Introduction

n applications, microsystems have to be self-powered; therefore, efficient energy scavenging is crucial. The self-powered microsystems are designed to avoid the replacement of energy cells and miniature sensing devices. Vibration-based energy harvesting is a process of capturing ambient kinetic energy and converting it into usable electricity. The growing demand of cell phone devices such as miniature wireless sensor networks, the recent advent of the extremely low power controlled circuit and MEMS devices make such renewable power sources very attractive. In addition, the energy harvesting process is practicable with environmental vibrations such as running machines and human body movement. However, the wide range of environmental energy keeps harvester low efficiency when deployed in a stochastic surrounding vibration.