Energy scavenging using MEMS based power generator

Abstract

Over the past few years, there has been a huge reduction in size and power consumption of MEMS devices like transducers and sensors. These devices are usually designed to run on batteries the replacement of batteries is not practical. The limited lifespan of batteries may induce costly maintenance, in the case of contaminated areas for instance. Moreover, batteriesdying without warning cause serious problems in safety monitoring applications. That led to a surge of research in the area of energy harvesting. Sustainable power generation may be achieved in converting ambient energy into electrical energy. Some possible ambient energy sources are, for instance, thermal energy, light energy and mechanical energy. After an extensive survey of potential energy harvesting methods, the conversion of ambient vibrations to electricity was chosen as a method for further research. Since mechanical vibrations exist in most systems, many works focused on vibration-driven generators. In this field, the electromagnetic induction is well suited for the mechanical to electrical energy conversion. The design of the mechanical system that transmits the surrounding vibratory energy to the electromagnetic generator is a critical importance. This thesis presents an optimization of an electromagnetic microgenerator. It describes the theory, design and simulation of an energy converter based on electromagnetic induction. The objectives of this research are designing, improving the performance and operational reliability of electromagnetic microgenerator. These have been achieved by identifying the desirable design features of the electromagnetic microgenerator. Extensive analytical investigation has been conducted to develop an efficient design of an electromagnetic microgenerator. This thesis deals with the design and simulation of a number of suspension structures to be used for supporting the moving magnet of an electromagnetic microgenerator. These suspension structures were designed by modeling and finite element method simulation using COMSOL Multiphysics. This helped in understanding the critical aspects of the design at the same time leading to the determination of the optimum parameters for the structures, such as static deflection.