Nano-porous SIO2 electret with high surface potential and high thermal resistance

Abstract

This paper proposes a new electret with high surface potential and high thermal resistance, which is made of nano-porous SiO₂. Electrical charge density in the nano-porous SiO₂ is higher than that in a normal (i.e., nonporous) SiO₂ because there are many voids in the nano-porous SiO₂ and the interface between void and SiO₂ traps electrical charges strongly. Therefore, decrease rate of the trapped charge density in the nano-porous SiO₂ is lower than that of normal SiO₂. Since SiO₂ is thermally stable, thermal stability of the electrical charge in nano-porous SiO₂ electret is better than that in a polymer electret. Output power generated by vibration energy harvesting using the nano-porous SiO₂ electret is also larger than that using the normal SiO₂ or polymer electret.