Power Variation with Electret Surface Potential and Frequency of Vibration in Vertical Vibration based Cantilever-Electret Micro-Power Generation

A cantilever-electret based electrostatic micro-power generator for energy harvesting was set up in which Cyclic Transparent Optical Polymer (CYTOP) was used as the electret, and the upper electrode was made in form of an Ashaped cantilever which was fabricated from materials of copper with embedded glass epoxy. The cantilever was vibrated in the vertical direction in close to contact point mode of operation. Experimental result showed that the average output power increases with increasing electret surface potential, and the minimum distance to contact point decreases with increasing electret surface potential. Also, variation of output power with frequency was investigated by first observing the natural vibration of the cantilever amplitude with frequency. The natural amplitude was found to decrease with increasing frequency, thus making the average output power to decrease with increasing frequency. However, for the fabricated cantilever when operated over a wide frequency range, it was further confirmed by experiments that the output power variation peaks around 40Hz with maximum output power of 2.7nW with 1MΩ externally connected load and then decreases with increasing frequency.