A magnetically coupled direction-switching tunable piezoelectric vibration energy harvester utilizing a seesaw-like exciter

Abstract Harvesting green and sustainable energy from the environment to power micropower electronics is the aim of this paper. To improve the environmental adaptability of existing piezoelectric vibration energy harvesters, this paper proposes a magnetically coupled direction-switching tunable piezoelectric vibration energy harvester utilizing a seesaw-like exciter (MST-PVEH). The MST-PVEH consists of an exciter and two combined transducers. Instead of direct spring traction, the harvester used a spring-rope combination traction structure, which enabled the collection of ultra-low frequency vibration energy. Vibration commutation and energy transfer between the exciter and the combined transducer were achieved using magnetic coupling. The effects of excitation and structural parameters on the power generation performance of the harvester were investigated using theoretical simulations and tests. The results show that MST-PVEH can be applied to harvest vibrational energy from 5.3 Hz to 20.2 Hz by changing the structural parameters of MST-PVEH. In addition, with a load resistance of 260 kΩ and an excitation frequency of 7 Hz, MST-PVEH reached a maximum output power density of 2.3 μ W cm −3 . Moreover, the MST-PVEH can illuminate up to 100 blue LEDs and continuously power a 2 mW temperature sensor and a 3 mW transmission module.