Integrated Electromagnetic/Thermal/Mechanical Analysis for MEMS Reliability

该建议将确定并克服与MEMS器件（特别是RF-MEMS）的可靠操作相关的困难。通过对MEMS器件中电磁/热/机械耦合的综合建模、模型的实验验证以及耦合对器件可靠性影响的量化，实现了这一目标。为满足RF MEMS仿真的需要，本研究旨在建立一个综合的多物理场模型并进行实验验证。研究的问题是1）什么是MEMS中的电磁，热，和机械效应之间的耦合，2）什么数值求解算法是适合于一个集成的多域模型，3）什么类型的实验可以有效地验证多域耦合模型。每个研究问题的处理如下（按数字顺序）：1。该模型将针对1）RF激励引起的焦耳加热，2）温度变化引起的热应变，3）电场引起的静电压力，以及4）机械变形引起的电荷重新分布进行开发。考虑到所提出的多物理场模型产生的FE矩阵的大小和可能的病态，由PI开发的不完全LU（ILU）预处理器将与基于GMRES的鲁棒求解器一起使用。利用高分辨率红外成像系统和高速数字信号分析仪直接观测RF-MEMS开关在工作过程中的温度分布，以验证所建立的耦合模型。该项目结合了我们在电磁、热学和机械科学与工程方面的建模和实验专业知识，以解决与RF MEMS应用相关的高度多学科的可靠性问题。 我们的理论和实验任务是非常互补的，将有助于实现我们的研究目标。目标仿真工具与我们的实验能力相结合，将帮助我们开发具有高性能和可靠性的RF MEMS，并将为无线通信相关技术做出重大贡献。

This proposal will identify and overcome the difficulty associated with the reliable operation of MEMS devices, RF-MEMS in particular. This objective is addressed through the integrated modeling of electromagnetic/thermal/mechanical couplings in MEMS devices, experimental validation of the model, and quantification of the coupling effects for device reliability.To meet the need of simulating RF MEMS, the proposal research aims at the development of an integrated multi-physics model and its experimental verification. Research issues are 1) what is the coupling among electromagnetic, thermal, and mechanical effects in MEMS, 2) what numerical solution algorithms are suitable for an integrated multi-domain model, 3) what types of experiments can effectively verify the multi-domain coupling models. Each research issue is approached as follows (in numerical order):1. The model will be developed for 1) Joule heating caused by RF excitation, 2) thermal strain caused by temperature change, 3) electrostatic pressure caused by the electric field, and 4) electric charge redistribution caused by mechanical deformation.2. Considering the size and possible ill-condition of the FE matrix resulting from the proposed multi-physics model, the incomplete LU (ILU) preconditioner developed by a PI, will be used with robust solvers based on GMRES.3. The direct observation of temperature distribution of a RF-MEMS switch during its operation will be done using a high resolution infrared imaging system and a high-speed digital signal analyzer, to verify the developed coupling model.This project combines our modeling and experimental expertise in electromagnetic, thermal, and mechanical science and engineering to address the highly multidisciplinary reliability problems associated with RF MEMS applications. Our theoretical and experimental tasks are very complementary to each other and will serve well to achieve our research goals. The aimed simulation tool, combined with our experimental capabilities, will help us develop RF MEMS with high performance and reliability, and will significantly contribute to technologies related to wireless telecommunications.