Jia Yu, Du Sijun, Seshia Ashwin A
Nanoscience Centre, University of Cambridge, Cambridge, CB3 0FF, United Kingdom.
Department of Mechanical Engineering, University of Chester, Chester, CH1 2NF, United Kingdom.
Sci Rep. 2016 Jul 22;6:30167. doi: 10.1038/srep30167.
This paper contends to be the first to report the experimental observation of up to 28 orders of parametric resonance, which has thus far only been envisioned in the theoretical realm. While theory has long predicted the onset of n orders of parametric resonance, previously reported experimental observations have been limited up to about the first 5 orders. This is due to the rapid narrowing nature of the frequency bandwidth of the higher instability intervals, making practical accessibility increasingly more difficult. Here, the authors have experimentally confirmed up to 28 orders of parametric resonance in a micromachined membrane resonator when electrically undamped. While the implication of this finding spans across the vibration dynamics and transducer application spectrum, the particular significance of this work is to broaden the accumulative operational frequency bandwidth of vibration energy harvesting for enabling self-powered microsystems. Up to 5 orders were recorded when driven at 1.0 g of acceleration across a matched load of 70 kΩ. With a natural frequency of 980 Hz, the fundamental mode direct resonance had a -3 dB bandwidth of 55 Hz, in contrast to the 314 Hz for the first order parametric resonance; furthermore, the half power bands of all 5 orders accumulated to 478 Hz.
本文声称首次报告了高达28阶参量共振的实验观测结果，迄今为止这仅在理论领域中被设想过。虽然长期以来理论预测了n阶参量共振的发生，但先前报道的实验观测仅限于大约前5阶。这是由于较高不稳定区间的频率带宽具有快速变窄的特性，使得实际获取越来越困难。在此，作者在微机械薄膜谐振器处于电无阻尼状态时，通过实验证实了高达28阶的参量共振。虽然这一发现的影响涵盖振动动力学和换能器应用领域，但这项工作的特别意义在于拓宽振动能量收集的累积工作频率带宽，以实现自供电微系统。在70 kΩ的匹配负载上以1.0 g的加速度驱动时记录到了高达5阶。固有频率为980 Hz时，基模直接共振的 -3 dB带宽为55 Hz，而一阶参量共振的带宽为314 Hz；此外，所有5阶的半功率带宽累积为478 Hz。
