Modeling and design of V-shaped piezoelectric vibration energy harvester with stopper for low-frequency broadband and shock excitation

For low-frequency broadband and shock energy harvesting, a compact design of V-shaped piezoelectric vibration energy harvester (V-PVEH) with impact stopper is proposed. Euler beam model for qualitative comparison, FEA model in COMSOL for structure design, and lumped parameters model with nonlinearity analysis for impact induce broadband and shock input are discussed comprehensively with experimental validation. • A V-PVEH with stopper is proposed with RMS power of 0.442 mW at 0.1 g with a low resonant frequency of 12 Hz. • Impact stopper design achieves 5−19 V voltage output at the acceleration of 0.4 g with the broadband of 8−15 Hz. • Biomechanical shock on feet at 1 Hz and quick capacitor charge power of 0.1 mW are testified for wearable V-PVEH. • FEA design and lumped parameters model with nonlinearity analysis for broadband and shock input are discussed. Broadband low-frequency vibration and shock energies are ubiquitous such as biomechanical motion, which can be harvested to power wearable electronics. This paper proposes a compact design of V-shaped piezoelectric vibration energy harvester (V-PVEH) with impact stopper. To demonstrate V-PVEH having high power density, Euler beam model is proposed for qualitative comparison between V-PVEH and cantilevered piezoelectric vibration energy harvester (C-PVEH). FEA model in COMSOL for V-PVEH structure design is proposed especially for the stress check. Modal analysis, two bimorphs connection style, tip mass thickness, and acceleration amplitude are discussed in the experimental vibration validation. A peak voltage of 11.5 V at a low resonant frequency of 12 Hz and a maximum power of 0.442 mW are shown in experiments under the excitation of 0.1 g. A lumped parameters model with nonlinearity analysis for impact induced broadband and shock input is discussed comprehensively. The stopper design in V-PVEH can not only limit the vibration amplitude and prevent overload, but also form broadband of 8−15 Hz and generate large voltage output of 5−19 V when impact occurs at an acceleration of 0.4 g. Except for resonating excitation, biomechanical shock energy harvesting with ultra-low frequency of 1 Hz is testified for wearable V-PVEH to charge a 10 μF capacitor to 10 V in 5 s by stamping feet. Above all, V-PVEH with stopper is believed to show good performance in broadband low-frequency vibration and biomechanical shock energy harvesting.