Inspired by L-shaped hammer stockbridge damper: A multi-band dual-beam coupled vibration piezoelectric energy harvester

Inspired by L-shaped hammer Stockbridge damper on overhead transmission lines, this work proposes a novel multi-band dual-beam coupled vibration piezoelectric energy harvester for efficiently harvesting cable vibration energy. The harvester's core comprises two dual-beam piezoelectric oscillators, which together can generate a total of four harvesting frequency bands through structural parameter adjustments, extending the operational range. To evaluate performance, finite element analysis and experiments were used to investigate the influence of key parameters. The work revealed that the beam spacing (D), length ratio (L_r), and additional mass (M₂) significantly affected the second-order vibration mode. Specifically, D = 38 mm, L_r = 0.54, and M₂ = 3 g represented the critical points for the transition of the second-order vibration mode. The coupled structure enables the specific L_r and M₂ to effectively enhance the output of the floating cantilever beam at its first-order resonance. Furthermore, the work investigated the harvester's capability to harvest vibration energy from different directions. Under baseline conditions, the power densities at first-order resonance for the elastic supporting beam and floating cantilever beam are 16.967 mW/cm³ and 1.767 mW/cm³, respectively, and 4.45 mW/cm³ and 11.20 mW/cm³ at second-order resonance, providing stable power to wireless sensor nodes in the environment.