The self-powered CO2gas sensor based on gas discharge induced by triboelectric nanogenerator

Nowadays, the gas sensors for carbon dioxide (CO2) generally have the drawbacks of complex material preparation, high working temperature and depending on external power supply, which limits its application in the Internet of things (IoT). Here, a self-powered CO2gas sensor is developed based on the gas discharge induced by the triboelectric nanogenerator (TENG). As CO2is added into N2, the negative CO2ions produced in the discharge process will obstruct the formation of plasma, which increases the threshold voltage of gas discharge and changes the discharge characteristics. Based on these phenomena, different kinds of CO2gas sensing modes are proposed. The first mode is threshold concentration detection mode, in which the gas discharge will be disappeared as the concentration of CO2reaches a threshold value. Through adjusting the distance between two discharge electrodes, the detectable threshold concentrations can be regulated from 1000 to 200,000 ppm. Based on the dependence of discharge frequency and discharge current on the CO2concentration, the step mode and continuous detection mode are proposed, which can be used to detect the gas concentrations of CO2lower than the threshold concentration. The TENG-based self-powered CO2gas sensor operates at room temperature, has high detection sensitivity and requires no external power supply, which has potential applications for constructing self-powered gas sensing networks oriented to IoT.