Abstract
A piezoelectric energy harvester with a multi-mode dynamic magnifier is proposed and modeled in this paper. The dynamic magnifier consists of an intermediate beam with a tip mass, which is placed between the fixed end of the energy harvesting beam and the vibrating base structure. The piezoelectric element is bounded to the harvesting beam to harvest the vibration energy. With proper choice of the design parameters of the magnifier, the harvested electric power can be significantly increased due to the bandwidth extension, which enables energy harvesting from the ambient vibration in a larger range of frequency. Theoretical analysis is carried out with 4 × 4 chain matrix representation. Numerical examples are presented to illustrate the merits of the dynamic magnifier in comparison with the conventional piezoelectric energy harvesters. The results show that electric power produced by the harvesting beam is amplified for efficient energy harvesting over a broader frequency range.