Electrets-based electrostatic energy harvester for harvesting electrical energy from the ambient vibration is introduced and described in this paper. A new design of electrode structure called the trapezoidal electrodes and its electrets counterpart are designed, modeled and analyzed thoroughly to evaluate its performance. First, the theory is explained and the mathematical analysis is performed using Matlab/Simulink tool. Results of the analysis shows that the average output power harvested from the trapezoidal electrodes is ~1 mW from 20 Hz at 1 g inputs. Then, the 3D model of the electrodes and electrets structures are constructed, simulated and analyzed with Finite Element Modeling/Analysis (FEM/FEA) tool. Further, mechanical analysis carried out on the trapezoidal electrodes model indicates that it displaces laterally at 94 μm and resonates at 113 Hz whereas the electrostatic analysis unveils 1895 pC of charge density induced on the trapezoidal electrodes from 450 VDC electrets potential. The optimized parameters derive from the analyses are used as a reference for fabrication of MEMS (Micro Electro-Mechanical System) physical device on a standard CMOS process technology.

Date Published: 28 May 2013
PDF: 12 pages
Proc. SPIE 8728, Energy Harvesting and Storage: Materials, Devices, and Applications IV, 87280Z (28 May 2013); doi: 10.1117/12.2010079

Published in SPIE Proceedings Vol. 8728:
Energy Harvesting and Storage: Materials, Devices, and Applications IV
Nibir K. Dhar; Palani Balaya; Achyut K. Dutta, Editor(s)