Multiphysics analysis of magnetic coupling piezoelectric energy harvester

In the field of wireless sensor networks, piezoelectric energy harvesting technology offers a promising solution to the long-term power supply challenges of sensor nodes. However, conventional piezoelectric energy harvesters (PEHs) suffer from narrow potential wells, limiting output performance. To address this, a nonlinear magnetic coupling piezoelectric energy harvester (NM-PEH) is proposed, leveraging the attractive force between a tip magnet and external magnets to broaden the potential well, thereby increasing output voltage and reducing resonant frequency. Firstly, a mathematical model is established, incorporating the distributed parameters of the tip magnet and the angular arrangement of the external magnets. The effects of horizontal and vertical magnetic spacing and magnet inclination angle on potential energy and voltage output are analyzed. Subsequently, dynamic magnetic coupling effect is introduced into finite element simulations in both the time and frequency domains to analyze the impact of structural parameters on voltage and resonant frequency. Finally, an experimental testing platform is constructed to validate the theoretical model and simulation results. The results show that the NM-PEH prototype exhibits a significant improvement over the conventional PEH, with the resonant frequency reduced by 7.1 Hz and the output voltage increased by 17.88 V. And further demonstrate the consistency among theory, simulation, and experiments. This study provides a reference for design and development of magnetic coupling piezoelectric energy harvesters. © 2001 Elsevier Science. All rights reserved.