STAR-SHAPED PIEZOELECTRIC MECHANICAL ENERGY HARVESTERS FOR MULTIDIRECTIONAL SOURCES

ABSTRACT This work deals with multidirectional and multimodal piezoelectric mechanical energy harvesters, proposing a star-shaped device composed by a tri-leg L-shaped structure with piezoelectric patches at six locations. Inertial pendular masses are strategically attached to the structure to harvest energy due to three-direction excitation sources. The device is modeled using finite element method and simulations are carried out to optimize the system design to operate in the required frequency range. System performance is investigated considering different ambient conditions including random excitations that represent the unavoidable source uncertainties. Results for in-plane and out-of-plane excitations show that the proposed device has potential to extract energy from multidirectional sources with a wideband frequency spectrum, serving as an alternative to conventional single-mode harvester with unidirectional sensitivity.