Abstract
Electret that can be used in the liquid environment has been realized for the first time toward better performance of electret-based generators and actuators. By using super-lyophobic overhanging pillar surface, stable Cassie-Baxter (CB) state is sustained even with low-surface-tension hexadecane liquid and with high surface potential. Pillar surface with a SiO_2 electret layer has been successfully charged with soft X-ray photoionization previously developed. Surface potential as high as -150 V has been sustained after applying hexadecane droplet on the pillar surface. The interface behavior of CB droplets is systematically examined by changing the surface potential of the pillar.
