  In this paper, design, fabrication and characterization issues of a bulk
silicon-based, vibration powered, electric energy generator are addressed. The
converter is based on an In-Plane Overlap Plate (IPOP) configuration [1].
Measurements have shown that with a theoretically lossless electronics and a
starting voltage of 5 V, power density of 58 $\mu$W/cm3 is achievable at the
resonance frequency of 290 Hz. It can be further improved by reducing the
parasitic capacitance, which can be achieved by silicon etching, but a
considerable mass is lost. In [2], it is shown that 19% of mass reduction
improves power density from 12.95 $\mu$W/cm3 to 59 $\mu$W/cm3. Hence an
enhancement in fabrication process is proposed, which is termed as Backside
DRIE. It helps in increasing power density without loosing an important
quantity of mass. Simulations have shown that 2.5% of mass removal improves
power density up to 76.71 $\mu$W/cm3. Initial simulation results and problems
of associated electronics are also discussed.
