Simulation and experiments of broadband piezoelectric energy harvesting devices

Abstract

PZT Cantilever has been widely applied in enery harvesting system due to simple structure and high electromechanical conversion efficiency. Cantilever without mass attachment has a narrow bandwidth and low efficiency. The performance of the cantilever type harvesting device can be improved by attached with multiply mass at the end of the cantilever. Simulation and experimental results show that resonant frequency is reduced with the increase of numbers of mass, and bandwidth is broadened with numbers of mass.

Design and Analysis of a 2-DOFs Right-angle-shape Piezoelectric Energy Harvester

“…Wu. [7] designed and fabricated a 2-DOFs piezoelectric energy harvester which comprises one main cantilever and an inner secondary cantilever, it can achieve two voltage peaks at the two close resonant frequencies in the environment frequency less than 24Hz; Hu [8] presented a design of a 3-DOFs Mshaped piezoelectric energy harvester comprises a main beam and two folded auxiliary beams interconnected through the proof mass at the end of the main cantilever, it can tune the resonant frequencies of first three orders in the environment frequency less than 30Hz close enough to obtain a utility wide bandwidth; Wang [9] designed and fabricated a cantilever type harvester attached with multiply mass at the end of the cantilever, the resonant frequency is reduced with the increase of the numbers of mass, and bandwidth is broadened with numbers of mass. It can be summarized that increasing the degree-of-freedoms of the harvester can effectively reduce the resonant frequency interval results in multiple operating frequency bands at low-frequency environment, but for one single operation bandwidth widening is not satisfactory; increasing the numbers of mass can effectively broaden the single operation bandwidth, but it does not shorten the resonant frequency interval or increase the number of operating frequency bands in the low-frequency environment.…”

Piezoelectric vibration energy harvesting with asymmetric hybrid bracing beam

“…This structure can effectively improve the energy output in the high frequency range, but the device’s own weight is large and the natural frequency of energy harvesting is high. Wang Hai et al 14 proposed a multi-mass piezoelectric energy harvesting structure, whose first-order natural frequency reached the lowest 28 Hz and the maximum output power reached 31 mW. However, with the increase of mass blocks, the piezoelectric ceramics were prone to fracture and the stability of the piezoelectric energy harvesting system was reduced.…”