Theoretical comparison of the energy harvesting capability among various electrostatic mechanisms from structure aspect

This paper provides (i) a comparison of the energy harvesting capabilities of three different electrostatic mechanisms, and (ii) discussion on the relations among the contributing parameters involved in maximizing the energy output that can be harvested from an electrostatic microelectromechanical system (MEMS) device. The three mechanisms considered in this paper are namely the in-plane overlap, in-plane gap closing and out-of-plane gap closing converters. In this analytical modeling, the mass of the movable loads as well as the cross-sectional areas of the devices’ active regions were set to be the same for all the mechanisms, while we assumed these electrostatic mechanisms are operated in ideal vacuum environment. A maximum output energy density of 0.547 μJ mm−3 has been obtained for the case in which the movable load has a volume of 5 mm3.