Scalable manufacture of efficient, highly stable, and compact 3D imitation skin-based elastic triboelectric nanogenerator for energy harvesting and self-powered sensing

Integration of nanogenerator (NG) with textile technology will promote the widespread application of next-generation flexible smart wearable devices. However, the current textile-based NGs prepared from metal nanowires and carbon-based conductive fibers still face matrix non-degradability, structural instability, high cost and difficulty in large-scale production. Herein, inspired by the structure of sebum barrier-hair-epidermal layer from human skin, an inexpensive and general PCR-TENG is constructed by polypyrrole modified cotton yarns as an elastic layer, glycerol-plasticized silk fibroin (RG) film as an epithelial layer, and polyvinyl alcohol (PVA) film as the subcutaneous layer, via casting and bidirectional cilia implantation strategy. Among them, the PCR-TENG with an area of only 2 cm(2) has an open circuit voltage output of >350 mV and high stability (8000 compressions). Furthermore, PCR-TENG allows the identification of various types of body motion by a correlation between gestures and corresponding electrical signals. It can be used for tiptoe posture monitoring during "The Lazy Exercises" and somatosensory feedback for prosthesis-wearing patients facing multiple road conditions. The good stability and pressure response of the yarn-based elastic interlayer enables it to collect the kinetic energy of disordered motions of different amplitudes and achieve real-time and stable joint motion monitoring in the rehabilitation training of patients with hand spasticity. Additionally, we can also design fabric-based PCR-TENG via large-scale 3D fabric weaving. Our work provides new insights for the design and application of next-generation self-powered intelligent wearable devices.