic high-precision wearing requirements.

Description

Technical Field

[0001] This disclosure relates to the field of transparent elastic electronic skin technology, and in particular to a transparent elastic electronic skin for wearable optoelectronic devices and a method for preparing the same. Background Technology

[0002] With the rapid development of flexible electronics, the Internet of Things, and personalized medical monitoring, transparent and stretchable optoelectronic devices, as core components of wearable devices, are becoming a hot topic in research and application. These devices show great potential in health monitoring (such as heart rate, blood oxygen, and epidermal electrophysiological signal detection), human-computer interaction interfaces, bionic sensing, and augmented reality displays. Unlike traditional rigid devices, wearable optoelectronic devices need to be directly attached to the skin or integrated into clothing. This requires them to not only possess excellent optoelectronic performance but also to meet multiple requirements such as wearing comfort, motion adaptability, and long-term biocompatibility. Therefore, in existing technologies, a transparent electronic skin is often added to the surface of wearable optoelectronic devices, as disclosed in patent TWM643081U. This not only improves the wearing comfort of the wearable optoelectronic device but also lays the foundation for visual interaction, transparent display, and accurate transmission of optical signals.

[0003] In practical applications, traditional transparent electronic skin generally suffers from poor optical transparency, poor mechanical elasticity, and poor breathability and moisture permeability. To address this, some researchers have attempted to use a porous electrospun nanofiber membrane with patent CN113215822A to endow transparent electronic skin with good breathability and moisture permeability, optical transparency, and mechanical elasticity.

[0004] While porous electrospun nanofiber membranes can effectively improve the breathability, moisture permeability, optical transparency, and mechanical elasticity of transparent electronic skin, they suffer from poor conductivity. Therefore, some researchers have attempted to add electrode layers to electrospun nanofiber membranes, such as the single-electrode transparent flexible electronic skin described in patent AU2020103760A4. However, because the electrode layer of the single-electrode transparent flexible electronic skin is made of indium tin oxide or gold, the electrode layer is prone to cracking, breaking, or detaching during tensile deformation due to the high brittleness and poor bending resistance of indium tin oxide or gold. This causes a sharp increase in the resistance of the single-electrode transparent flexible electronic skin and even circuit failure.

[0005] In response, some scholars have attempted to incorporate electrospun nanofiber membranes into the flexible conductive network structure of patent KR1020170095054A to effectively address the problems caused by the high brittleness and poor bending resistance of indium tin oxide or gold. However, the aforementioned patent requires solvent etching of the substrate's sacrificial layer after completing the metal pattern to separate the transparent electrodes from the substrate. This etching process, due to the significant external force, easily damages the original micro- and nano-pores of the electrospun nanofiber membrane, thus severely impairing the material's air and moisture permeability.

[0006] Therefore, there is an urgent need to develop a transparent elastic electronic skin that combines high transparency, high elasticity, excellent conductivity stability, suitable adhesion, and good breathability and moisture permeability to better adapt to the application of next-generation flexible and wearable optoelectronic devices. Summary of the Invention

[0007] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a transparent elastic electronic skin for wearable optoelectronic devices that, through water transfer printing, gently peels off the aqueous sacrificial layer, maximally protecting the original pore structure of the elastic fiber membrane and the accuracy of the electrode pattern layer. This facilitates the fabrication of a transparent elastic electronic skin that also possesses high light transmittance, high mechanical elasticity, excellent air and moisture permeability, stable conductivity, and suitable adhesion, thereby better meeting the requirements of long-term dynamic high-precision wearing. The method for fabricating this transparent elastic electronic skin is as follows.

[0008] The purpose of this disclosure is achieved through the following technical solution: A method for fabricating transparent, elastic electronic skin for wearable optoelectronic devices includes the following steps: Obtain an electrode patterned carrier; wherein, one side of the electrode patterned carrier is sequentially provided with a water-soluble sacrificial layer and an electrode pattern layer; The elastic polymer spinning solution is electrospun onto the electrode pattern layer of the electrode patterning carrier to obtain an elastic fiber membrane-electrode patterning carrier. The elastic fiber membrane-electrode patterned carrier is immersed in water or ethanol solution to peel off the elastic fiber membrane-electrode patterned layer from the carrier, thereby obtaining a conductive elastic fiber precursor membrane A. The conductive elastic fiber precursor film A is spin-coated with a polymer functional solution and then dried and cured to obtain the conductive elastic fiber precursor film B. The electrode pattern layer of the conductive elastic fiber precursor film B is selectively wetted with liquid conductive metal to obtain the transparent elastic electronic skin of the wearable optoelectronic device.

[0009] In one embodiment, the water-soluble sacrificial layer is obtained by heat treatment of a water-soluble polymer solution.

[0010] In one embodiment, the water-soluble polymer solution includes at least one selected from dextran solution, polyvinyl alcohol solution, polyethylene oxide solution, polyacrylic acid solution, gelatin solution, sodium alginate solution, chitosan solution, sodium carboxymethyl cellulose solution, hydroxyethyl cellulose solution, and hydroxypropyl methyl cellulose solution.

[0011] In one embodiment, the conditions for peeling the electrode pattern layer from the electrode patterning carrier are: temperature 20°C to 40°C, and dissolution time of 1 minute to 30 minutes.

[0012] In one embodiment, the spin coating operation is a two-stage spin coating operation, which includes a pre-spinning operation and a high-spinning operation.

[0013] In one embodiment, in an inert gas protected environment, a liquid conductive metal is used to selectively wet the intersections of the conductive networks of the electrode pattern layer of the conductive elastic fiber precursor film B.

[0014] In one embodiment, the liquid conductive metal includes at least one of gallium, indium, and tin.

[0015] A transparent elastic electronic skin for wearable optoelectronic devices is prepared using the transparent elastic electronic skin preparation method for wearable optoelectronic devices described in any of the above embodiments.

[0016] In one embodiment, the transparent elastic electronic skin of the wearable optoelectronic device includes an electrode pattern layer, an elastic fiber membrane, a polymer functional layer, and a compliant conductive coating. The elastic fiber membrane and the polymer functional layer are sequentially disposed on a first side of the electrode pattern layer, and the compliant conductive coating is disposed on a second side of the electrode pattern layer; and / or, The adhesive force of the transparent elastic electronic skin of the wearable optoelectronic device is not less than 2 kPa; the surface contact angle of the transparent elastic electronic skin of the wearable optoelectronic device is greater than 130°; the rate of change of resistance under tensile bending of the transparent elastic electronic skin of the wearable optoelectronic device is less than 10%; and / or, The electrode linewidth of the electrode pattern layer of the transparent elastic electronic skin of the wearable optoelectronic device is 8μm~20μm.

[0017] Compared with the prior art, this disclosure has at least the following advantages: 1) Since a water-soluble sacrificial layer and an electrode pattern layer are sequentially disposed on one side of the electrode pattern carrier, an elastic polymer spinning solution is electrospun onto the electrode pattern layer of the electrode pattern carrier to obtain an elastic fiber membrane-electrode pattern carrier. When the elastic fiber membrane-electrode pattern carrier is immersed in water or ethanol solution, the water-soluble sacrificial layer of the electrode pattern carrier will dissolve, allowing the electrode pattern layer to be peeled off from the electrode pattern carrier. This process is called water transfer printing and gentle peeling, which does not require solvent etching of the sacrificial layer. It effectively avoids the problem that traditional etching is prone to damaging the original micro-nano pores of the electrospun nanofiber membrane due to the large external force, thereby maximizing the protection of the original pore structure of the elastic fiber membrane and the accuracy of the electrode pattern layer, and thus ensuring that the transparent elastic electronic skin of the wearable optoelectronic device finally prepared has good air and moisture permeability.

