Multi-band vibration energy harvesting via dual defect states in perforated metamaterial plate with bidirectional composite cylindrical resonators

Metamaterial-based targeted harvesting of multi-band low-frequency vibrations through engineered defect states enables efficient power generation for distributed micro-sensors. This study designs a novel piezoelectric energy harvester (PEH) using a perforated metamaterial plate with dual point defects. The structure leverages synergistic local resonance and complex bandgap modulation to concentrate vibrational energy at multiple defect-band frequencies while broadening the harvesting bandwidth. Under defect-band excitation, flexural waves localize energy in defect regions. Integrated piezoelectric transducers at these sites convert amplified flexural wave energy into electricity. Finite element simulations analyze the impacts of dual-defect distance, hole radius, and circuit connection on conversion efficiency. Results demonstrate that reducing defect distance from 30 mm to 10 mm increases defectband output voltage by 97.81% through enhanced coupling and energy localization. Larger hole radii correlate with stronger energy localization. A series-connected Type 1 dual-defect metamaterial plate (DMP1) with a hole radius of 1 mm achieves optimal voltage performance, where the dual-PEH system yields a total output power of 265.77 μW (230.28 μW at defect band 1 and 35.49 μW at defect band 2) under a load resistance of 56.23 kΩ. This multi-band energy capture strategy provides a novel power solution for Structural Health Monitoring (SHM) sensors.