All‐Fiber Electronic Skin Based on Asymmetric Wool/PTFE Structure for Energy Harvesting and Self‐Powered Sensing

This paper reports on a fully textile electronic skin (e-skin) based on an asymmetric wool/polytetrafluoroethylene (PTFE) structure, which is fabricated through an innovative filling core yarn and weft interweaving technique, enabling self-driven contact detection and motion sensing functions. The e-skin features a three-layer woven structure, with the outer layer made of PTFE (high dielectric constant, superhydrophobic), the inner layer composed of wool (hygroscopic, skin-friendly), and a middle layer embedded with silver-plated nylon (SPN) conductive yarns forming a flexible electrode array. Benefiting from its asymmetric design, this material exhibits excellent triboelectric performance (open-circuit voltage of 37 V, short-circuit current of 58 nA), breathability (341.9 mm/s), and mechanical durability (over 1000 cycles). Through modification with a polyacrylic acid coating, the PTFE side demonstrates superhydrophobicity (contact angle > 150°) and self-cleaning capabilities. In practical applications, this e-skin can accurately monitor the bending angle of the elbow joint (30°∼120°, R2 = 0.979) and recognize sliding gestures through differences in voltage waveforms. Additionally, it can drive commercial electronic devices and charge capacitors (4.7 µF capacitor charged to 4.5 V within 100 s). This study provides a scalable textile-based solution for developing comfortable and durable self-driven electronic skin, suitable for human-computer interaction and health monitoring applications.