[0018] 2) Furthermore, since water or ethanol molecules can penetrate the porous structure of the elastic fiber membrane and dissolve the water-soluble sacrificial layer, the adhesion between the electrode pattern layer and the wafer is eliminated. During electrospinning, the electrode pattern layer can form a physical interlock with the elastic fiber membrane, making the connection strength between the elastic fiber membrane and the electrode pattern layer higher than the temporary adhesion force between the water-based sacrificial layer and the wafer. At the same time, the high elasticity of the elastic fiber membrane allows it to adapt to peeling stress through deformation, avoiding brittle fracture and maximizing the protection of the original porous structure of the elastic fiber membrane. This ensures that the electrode pattern layer can be completely peeled off from the carrier without applying a large external force, thereby ensuring that the electrode pattern layer can be accurately transferred to the surface of the elastic fiber membrane. This ensures both the accuracy of the electrode pattern layer and the tightness of the connection between the electrode pattern layer and the elastic fiber membrane, thus ensuring the connection strength between the electrode pattern layer and the elastic fiber membrane. This is especially suitable for the application of transparent elastic electronic skin for wearable optoelectronic devices with high precision requirements.

[0019] 3) By electrospinning the elastic polymer spinning solution onto the electrode pattern layer of the electrode patterning carrier, on the one hand, it ensures that the selection and orientation structure of the elastic polymer spinning solution can be better optimized under electrospinning conditions, so that the elastic polymer spinning solution forms a highly oriented fiber network structure during the deposition process. This ordered arrangement significantly reduces the probability of disordered scattering of light at the fiber-air interface, allowing light to form a relatively uniform light transmission path along the fiber alignment direction, thereby improving the light transmittance of the transparent elastic electronic skin of wearable optoelectronic devices, achieving a visible light transmittance of over 90%. This successfully solves the problem of high scattering and low light transmittance caused by the disordered structure of traditional porous materials, and also overcomes the technical limitation of poor air permeability due to the dense structure of highly transparent materials. On the other hand, the elastic polymer spinning solution is deposited directly on the electrode pattern layer, effectively avoiding the compression of the pores of the elastic fiber membrane by subsequent processes, preserving the original pore structure of the elastic fiber membrane to the maximum extent, and further ensuring that the transparent elastic electronic skin of the prepared wearable optoelectronic device has good air and moisture permeability.

[0020] 4) The conductive elastic fiber precursor film A is spin-coated with a polymer functional solution and then dried and cured to obtain the conductive elastic fiber precursor film B. The polymer functional solution after spin-coating fills part of the pores of the elastic fiber film and covers its surface, effectively reducing light scattering and reflection, and further improving the light transmittance of the transparent elastic electronic skin for wearable optoelectronic devices. Furthermore, the dried and cured polymer functional solution forms a polymer functional layer, which enhances the mechanical strength and toughness of the transparent elastic electronic skin for wearable optoelectronic devices, ensuring that the prepared transparent elastic electronic skin has high porosity, high tensile strength, and good mechanical strength and toughness. In addition, the conductive elastic fiber precursor film B achieves moderate adhesion to the skin through the regulation of the polymer functional layer, i.e., the adhesion force is not less than 2 kPa. This moderate adhesion force ensures imperceptible, conformal adhesion to the wearable optoelectronic device on the dynamic skin surface, without causing discomfort or damage during peeling due to excessive adhesion force, significantly improving the long-term wearing comfort of the transparent elastic electronic skin for wearable optoelectronic devices.

[0021] 5) By selectively wetting the electrode pattern layer of the conductive elastic fiber precursor film B with liquid conductive metal, a compliant conductive coating is formed at the intersection of the conductive network of the electrode pattern layer. Due to the good ductility and conductivity of the liquid conductive metal, not only is the conductivity of the transparent elastic electronic skin of the wearable optoelectronic device improved, but it is also ensured that it can adapt to the interface strain through its own deformation when stretched. This effectively alleviates the problem that traditional rigid metal electrodes are prone to cracking and causing a sharp increase in resistance when stretched. In particular, with the application of the electrode pattern layer, it is ensured that the transparent elastic electronic skin of the wearable optoelectronic device can withstand a large strain of 600% elongation at break under dynamic stretching, and the resistance change rate is maintained within 10% under stretching and bending, showing excellent electrical stability and fatigue resistance. This ensures that the transparent elastic electronic skin of the prepared wearable optoelectronic device has high light transmittance, high mechanical elasticity, excellent air and moisture permeability and stable conductivity, so as to better meet the requirements of long-term dynamic high-precision wearing. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a flowchart of a method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to an embodiment of the present invention; Figure 2 This is a magnified optical microscope image and a breathability demonstration image of the transparent elastic electronic skin of the wearable optoelectronic device in Embodiment 1 of the present invention; Figure 3 This is a schematic diagram showing the connection between the directional electrode pattern layer and the compliant conductive coating of the transparent elastic electronic skin of the wearable optoelectronic device in Embodiment 1 of the present invention. Figure 4 The graph shows the resistance changes of the transparent elastic electronic skin of the wearable optoelectronic device in Embodiment 1 of the present invention under stretching or bending cycles, as well as the resistance changes under different deformations. Detailed Implementation

[0024] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0025] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] Please see Figure 1 To better understand the technical solution and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments. One embodiment of the method for preparing transparent elastic electronic skin for wearable optoelectronic devices includes some or all of the following steps: S101. Obtain an electrode patterned carrier; wherein, a water-soluble sacrificial layer and an electrode pattern layer are sequentially disposed on one side of the electrode patterned carrier to ensure that the water-soluble sacrificial layer can dissolve when immersed in water or ethanol solution, thereby achieving the peeling of the electrode pattern layer from the carrier.

[0028] In one embodiment, the electrode patterning carrier includes a carrier, a water-soluble sacrificial layer, and an electrode patterning layer, which are sequentially disposed on the carrier.

[0029] In one embodiment, the carrier of the electrode patterning carrier is a wafer.

[0030] In one embodiment, the wafer is a silicon dioxide wafer.

[0031] In one embodiment, the electrode pattern layer is a silver microelectrode pattern layer.

[0032] In one embodiment, obtaining the electrode patterning carrier includes the following specific steps: First, a silicon dioxide wafer carrier is obtained to ensure that the silicon dioxide wafer carrier can provide support for the water-soluble sacrificial layer and the electrode patterning layer; next, a water-soluble polymer solution is spin-coated onto the silicon dioxide wafer carrier, and then heat-treated to form a water-soluble sacrificial layer; subsequently, a negative photoresist is spin-coated onto the water-soluble sacrificial layer to form a photoresist layer; then, the spin-coated silicon dioxide wafer carrier is sequentially exposed and developed, and then a thick silver layer is deposited by vapor deposition; finally, a photoresist removal process is performed to form a high-resolution silver microelectrode patterning layer on the photoresist layer, such as... Figure 2 As shown, an electrode patterned carrier is obtained.

[0033] It is understood that the specific operational steps of spin-coating a water-soluble polymer solution onto a silicon dioxide wafer carrier, followed by heat treatment to form a water-soluble sacrificial layer, and then spin-coating a negative photoresist onto the water-soluble sacrificial layer to form a photoresist layer, as well as the subsequent exposure and development of the spin-coated silicon dioxide wafer carrier, followed by the deposition of a thick silver layer by vapor deposition, and then the removal of the photoresist, are all existing technologies. Therefore, they will not be described in detail in this disclosure.

[0034] In one embodiment, the water-soluble sacrificial layer is obtained by heat treatment of a water-soluble polymer solution.

[0035] In one embodiment, the water-soluble polymer solution includes at least one of dextran solution, polyvinyl alcohol solution, polyethylene oxide solution, polyacrylic acid solution, gelatin solution, sodium alginate solution, chitosan solution, sodium carboxymethyl cellulose solution, hydroxyethyl cellulose solution, and hydroxypropyl methyl cellulose solution to ensure that the water-soluble sacrificial agent can dissolve in water or ethanol solution, thereby ensuring that the electrode pattern layer can be completely peeled off from the silicon dioxide wafer carrier, reducing the damage to the electrode pattern layer and elastic fiber membrane during peeling, and thus maximizing the protection of the original pore structure of the elastic fiber membrane and the accuracy of the electrode pattern layer.

[0036] In one embodiment, the thickness of the water-soluble sacrificial layer is 0.5 μm to 5 μm to ensure that the water-soluble sacrificial layer is thin enough to ensure that it can dissolve quickly when immersed in water or ethanol solution, thereby achieving rapid and complete separation of the electrode pattern layer from the silicon dioxide wafer carrier.

