An electromagnetic energy harvesting circuits for self-powered wireless sensor network

This paper presents a self-powered electromagnetic energy harvesting scheme by using a composite structure and a self-powered supply circuit. The energy of the vibrating wave induced from the magnetostrictive Terfenol-D plate can be converged by using an ultrasonic horn and the more vibrating energy can be converted into electric energy. A new switched capacitor network for storing and accumulating the electric energy is developed. By connecting storing capacitors in parallel or series, the energy is charged into the storage capacitors at long time, and is charged at very short time. As a result, a higher output voltage/power can be obtained. The self-powered supply with a weak power (20 muW) may drive wireless sensors with higher power consumption (75 mW) in a distance of 60 m and a short period of 620 ms.