Novel leather-based pressure-sensitive sensing electronic skin and preparation method thereof
By using tanner-free leather treatment and constructing a conductive network, the problems of poor breathability and skin affinity of traditional synthetic polymer materials have been solved, resulting in a highly sensitive and fast-responding leather-based pressure-sensitive electronic skin suitable for wearable devices.
Patent Information
- Application Number
- CN202511813023.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-02-27
AI Technical Summary
Existing synthetic polymer materials have poor breathability and skin-friendliness when used in electronic sensor skin, making it difficult to achieve excellent wearability and environmental friendliness.
Using tanner-free leather as the base material, a three-dimensional conductive network is constructed through nonionic surfactant treatment and drying followed by elution, and conductive materials are loaded to form leather-based pressure-sensitive electronic skin.
The prepared leather-based pressure-sensitive electronic skin has high sensitivity, fast response speed, can output stable electrical signals, recognize human movement, and has excellent breathability and skin-friendliness.
Smart Images
Figure CN121577206A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of flexible electronic sensing technology, specifically to a novel leather-based pressure-sensitive electronic skin and its preparation method. Background Technology
[0002] Electronic skin is a flexible electronic device that mimics the human skin's ability to sense external stimuli (such as pressure, tension, and temperature). It has broad application prospects in fields such as human-computer interaction, health monitoring, wearable devices, and intelligent robots (Zou BH, Chen YY, Liu YH, et al. Repurposed leather with sensing capabilities for multifunctional electronicskin[J]. Advanced Science, 2019, 6(3).). To achieve good wearability, research has been conducted on sensing electronic skin constructed using various synthetic polymer flexible materials as substrates. Traditional substrates include polydimethylsiloxane (PDMS) and Ecoflex. However, these synthetic polymer materials often suffer from problems such as poor air permeability and poor skin affinity (Ma Z, Huang Q, Xu Q, et al. Permeable superelasticliquid-metal fibre mat enables biocompatible and monolithic stretchable electronics[J]. Nature Materials, 2021, 20(6): 859-868. Yang B, Yuan W, GaoF, et al. A review of membrane-based air dehumidification[J]. Indoor and Built Environment, 2015, 24(1): 11-26.).
[0003] Leather, with its breathability, softness, and skin-friendly properties, is an excellent wearable material. Furthermore, the main component of leather, collagen fibers, is a typical structural protein, thus possessing natural skin-friendliness. In addition, collagen fibers have a 3D multi-layered fiber network structure ranging from micrometers to nanometers, enabling cross-scale structural deformation at both the micro and nanoscales. Therefore, leather can be modified to achieve sensing functions through conductive modifications. Currently, research on leather-based electronic skin mainly uses chrome-tanned leather as the substrate (Ke L, Wang YP, Ye XX, et al. Collagen-based breathable, humidity-ultrastable and degradable on-skin device[J]. Journal of Materials Chemistry C, 2019,7(9):2548-2556. Zou BH, Chen YY, Liu YH, et al. Repurposed leatherwith sensing capabilities for multifunctional electronic skin[J]. Advanced Science, 2019,6(3). Wei YJ, Hao BC, Wang YN, et al. Tannery solid waste-derived cross-scale deformable piezoresistive sensors for monitoring humanbody motions[J]. Journal of Materials Chemistry C, 2022, 10(21): 8199-8205.). In the future, from the perspective of skin-friendly, green and sustainable wearable devices, tanner-free leather, which does not contain any tanning agents, has a natural advantage in the development of leather-based pressure-sensitive electronic skin.
[0004] In view of this, the present invention is proposed. Summary of the Invention
[0005] The present invention aims to solve at least one of the above technical problems, and provides a novel leather-based pressure-sensitive electronic skin and its preparation method.
[0006] To achieve the above objectives, the first technical solution adopted by this invention is as follows: A novel leather-based pressure-sensitive electronic skin uses tanner-free leather as a substrate and constructs a three-dimensional conductive network in the tanner-free leather; The method for preparing the tanner-free leather includes: soaking the raw hide with a nonionic surfactant or an aqueous solution thereof, drying it, washing off the nonionic surfactant, and drying it again.
[0007] Furthermore, the three-dimensional conductive network is formed from tanned leather through conductive modification.