[0037] In one embodiment, the mass concentration of the water-soluble polymer solution is 10% to 30%.

[0038] In one embodiment, the thickness of the silver microelectrode pattern layer is 100nm~500nm.

[0039] In one embodiment, the electrode linewidth of the silver microelectrode pattern layer is 8μm to 20μm.

[0040] In one embodiment, before obtaining the silicon dioxide wafer carrier, the silicon dioxide wafer needs to be cleaned to remove dust and dirt from its surface, ensuring that the water-soluble polymer solution can adhere well to the surface of the silicon dioxide wafer.

[0041] In one embodiment, the heat treatment conditions for the water-soluble polymer solution are: a temperature of 60°C to 120°C and a time of 10 min to 30 min.

[0042] S102. The elastic polymer spinning solution is electrospun onto the electrode pattern layer of the electrode patterned carrier to obtain an elastic fiber membrane-electrode patterned carrier.

[0043] It's understandable that a profound inherent contradiction exists between high transparency and good breathability and moisture permeability in the design of transparent electronic skin for wearable optoelectronic devices. From an optical perspective, high light transmittance requires as few heterogeneous interfaces as possible within the transparent electronic skin and a uniform optical path, which tends to favor media with dense structures or well-matched refractive indices. However, from a mass transfer perspective, efficient breathability and moisture permeability require the transparent electronic skin to have interconnected pore channels of suitable size, which inevitably introduces a large number of solid-gas interfaces, becoming centers of light scattering. Existing technologies often compromise between transparency and breathability: dense elastic films are transparent but not breathable, while porous fiber membranes are breathable but prone to severe light scattering.

[0044] Some studies have attempted to balance these two aspects by fabricating extremely thin porous layers (such as submicron-scale fiber meshes), but these ultrathin films typically suffer from poor mechanical strength, durability, and processability, making it difficult to independently support device structures and meet practical wearable requirements. Furthermore, for bioelectronic devices used for long-term continuous monitoring, the transparent electronic skin needs to have good adaptability to the skin interface, ensuring both a comfortable fit and allowing the skin to breathe normally. Currently, many traditional transparent electronic skins suffer from non-breathable substrates, which can easily cause skin stuffiness and discomfort during prolonged wear, affecting the user's continuous wearing experience.

[0045] Therefore, in this disclosure, by electrospinning the elastic polymer spinning solution onto the electrode pattern layer of the electrode patterned carrier, the selection and orientation structure of the elastic polymer spinning solution can be optimized under electrospinning conditions. This allows the elastic polymer spinning solution to form a highly oriented fiber network structure during deposition. This ordered arrangement significantly reduces the probability of disordered light scattering at the fiber-air interface, enabling light to form a relatively uniform light transmission path along the fiber alignment direction. This improves the light transmittance of the transparent elastic electronic skin for wearable optoelectronic devices, achieving a visible light transmittance of over 90%. This successfully solves the problem of high scattering and low light transmittance caused by the disordered structure of traditional porous materials, and also overcomes the limitations of traditional high-transparency materials due to their structural problems. The technology of dense structure with poor breathability is limited; on the other hand, the elastic polymer spinning solution is directly deposited on the electrode pattern layer, which effectively avoids the compression of the pores of the elastic fiber membrane by subsequent processes, and retains the original pore structure of the elastic fiber membrane to the maximum extent. This further ensures that the transparent elastic electronic skin of the wearable optoelectronic device has good breathability and moisture permeability. In particular, with the application of polymer functional layer, the added polymer functional layer can improve the mechanical strength and toughness of the transparent elastic electronic skin of the wearable optoelectronic device without affecting the original pore structure of the elastic fiber membrane. This ensures that the transparent elastic electronic skin of the wearable optoelectronic device has high porosity, high tensile strength, good mechanical strength and toughness, so as to meet the requirements of long-term wearing comfort.

[0046] In one embodiment, when the elastic polymer spinning solution is electrospun onto the electrode pattern layer of the electrode patterning carrier, the electrospinning parameters are: infusion rate 0.8 mL / h~3.0 mL / h, voltage 10 kV~20 kV, receiving distance 5 cm~20 cm, roller speed 1000 rpm~2000 rpm, ambient temperature 20℃~30℃, and relative humidity 45%~55%. This allows the elastic polymer spinning solution to be highly oriented under the synergistic effect of the electric field and centrifugal force, ensuring that an elastic fiber film with an orientation degree greater than 80% can be obtained on the surface of the electrode pattern layer. This significantly reduces the disordered scattering of light at the fiber-air interface, allowing light to pass through efficiently along the fiber direction. This, in turn, ensures the high light transmittance of the transparent elastic electronic skin of the wearable optoelectronic device, while also improving the tensile elasticity and mechanical strength of the transparent elastic electronic skin of the wearable optoelectronic device.

[0047] It should be noted that, since the electrode pattern layer and the electrode patterning carrier in this disclosure are separated by water transfer printing and gentle peeling, if the connection between the spun elastic fiber membrane and the electrode pattern layer is weak, the elastic fiber membrane may detach during the water transfer printing and gentle peeling process. To ensure good connection between the elastic fiber membrane and the electrode pattern layer, the conventional approach is to heat-set the spun elastic fiber membrane. However, this makes the fabrication process of the transparent elastic electronic skin for wearable optoelectronic devices more complex, resulting in low production efficiency, and also affects the peeling time and difficulty between the electrode pattern layer and the carrier.

[0048] Therefore, in this disclosure, by reasonably controlling the parameters of electrospinning, the elastic polymer spinning solution can achieve physical integration with the electrode pattern layer under the following conditions: injection speed of 0.8 mL / h to 3.0 mL / h, voltage of 10 kV to 20 kV, receiving distance of 5 cm to 20 cm, roller speed of 1000 rpm to 2000 rpm, ambient temperature of 20℃ to 30℃, and relative humidity of 45% to 55%. Specifically, the peel strength between the electrode pattern layer and the elastic fiber membrane is not less than 0.5 N / cm, making the connection strength between the elastic fiber membrane and the electrode pattern layer higher than the temporary adhesion force between the aqueous sacrificial layer and the wafer. Thus, without needing to modify the elastic fiber after spinning... With the additional heating and shaping process, the problem of elastic fiber membrane falling off during the gentle peeling process of water transfer printing is reduced. Furthermore, since the elastic fiber membrane can still remain wet after spinning, the wetting time of water or ethanol solution on the elastic fiber membrane is reduced, ensuring that water or ethanol molecules can quickly and smoothly penetrate into the porous structure of the elastic fiber membrane, the conductive network of the electrode pattern layer, and enter the water-soluble sacrificial layer. This allows water or ethanol molecules to dissolve quickly and fully with the water-soluble sacrificial layer, which is conducive to the rapid and complete peeling of the electrode pattern layer from the carrier. This not only reduces the difficulty of peeling the electrode pattern layer from the carrier but also improves the peeling efficiency.

[0049] In one embodiment, the elastic fiber membrane-electrode patterning carrier includes a carrier, an aqueous sacrificial layer, an electrode patterning layer, and an elastic fiber membrane, wherein the aqueous sacrificial layer, the electrode patterning layer, and the elastic fiber membrane are sequentially stacked on the carrier.

[0050] In one embodiment, the mass concentration of the elastic polymer spinning solution is 5% to 20%.

[0051] In one embodiment, the elastic polymer spinning solution is a mixture of an elastomeric polymer and a solvent.

[0052] In one embodiment, the elastomeric polymer includes one or more of the following: styrene-based thermoplastic elastomers, polyurethane elastomers, polyolefin elastomers, polyester elastomers, polyamide elastomers, silicone elastomers, acrylate elastomers, fluorinated elastomers, polyisoprene, polyurea, polyether esters, and polybutadiene.

[0053] In one embodiment, the molecular weight of the elastomeric polymer is 10,000 g / mol to 100,000 g / mol; further, the molecular weight of the elastomeric polymer is 70,000 g / mol to 90,000 g / mol.

