A Stretchable Yarn Embedded Triboelectric Nanogenerator as Electronic Skin for Biomechanical Energy Harvesting and Multifunctional Pressure Sensing

Abstract

Flexible and stretchable physical sensors capable of both energy harvesting and self-powered sensing are vital to the rapid advancements in wearable electronics. Even so, there exist few studies that can integrate energy harvesting and self-powered sensing into a single electronic skin. Here, a stretchable and washable skin-inspired triboelectric nanogenerator (SI-TENG) is developed for both biomechanical energy harvesting and versatile pressure sensing. A planar and designable conductive yarn network constructed from a three-ply-twisted silver-coated nylon yarn is embedded into flexible elastomer, endowing the SI-TENG with desired stretchability, good sensitivity, high detection precision, fast responsivity, and excellent mechanical stability. With a maximum average power density of 230 mW m^-2 , the SI-TENG is able to light up 170 light-emitting diodes, charge various capacitors, and drive miniature electronic products. As a self-powered multifunctional sensor, the SI-TENG is adopted to monitor human physiological signals, such as arterial pulse and voice vibrations. Furthermore, an intelligent prosthetic hand, a self-powered pedometer/speedometer, a flexible digital keyboard, and a proof-of-concept pressure-sensor array with 8 × 8 sensing pixels are successively demonstrated to further confirm its versatile application prospects. Based on these merits, the developed SI-TENG has promising applications in wearable powering technology, physiological monitoring, intelligent prostheses, and human-machine interfaces.

Keywords: electronic skin; energy harvesting; human-machine interfaces; pressure sensing; triboelectric nanogenerators.