Performance of a constant-stress piezoelectric generator for battery-less remote control/switch

Abstract

This paper introduced a novel constant-stress piezoelectric cantilever generator (CSPCG) for human-powered battery-less remote controls(switches). The CSPCG consists of a piezoelectric monomorph cantilever and a deflection-limiting device (DLD). The DLD was designed to be a circular arc to shape the bended cantilever and yield constant strain through length. Considering the energy converting ability and reliability, the DLD's radius was figured out as a function of working stress and thickness of the piezoelectric plate and substrate plate. Contrasted with a deflection-free piezoelectric cantilever generator (DFPCG), the energy performance of the CSPCG was evaluated. Research results show that the two generators share the same optimal thickness ratio for them to achieve the maximal electric energy output. When the same stress and end-deflection were provided, the electric-energy generation of the CSPCG is above 4 and 1.5 times that of the DFPCG, respectively. While, the stress and end-deflection of the CSPCG is only 0.49 and 0.77 times that of the DFCPG when equal electric energy is generated. This suggests that a CSPCG with a DLD can enhance energy-generating capability and reliability, or decrease end-displacement of piezoelectric cantilever. A CSPCG was fabricated and used to power a low-power remote-control circuit at one-push excitation.