Flexible, multifunctional, ultra-light and high-efficiency liquid metal/polydimethylsiloxane sponge-based triboelectric nanogenerator for wearable power source and self-powered sensor

Triboelectric nanogenerator (TENG) has emerged as a promising solution for self-powered wearable electronic devices. However, challenges such as low energy collection efficiency and limited durability persist, particularly when subjected to mechanical input from multiple directions. Herein, we introduced a straightforward method to create a flexible liquid metal (LM)-embedded polydimethylsiloxane (PDMS) sponge-based single-electrode TENG (LMPST). Unlike traditional systems, the LMPST exhibited overwhelming merits of exceptional mechanical properties, high output performance, remarkable durability, lightweight design, multi-functionality, and a simple fabrication process due to the outstanding conductivity and liquid nature of LM within the flexible porous PDMS sponge. The LMPST demonstrated superior open-circuit voltage (82 V), short-circuit current (1.66 μA), and maximum power density (2.89 W/m2) with outstanding stability (27000 cycles) under omnidirectional mechanical input, which were unattainable by conventional systems. Furthermore, the LMPST successfully realized various practical applications, including force sensing, energy harvesting, motion detection, message transmission, and human-machine interaction. This study lays a solid foundation for the development of advanced materials and devices to drive progress in wearable electronics and smart systems.