Snap-Through and Mechanical Strain Analysis of a MEMS Bistable Vibration Energy Harvester
Snap-Through and Mechanical Strain Analysis of a MEMS Bistable Vibration Energy Harvester
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DOI：
10.1155/2019/6743676
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发表时间：
2019-01-01
影响因子：
1.6
通讯作者：
Berfield, Thomas A.
中科院分区：
文献类型：
--
作者：
Derakhshani, Masoud;Berfield, Thomas A.
由于难以在低驱动频率下最大化功率输出，通过微机电系统（MEMS）规模器件进行基于振动的能量收集面临许多挑战。本研究研究了一种独特设计的微尺度双稳态振动能量采集器的性能，该采集器具有涂有压电层的中央屈曲梁。在这种设计中，中央梁通过使用扭杆固定在其中点，而扭杆又连接到两个悬臂臂，旨在诱导中央弯曲梁的双稳态运动。诱导稳定状态之间切换的能力是提高MEMS功率输出的关键策略。本研究提出了一个模型来分析耦合结构的静态和动态行为，重点研究了压电层内延伸应变的演变。考虑了不同初始屈曲应力水平、驱动频率和驱动振幅的情况，以确定可行的能量收集机制。结果表明，在驱动频率范围内，双稳态开关或屈曲梁的通断运动显著增加了功率生产潜力。这些结果表明，最佳的振动清除需要一种平衡初始屈曲应力水平和特定环境下预期驱动频率范围的方法。
Vibration-based energy harvesting via microelectromechanical system- (MEMS-) scale devices presents numerous challenges due to difficulties in maximizing power output at low driving frequencies. This work investigates the performance of a uniquely designed microscale bistable vibration energy harvester featuring a central buckled beam coated with a piezoelectric layer. In this design, the central beam is pinned at its midpoint by using a torsional rod, which in turn is connected to two cantilever arms designed to induce bistable motion of the central buckled beam. The ability to induce switching between stable states is a critical strategy for boosting power output of MEMS. This study presents the formulation of a model to analyze the static and dynamic behaviors of the coupled structure, with a focus on the evolution of elongation strain within the piezoelectric layer. Cases of various initial buckling stress levels, driving frequencies, and driving amplitude were considered to identify regimes of viable energy harvesting. Results showed that bistable-state switching, or snap-through motion of the buckled beam, produced a significant increase in power production potential over a range of driving frequencies. These results indicate that optimal vibration scavenging requires an approach that balances the initial buckling stress level with the expected range of driving frequencies for a particular environment.