Self-powered and self-calibrated sensing system for real-time environmental monitoring

Self-powered sensing related to triboelectric nanogenerator (TENG) as a sustainable self-sufficient power source for environmental monitoring by harvesting energy from a living environment is critical in the field of energy and environmental science. However, features of small energy-density and irregularity of environmental energy make it difficult to use directly for real-time environmental monitoring. Here, we report a self-powered and self-calibrated environmental monitoring system (SSEMS) composed of TENG, a calibration resistor, and a sensor network in parallel for real-time temperature and humidity monitoring. The calibration resistor can monitor in real time the irregular output of TENG from the irregularity of rainfalls. SSEMS uses this calibrating signal to calibrate the sensing signal in real time, achieving accurate sensing with an error margin less than 5.0%. We applied SSEMS under waterfalls and rainfalls to monitor in real time the environmental temperature and relative humidity with a sensing error as low as 1.0%. This work promotes self-powering technology one step further to practical applications.