Vibration-driven MEMS energy harvester with vacuum UV-charged vertical electrets

Our target is to realize a vibration-driven MEMS generator with vertical electrets for energy harvesting applications. With the aid of a novel high-speed charging method using vacuum UV irradiation, we have realized vertical electrets on the sidewall of comb fingers. An early prototype of in-plane electret generator with parylene electrets has been successfully microfabricated through a single-wafer approach. Uniform surface potential on the vertical electrets of the comb fingers is confirmed with a Kelvin force microscopy (KFM) measurement. Power generation with the prototype has been also demonstrated.