Energy harvesting of a metamaterial beam with acoustic black holes

This paper proposed an improved metamaterial piezoelectric beam with the acoustic black holes (ABHs) for low-frequency energy harvesting. The ABHs are embedded in the local resonant beams distributed on both sides of the primary beam. Piezoelectric plates are attached to the ABHs, leveraging the energy-focusing effect to enhance the energy harvesting performance. Finite element simulation results indicate that the energy harvesting electrical energy has improved by 6.92 times compared to the traditional metamaterial resonant beam without ABHs. Parameter analysis indicates that increasing the number of local resonators and extending the length of the piezoelectric patches can further enhance energy harvesting performance. However, reducing the truncation thickness of the ABH boosts energy harvesting but compromises structural strength. Extending the ABH length and increasing load resistance within the appropriate range are conducive to energy harvesting. Besides, the optimal load resistance varies with frequency. These findings provide useful guidance for future applications of improved metamaterial beam.