Auxetic metastructure-assisted yarn based self-powered e-textiles for efficient energy harvesting and motion monitoring via contact-sliding-expansion strategy

Emergent triboelectric nanogenerators (TENGs) with ascendant self-powering, high sensitivity, and portability natures hold promising for advanced wearable electronics. However, wearable TENGs are still confronted with challenges regarding seamless integration with electronic textiles (e-textiles), energy harvesting efficiency, and long-term operational stability. Here, we propose an innovative contact-sliding-expansion strategy for the on-demand fabrication of auxetic metastructure-assisted yarns based self-powered e-textiles for efficient energy harvesting and motion monitoring, which exquisitely combines a helical twisting fabrication with Negative Poisson’s ratio structural design to furthest endow Auxetic-yarns with superior sensitivity and power density under various kinematic deformations. Specifically, the yarns utilize coaxial core-shell structured collagen aggregate and polyvinyl chloride conductive fibers as the positive and negative triboelectric layers, respectively, and then were subtly used as the weft for incorporating into the e-textiles through a plain weave process with a maximum output voltage of 164 V and a power density of 0.051 W·m⁻². Furthermore, the e-textiles were harmoniously integrated into smart clothing and demonstrated exceptional sensitivity (2.35 V·kPa⁻¹ ) in detecting movements at body joints. Through real-time signal transmission and processing, the e-textiles accurately achieved posture recognition, fall detection, and multitudinous health monitoring, providing potential for practical application in wearable devices, healthcare, and intelligent control systems.