Low-frequency vibration-based interdigital piezoelectric energy harvester and autonomous power regulating circuit

According to the difficult replacement and poor endurance of the battery for wireless sensor network nodes, a low-frequency vibration-based interdigital piezoelectric energy harvester and power regulating circuit (PRC) have been developed in this Letter. The proposed vibration pick-up structure consists of a rectangular flexible frame and series of cantilever beams interdigitally bonded to it. An efficient autonomous PRC with the function of energy storage, switch control, voltage regulation was also proposed. Experiment results show that a maximise output power of 18.8 μW could be produced by the proposed vibration energy harvesting system. The system´s energy conversion efficiency could reach up to 72.3%, which made it the promising candidate of power supply for low power micro electron devices.