Hierarchical Structure by Self‐sedimentation of Liquid Metal for Flexible Sensor Integrating Pressure Detection and Triboelectric Nanogenerator

Abstract

AbstractMultifunctional integration is a pivotal aspect in the development of flexible sensors that facilitate augmented interaction with the physical environment. However, contemporary multifunctional flexible sensors face challenges arising from their complex structures and high costs. Therefore, polydimethylsiloxane (PDMS) /liquid metal (LM) films with a hierarchical structure prepared via the gravity‐induced deposition of LM are applied to multifunctional flexible sensors. PDMS/LM films exhibit remarkable flexibility and function as flexible electrodes for pressure sensors as well as a single‐electrode mode triboelectric nanogenerator (TENG). The porous PDMS/carbon nanotube (CNT) dielectric with an array structure is developed for pressure sensing, showing commendable sensitivity (0.671 kPa−1) even under low pressures (0–17 kPa). Compared with solid and porous dielectrics, its sensitivity is improved over the entire pressure range. The sensor achieves a response time of ≈80 ms and demonstrates exceptional stability. Furthermore, when the PDMS/LM film with a hierarchical structure functions as a TENG, it can serve as a self‐powered sensor for measuring dynamic forces and aid in material recognition with the assistance of capacitive pressure sensing. This study provides a new perspective on the simplified design and integration of multifunctional flexible sensors.