OHA Ceramic Electret for Vibration Energy Harvesting

Abstract

With a motivation for developing oxy-hydroxyapatite (OHA) ceramic-electret applicable to vibration energy harvesting, the poling characteristics of OHA ceramics were investigated in terms of microstructure using thermally stimulated depolarization current (TSDC). OHA is a hydroxyapatite (Ca10(PO4)6(OH)2)-derivative material, in which the OH- ions are partially substituted by O2- ions and vacancies (Ca10(PO4)6(OH)2-xOx/2). Patterned electret using 14-mm diameter OHA ceramic was prototyped with stripe-shaped electrodes, which serve as the electrostatic shield on the surfaces. The relationship between surface potential and the pattern width of the electrodes was experimentally examined, and the power generation characteristics were investigated.