Shear-Mode-Based Cantilever Driving Low-Frequency Piezoelectric Energy Harvester Using 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3

Energy harvesting from external mechanical excitation has become a hot interest area, and relaxor piezoelectric single crystal (1 - x)Pb(Mg
_1/3
Nb
_2/3
)O
₃
-xPbTiO
₃
(PMN-xPT or PMN-PT) has attracted continuous attention due to the well-known ultrahigh shear-mode electromechanical response. To exploit the low-frequency application of excellent shearmode performance of the PMN-PT single crystal, we proposed a Shear-mode-based CANtilever Driving Low-frequency Energy harvester. The device is composed of two symmetrically assembled sandwich structures and a cantilever, in which sandwich structures can be driven by the cantilever. An analytical method was used to illustrate the high output mechanism, and a finiteelement method model of the device was also established to optimize the generated electric energy in this device. The electrical properties of the device under different excitation frequencies and load resistances were studied systematically. The maximum voltage and power density at resonance frequency (43.8 Hz) were measured to be 60.8 V and 10.8 mW/cm
³
under a proof mass of 13.5 g, respectively. Both theoretical and experimental results demonstrate the considerable potential of the resonance-excited shear-mode energy harvester applied to wireless sensors and low-power portable electronics.