[0008] Furthermore, it also includes the step of using polymer coatings to construct a three-dimensional conductive network on tanner-free leather.
[0009] The second technical solution adopted in this invention is: A method for preparing a novel leather-based pressure-sensitive electronic skin, comprising: After soaking and drying the raw hide with a nonionic surfactant or its aqueous solution, the nonionic surfactant is washed off and dried again to obtain tanning-free leather. Conductive materials are loaded onto the surface of tanner-free leather to form a three-dimensional conductive network.
[0010] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a method of "impregnating and drying raw hides with a nonionic surfactant, then eluting the nonionic surfactant with an organic solvent and drying the organic solvent again" to prepare tanner-free leather. In some preferred embodiments, the nonionic surfactant Tween 20 can be used. Tween 20 fully impregnates between collagen fibers, acting as a steric hindrance medium to maintain the dispersion of collagen fibers in the raw hide after drying and impregnation. This achieves the preparation of skin-friendly, soft, stretchable, water-permeable, and highly wearable tanner-free leather without the use of traditional tanning agents.
[0011] The novel leather-based pressure-sensitive electronic skin sensor provided by this invention has a sensitivity of up to 39.31 kPa. -1 The response speed is ~300 ms; at the same time, the novel leather-based pressure-sensitive electronic skin provided by this invention can output stable and accurate electrical signals, and can recognize finger bending and elbow bending to realize human movement. Attached Figure Description
[0012] Figure 1 Images a, b, and c in this image are scanning electron microscope (SEM) images of the multi-level structure of collagen fibers in tanner-free leather prepared in Example 1. Figure 2 Image of the novel leather-based pressure-sensitive electronic skin prepared in Example 2; Figure 3 Sensitivity diagram of the novel leather-based pressure-sensitive electronic skin prepared in Example 2; Figure 4In Figure 2, a, b, and c represent the I-t curves of the novel leather-based pressure-sensitive electronic skin prepared in Example 2 under different pressures, the I-t curve of the reaction time at 0.22 kPa pressure, and the I-t curves at different frequencies, respectively. Figure 5 In Figures a and b, respectively, the I-t curves of the novel leather-based pressure-sensitive electronic skin prepared in Example 2 are used to identify finger bending and elbow bending. Detailed Implementation
[0013] The present invention will be specifically described below through embodiments, and the technical solution of the present invention is not limited to the specific embodiments listed below. It should be pointed out that the embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-described content are also considered to fall within the scope of protection of the present invention.
[0014] The first embodiment of the present invention provides a novel leather-based pressure-sensitive electronic skin, which uses tanner-free leather as a substrate and constructs a three-dimensional conductive network in the substrate; The method for preparing the tanner-free leather includes: soaking the raw hide with a nonionic surfactant or an aqueous solution thereof, drying it, washing off the nonionic surfactant, and drying it again.
[0015] It should be noted that the three-dimensional conductive network is formed by conductive modification of tanned leather.
[0016] In some preferred embodiments, the aforementioned method further includes the step of constructing a three-dimensional conductive network of tanner-free leather using a polymer surface treatment.
[0017] The second embodiment of the present invention provides a method for preparing a novel leather-based pressure-sensitive electronic skin, comprising: Raw hides are soaked and dried using a nonionic surfactant or its aqueous solution, then the nonionic surfactant or its aqueous solution is washed off and dried again to obtain tanner-free leather. A conductive material is then loaded onto the surface of the tanner-free leather to form a three-dimensional conductive network.
[0018] The present invention utilizes a unique method for preparing tanner-free leather and constructs a three-dimensional conductive network on this basis to achieve pressure-sensitive sensing. Ultimately, it leverages the unique cross-scale deformation capability of tanner-free leather to achieve sensing and human motion recognition functions.
[0019] Example 1 500 g of acid-treated cowhide and 500 g of Tween 20 were placed in a drum and rotated at 15 rpm for 1.0 h. The cowhide was then dried on a stretcher at 45°C for 6.0 h to obtain a dried hide blank. The dried hide blank was then immersed in 1000 g of ethyl acetate for 6.0 h, the solution was changed, and it was immersed again in 1000 g of ethyl acetate for 6.0 h. The resulting hide blank was then dried at room temperature to obtain tanning-free leather.
