Eur. Phys. J. Spec. Top. (2022) 231: 4205-4211
https://doi.org/10.1140/epjs/s11734-022-00577-8

Regular Article

Optimization of a vibrating MEMS electromagnetic energy harvester using simulations

¹ Université de Toulouse, INSA-CNRS-UPS, LPCNO, 135 Av. Rangueil, 31077, Toulouse, France
² Laboratoire d’Analyse et d’Architecture des Systèmes, CNRS, 7 avenue du Colonel Roche, 31077, Toulouse, France
³ Georgia Tech-CNRS International Research Laboratory, School of Electrical and Computer Engineering, Atlanta, GA, USA
⁴ Université Grenoble Alpes, Institut Néel, 38042, Grenoble, France

ⁿ lmlacroi@insa-toulouse.fr
^p tblon@insa-toulouse.fr

Received: 14 January 2022
Accepted: 9 April 2022
Published online: 4 May 2022

Abstract

Nowadays, wireless sensor networks (WSN) are becoming essential in our daily life. However, a major constraint concerns the energy power supply. Indeed, batteries need to be recharged or replaced often which implies a limited lifetime for WSN nodes. One alternative consists in harvesting mechanical energy from surrounding vibrations of the environment. Using finite element simulations, we report here a complete guideline to optimize a MEMS electromagnetic energy harvester consisting of an in-plane vibrating silicon frame supporting an array of micromagnets that faces a static 2D micro-coil. The dimensioning of the magnet array and the specific design of the coil are addressed, considering patterned 50 $\mathrm{\mu }$m thick NdFeB films with out of plane magnetization. The optimization of the electromechanical coupling which allows to efficiently convert the energy results from a trade-off between the high magnetic flux gradients produced by the micromagnets and the maximum number of turns of the facing coil.