Parametrically excited MEMS vibration energy harvesters with design approaches to overcome the initiation threshold amplitude
Parametrically excited MEMS vibration energy harvesters with design approaches to overcome the initiation threshold amplitude
复制标题
参数激励 MEMS 振动能量收集器，其设计方法可克服起始阈值振幅
DOI：
10.1088/0960-1317/23/11/114007
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发表时间：
2012
影响因子：
2.3
通讯作者：
A. Seshia
中科院分区：
文献类型：
--
作者：
Y. Jia;Jize Yan;K. Soga;A. Seshia
基于共振的振动采集器传统上依赖于访问直接激发共振的基本模式以最大化机械到电力转换的转换效率。本文探讨了参数共振的使用，它不同于前者，共振引起的振幅增长，不受线性阻尼的限制，其中可以提供更高和更宽的非线性峰值。已经构建了一个数值模型，以证明对公约的潜在改进。尽管有前途的潜力，阻尼相关的启动阈值振幅之前，必须获得这种替代的共振现象。已经探索了被动地降低该引发阈值的设计方法。此外，用25和10 μm厚的器件硅制作了三种代表性的MEMS设计。这些设备包括基于静电放电的采集器，有或没有额外的设计修改，以克服启动阈值幅度。最佳性能记录为25 μm厚的阈值辅助MEMS原型，器件体积为0.147 mm3。当以4.2 ms−2驱动时，该原型在基本谐振模式下的峰值功率输出为10.7 nW，在主参数谐振模式下的峰值功率输出为156 nW，并且启动阈值比纯参数原型降低了23倍。半功率带宽也观察到的参数激励的情况下，大约一倍。
Resonant-based vibration harvesters have conventionally relied upon accessing the fundamental mode of directly excited resonance to maximize the conversion efficiency of mechanical-to-electrical power transduction. This paper explores the use of parametric resonance, which unlike the former, the resonant-induced amplitude growth, is not limited by linear damping and wherein can potentially offer higher and broader nonlinear peaks. A numerical model has been constructed to demonstrate the potential improvements over the convention. Despite the promising potential, a damping-dependent initiation threshold amplitude has to be attained prior to accessing this alternative resonant phenomenon. Design approaches have been explored to passively reduce this initiation threshold. Furthermore, three representative MEMS designs were fabricated with both 25 and 10 μm thick device silicon. The devices include electrostatic cantilever-based harvesters, with and without the additional design modification to overcome initiation threshold amplitude. The optimum performance was recorded for the 25 μm thick threshold-aided MEMS prototype with device volume ∼0.147 mm3. When driven at 4.2 ms−2, this prototype demonstrated a peak power output of 10.7 nW at the fundamental mode of resonance and 156 nW at the principal parametric resonance, as well as a 23-fold decrease in initiation threshold over the purely parametric prototype. An approximate doubling of the half-power bandwidth was also observed for the parametrically excited scenario.