[0054] In one embodiment, the solvent includes one or more of chloroform, tetrahydrofuran, N,N-dimethylformamide, N-methylpyrrolidone, dimethyl sulfoxide, toluene, acetone, ethyl acetate, dichloromethane, 1,2-dichloroethane, N,N-dimethylacetamide, 1,4-dioxane, cyclohexane, methyl ethyl ketone, butyl acetate, n-hexane, xylene, methyl isobutyl ketone, diethyl ether, methanol, ethanol, and isopropanol.

[0055] S103. Immerse the elastic fiber membrane-electrode patterned carrier in a water or ethanol solution to peel the elastic fiber membrane-electrode patterned layer off the carrier to obtain a conductive elastic fiber precursor membrane A.

[0056] It is understood that when the elastic fiber membrane-electrode patterning carrier is immersed in water or ethanol solution, the water-soluble sacrificial layer of the electrode patterning carrier will dissolve, allowing the electrode pattern layer to be peeled off from the electrode patterning carrier. This is a gentle peeling process using water transfer printing, which eliminates the need for solvent etching of the sacrificial layer. This effectively avoids the problem of traditional etching damaging the original micro-nano pores of the electrospun nanofiber membrane due to the large external force, thereby maximizing the protection of the original pore structure of the elastic fiber membrane and the accuracy of the electrode pattern layer. This ensures that the transparent elastic electronic skin of the wearable optoelectronic device obtained in the end has good breathability and moisture permeability.

[0057] Furthermore, because water or ethanol molecules can penetrate the porous structure of the elastic fiber membrane and dissolve the water-soluble sacrificial layer, the adhesion between the electrode pattern layer and the wafer is eliminated. During electrospinning, the electrode pattern layer can physically interlock with the elastic fiber membrane, making the connection strength between the elastic fiber membrane and the electrode pattern layer higher than the temporary adhesion force between the water-based sacrificial layer and the wafer. At the same time, the high elasticity of the elastic fiber membrane allows it to adapt to peeling stress through deformation, avoiding brittle fracture and maximizing the protection of the original porous structure of the elastic fiber membrane. This ensures that the electrode pattern layer can be completely peeled off from the carrier without applying a large external force, thereby ensuring that the electrode pattern layer can be accurately transferred to the surface of the elastic fiber membrane. This ensures both the accuracy of the electrode pattern layer and the tightness of the connection between the electrode pattern layer and the elastic fiber membrane, thus ensuring the connection strength between the electrode pattern layer and the elastic fiber membrane. This is especially suitable for the application of transparent elastic electronic skin for wearable optoelectronic devices with high precision requirements.

[0058] In one embodiment, the conditions for peeling the electrode pattern layer from the electrode patterning carrier are: temperature 20°C to 40°C and dissolution time of 1 minute to 30 minutes, so as to ensure that the aqueous sacrificial layer can be fully dissolved and the electrode pattern layer is completely peeled off from the aqueous sacrificial layer.

[0059] In one embodiment, the conductive elastic fiber precursor film A includes a phase-stacked electrode pattern layer and an elastic fiber film.

[0060] S104. The conductive elastic fiber precursor film A is spin-coated with a polymer functional solution and then dried and cured to obtain the conductive elastic fiber precursor film B.

[0061] It is understood that spin-coating the conductive elastic fiber precursor film A with a polymer functional solution fills part of the pores of the elastic fiber film and covers its surface, effectively reducing light scattering and reflection, and further improving the light transmittance of the transparent elastic electronic skin of the wearable optoelectronic device. Furthermore, the dried and cured polymer functional solution forms a polymer functional layer with a microporous structure, allowing the polymer functional layer to form a continuous light-transmitting channel with the unfilled pores of the elastic fiber film. This ensures that the added polymer functional layer, without affecting the porous structure and inherent breathability and moisture permeability of the polymer elastic fiber precursor film, also improves the mechanical strength and toughness of the transparent elastic electronic skin of the wearable optoelectronic device, ensuring that the prepared transparent elastic electronic skin of the wearable optoelectronic device has high porosity, high tensile strength, and good mechanical strength and toughness.

[0062] Furthermore, the conductive elastic fiber precursor film B achieves moderate adhesion to the skin through regulation with the polymer functional layer, i.e., the adhesion force is not less than 2 kPa. This moderate adhesion force ensures imperceptible and highly conformal adhesion of wearable optoelectronic devices to the dynamic skin surface, while avoiding discomfort or damage during peeling due to excessive adhesion force, significantly improving the long-term wearing comfort of the transparent elastic electronic skin of wearable optoelectronic devices.

[0063] In one embodiment, the spin coating operation is a two-stage spin coating operation, which includes a pre-spinning operation and a high-spinning operation.

[0064] In one embodiment, the conductive elastic fiber precursor membrane A is first pre-spinned using a polymer functional solution. This promotes the initial adhesion and spreading of the polymer functional solution on the surface and interior of the elastic fiber membrane of the conductive elastic fiber precursor membrane A. Simultaneously, it allows for partial controllable permeation of the polymer functional solution, effectively preventing the polymer functional solution from completely occupying the porosity of the elastic fiber membrane, thus ensuring that the elastic fiber membrane and the polymer functional layer can form a continuous light-transmitting channel. Then, a high-speed spin operation is performed. The strong shear force generated by the high-speed spin stretches the liquid film of the polymer functional solution to a uniform state. After drying and curing, an ultra-thin, uniform, highly flat, crack-free, highly adhesive, and highly transparent polymer functional layer is formed on the surface of the elastic fiber membrane. This ensures that the added polymer functional layer does not affect the porous structure and inherent air and moisture permeability of the elastic fiber membrane.

[0065] In one embodiment, the pre-spinning operation has a rotation speed of 300 rpm to 800 rpm and a duration of 10 s to 20 s; the high-spinning operation has a rotation speed of 1000 rpm to 2000 rpm and a duration of 20 s to 30 s.

[0066] In one embodiment, the mass concentration of the polymer functional solution is 5% to 30%.

[0067] In one embodiment, the polymer functional solution includes one or more of the following: polyurethane solution, acrylate polymer solution, silicone resin solution, epoxy resin solution, polyurea solution, polycarbonate solution, polyester solution, polyamide solution, polyvinyl alcohol solution, polyvinylpyrrolidone solution, polystyrene solution, polymethyl methacrylate solution, polyvinyl chloride solution, polyvinylidene chloride solution, fluoropolymer solution, polyimide solution, polyetheretherketone solution, polybenzimidazole solution, polysulfone solution, polyethersulfone solution, polylactic acid solution, polycaprolactone solution, cellulose derivative solution, and chitosan solution.

[0068] In one embodiment, the polymer functional solution is a water-based emulsion, a solvent-based solution, a UV-curable resin, or a hot melt to complete the spin coating operation.

[0069] In one embodiment, the refractive index of the polymer functional solution matches that of the elastic fiber membrane, ensuring that the partially infiltrated polymer functional solution can connect within the pores of the elastic fiber membrane to form a transition refractive section. This further reduces light loss at the interface between the polymer functional layer and the elastic fiber membrane, better guaranteeing the high light transmittance of the transparent elastic electronic skin for wearable optoelectronic devices. Furthermore, some... In one embodiment, the refractive index of the polymer functional solution is similar to that of the elastic fiber membrane.

[0070] In one embodiment, the molecular weight of the polymer functional solution is 10,000 to 100,000 g / mol.

[0071] In one embodiment, the polymer functional solution is an acrylate UV-curable resin.

[0072] In one embodiment, the polymer functional solution is a silicone resin. The silicone resin includes at least one of polydimethylsiloxane, methylphenyl silicone resin, and silicone-modified polyurethane.

[0073] In one embodiment, the acrylate UV-curable resin includes at least one of polyurethane acrylate, epoxy acrylate, and polyester acrylate.

[0074] In one embodiment, drying and curing is performed using ultraviolet light.

[0075] S105. Selectively wet the electrode pattern layer of the conductive elastic fiber precursor film B using liquid conductive metal to obtain the transparent elastic electronic skin of the wearable optoelectronic device.

