A Novel Semicircular Arc Piezoelectric Energy Harvesting System With Dual Folded Beams and Its High-Performance Interface Circuit

To address the narrow bandwidth and low power density of conventional piezoelectric energy harvesters, a novel semicircular arc piezoelectric energy harvesting system with dual folded beams (SAPEH-DFB) is designed in this work. Distinct from traditional linear structures, the unique semicircular geometry integrated with folded beams enables effective multi-directional energy harvesting and significantly broadens the operating bandwidth through multi-mode coupling. Furthermore, a modified self-powered parallel synchronized switch interface (SP-PSSHI) is introduced. By integrating the rectifier bridge structure into the switching circuit, this design improves circuit integration and maximizes energy extraction. This circuit is specifically optimized to mitigate the energy cancellation caused by phase differences among the multiple beams. Experimental results demonstrate that the optimal configuration (PEH B) achieves a broad bandwidth of 58 Hz. It delivers a maximum output power of 5.79 mW with a normalized power density (NPD) of 164.8 μW·g⁻²·mm⁻³, maintaining high performance across multiple vibration modes. In addition, the proposed interface circuit further enhances the output power by up to approximately 15.8% compared to standard circuits, enabling effective power supply in the wearable devices and microsensors.