A Stretchable Solid Ionic Electrode-Based Triboelectric Nanogenerator for Biomechanical Energy Harvesting and Self-Powered Sensors

Stretchable power devices and self-powered sensors have become increasingly desired for wearable electronics and artificial intelligence. In this study, an all-solid-state triboelectric nanogenerator (TENG) is reported, whose one solid-state structure prevents delamination during stretch and release cycles and increasing the patch adhesive force (3.5 N) and strain (586% elongation at break). Through the synergetic virtues of stretchability, ionic conductivity, and excellent adhesion to the tribo-layer, reproducible open-circuit voltage (V_OC) of 84 V, charge (Q_SC) of 27.5 nC, and short-circuit current (I_SC) of 3.1 µA after drying at 60°C or 20,000 contact-separation cycles are obtained. Apart from contact-separation, this device shows unprecedented electricity generation through stretch–release of solid materials leading to a linear relationship between V_OC and strain. For the first time, this work provides a clear explanation of the working mechanism of contact-free stretching–releasing and investigates the relationships of exerted force, strain, thickness of the device, and electric output. Benefitting from the one solid-state structure, this contact-free device remains stable even after repeated stretch–release cycling, maintaining 100% of its V_OC after 2500 stretch–release cycles. These findings provide a strategy toward highly conductive and stretchable electrodes for harvesting mechanical energy and health monitoring. © 2023 Wiley-VCH GmbH