This paper presents a combined nonlinearity mechanism for the enhanced capability in shaping double well potential energy of MEMS bi-stable energy harvester, which is critical for both wideband inter-well oscillation and high power output. In comparison with conventional magnetic-induced bi-stable energy harvester adopting linear mechanical support, mechanical nonlinearity is incorporated and cooperates with magnetic nonlinearity for effective potential well tuning. With specific control of this mechanical nonlinearity, system linear and nonlinear stiffness could be proportionally adjusted for the independent control of well-gap separating adjacent potential well. Moreover, higher restoring force governed by mechanical nonlinearity could be achieved for the counteraction of magnetic force within smaller deformation, bringing the effective narrowing of well-gap. Therefore, with the incorporation of mechanical nonlinearity, the well-gap could be independently adjusted within much wider range, while maintaining the corresponding barrier depth constant, which could contribute to the significant bandwidth extension of inter-well oscillation. The analysis result shows that at frequency-sweep excitation with acceleration of 1 g, the prototype with well-gap of 1.4 mm and barrier depth of 6 μJ achieves normalized power density of 36 mW cm⁻³ g⁻² and wideband inter-well oscillation of 77 Hz, covering 85.6% of frequency range from 10 to 100 Hz. The test under random excitation confirms the role of the proposed mechanism in inducing effective potential well shaping for comprehensive performance enhancement of bi-stable energy harvester, and could be further applied to the recently proposed high-energy orbit sustaining strategy to achieve ultra-wide unique inter-well motion.

本文提出了一种组合非线性机制，用于增强 MEMS 双稳态能量收集器的双阱势能整形能力，这对于宽带井间振荡和高功率输出都至关重要。与采用线性机械支撑的传统磁感应双稳态能量收集器相比，机械非线性被纳入并与磁非线性配合以实现有效的势阱调谐。通过对这种机械非线性的特定控制，可以按比例调整系统线性和非线性刚度，以实现对相邻潜在井的井隙分离的独立控制。此外，可以在较小的变形内抵消磁力，从而实现由机械非线性控制的较高恢复力，带来井隙的有效缩小。因此，通过引入机械非线性，可以在更宽的范围内独立调整井隙，同时保持相应的势垒深度恒定，这有助于显着扩展井间振荡的带宽。分析结果表明，在加速度为 1 g 的扫频激励下，样机的井隙为 1.4 mm，势垒深度为 6μ J 实现了 36 mW cm ^-3 g ^{-2 的}归一化功率密度和 77 Hz 的宽带井间振荡，覆盖了 10 至 100 Hz 频率范围的 85.6%。随机激励下的测试证实了所提出的机制在诱导有效势阱成形以提高双稳态能量收集器综合性能方面的作用，并可进一步应用于最近提出的高能轨道维持策略，以实现超宽独特井间运动。