[0076] It is understood that by selectively wetting the electrode pattern layer of the conductive elastic fiber precursor film B with liquid conductive metal, a compliant conductive coating can be formed at the intersection of the conductive network of the electrode pattern layer. Because liquid conductive metal has good ductility and conductivity, it not only improves the conductivity of the transparent elastic electronic skin of wearable optoelectronic devices, but also ensures that it can adapt to interfacial strain through its own deformation during stretching. This effectively alleviates the problem of traditional rigid metal electrodes easily cracking and causing a sharp increase in resistance during stretching. Especially with the application of the electrode pattern layer, it ensures that the transparent elastic electronic skin of wearable optoelectronic devices can withstand a large strain of 600% elongation at break under dynamic stretching, and the rate of resistance change remains within 10% under stretching and bending. Figure 4As shown, it exhibits excellent electrical stability and fatigue resistance, ensuring that the transparent elastic electronic skin of the prepared wearable optoelectronic device has high light transmittance, high mechanical elasticity, excellent air and moisture permeability and stable conductivity, so as to better meet the requirements of long-term dynamic high-precision wearing.

[0077] In one embodiment, under an inert gas protective environment, a liquid conductive metal is used to selectively wet the intersections of the conductive networks in the electrode pattern layer of the conductive elastic fiber precursor film B, such as... Figure 3 As shown, multiple discontinuous conductive connections are formed at the intersections of the conductive networks, and each of the conductive connections together forms a compliant conductive coating.

[0078] It is understandable that, since the compliant conductive coating does not completely fill the electrode pattern layer, conductive connections are only added at the intersections of the conductive networks in the electrode pattern layer to ensure that the added compliant conductive coating is appropriate. In this way, the added compliant conductive coating can improve the conductivity of the electrode pattern layer, while avoiding the impact of excessive compliant conductive coating on the toughness and elasticity of the transparent elastic electronic skin of the wearable optoelectronic device. This reduces the problem of cracks easily generated when the transparent elastic electronic skin of the wearable optoelectronic device is stretched, which leads to a sharp increase in resistance.

[0079] In one embodiment, the liquid conductive metal includes at least one of gallium, indium, and tin.

[0080] In one embodiment, the liquid conductive metal can be a pure metal, alloy, or eutectic mixture of one or more of gallium, indium, and tin.

[0081] The aforementioned method for fabricating transparent elastic electronic skin for wearable optoelectronic devices utilizes a combination of electrospinning and gentle water transfer printing to maximize the protection of the pore structure of the elastic fiber membrane and the precision of the electrode pattern layer. Subsequent spin-coating of the polymer functional solution allows the solution to cover the surface of the elastic fiber membrane and partially penetrate its pores, achieving encapsulation and refractive index matching. While preserving the pore structure of the elastic fiber membrane to maintain high air and moisture permeability, this process also reduces light scattering at the interface between the elastic fiber membrane and the polymer functional layer, ensuring that the visible light transmittance of the transparent elastic electronic skin for wearable optoelectronic devices exceeds 90%, overcoming the traditional bottleneck of high light transmittance in porous structures. Finally, selective wetting of the electrode pattern layer using liquid conductive metal ensures that the liquid conductive metal... The compliant conductive coating formed by the metal can connect with the electrode pattern layer to form a stable intermetallic compound interface. In this way, while improving the high conductivity of the transparent elastic electronic skin of wearable optoelectronic devices, it also enhances the bonding strength between the compliant conductive coating and the electrode pattern layer. This ensures that the compliant conductive coating can adapt to the interfacial strain through its own deformation when stretched, thereby effectively alleviating the problem that traditional rigid metal electrodes are prone to cracking and causing a sharp increase in resistance when stretched. This ensures that the transparent elastic electronic skin of wearable optoelectronic devices has stable conductivity. The operation process is not only simple and efficient, but also ensures that the prepared transparent elastic electronic skin of wearable optoelectronic devices has high light transmittance, high mechanical elasticity, excellent air and moisture permeability, stable conductivity and suitable adhesion, so as to better meet the needs of wearable optoelectronic devices for long-term dynamic high-precision wearing.

[0082] This disclosure also provides a transparent elastic electronic skin for wearable optoelectronic devices, prepared using the method for preparing transparent elastic electronic skin for wearable optoelectronic devices described in any of the above embodiments. It is understood that, because the transparent elastic electronic skin for wearable optoelectronic devices of this disclosure simultaneously possesses high light transmittance, high mechanical elasticity, excellent breathability and moisture permeability, stable conductivity, and suitable adhesion, it can integrate multiple optoelectronic devices to achieve functions such as display and photoelectric physiological signal detection.

[0083] In one embodiment, the transparent elastic electronic skin of the wearable optoelectronic device includes an electrode pattern layer, an elastic fiber membrane, a polymer functional layer, and a compliant conductive coating. The elastic fiber membrane and the polymer functional layer are sequentially disposed on a first side of the electrode pattern layer, and the compliant conductive coating is disposed on a second side of the electrode pattern layer. The added polymer functional layer helps to improve the light transmittance, mechanical elasticity, breathability, and adhesion of the transparent elastic electronic skin of the wearable optoelectronic device, and the added compliant conductive coating can give the transparent elastic electronic skin of the wearable optoelectronic device stable conductivity.

[0084] In one embodiment, the electrode pattern layer is a silver microelectrode pattern layer.

[0085] In one embodiment, a high-resolution silver microelectrode pattern layer is formed on a wafer using a photolithography process.

[0086] In one embodiment, the silver microelectrode pattern layer is formed with multiple conductive networks, and the polymer functional layer is embedded in the conductive networks, thereby realizing the interlocking of the silver microelectrode pattern layer and the polymer functional layer.

[0087] In one embodiment, the compliant conductive coating includes a plurality of discontinuous conductive connections, each conductive connection being disposed at an intersection of the conductive network.

[0088] In one embodiment, the thickness of the compliant conductive coating is 100 nm to 500 nm.

[0089] In one embodiment, the adhesive force of the transparent elastic electronic skin of the wearable optoelectronic device is not less than 2 kPa, so as to achieve imperceptible and highly conformal attachment of the transparent elastic electronic skin of the wearable optoelectronic device, and meet the requirements of long-term and dynamic wearing.

[0090] In one embodiment, the surface contact angle of the transparent elastic electronic skin of the wearable optoelectronic device is greater than 130°, the elongation at break of the transparent elastic electronic skin of the wearable optoelectronic device exceeds 600%, the tensile strength of the transparent elastic electronic skin of the wearable optoelectronic device is 8MPa~18MPa, and the toughness of the transparent elastic electronic skin of the wearable optoelectronic device is 35MJm. -3 ~60MJm -3 The moisture permeability of the transparent, elastic electronic skin for wearable optoelectronic devices is 800 gm. -2 day -1 ~1500gm -2 day -1 The breathability of the transparent, elastic electronic skin for wearable optoelectronic devices is 200 mmS. -1 ~300mms -1 .

[0091] In one embodiment, the resistance change rate of the transparent elastic electronic skin of the wearable optoelectronic device under stretching and bending is less than 10%, to ensure that the transparent elastic electronic skin of the wearable optoelectronic device has stable conductivity.

[0092] The following are some specific examples. When %, it refers to a percentage by weight. It should be noted that the following examples do not exhaustively list all possible scenarios, and unless otherwise specified, the materials used in the examples are commercially available.

