Stretchable and Shape‐Adaptable Triboelectric Nanogenerator Based on Biocompatible Liquid Electrolyte for Biomechanical Energy Harvesting and Wearable Human–Machine Interaction

Abstract The significant demand of sustainable power sources has been triggered by the development of wearable electronics (e.g., electronic skin, human health monitors, and intelligent robotics). However, tensile strain limitation and low conformability of existing power sources cannot match their development. Herein, a stretchable and shape‐adaptable liquid‐based single‐electrode triboelectric nanogenerator (LS‐TENG) based on potassium iodide and glycerol (KI‐Gly) liquid electrolyte as work electrode is developed for harvesting human motion energy to power wearable electronics. The LS‐TENG demonstrates high output performances (open‐circuit voltage of 300 V, short‐circuit current density of 17.5 mA m –2 , and maximum output power of 2.0 W m –2 ) and maintains the stable output performances without deterioration under 250% tension stretching and after 10 000 cycles of repeated contact‐separation motion. Moreover, the LS‐TENG can harvest biomechanical energy, including arm shaking, human walking, and hand tapping, to power commercial electronics without extra power sources. The LS‐TENG attached on different joints of body enables to work as self‐powered human motion monitor. Furthermore, a flexible touch panel based on the LS‐TENG combined with a microcontroller is explored for human–machine interactions. Consequently, the stretchable and shape‐adaptable LS‐TENG based on KI‐Gly electrolyte would act as an exciting platform for biomechanical energy harvesting and wearable human–machine interaction.