Self-powered smelling electronic-skin based on the piezo-gas-sensor matrix for real-time monitoring the mining environment

Abstract A flexible self-powered smelling electronic-skin (e-skin) for real-time monitoring the mining environment has been fabricated from piezo-gas-sensor matrix of ZnO-based composite nanowires (NWs) via soft photolithography technique. The e-skin includes four sensing units (relative humidity: bare ZnO NWs, ethanol: Pd/ZnO NWs, hydrogen sulfide: CuO/ZnO NWs, and methane: TiO 2 /ZnO NWs) and can cross-reactively detect relative humidity (RH), ethanol, hydrogen sulfide (H 2 S) and methane (CH 4 ) in the surrounding gas atmosphere without external electrical power supply or battery. The e-skin attached on human body can be driven by body motions, and the piezoelectric impulse of the piezo-gas-sensior matrix serves as the power supply. The responses of the four sensing units are 87.76% against 90% RH, 59.82% against 1000 ppm ethanol, 79.27% against 500 ppm H 2 S and −87.50% against 500 ppm CH 4 , respectively. High response, selectivity and stability have been achieved from the sensing units. The present results could provoke a possible new research direction for promoting the practical application of flexible self-powered smelling electronic-skin in specific occasion.