Resonance-Tunable Piezoelectric Vibration Energy Harvester with Core-Less Structure Using Prism-Assisted 3D Lithography

This paper proposes a piezoelectric vibration energy harvester (PVEH) with a core-less (CL) structure. The CL structure features a hole in the center, which reduces the bending stiffness. FEM analysis showed that the CL structure had a lower resonance frequency and increased output power compared to the core-embedded(CE) structure. Additionally, the resonance frequency was minimized using a single layer of the CL structure. Excitation experiments showed resonance frequencies of 38.9 Hz for the zigzag structure and 49.7 Hz for the 2-layer structure. This indicates that the resonance frequency can be tuned within a range of 10.8 Hz by simply adjusting the stage angle in prism-assisted 3D lithography.