We develop a MEMS-friendly electret film using CYTOP,
and examine its performance with a prototype micro seismic
generator. We also evaluate the electrostatic force with a simplified
model. The following conclusions can be derived:
(1) The maximum output power of 0.278 mW and peak-to-peak
voltage of 120 V have been obtained at 20 Hz oscillation with 4
MΩ external load. Therefore, energy harvesting on the order of
1 mW is feasible with electret generators.
(2) The present generator model can mimic the response of the
in-plane electret generator with sufficient accuracy.
(3) When two separate generators with a 180˚ phase difference
are integrated on a single chip, the in-plane electrostatic force
becomes smaller by two orders of magnitude. The trend of the
in-plane force is much different from previous models, such as
velocity-damped resonant generator.
This work is supported through the New Energy and Industrial
Technology Development Organization (NEDO) of Japan.
Photomasks are made using the EB writer F5112+VD01 at the
University of Tokyo VLSI Design and Education Center
(VDEC), which is donated by ADVANTEST Corporation.