Bidirectional Piezoelectric Energy Harvester.

This paper represents a numerical and experimental investigation of the bidirectional piezoelectric energy harvester. The harvester can harvest energy from the vibrating base in two perpendicular directions. The introduced harvester consists of two cantilevers that are connected by a particular angle and two seismic masses. The first mass is placed at a free end of the harvester while the second mass is fixed at the joining point of the cantilevers. The piezoelectric energy harvester employs the first and the second out of plane bending modes. The numerical investigation was carried out to obtain optimal geometrical parameters and to calculate the mechanical and electrical characteristics of the harvester. The energy harvester can provide stable output power during harmonic and impact-based excitation in two directions. The results of the investigations showed that energy harvester provides a maximum output power of 16.85 µW and 15.9 4 µW when the base has harmonic vibrations in and directions, respectively. Maximum output of 4.059 nW/N and 3.1 nW/N in and directions were obtained in case of impact based excitation.