A multi-degree-of-freedom electrostatic mems power harvester

This paper reports the design, modeling and experimental characterization of a multi-degree-of freedom electrostatic vibration energy harvester. The potential of harvesting vibrational energy at multiple input frequencies and achieving displacement amplification in the response is investigated. To better understand the device performance at a system level, a numerical model which incorporates mechanical and electrical analysis in a charge constrained conversion circuit is developed. Experimental results on a microfabricated prototype demonstrate a maximum measured output power of 0.076 ?W at 1.4 kHz for an external load of 5.1 M?. We also experimentally demonstrate that the output power varies with the square of input acceleration and DC bias voltage