Flexible substrate electrostatic energy harvester

Energy harvesting is attractive for powering wireless sensors, especially in applications such as body sensor networks and pervasive sensing, where power source replacement or recharging is impractical. A MEMS (micro-electro-mechanical systems) electrostatic harvesting device suitable for body motion has been reported previously, using a rolling rod as the proof mass. A new rolling rod device is presented, employing a flexible substrate to allow the formation of a concave structure. Suitable rod confinement and increased rod-plate capacitance are achieved. Regular power transduction even under impulse motion excitation is reported, supplying 0.5 mu W of output power.