[0093] (1) A 2µm aqueous sacrificial layer was formed by spin-coating a dextran aqueous solution (10% by mass) onto a cleaned silicon dioxide wafer and heat-treating it (at 80°C for 15 min). Then, a negative photoresist was spin-coated, exposed to ultraviolet light, and developed. A 300nm thick silver layer was deposited by vapor deposition and then the photoresist was removed to obtain a silver microelectrode patterned carrier with a linewidth of 8µm. (2) The patterned carrier of silver microelectrode is fixed on the surface of the roller of the receiving device of electrospinning; thermoplastic polyurethane (TPU, molecular weight 80000g / mol) is dissolved in N,N-dimethylformamide to prepare an elastic polymer spinning solution with a mass concentration of 10%; then, under the conditions of a pouring speed of 0.8mL / h, an applied voltage of 15kV, a spinning distance of 15cm, an ambient temperature of 25±2℃, a relative humidity of 40±5%, and a roller speed of 1200rpm, the elastic polymer spinning solution is electrospun onto the electrode pattern layer of the patterned carrier of silver microelectrode to obtain an elastic fiber membrane-electrode patterned carrier; (3) After spinning, the elastic fiber membrane-electrode patterned carrier is completely immersed in deionized water at 25°C for 3 minutes to completely dissolve the dextran sacrificial layer and obtain conductive elastic fiber precursor membrane A. (4) Spin-coat an 8% (w / w) amount of silicone resin (specifically polydimethylsilane, molecular weight 50000 g / mol) onto the electrode-free side of the conductive elastic fiber precursor membrane A. The spin-coating speed is first 500 rpm for 15 s, then 3000 rpm for 30 s, and then cured at 80°C for 1 hour to form a polymer functional layer with a thickness of 1.5 μm, thus obtaining the conductive elastic fiber precursor membrane B. (5) In a nitrogen-protected environment, a compliant conductive coating with a thickness of 300 nm was formed at the intersection of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B using liquid gallium indium tin alloy. The resulting coating exhibited 85% fiber orientation, 93.2% transmittance in the visible light band, a thickness of 8.2 μm, a surface contact angle of 132.5°, an electrode pattern layer linewidth of 8.1 μm, a resistivity change rate under tensile bending of 7.2%, an elongation at break of 610%, a tensile strength of 15.3 MPa, and a toughness of 48.2 MJm. -3 The moisture permeability is 980.5 gm. -2 day -1 Breathability is 290.3 mm. -1 A transparent, elastic electronic skin for wearable optoelectronic devices with an adhesion force of 2.52 kPa to the skin.

[0094] Example 2 (1) A dextran aqueous solution (10% by mass) was spin-coated onto a cleaned silicon dioxide wafer and heat-treated (at 85°C for 12 min) to form a 2.5 μm thick aqueous sacrificial layer. Then, a negative photoresist was spin-coated, exposed to ultraviolet light, developed, and a 300 nm thick silver layer was deposited by vapor deposition. After the photoresist was removed, a silver microelectrode patterned carrier with a linewidth of 15 μm was obtained. (2) The patterned carrier of silver microelectrode is fixed on the surface of the roller of the receiving device of electrospinning; thermoplastic polyurethane (TPU, molecular weight 90000g / mol) is dissolved in N,N-dimethylformamide to prepare an elastic polymer spinning solution with a mass concentration of 10%; then the elastic polymer spinning solution is electrospun on the electrode pattern layer of the patterned carrier of silver microelectrode at a pouring speed of 0.8mL / h, a voltage of 15kV, a spinning distance of 15cm, an ambient temperature of 25±2℃, a relative humidity of 40±5% and a rotation speed of 1000rpm to obtain an elastic fiber membrane-electrode patterned carrier. (3) After spinning, the elastic fiber membrane-electrode patterned carrier is immersed in deionized water at 25°C for 3 minutes to completely dissolve the dextran sacrificial layer and obtain conductive elastic fiber precursor membrane A. (4) A waterborne polyurethane (molecular weight 60000 g / mol) with a mass concentration of 30% was spin-coated on the electrode-free side of the elastic fiber membrane of the conductive elastic fiber precursor membrane A. The spin-coating speed was first 500 rpm for 20 s, then 2500 rpm for 30 s, and then cured at 80°C for 1 hour to form a polymer functional layer with a thickness of 4.5 μm, thus obtaining the conductive elastic fiber precursor membrane B. (5) In a nitrogen-protected environment, a compliant conductive coating with a thickness of 350 nm was formed at the intersection of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B using liquid gallium indium tin alloy. The resulting coating exhibited 82% fiber orientation, 91.4% transmittance in the visible light band, a thickness of 12.1 μm, a surface contact angle of 131.8°, a linewidth of 15.2 μm in the electrode pattern layer, a resistivity change rate under tensile bending of 8.5%, an elongation at break of 606%, a tensile strength of 14.2 MPa, and a toughness of 45.3 MJm. -3 The moisture permeability is 950.2 gm. - 2 day -1 Breathability is 270.5 mm. -1 A transparent, elastic electronic skin for wearable optoelectronic devices with an adhesion force of 2.34 kPa to the skin.

[0095] Example 3 (1) A dextran aqueous solution (10% by mass) was spin-coated onto a cleaned silicon dioxide wafer and heat-treated (at 90°C for 10 min) to form a 3 μm thick aqueous sacrificial layer. Then, a negative photoresist was spin-coated, exposed to ultraviolet light, and developed. A 300 nm thick silver layer was deposited by vapor deposition and then the photoresist was removed to obtain a silver microelectrode patterned carrier with a linewidth of 20 μm. (2) Fix the patterned carrier of silver microelectrode onto the surface of the roller of the receiving device of electrospinning; dissolve thermoplastic polyurethane (TPU, molecular weight 70000g / mol) in N,N-dimethylformamide to prepare an elastic polymer spinning solution with a mass concentration of 10%; then electrospin the elastic polymer spinning solution onto the electrode pattern layer of the patterned carrier of silver microelectrode at an infusion rate of 0.8mL / h, an applied voltage of 15kV, a spinning distance of 15cm, an ambient temperature of 25±2℃, a relative humidity of 40±5% and a rotation speed of 1500rpm to obtain an elastic fiber membrane-electrode patterned carrier. (3) After spinning, the elastic fiber membrane-electrode patterned carrier is immersed in deionized water at 25°C for 3 minutes to completely dissolve the dextran sacrificial layer and obtain conductive elastic fiber precursor membrane A. (4) An acrylate UV-curable resin (specifically polyurethane acrylate with a molecular weight of 40,000 g / mol) was spin-coated onto the electrode-free side of the conductive elastic fiber precursor film A. The spin-coating speed was first 800 rpm for 20 s, and then 3000 rpm for 30 s. The film was then cured under a 365 nm UV lamp for 60 s to form a polymer functional layer with a thickness of 2.8 μm, thus obtaining the conductive elastic fiber precursor film B. (5) In a nitrogen-protected environment, a compliant conductive coating with a thickness of 400 nm is formed at the intersection of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B using liquid gallium indium tin alloy. This results in a transparent elastic electronic skin for wearable optoelectronic devices with 85% fiber orientation, 90.8% transmittance in the visible light band, a thickness of 10.3 μm, a surface contact angle of 133.2°, a linewidth of 20.3 μm in the electrode pattern layer, a resistance change rate of 9.1% under tensile bending, an elongation at break of 601%, a tensile strength of 13.6 MPa, a toughness of 42.7 MJ m-3, a moisture permeability of 930.8 g m-2 day-1, an air permeability of 260.8 mm s-1, and an adhesion force of 2.18 kPa to the skin.

[0096] Example 4 (1) A dextran aqueous solution (10% by mass) was spin-coated onto a cleaned silicon dioxide wafer and heat-treated (at 80°C for 15 min) to form a 2 μm thick aqueous sacrificial layer. Then, a negative photoresist was spin-coated, exposed to ultraviolet light, and developed. A 300 nm thick silver layer was deposited by vapor deposition and then the photoresist was removed to obtain a silver microelectrode patterned carrier with a linewidth of 8 μm. (2) The patterned carrier of silver microelectrode is fixed on the surface of the roller of the receiving device of electrospinning; styrene-ethylene-butene-styrene block copolymer (molecular weight 100000 g / mol) is dissolved in N,N-dimethylformamide and tetrahydrofuran mixed solvent (mass ratio 1:9) to prepare an elastic polymer spinning solution with a mass concentration of 10%; then, under the conditions of a pouring speed of 3.0 mL / h, an applied voltage of 13 kV, a spinning distance of 18 cm, an ambient temperature of 25±2℃, a relative humidity of 40±5% and a rotation speed of 2000 rpm, the elastic polymer spinning solution is electrospun on the electrode pattern layer of the patterned carrier of silver microelectrode to obtain an elastic fiber membrane-electrode patterned carrier; (3) After spinning, the elastic fiber membrane-electrode patterned carrier is immersed in deionized water at 25°C for 3 minutes to completely dissolve the dextran sacrificial layer and obtain conductive elastic fiber precursor membrane A. (4) A waterborne polyurethane (molecular weight 55000 g / mol) with a mass concentration of 30% was spin-coated on the electrode-free side of the elastic fiber membrane of the conductive elastic fiber precursor membrane A. The spin-coating speed was first 500 rpm for 20 s, then 3000 rpm for 30 s, and then cured at 80°C for 1 hour to form a polymer functional layer with a thickness of 2.5 μm, thus obtaining the conductive elastic fiber precursor membrane B. (5) In a nitrogen-protected environment, a compliant conductive coating with a thickness of 300 nm was formed at the intersection of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B using liquid gallium indium tin alloy. The resulting coating exhibited 88% fiber orientation, 92.5% transmittance in the visible light band, a thickness of 9.8 μm, a surface contact angle of 132.8°, an electrode pattern layer linewidth of 8.2 μm, a resistivity change rate under tensile bending of 8.4%, an elongation at break of 638%, a tensile strength of 14.1 MPa, and a toughness of 47.9 MJm. -3 The moisture permeability is 958.4 gm. -2 day -1 Breathability is 268.3 mm. -1 A transparent, elastic electronic skin for wearable optoelectronic devices with an adhesion force of 2.21 kPa to the skin.

