Younis, Mohammad Ibrahim.
Investigation of the Mechanical Behavior of Microbeam-Based MEMS Devices.
Degree: MS, Engineering Science and Mechanics, 2001, Virginia Tech
An investigation into the responses of microbeams to electric actuations is presented. Attention is focused mainly on the use of microbeams in two important MEMS-based devices: capacitive microswitches and resonant microsensors. Nonlinear models are developed to simulate the behavior of the microbeams in each device. The models account for mid-plane stretching, an applied axial load, a DC electrostatic force, and, for the case of resonant sensors, an AC harmonic force. Further, a novel method that uses a reduced-order model is introduced for simulating the behavior of microbeams under a DC electrostatic force.
The presented method shows attractive features, like for example, a high stability near the pull-in and a low computational cost. Thus, it can be of significant benefit to the development of MEMS design software.
The static behavior of microbeams under electrostatic forces is studied using two methods. One method employs a shooting technique for solving the boundary-value problem that governs the static behavior. The second method is based on solving an algebraic system of equations obtained from the reduced-order model.
Further, the eigenvalue problem describing the vibrations of a microbeam around its statically deflected position is solved using a shooting method to obtain the microbeam mode shapes and natural frequencies.
The dynamic behavior of resonant microbeams is also investigated. A perturbation method, the method of multiple scales, is used to obtain two first-order nonlinear ordinary-differential equations that describe the amplitude and phase of the response and its stability.
The results show that an inaccurate representation of the system nonlinearities may lead to an erroneous prediction of the nonlinear resonance frequency of a microbeam. The case of three-to-one internal resonance between the lowest two modes is treated. Finally, the reduced-order model is used to study the dynamic behavior of the electrostatically actuated microbeams.
The proposed models are validated by comparing their results with experimental results available in the literature.
Advisors/Committee Members: Nayfeh, Ali H. (committeechair).
Subjects/Keywords: MEMS; Pull-in; Capacitive Microswitches; Electrostatic Resonators; Reduced-Order Model
to Zotero / EndNote / Reference
APA (6th Edition):
Younis, M. I. (2001). Investigation of the Mechanical Behavior of Microbeam-Based MEMS Devices. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/31032
Chicago Manual of Style (16th Edition):
Younis, Mohammad Ibrahim. “Investigation of the Mechanical Behavior of Microbeam-Based MEMS Devices.” 2001. Masters Thesis, Virginia Tech. Accessed April 18, 2021.
MLA Handbook (7th Edition):
Younis, Mohammad Ibrahim. “Investigation of the Mechanical Behavior of Microbeam-Based MEMS Devices.” 2001. Web. 18 Apr 2021.
Younis MI. Investigation of the Mechanical Behavior of Microbeam-Based MEMS Devices. [Internet] [Masters thesis]. Virginia Tech; 2001. [cited 2021 Apr 18].
Available from: http://hdl.handle.net/10919/31032.
Council of Science Editors:
Younis MI. Investigation of the Mechanical Behavior of Microbeam-Based MEMS Devices. [Masters Thesis]. Virginia Tech; 2001. Available from: http://hdl.handle.net/10919/31032