Design and performance study of low frequency magnetic coupling bistable piezoelectric and electromagnetic energy harvester

Abstract

Aiming to achieve higher energy output under wider bandwidth, a low frequency magnetic coupling bistable piezoelectric and electromagnetic energy harvester is proposed. Two opposite-polarity magnets are introduced into the M-shaped structure. The introduction of magnetic repulsion force can broaden energy harvesting bandwidth and break through the potential well with smaller external excitation. The primary variables are obtained by state equations. The dynamic response and energy harvesting characteristics are obtained by comparing further numerical analysis with experimental methods. Compared with the theoretical and experimental results, both magnetic repulsion and bistable M-shaped structure can effectively improve the energy harvesting characteristics and dynamic response. The maximum output power of piezoelectric and electromagnetic modules is 0.17 mW and 1.24 mW respectively. Due to the structure influence, the maximum bandwidth of energy harvesting increases by 35.71 % than the minimum, the average growth rate of piezoelectric output voltage can reach 0.42V/mm during disorder motion and intra-well motion, piezoelectric and electromagnetic power also increase by 57.57 % and 55.45 % respectively. which enhances environmental adaptability and has great potential for monitoring and energy harvesting in low-frequency vibration environments.