Effect Of Packaging Pressure On Energy Harvesting From Vibration Source

In this paper, we have studied the effect of air pressure damping on the vibration-based energy harvesting devices. The device we used is an electrostatic energy harvester with an out-of-the-plane gap closing scheme. A broadened bandwidth is observed at 4 Pa when the acceleration is increased from 0.5 m/s(2). A power output of 2.2 mu W is achieved at the air pressure of 4 Pa when a low acceleration of 0.5 m/s(2) is applied, while the power output is only 0.02 mu W at atmosphere with an acceleration of 1.2 m/s(2). Detailed study is made to investigate the waveform of the displacement and the voltage output. Nonlinearity is observed at low air gas pressure about 239 Pa and it is more significant at 4 Pa.