Capacitive Vibration Energy Harvesting with Resonance Tuning

Electromechanical conversion of mechanical vibration into electrical energy looks very attractive for industrial applications recently proposed and involving wireless sensors networks. A preliminary analysis of the energy scavenger configuration is proposed by investigating the performance of microsystems based on the electrostatic coupling and testing the power scavenged by a capacitive microscavenger, with out-of-plane gap closing layout. This study includes some key features of the mechatronic design of the energy scavenger. Some strategies for tuning the MEMS resonance frequency on the exciting vibration are investigated. An original procedure based on the static electro-mechanical coupling is introduced. A parametric modeling of the microscavenger is performed and experimentally validated. This investigation allows comparing the performance of the energy harvesting strategy to the configuration with in-plane motion of electrostatic benders and to the performance of bimorph piezoelectric transducers.