Electret energy harvesting based on fringe electrical field change inside trenched ferroelectric

This paper proposes an electret energy harvesting method based on fringe electrical field change inside a trenched ferroelectric. A comb-shaped CYTOP electret with grounded base electrode and a comb-shaped counter electrode are interdigitally fabricated on an insulating substrate. Between electret and electrode, fringe electrical field is generated, forming a comb-shaped planar capacitor. As a suspended structure with trenched ferroelectric (seismic mass) is motion-driven over the substrate, the capacitance changes because a dielectric constant equivalently changes, from which an electrical power is taken out. The experimental output power of 0.75 μW was achieved at 10 μm gap between seismic mass and substrate for 80 Hz/80 μm forced vibration.