This paper focuses on several aspects extending the dynamical efficiency of a cantilever beam vibrating in the third mode. A few ways of producing this mode stimulation, namely vibro-impact or forced excitation, as well as its application for energy harvesting devices are proposed. The paper presents numerical and experimental analyses of novel structural dynamics effects along with an optimal configuration of the cantilever beam. The peculiarities of a cantilever beam vibrating in the third mode are related to the significant increase of the level of deformations capable of extracting significant additional amounts of energy compared to the conventional harvester vibrating in the first mode. Two types of a piezoelectric vibrating energy harvester (PVEH) prototype are analysed in this paper: the first one without electrode segmentation, while the second is segmented using electrode segmentation at the strain nodes of the third vibration mode to achieve effective operation at the third resonant frequency. The results of this research revealed that the voltage generated by any segment of the segmented PVEH prototype excited at the third resonant frequency demonstrated a 3.4–4.8-fold increase in comparison with the non-segmented prototype. Simultaneously, the efficiency of the energy harvester prototype also increased at lower resonant frequencies from 16% to 90%. The insights presented in the paper may serve for the development and fabrication of advanced piezoelectric energy harvesters which would be able to generate a considerably increased amount of electrical energy independently of the frequency of kinematical excitation.

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This research work considers a more efficient vibro-impacting piezoelectric energy harvester (VIPEH) structure, which is intended both to prevent the device from excessive displacements as well as to increase its operational bandwidth in actual excitation conditions. Multi-physics finite element model of the VIPEH was developed in Comsol with the objective to analyze influence of stopper location on the mechanical and electrical characteristics of the piezoelectric transducer, followed by the experimental study of two device configurations. Numerical and experimental results revealed that stopper location influences the magnitude of generated voltage since, at certain stopper location points, higher vibration modes are excited during the impact.