微机械谐振器多模态耦合形成机理、动力学性能调节与降噪方法

Multi-mode coupling mechanism and complex nonlinear dynamic properties of micromechanical resonators, are not only the very challenging fundamental research of dynamical design theory, but also the extremely urgent technical problems of application researches, including the design, performance optimization and testing methods. In this project, the mechanism of multi-mechanical mode coupling, the dynamical properties, the corresponding device design and the vibration control methods of the micromechanical resonators are thoroughly studied. The following work are to be carried out: the mechanism of multi-mechanical mode coupling, the topology optimization design of coupling structural unit and mechanical model of micromechanical resonators are researched; the influence law of surface effect and scale effect on the multi-mechanical mode coupling phenomenon is revealed; complex nonlinear dynamic characteristics, such as mode distortion and bifurcation, of multi-mode coupled resonators under forced vibration are analyzed; the design, fabrication and testing of multi-mode coupled micromechanical resonators are investigated, the methods of dynamic tuning of device performance and phase noise reduction are proposed. Therefore, the mechanical models of multimodal coupling in micromechanical resonators are established, the mechanism of multimodal coupling and the energy transfer path of the multimodal coupled resonators are revealed, novel micromechanical resonators with high sensitivity, high signal-to-noise ratio and good stability are prepared after the implementation of this project.

微机械谐振器的多模态耦合形成机理与复杂非线性动力学特性，既是当下动力学设计理论中的极具挑战性基础研究，也是微机械谐振器设计、性能优化与试验测试方法等应用研究中迫切需要解决的技术难题。本项目针对微机械谐振器多机械模态耦合现象的形成机理、动力学特性、相应器件设计与振动控制方法等方面，拟开展如下研究：厘清微机械谐振器的多机械模态耦合形成机理，建立评估耦合强度的力学模型，提出耦合结构单元的拓扑优化设计与动态调节方法；揭示表面效应与尺度效应对谐振器多模态耦合现象的作用机制和影响规律；分析多模态耦合谐振器模态畸变与分叉等复杂非线性动力学特性；研究多模态耦合微机械谐振器设计、性能动态调节与相位噪声抑制方法。因此，本项目的实施，将构建微机械谐振器多模态耦合现象的力学模型，厘清其形成机理和多模态耦合谐振器的能量传递规律，制备出基于多机械模态耦合原理的高灵敏度、高信噪比与良好稳定性微机械谐振器。

微机械谐振器作为微机电系统 (MEMS) 中核心的功能器件，是实现电能、声能、磁能和光能等能量与机械能之间转换的微机电敏感机械结构，在机械电子、信息通讯、航空航天、生物医学与能源环境等领域有着重要的应用。谐振器尺度的缩减使器件具有高谐振频率、超高灵敏度和高品质因子等诸多优点，同时也提出了一些具有挑战性的科学问题，微机械谐振器之间的多机械模态耦合现象会使器件动力学响应变得更加复杂，谐振器的动力学行为越发难以定量分析与预测，为谐振器的设计与加工均带来前所未有的挑战。针对微纳机械谐振器件非线性模态耦合效应与动力学设计理论，建立了基于原子晶格振动的晶格动力学模型和一种修正的宏观唯象模型，发现了纳米谐振器机械应力诱导的拉曼增强现象，提出了微纳机械谐振器件原子级缺陷力学性能的表征方法，揭示了built-in应力作用下石墨烯缺陷特征峰和密度的演化规律；研究了微机电谐振器的弱模态耦合效应和分岔跳跃等非线性效应的作用机理；发展了一种基于纳米气泡阵列的石墨烯谐振器件局部应力调控方法，厘清了石墨烯气体传感器的吸附动力学特性。总结了二维纳米机械谐振器件制备、驱动与测试技术，分析了纳米机电谐振器的非线性模态耦合与非线性阻尼的产生力学机理与其动力学性能调节规律；阐明了多重光选区曝光复杂边界约束下柔性微机电系统表面形貌形成机理与演化规律，提出一种显著提高界面黏合强度的柔性MEMS器件多形态表面失稳形貌力学调控方法，研制了一种机械应力调制的多尺度共形褶皱衍射光栅与可原位动态切换的柔性衍射光栅，搭建了一种可批量制造微纳米表面器件的功能化“微模具”平台。本项研究成果将促进柔性微纳结构大批量制造技术与功能器件方面应用，提高研究成果的社会贡献。