微机电系统的建模、分析与操控

With the maturity of Microelectromechanical systems (MEMS), device modeling and optimal control is becoming increasingly important. MEMS devices are required to provide more sophisticated functions and improved performance. This project builds on the applicant's solid foundation and strong track record in MEMS research. The proposed research is focused on investigating the characteristics of MEMS micromirrors and capacitive micromachined ultrasound transducers (CMUTs), and formulate effective control strategies to improve their performance. By utilizing nonlinear control theories and applying them to MEMS devices, we are able to improve MEMS devices' robustness as well as their transient and steady state performance. The key scientific problems to be addressed in the project include modeling and analyses of MEMS micromirror and CMUT systems, nonlinear control of electrostatic and electromagnetic actuation of MEMS micromirror and optimization of their pull-in dynamic. The ultimate goal of the project is to develop accurate models to describe the nonlinear behaviours of MEMS micromirrors and CMUTs. In addition, nonlinear control strategies will be formulated to improve the performance of these MEMS-based medical devices.

微机电系统的成熟发展和应用要求微机电器件具备更先进的功能和更优良的性能。因此，关于微机电系统的建模和优化控制的研究尤为重要。本项目是申请人基于微机电系统领域的坚实研究基础，探索和深入理解MEMS微镜和CMUT等微机电系统内部机理特性，研究和拓展非线性控制理论在MEMS微镜和CMUT等微机电系统上的应用，给出实现提高微机电系统鲁棒性、暂态和稳态性能的非线性控制系统设计方案。本项目拟解决的关键科学问题包括MEMS微镜和CMUT系统的精确数学建模和分析,静电/电磁驱动MEMS微镜和CMUT系统的下拉动态优化研究及其非线性反馈闭环控制。研究目标是探索MEMS微镜和CMUT等微机电系统建模和非线性控制的体系化理论，探索利用非线性控制提高基于MEMS微镜和CMUT微机电系统的医学成像设备辨识精度的机理。

本项目探索和深入理解微机电（MEMS）微镜和电容式超声换能器（CMUT）等微机电系统的内部机理特性，研究和拓展非线性控制理论在MEMS微镜和CMUT等微机电系统上的应用，给出实现提高微机电系统鲁棒性、暂态和稳态性能的非线性控制系统设计方案。..项目所取得的主要成果包括：.（1）以带侧面电极2维静电驱动MEMS扭转微镜和电磁驱动MEMS扭转微镜的动力学模型作为研究对象，结合基于MEMS微镜的光开关和成像等领域的实际性能要求，以滑模控制理论为基础设计控制器提高MEMS扭转微镜的暂态响应、扫描定位精度和实现精确跟踪扫描控制。..(2) 根据CMUT的结构特点，利用有限元分析软件ANSYS 15.0建立了CMUT的三维简化有限元模型，对模型进行了改善，考虑了顶部电极对薄膜形变的影响，并且对改进后的模型进行了模态分析，研究了结构的固有振动频率。同时，基于建立的CMUT模型，利用滑模控制算法改善CMUT器件的抗干扰性能等。..随着微机电系统(MEMS)的发展，MEMS扭转微镜和CMUT器件在光开关、高清晰显示、光学相干断层扫描、数字投影和条形码扫描等领域具有极好的应用前景。本项目的研究对提高基于MEMS微镜和CMUT微机电系统的医学成像设备辨识精度的机理具有重要意义。..项目组在Micromachines、Sensor、Nonlinear Dynamics、Journal of Micromechanics and Microengineering等国内外重要期刊发表论文9篇。相关工作获3M Nano国际会议优秀学生论文提名奖（2014）及关肇直优秀张贴论文奖（2015）。