Piezoelectric Transduction Mechanism For Vibration Based Energy Harvesting.

Abstract

Piezoelectric energy harvesting is a promising technology for extracting the power from environmental vibrations. It generates the electrical power of few orders of amplitudes which is sufficient to drive several autonomous electrical devices. Such vibration-based energy harvester generates the most energy when the generator is excited at its resonance frequency. When the external frequency shifts, the performance of the generator drastically reduces. In this line, present work first studies the various factors affecting the amount of power harvested. Simplest model to be started is with a single degree of freedom lumped parameter model of cantilever bimorph equivalent system with a tip-mass. To enhance the power harvesting capability of such simplest system over a wide bandwidth range, a two degree of freedom harvester system is explained in the present work. Its capability to work over a range of frequency is mathematically predicted. The system can be generalized for any number of degrees of freedom. The continuous beam models based on Euler and Rayleigh’s theory are next import issues considered in this thesis. The equations of motion are obtained from Hamilton’s principle and are solved by Galerkin’s method with one mode approximation., an experimental analysis is conducted at laboratory level by providing the sinusoidal base excitation using a vibration shaker to a thin brass BZT bimorph cantilever with tip-mass. The open-circuit voltage history obtained from the piezoceramic layer is reported.