[0097] Example 5 (1) A dextran aqueous solution (10% by mass) was spin-coated onto a cleaned silicon dioxide wafer and heat-treated (at 80°C for 15 min) to form a 2 μm thick aqueous sacrificial layer. Then, a negative photoresist was spin-coated, exposed to ultraviolet light, and developed. A 300 nm thick silver layer was deposited by vapor deposition and then the photoresist was removed to obtain a silver microelectrode patterned carrier with a linewidth of 8 μm. (2) The patterned carrier of silver microelectrode is fixed on the surface of the roller of the receiving device of electrospinning; polycaprolactone (molecular weight 60000g / mol) is dissolved in chloroform to prepare an elastic polymer spinning solution with a mass concentration of 14%; then the elastic polymer spinning solution is electrospun on the electrode pattern layer of the patterned carrier of silver microelectrode at an infusion rate of 0.9mL / h, an applied voltage of 20kV, a spinning distance of 16cm, an ambient temperature of 25±2℃, a relative humidity of 40±5% and a rotation speed of 2000rpm to obtain an elastic fiber membrane-electrode patterned carrier. (3) After spinning, the elastic fiber membrane-electrode patterned carrier is immersed in deionized water at 25°C for 3 minutes to completely dissolve the dextran sacrificial layer and obtain conductive elastic fiber precursor membrane A. (4) A waterborne polyurethane (molecular weight 50000 g / mol) with a mass concentration of 30% was spin-coated on the electrode-free side of the elastic fiber membrane of the conductive elastic fiber precursor membrane A. The spin-coating speed was first 500 rpm for 20 s, then 3000 rpm for 30 s, and then cured at 80°C for 1 hour to form a polymer functional layer with a thickness of 2.8 μm, thus obtaining the conductive elastic fiber precursor membrane B. (5) In a nitrogen-protected environment, a compliant conductive coating with a thickness of 300 nm was formed at the intersections of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B using liquid gallium indium tin alloy. The resulting coating exhibited 87% fiber orientation, 90.8% visible light transmittance, a thickness of 10.2 μm, a surface contact angle of 134.4°, an electrode pattern layer linewidth of 8.1 μm, a resistivity change rate under tensile bending of 9.3%, an elongation at break of 626%, a tensile strength of 13.5 MPa, and a toughness of 45.2 MJm. -3 The moisture permeability is 942.6 gm. - 2 day -1 Breathability is 261.8 mm. -1 A transparent, elastic electronic skin for wearable optoelectronic devices with an adhesion force of 2.18 kPa to the skin.

[0098] Example 6 (1) A dextran aqueous solution (10% by mass) was spin-coated onto a cleaned silicon dioxide wafer and heat-treated (at 80°C for 15 min) to form a 2 μm thick aqueous sacrificial layer. Then, a negative photoresist was spin-coated, exposed to ultraviolet light, and developed. A 300 nm thick silver layer was deposited by vapor deposition and then the photoresist was removed to obtain a silver microelectrode patterned carrier with a linewidth of 8 μm. The silver microelectrode patterned carrier has a silver microelectrode pattern layer thickness of 300 nm and a linewidth of 8 μm. (2) The patterned carrier of silver microelectrode is fixed on the surface of the roller of the receiving device of electrospinning; polyvinylidene fluoride (molecular weight 180000g / mol) is dissolved in N,N-dimethylformamide to prepare an elastic polymer spinning solution with a mass concentration of 16%; then, under the conditions of a pouring speed of 1.2mL / h, an applied voltage of 25kV, a spinning distance of 14cm, an ambient temperature of 25±2℃, a relative humidity of 40±5% and a rotation speed of 2000rpm, the elastic polymer spinning solution is electrospun on the electrode pattern layer of the patterned carrier of silver microelectrode to obtain an elastic fiber membrane-electrode patterned carrier. (3) After spinning, the elastic fiber membrane-electrode patterned carrier is immersed in deionized water at 25°C for 3 minutes to completely dissolve the dextran sacrificial layer and obtain conductive elastic fiber precursor membrane A. (4) A waterborne polyurethane (molecular weight 45000 g / mol) with a mass concentration of 30% was spin-coated on the electrode-free side of the elastic fiber membrane of the conductive elastic fiber precursor membrane A. The spin-coating speed was first 500 rpm for 20 s, then 3000 rpm for 30 s, and then cured at 80°C for 1 hour to form a polymer functional layer with a thickness of 2.2 μm, thus obtaining the conductive elastic fiber precursor membrane B. (5) In a nitrogen-protected environment, a compliant conductive coating with a thickness of 300 nm was formed at the intersection of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B using liquid gallium indium tin alloy. The resulting coating exhibited 86% fiber orientation, 92.3% visible light transmittance, 9.5 μm thickness, a surface contact angle of 135.2°, an electrode pattern layer linewidth of 10.1 μm, a resistivity change rate under tensile bending of 7.9%, an elongation at break of 602%, a tensile strength of 22.6 MPa, and a toughness of 35.8 MJm. -3 The moisture permeability is 945.2 gm. - 2 day -1 Breathability is 265.4 mm. -1 A transparent, elastic electronic skin for wearable optoelectronic devices with an adhesion force of 2.15 kPa to the skin.

[0099] Comparative Example 1 The difference from Example 1 is that the 1200 rpm roller in step (2) is replaced with a 200 rpm roller, while the rest remain the same.

[0100] Comparative Example 2 The difference from Example 1 is that step (4) of spin-coating the polymer functional layer is omitted, while the rest remains unchanged.

[0101] Comparative Example 3 The difference from Example 1 is that step (5) of selective wetting of the liquid conductive metal is omitted, while the rest remains unchanged.

[0102] Comparative Example 4 The difference from Example 1 is that the thermoplastic polyurethane in step (2) is replaced with the rigid polymer polyethylene terephthalate (PET), and peeling is attempted after completing the spin-coating of the polymer functional layer in step (4), while the rest remains unchanged.

