Integrated Electromagnetic/Thermal/Mechanical Analysis for MEMS Reliability

这项建议将确定并克服与MEMS设备，特别是RF-MEMS设备的可靠运行相关的困难。通过对MEMS器件中电磁/热/机械耦合的集成建模、模型的实验验证以及耦合效应对器件可靠性影响的量化来实现这一目标。为了满足模拟射频MEMS的需要，本研究旨在开发一种集成的多物理模型并进行实验验证。研究问题包括：1)MEMS中电磁、热和机械效应之间的耦合是什么，2)什么样的数值求解算法适用于集成的多域模型，3)什么样的实验可以有效地验证多域耦合模型。每个研究问题按数值顺序如下：1.该模型将用于1)射频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。考虑到所提出的多物理模型所产生的有限元矩阵的大小和可能的病态，由PI开发的不完全LU(ILU)预条件将与基于GMRES的稳健求解器一起使用。我们将使用高分辨率红外成像系统和高速数字信号分析仪直接观察RF-MEMS开关运行期间的温度分布，以验证开发的耦合模型。该项目结合了我们在电磁、热学、机械科学和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。我们的理论任务和实验任务是相辅相成的，将很好地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，将帮助我们开发高性能和可靠性的RFMEMS，并将对无线电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.