Energy harvesting from topological interface states in an elastic beam array system

Recent discoveries of exotic topological phenomena in mechanical phononics and metamaterials have become a prominent focus in engineering research. These findings not only expanded the functionality and potential applications of such artificial materials and structures but also went well beyond the initial identification of effects such as band gaps. In this study, we propose energy harvesting from localized interface modes in a periodic beam array system. The system is composed of elastically connected parallel beams, with bimorph piezoelectric beams considered at the interface. We derive a system of governing equations, and respective eigenvalue problems for both the full finite lattice model and a reduced-order model based on Bloch mode synthesis are defined and solved. We analyze the topological properties, eigenspectrum, frequency–voltage relationships, and steady-state responses to explore localized interface modes and their energy harvesting capabilities. Additionally, we investigate the robustness of the frequency of topologically protected interface modes in the presence of a mass defect in the lattice, demonstrating the efficiency of the proposed energy harvesting system.