[0103] The transparent elastic electronic skins for wearable optoelectronic devices prepared in Examples 1-6 and Comparative Examples 1-4 were tested for light transmittance, mechanical properties, air and moisture permeability, conductivity, and adhesion to the skin. The experimental data are shown in Table 1 below. The method for detecting transmittance is as follows: a UV-Vis spectrophotometer is used to measure the transmittance of the sample in the visible light band (400nm-800nm). Five different locations are randomly selected for each sample for testing, and the arithmetic mean of the transmittance at 550nm is taken. Contact angle detection method: Using a contact angle meter, deionized water droplets are added to the sample surface, with the droplet volume controlled between 2 and 5 μL. The static contact angle of the droplet on the sample surface is measured using high-speed imaging and software fitting, and the average value is taken from at least 5 different locations. Method for detecting the rate of change of resistance: The sample is fixed on a self-built tensile stage, with digital source meters connected to both ends. A four-probe method is used to monitor the change in resistance of the sample in real time during tensile, bending, or cyclic deformation. The formula for calculating the rate of change of resistance is: ,in The initial resistance, The resistance after deformation. Record the rate of change of resistance during 1000 stretching or bending cycles; Method for testing elongation at break: Cut the sample into dumbbell-shaped standard specimens, perform tensile testing using a universal testing machine, and record the elongation at break. Elongation at break (%) = (gauge length at break - original gauge length) / original gauge length × 100%. Each sample is tested 5 times and the average value is taken. Method for testing tensile strength: Test simultaneously with elongation at break, record the maximum tensile force at which the specimen breaks, and calculate the breaking strength (MPa) as: maximum tensile force (N) / cross-sectional area of ​​the specimen (mm²). 2 The cross-sectional area of ​​the sample is equal to the width of the sample and the thickness of the sample. Each sample is tested 5 times and the average value is taken. Toughness testing method: The stress-strain curve obtained from the above tensile test is integrated to calculate the area under the stress-strain curve, which represents the energy absorbed per unit volume before the material fractures. Each sample is tested 5 times and the average value is taken. The air permeability test method is as follows: Using an air permeability tester, under a test pressure difference of 125 Pa, the airflow rate passing vertically through a unit area sample per unit time is measured. Air permeability (mm² / s²) is then determined. -1 = Airflow rate (mm) 3 / s) / Effective test area of ​​sample (mm) 2 For each sample, 10 different locations were randomly selected for testing, and the arithmetic mean was taken. Method for testing moisture permeability: The moisture permeability is determined using the permeation cup method under conditions of 20℃ and 60% relative humidity, measuring the mass of water vapor passing through a unit area of ​​sample over 24 hours. Moisture permeability (gm³) is the percentage of water vapor passing through the sample. -2 day -1 = Mass of water vapor transmitted over 24 hours (g) / Effective transmission area of ​​the sample (m²) 2 Each sample was tested three times and the average value was taken. Conductivity detection method: Use a four-probe tester to directly measure the surface resistance or sheet resistance of the sample, and calculate the conductivity by combining the specific length and width of the electrode pattern layer; Method for testing adhesion to skin: A transparent, elastic electronic skin is attached to a substrate simulating the surface of skin. A 90° peel test is performed at a constant rate using a universal testing machine. The peel force is recorded, and then converted to force per unit width based on the sample width. The average adhesion strength can be estimated by dividing the peel force by the contact area.

[0104] Table 1 Summary of Comprehensive Performance Data for Transparent Elastic Electronic Skin As can be seen from Examples 1-6, because Examples 1-6 utilize a combination of electrospinning and water transfer printing with gentle peeling, the original pore structure of the elastic fiber membrane and the precision of the electrode pattern layer are preserved to the greatest extent. Simultaneously, the use of spin-coated polymer functional solutions and selective wetting of the electrode pattern layer with liquid conductive metal effectively controls the relationship between the light transmittance, mechanical properties, breathability and moisture permeability, conductivity, and adhesion of the transparent elastic electronic skin for wearable optoelectronic devices. This ensures that the prepared transparent elastic electronic skin for wearable optoelectronic devices simultaneously possesses high light transmittance, high mechanical elasticity, excellent breathability and moisture permeability, stable conductivity, and suitable adhesion, better meeting the requirements of long-term dynamic high-precision wear. Among these, Example 1 exhibits the best overall performance.

[0105] As can be seen from the comparison between Example 1 and Comparative Example 1 in the table above, the roller speed used in Example 1 is much higher than that in Comparative Example 1. As a result, the transparent elastic electronic skin of the wearable optoelectronic device finally produced in Comparative Example 1 lacks a highly oriented structure (32%) and visible light transmittance (72.4%), making the overall performance of Comparative Example 1 significantly worse than that of Example 1.

[0106] As can be seen from the comparison between Example 1 and Comparative Example 2 in the table above, Comparative Example 2 does not contain a polymer functional layer, which results in the lack of visible light transmittance (84%) and adhesion of the transparent elastic electronic skin of the wearable optoelectronic device. This makes the overall performance of Comparative Example 1 significantly worse than that of Example 1.

[0107] As can be seen from the comparison between Example 1 and Comparative Example 3 in the table above, Comparative Example 3 does not contain a compliant conductive coating, resulting in a resistance change rate of more than 200% for the transparent elastic electronic skin of the final wearable optoelectronic device, making the overall performance of Comparative Example 3 significantly worse than that of Example 1.

[0108] In practical applications, the non-elastic polymer film used in Comparative Example 4, due to its high material rigidity and poor deformation ability, leads to stress concentration at the interface between the functional layer and the substrate. This results in film cracking, breakage, or difficulty in complete peeling during the peeling process, making the overall performance of Comparative Example 4 significantly worse than that of Example 1. Furthermore, the non-elastic film of Comparative Example 4 is prone to brittle fracture when stretched, failing to meet the requirements of flexibility and fit for wearable devices.

[0109] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the disclosed patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A method for fabricating transparent, elastic electronic skin for wearable optoelectronic devices, characterized in that, Includes the following steps: Obtain an electrode patterned carrier; wherein, one side of the electrode patterned carrier is sequentially provided with a water-soluble sacrificial layer and an electrode pattern layer; The elastic polymer spinning solution is electrospun onto the electrode pattern layer of the electrode patterning carrier to obtain an elastic fiber membrane-electrode patterning carrier. The elastic fiber membrane-electrode patterned carrier is immersed in water or ethanol solution to peel off the elastic fiber membrane-electrode patterned layer from the carrier, thereby obtaining a conductive elastic fiber precursor membrane A. The conductive elastic fiber precursor film A is spin-coated with a polymer functional solution and then dried and cured to obtain the conductive elastic fiber precursor film B. The electrode pattern layer of the conductive elastic fiber precursor film B is selectively wetted with liquid conductive metal to obtain the transparent elastic electronic skin of the wearable optoelectronic device.

2. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 1, characterized in that, The water-soluble sacrificial layer is obtained by heat treatment of a water-soluble polymer solution.

3. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 2, characterized in that, The water-soluble polymer solution includes at least one of the following: dextran solution, polyvinyl alcohol solution, polyethylene oxide solution, polyacrylic acid solution, gelatin solution, sodium alginate solution, chitosan solution, sodium carboxymethyl cellulose solution, hydroxyethyl cellulose solution, and hydroxypropyl methyl cellulose solution.

4. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 1, characterized in that, The conditions for peeling the electrode pattern layer from the electrode patterning carrier are: temperature 20℃~40℃, and dissolution time 1 minute~30 minutes.

5. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 1, characterized in that, The spin coating operation is a two-stage spin coating operation, which includes a pre-spinning operation and a high-spinning operation.

6. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 1, characterized in that, In an inert gas protected environment, liquid conductive metal is used to selectively wet the intersections of the conductive network of the electrode pattern layer of the conductive elastic fiber precursor film B.

7. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 1, characterized in that, The liquid conductive metal includes at least one of gallium, indium, and tin.

8. The method for preparing transparent elastic electronic skin for wearable optoelectronic devices according to claim 1, characterized in that, The electrode patterning carrier is a wafer.

9. A transparent, elastic electronic skin for wearable optoelectronic devices, characterized in that, It is prepared using the transparent elastic electronic skin preparation method for wearable optoelectronic devices according to any one of claims 1-8.

10. The transparent elastic electronic skin of the wearable optoelectronic device according to claim 9, characterized in that, The transparent elastic electronic skin of the wearable optoelectronic device includes an electrode pattern layer, an elastic fiber membrane, a polymer functional layer, and a compliant conductive coating. The elastic fiber membrane and the polymer functional layer are sequentially disposed on a first side of the electrode pattern layer, and the compliant conductive coating is disposed on a second side of the electrode pattern layer; and / or, The adhesive force of the transparent elastic electronic skin of the wearable optoelectronic device is not less than 2 kPa; the surface contact angle of the transparent elastic electronic skin of the wearable optoelectronic device is greater than 130°; the rate of change of resistance under tensile bending of the transparent elastic electronic skin of the wearable optoelectronic device is less than 10%; and / or, The electrode linewidth of the electrode pattern layer of the transparent elastic electronic skin of the wearable optoelectronic device is 8μm~20μm.

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