[0020] The tanner-free leather prepared in this embodiment has a multi-level fibrous structure ranging from micrometers to nanometers. Figure 1 This process enables multi-scale deformation during deformation. The prepared tanner-free leather exhibits high fiber dispersibility, a porosity as high as 48.27%, a tear strength of 167.98 N, and a tensile strength of 29.71 N / mm². -2 10 N mm -2 The specified elongation under load is 49.75%. Simultaneously, the prepared tanner-free leather exhibits excellent thermal stability, with a dry heat shrinkage rate of only 9.71% after heat treatment at 150℃ for 30 min, lower than the dry heat shrinkage rate (21.21%) of commercial chrome-tanned leather under the same conditions. Furthermore, the prepared tanner-free leather possesses excellent water vapor permeability, reaching as high as 5950 gm³. -2 d -1 .
[0021] Example 2 5.0 mg of multi-walled carbon nanotubes (MWCNTs) were added to 200 mL of ethyl acetate, followed by sonication for 0.5 h to obtain a MWCNTs suspension. The tannin-free leather (4.3 cm in diameter) prepared in Example 1 and the MWCNTs suspension were filtered to obtain MWCNT-loaded tannin-free leather. The MWCNT-loaded tannin-free leather (3.2 cm × 2.8 cm) was immersed in an ethyl acetate solution containing 10% PDMS for 0.5 h, then removed and dried. Subsequently, interdigitated electrodes were applied to obtain tannin-free leather-based pressure-sensitive electronic skin.
[0022] The novel leather-based pressure-sensitive electronic skin has high fiber dispersibility. When subjected to external pressure, the collagen fibers in the tanner-free leather can undergo reversible trans-scale deformation at both the nanoscale and microscale, thereby achieving sensing functionality.
[0023] The novel leather-based pressure-sensitive electronic skin prepared in this embodiment is as follows: Figure 2 As shown. This novel device exhibits high sensitivity, reaching 39.31 kPa⁻¹ in the pressure range of 0.11 kPa to 1.12 kPa, and 3.376 kPa⁻¹ in the pressure range of 1.12 kPa to 5.58 kPa. Figure 3 Under pressures of 0.11 kPa, 0.22 kPa, and 0.33 kPa, the novel leather-based pressure-sensitive electronic skin exhibits excellent current amplification stability. Figure 4 a). When a pressure of only 0.22 kPa is applied, the response time of this electronic skin is ~300 ms ( Figure 4 b). When the applied pressure is 0.22 kPa and the frequency increases from 0.16 Hz to 0.56 Hz, the frequency of the output current signal of the electronic skin increases synchronously and stably with the external pressure frequency, indicating that it can accurately identify changes in pressure frequency. Figure 4 c). Figure 5 The sensory monitoring performance of this electronic skin at different bending angles of the fingers and elbows is shown in the figure. As the bending angle of the fingers and elbows gradually increases, the output current signal of the electronic skin shows a significant increasing trend, indicating that the electronic skin can accurately identify different degrees of bending of the fingers and elbows. These results demonstrate that the novel leather-based pressure-sensitive electronic skin has excellent sensing capabilities and can recognize human movements involving finger and elbow bending.
[0024] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.
Claims
1. A novel leather-based pressure-sensitive electronic skin, characterized in that, A three-dimensional conductive network is constructed in a substrate using tanner-free leather as the substrate. The method for preparing the tanner-free leather includes: soaking the raw hide with a nonionic surfactant or an aqueous solution thereof, drying it, washing off the nonionic surfactant, and drying it again.
2. The novel leather-based pressure-sensitive electronic skin as described in claim 1, characterized in that, The three-dimensional conductive network is formed by conductive modification of tanned leather.
3. The novel leather-based pressure-sensitive electronic skin as described in claim 1, characterized in that, It also includes the step of using polymer coatings to construct tanner-free leather with a three-dimensional conductive network.
4. A method for preparing a novel leather-based pressure-sensitive electronic skin as described in any one of claims 1-3, characterized in that, Include: After soaking and drying the raw hide with a nonionic surfactant or its aqueous solution, the nonionic surfactant is washed off and dried again to obtain tanning-free leather. Conductive materials are loaded onto the surface of tanner-free leather to form a three-dimensional conductive network.