Since energy harvesters are suitable for powering small sensors and actuators, which commonly are at the micro scale, it is desirable to have the energy harvester in small scales too. My research has addressed the high frequency issue in MEMS energy harvesting. The energy harvesters should be tuned to ambient excitations and their fundamental resonance frequency should be below 50 Hz. The natural frequencies of conventional MEMS energy harvesters are in kilo Hertz range. We have developed two novel geometries for power harvesting and have performed extensive analytical and experimental studies on their energy harvesting potential. It was shown that using the geometries improves the power production by four orders of magnitude.