A tightly coupled electromagnetic-triboelectric hybrid generator for wind energy harvesting and environmental monitoring

Small distributed wind harvesters, offering flexible deployment, lower costs, and localized power, complement large wind turbines in wind energy utilization. This paper reports a tightly coupled electromagnetic-triboelectric hybrid generator (ETHG). The electromagnetic generator (EMG) component changes the magnetic field by rotating the magnetizing material, while the magnet and coil remain stationary to facilitate close integration with the triboelectric nanogenerator (TENG) component. Furthermore, the output performance of the TENG component is optimized by studying friction materials and electrode. Finally, at a wind speed of 18.28 m/s, the TENG and EMG components can provide open-circuit voltages of 936 V and 10.35 V, and short-circuit currents of 29.6 µA and 4.27 mA, respectively, and can charge a 3.3 mF commercial capacitor to 3.5 V in just 12.1 s. Additionally, the self-powered environmental temperature and humidity monitoring system assisted by the ETHG can continuously transmit environmental temperature and humidity information to receiver at 3-s intervals. This study provides guidance for distributed energy harvesting and has broad application prospects in environmental monitoring and self-powered sensor networks.