Development of a pre-packaged MEMS electret energy harvester before charging

Abstract

A novel MEMS electret vibration energy harvester sealed in a package before charging is developed, which should improve the package reliability and long-term stability of the charges. With an early prototype in package, vertical electret on the comb drives has been successfully charged with soft X-ray photoionization, and up to 3.58 μW has been obtained at 570 Hz and 2.2 g oscillation, which corresponds to the effectiveness as high as 42%.