Power Variation with External Load in Vertical Vibration based Electret-Cantilever Micro-Power Generation

We present a generator model to describe the generated electrical output power variation with external load for vertical vibration based electret-cantilever micro-power generator. The generator, being electrostatic, is represented by an equivalent current source model. A vertical vibration based electret-cantilever micro-power generator was set up in which CYTOP was used as the electret and the upper electrode was made in form of an A-shaped cantilever fabricated from materials of copper with embedded glass epoxy. Experiments were conducted on the set up in the laboratory to validate the model. The results (generated electrical output power variation) from experiments agree fully with expected characteristics from the mathematical model. Also, maximum average power was expended in the external load when its value is equal to the equivalent internal source resistance of the micro-power generator. Electret-cantilever micro-power generator is best suited for high impedance loads.