Triboelectric Nanogenerator Based on Flexible Liquid Metal‐Doped Conductive Hydrogel for Self‐Powered Multifunctional Sensing

Conductive hydrogel‐based triboelectric nanogenerator (TENG) is widely used in multiple fields. The incompatibility of conductive filler and hydrogel electrode may result in stress concentration or damage within hydrogel, thereby impacting the long‐term stability of TENG. Herein, a poly(vinyl alcohol) (PVA) hydrogel/liquid metal (LM) TENG is presented with simple fabrication, high output performance, and versatile applications. Flexible LM is incorporated into both the PVA hydrogel‐based electrode and Ecoflex friction layer to fabricate the PLL‐TENG (TENG of Ecoflex/LM friction material‐coated PVA/LM hydrogel electrodes). The LM doped into the Ecoflex friction layer improves the dielectric constant of the friction layer, resulting in the electrical performance of the constructed PLL‐TENG being 1.5 times that of the TENG with a pure Ecoflex friction layer (PL‐TENG). In single‐electrode mode, the open‐circuit voltage is 275 V, the short‐circuit current is 4.8 μA, and the transferred charge is 118 nC. The PLL‐TENG could easily light up to 293 light‐emitting diodes. In addition to energy harvesting, the PLL‐TENG has potential applications in wearable motion monitoring, high‐precision writing stroke recognition, and various other fields. This study presents substantial potential for the development of advanced materials and devices in the domains of flexible wearable sensors, electronic skin, and intelligent robotics.