Kavli Nanoscience Institute and Departments of Physics, Applied Physics, and Bioengineering, California Institute of Technology, Pasadena, California 91125, United States.
Nano Lett. 2013 Apr 10;13(4):1622-6. doi: 10.1021/nl400070e. Epub 2013 Mar 25.
Understanding and controlling nonlinear coupling between vibrational modes is critical for the development of advanced nanomechanical devices; it has important implications for applications ranging from quantitative sensing to fundamental research. However, achieving accurate experimental characterization of nonlinearities in nanomechanical systems (NEMS) is problematic. Currently employed detection and actuation schemes themselves tend to be highly nonlinear, and this unrelated nonlinear response has been inadvertently convolved into many previous measurements. In this Letter we describe an experimental protocol and a highly linear transduction scheme, specifically designed for NEMS, that enables accurate, in situ characterization of device nonlinearities. By comparing predictions from Euler-Bernoulli theory for the intra- and intermodal nonlinearities of a doubly clamped beam, we assess the validity of our approach and find excellent agreement.
理解和控制振动模式之间的非线性耦合对于先进的纳米机械器件的发展至关重要；它对从定量传感到基础研究的各种应用都有重要意义。然而，实现纳米机械系统 (NEMS) 中非线性的精确实验表征是有问题的。当前使用的检测和激励方案本身往往具有高度的非线性，并且这种不相关的非线性响应已经在许多先前的测量中被无意地卷积。在这封信中，我们描述了一种实验方案和一种专门为 NEMS 设计的高度线性转换方案，该方案可实现设备非线性的准确、原位表征。通过比较双端固支梁内模态和模态间非线性的 Euler-Bernoulli 理论预测，我们评估了我们方法的有效性，并发现了极好的一致性。
