Stretchable Self-Powered Generator for Multiple Functional Detection

Flexible electronics have brought considerable benefits to healthcare advancement by their powerful functions of mimicking human skin to quantitatively transform external stimuli into electronic signals with corresponding feedback instructions. Though the energy consumption also has been significantly reduced by self-powered units such as a triboelectric nanogenerator (TENG) and a piezoelectric nanogenerator (PENG), these generators cannot precisely reflect the movement lasting time with high precision. Traditional capacitive and resistive sensors can measure the duration time of external stimuli, but they fail to be self-powered. Here, a self-powered sensor is presented based on an Al/PPy/Au generator with the ability to record the magnitude and duration time of movement without sacrificing the high stretchability. The generator rendered a direct current output accessible through a Schottky contact between polypyrrole (PPy) and an aluminum electrode and a long-time-lasting output through the mechanical relaxation phenomenon of PPy. Based on this mechanism, the sensor is capable of sensing quantitative deformation and action duration. Furthermore, the sensor can recognize pentatonic scales and movement of fingers, shedding light on low-power-consuming flexible electronics and exhibiting promising applications in versatile sensory systems, intelligent medical diagnostic systems, and human–machine interactive interfaces.