Investigation of a d15 mode PZT-51 piezoelectric energy harvester with a series connection structure.

A d₁₅ mode piezoelectric energy harvester (PEH) with two PZT-51 elements in series connection (SC), in which the elements are arranged along the width direction, was fabricated, and it is compared with the traditional d₁₅ mode PEH with a single PZT-51 element (SPEH) to discuss the output peak-to-peak voltage (U_p-p). The energy harvesting performances of PEHSC are modeled by combining the single degree of freedom model and the electrical model with the piezoelectric constitutive equation of the d₁₅ mode. The energy harvesting performances of PEHSC were systematically measured at various frequencies and load resistances, and U_p-p and output power are 12.4 V and 8:7 W at a load resistance of 2:2 M and resonance frequency of 73 Hz. The experimental U_p-p of PEHSC and SPEH are 25.4 and 15.6 V at the resonance frequencies under open circuit condition, and this indicates that the SC structure can improve the energy harvesting performance for d₁₅ mode PEH. The experimental U_p-p, output power and the transient voltage-time curve of PEHSC are in agreement with the results of finite element numerical solutions and theoretical modeling, so they are acceptable. The d₁₅ mode and SC structure could potentially improve the energy harvesting performance of PEHs. [ABSTRACT FROM AUTHOR]