electrostatic transducers

Soft-X-ray-charged vertical electrets and its application to electrostatic transducers
M Honzumi, A Ueno, K Hagiwara… – … (MEMS), 2010 IEEE …,
… we develop ‘vertical’ electrets by using the soft X-ray technology, which can be used for in-plane
single-wafer electret transducers. … Corona discharge is a conventional charging method for electrets,
in which corona ions emitted from a high-voltage needle transfer their charges