High-Strength, High-Stability and Multifunctional Sheepskin-Based Organogel e-Skin for the Construction of Multimodal Flexible Sensors and Self-Powered Triboelectric Nanogenerators
Pengtao Zu, Jianxun Luo, Jialu Shen, Jin Zhou, Haibin Gu
Abstract
Gel-based electronic skin (e-skin) has recently emerged as one of the most promising interfaces for human-machine interaction and wearable devices, owing to its exceptional flexibility, extensibility, transparency, biocompatibility, high-quality physiological signal monitoring, and system integration suitability. However, conventional hydrogel-based e-skins may exhibit limitations in mechanical strength and stretchability compatibility, as well as poor environmental stability. To address these challenges, following a top-down fabrication strategy, this study innovatively integrates poly(methacrylic acid), titanium sulfate, and ethylene glycol (EG) into the three-dimensional collagen fiber network structure of zeolite-tanned sheepskin to successfully develop an organogel (SMEMT) e-skin, which exhibits superior high toughness, environmental stability, high transparency (74% light transmittance at 550 nm), antibacterial properties and ecological compatibility. The organogel e-skin demonstrates remarkable tensile properties with a fracture stress of 5.71 MPa and a breaking elongation of 67%. The incorporation of conductive media Ti 4+ ions within SMEMT established efficient electrical signal transmission pathways, enabling rapid detection of human motions and physiological signals (gauge factor = 1.02), as well as external pressure-induced changes in the conductive pathways of the organogel. Consequently, we successfully fabricated a trimodal sensor capable of strain sensing, bioelectrical sensing, and pressure sensing. Furthermore, the organogel can support the development of single-electrode triboelectric nanogenerator systems (S-TENG). This work presents a paradigm for the high added-value utilization of animal skin biomass resources, and the proposed multifunctional integration strategy opens new avenues for the design of next-generation sustainable electronic skins.