The Study On Optimization Design Of Vibration Energy Harvester

With the development of Micro-electromechanical technology, the energy consumptionof Micro-equipment has become lower. Because the advantages of low power consumptionMicro-electromechanical System (MEMS), its application becomes more widely.Nowadays, more and more MEMS’s applications need to work in a long term withoutman’s management. The equipment’s long term power supply becomes a key issue of itsapplication.Environment contains various forms of energy. Energy harvester is equipment that canharvest surrounding energy and transform into electric energy. Let energy harvester tosupply the electric energy that MEMS needs is a probable way to solve the problem. Afteranalysis the different forms of energy and different ways to convert energy, Author findvibration energy is widely exist in the environment, and it is probable to make use of thevibration energy harvester to supply power. Do research of those main methods to harvestvibration energy, have a conclusion that the method that use piezoelectric material totransform vibration energy is more feasible than the other two ways.In this dissertation, author has a detailed study of the piezoelectric effect andpiezoelectric type energy scavenger. Most vibration energy harvesters are working inresonant mode. The vibration frequency in surrounding is low, so it is need to lower theinherent frequency of energy harvester. Optimization in piezoelectric beam’s length andmass in the end to lower the natural frequency has faced a bottleneck. The length of beamand weight of mass can not increase without limit. In order to find another way to reducethe inherent frequency, design a non-axisymmetrical composite piezoelectric beam. Usefinite element analysis software to comparative analysis non-axisymmetrical and basicrectangular composite piezoelectric beam in the same dimensions. And then do research inthe size of non-axisymmetrical piezoelectric beam with its performance effect. Finally,have experiments of the two kinds of beams. The result show non-axisymmetrical beamhas better performance.The study on non-axisymmetrical composite piezoelectric beam has certaininnovation and research value.