Optimization of Energy Harvesting Performance and Local Resonance Instability Phenomenon Suppression in Piezoelectric Cantilever Beams with Arrayed Grooves

This study addresses the performance optimization of piezoelectric cantilever beam energy harvesters by proposing a design method based on surface arrayed groove modulation. Through systematic investigation of the effects of single grooves (upper surface, lower surface, and double-sided grooves) and arrayed grooves on the power generation performance of piezoelectric cantilever beams, the coupling mechanism of stiffness modulation, Local resonance instability phenomenon, and energy conversion in groove design is revealed. The results show that while single grooves can improve the output voltage by altering the neutral axis position, groove widths exceeding 20 mm induce Local resonance instability phenomenon, leading to energy dissipation. In contrast, arrayed grooves effectively suppress Local resonance instability phenomenon by uniformly distributing the grooves, significantly enhancing energy conversion efficiency. The optimized arrayed groove configuration (groove width: 4 mm, depth: 1 mm, number: 7) achieves a peak voltage of 549.525 mV, representing a 17.3% improvement over the ungrooved structure, without inducing narrow-bandwidth effects. Additionally, this design exhibits excellent process compatibility and can be fabricated using conventional machining methods, reducing costs by 30–45% compared to additive manufacturing. This study provides important optimization directions and technical references for the design of piezoelectric cantilever beam energy harvesters.