We present a study of the natural (resonance) frequencies of a tunable in-plane Microelectromechanical portal frame (U-shape) under DC electrostatic loads. The structure is designed and fabricated to excite the in-plane anti-symmetric (sway, first) and the symmetric (second) modes. Experimental results show high tunability of the resonance frequencies of both modes due to the electrostatic forces. Finite element simulations show good agreement with the experimental measurements. Further simulations are presented for the tunability of the natural frequencies of other higher-order modes using various electrode configurations. Frequency-response curves are presented for pure AC actuation of the first two modes showing strong nonlinear softening behavior due to the geometric nonlinearities of the portal frame. [2020-0269]

中文翻译：

---

U形微谐振器门架的动力学特性

我们对直流静电负载下可调谐平面微机电门户框架（U 形）的自然（共振）频率进行了研究。该结构被设计和制造成激发平面内反对称（摇摆，第一）和对称（第二）模式。实验结果表明，由于静电力，两种模式的共振频率都具有很高的可调性。有限元模拟显示与实验测量结果非常吻合。使用各种电极配置对其他高阶模式的固有频率的可调谐性进行了进一步的模拟。由于门式框架的几何非线性，前两种模式的纯交流驱动的频率响应曲线显示出强烈的非线性软化行为。[2020-0269]