Ultrasensitive, fast and flexible piezoresistive strain sensor based on Te nanomesh

Flexible, highly sensitive strain sensors operating at small strains have shown significant potential in applications such as pulsebeat detection and sound signal acquisition. In this study, we introduce ultrasensitive piezoresistive strain sensors designed to function effectively at small strains using a Te nanomesh. A large-area Te nanomesh is deposited onto a flexible polyimide substrate through physical vapor deposition, facilitating the on-site fabrication of strain sensors. The unique mesh structure imparts exceptional sensitivity to strain, achieving a remarkable gauge factor of up to 9.93 × 10⁸. By coating the strain sensors with a thin layer of polydimethylsiloxane, we significantly enhance their stability, with minimal degradation observed even after 1000 loading-releasing cycles. The performance of these strain sensors is contingent on the mesh's density, which can be precisely controlled by adjusting the growth time of the Te nanomesh. Furthermore, our strain sensor exhibits a rapid response time of less than 4 ms, indicating its swift responsiveness. To demonstrate the superior performance of these strain sensors, we showcase their efficacy in monitoring finger bending, ruler vibrations, and sphygmus. Our findings introduce a novel design concept for flexible strain sensors and represent a significant advancement in wearable electronics and human-machine interaction technologies.