MEMS Wideband Energy Harvesting using Array of Linear and Nonlinear Generators

Abstract

A MEMS wideband energy harvesting array design using linear and nonlinear generators is reported in this paper. An array comprising of four electrostatic energy harvesters using linear, softening, hardening springs and mechanical stoppers connected in parallel can work over a wide frequency range. Novel nonlinear spring design produces spring softening and hardening behaviors. Mechanical stoppers further enhance the operating frequency range of the hardening spring energy harvester. Mathematical model of the electromechanical system is derived and optimized using MATLAB. The system is built using Coventorware/MEMS+®. Simulation results indicated a maximum normalized power density of 1.97 µWs4/cm3-m2 is achieved over 600 Hz-1350 Hz frequency range. Moreover, following the method developed in this work, the device size is reduced by 89% compared to traditional array design technique.