Modeling of Multiple Cantilevers System for Broadband Vibration Energy Harvester

Piezoelectric energy harvester has the capability in powering small scale semiconductor devices particularly in the low power sensors applications in Internet of Things (IoT) environment. It is known that the bandwidth and power of these energy harvesters can be improved by increasing the number of cantilevers in the system. This research presents the electromechanical model of multimode piezoelectric energy harvesters with different polarity connections between the cantilever beams to improve the broadband performance of frequency response in the system. The theoretical model and experimental results of the proposed multi-mode system exhibited a significant escalation of output voltage at the gap between two resonance frequencies when the polarity configuration in the cantilever connection is reversed accordingly. The outcomes designate that by interchanging the polarity of the electrical connection between the cantilever beams, the output voltage between the resonance frequency of the multi-mode system can be increase significantly in comparison with the conventional series interconnection.