Relationship between piezoelectric properties of ceramics and output performance of 33-mode piezoelectric energy harvesters

Abstract

Ring-type 33-mode piezoelectric energy harvesters (PEHs) were fabricated using Pb(Zr,Ti)O-3 and (Na,K)NbO3-based piezoelectric ceramics. The relationship between the output performance of the PEH and the piezoelectric properties of the ceramics was investigated. Ring-type PEHs were selected for this investigation because they can be mounted on a specimen holder at the same position, ensuring structurally reliable output performance. The k(eff)(2) x Q(m)/S-33(E) value, which was reported as a figure of merit (FOM) of the PEH under resonance condition, could not adequately explain the output performances of the 33-mode PEH with a specimen holder much larger than the size of the specimen. The d(33) x g(33) value, which is a FOM derived from the theoretical output power of the 33-mode PEH, can explain the variation of the output power of the 33-mode PEH with a large specimen holder. However, since the variation of the output power was more accurately explained by the d(33) x g(33) x k(eff)(2) value, this was suggested as a new FOM of the output power of the ring-type 33-mode PEH with a large specimen holder.