Fabrication And Characterization Of The Wideband Vibration Energy Harvester

As microelectronic devices consumes lower and lower power,environmental energy harvesting makes it possible that wireless sensor nodes becomes battery-free and self-powered.The vibration energy is one of the most widely used energy in the environment.At present,piezoelectric vibration energy harvesters are linear systems at most cases,and have a narrow bandwidth.In this paper the wideband vibration energy harvester was studied.In this paper,the piezoelectric energy harvester was studied on basis on the nonlinear vibration theory.It was deposited on Ti and fabricated from an improved dip-coating process with a layer of PZT film on the substrate surface.In order to broaden the bandwidth,the length,width and thickness of the cantilever were20mm,12mm and 50?m respectively,and it was attached a weight of 0.6422g on the free end of the cantilever.When the excitation acceleration is 2m/s~2,with increasing the frequency or decreasing the frequency,the energy harvesting efficiency of the harvester sharply increased correspondingly at16Hz and 14.3Hz,indicating that the frequency band width was 1.7Hz.In addition,when the load was 68k?,its maximum output power was 0.406?W.This paper also qualitatively analyzed the influence of the vibration acceleration,the cantilever length and the proof mass weight on the energy harvester.It was found experimentally that the acceleration was an external factor,which was only positively related to the output voltage of the energy harvester.The cantilever length and the proof mass weight were the internal factors.The increase of both the length and the weight could reduce the working frequency of the device.In addition,the increase of the length and the decrease of the weight could increase the bandwidth of the device.However,they will reduce the output power of the device.At the end of this paper,the research result were summarized and some improvement suggestions were proposed,hoping to manufacture a vibration energy harvester with higher energy conversion efficiency.