Development of Electric Power Measurement for Energy Harvesting using Unimorph-type Piezoceramics

摘要

In this study, a new electric power generation measurement system was developed for piezoelectric energy harvesting using unimorph-type piezoceramics. Relationships between electric power and material constants such as d_(33), d_(31), g_(31), k_(31), ε_(33)~T/ε_0, S_(11)~E, Q_e and Q_m were investigated using various lead zirconium titanate (Pb(Zr,Ti)O_3, PZT) ceramics with different material constants. Using the equipment, pulse-type stress was applied to unimorph-type piezoceramics. Then, optimum measurement conditions were determined. Under these conditions, the electric power for piezoelectric energy harvesting was measured as a function of the material constants. Finally, it was clarified that for piezoelectric energy harvesting using a unimorph-type device, the figure of merit was combination of the 3 kinds of material constants such as large d_(31), small ε_(33)~T/ε_0, and large s_(11)~E.