Analysis and characterization of triangular electrode structures for electrostatic energy harvesting

作者：Hoffmann Daniel^*; Folkmer Bernd; Manoli Yiannos

来源：Journal of Micromechanics and Microengineering, 2011, 21(10): 104002.

DOI：10.1088/0960-1317/21/10/104002

This paper investigates triangular electrode structures for electrostatic energy-harvesting devices. By analysis of the electrode geometry, we identified the angle a, which is half the angle defined by the two equal sides of the isosceles triangle, to be an important design parameter. Moreover, triangular electrodes provide a larger capacitance change per unit displacement and also a larger total capacitance change than area-overlap and gap-closing designs. Fabricated devices were characterized using two different circuit configurations. Our results show a nonlinear frequency response (softening behaviour) due to the nonlinear capacitance characteristic of the triangular electrodes. However, the nonlinear capacitance characteristic allows tuning the resonance frequency of the device. We also observed that a bias voltage as low as 8 V allows effective operation of the energy-harvesting device. Finally, we demonstrate successful charging of a 20 mu F energy storage capacitor to a practical voltage level of 3.5 V. The harvested energy was applied to a low power transmission module which successfully transmitted a data communication protocol.

• 出版日期2011-10