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MEMS Devices (mem + device)

Distribution by Scientific Domains

Engineering	50%

Selected Abstracts

Reliability Aspects of Microsystems for Automotive Applications,

ADVANCED ENGINEERING MATERIALS, Issue 4 2009
Roland Müller-Fiedler
Abstract The implementation of microsystems in automotive applications is certainly one of the driving forces for the success of MEMS as an industrial technology on mass production level. In many cases, automotive systems based on microsensors are critical to safety. Consequently, microsystems have to assure an accurate, reliable, and failsafe operation during the entire lifetime of the vehicle. Since, the car represents a harsh environment for electronic or mechanical systems and components, reliability issues of MEMS have moved more and more into the focus of research and development. In particular, reliability aspects related to packaging and assembly have become a key issue in lifetime investigations. The packaging of microsystems comprises a variety of materials and material combinations, that directly affect the stability of MEMS components. Therefore, sophisticated characterization methods are needed to extract the reliability-relevant material parameters. This paper gives an introduction into investigations of the stability assessment of glass frit bonding as well as new bonding technologies based on metallic sealing of MEMS devices. [source]

A methodology for fast finite element modeling of electrostatically actuated MEMS

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 13 2009
Prasad S. Sumant
Abstract In this paper, a methodology is proposed for expediting the coupled electro-mechanical finite element modeling of electrostatically actuated MEMS. The proposed methodology eliminates the need for repeated finite element meshing and subsequent electrostatic modeling of the device during mechanical deformation. We achieve this by using an approximation of the charge density on the movable electrode in the deformed geometry in terms of the charge density in the non-deformed geometry and displacements of the movable electrode. The electrostatic problem has to be solved only once and thus this method speeds up the coupled electro-mechanical simulation process. The proposed methodology is demonstrated through its application to the modeling of four MEMS devices with varying length-to-gap ratios, multiple dielectrics and complicated geometries. Its accuracy is assessed through comparisons of its results with results obtained using both analytical solutions and finite element solutions obtained using ANSYS. Copyright © 2008 John Wiley & Sons, Ltd. [source]

EM design of broadband RF multiport toggle switches

INTERNATIONAL JOURNAL OF RF AND MICROWAVE COMPUTER-AIDED ENGINEERING, Issue 4 2004
W. Simon
Abstract Radio frequency (RF) MEMS is an emerging sub-area of MEMS technology that is revolutionizing RF and microwave applications. RF MEMS devices have a broad range of optional applications in military and commercial wireless communication, and navigation and sensor systems. This article presents the EM design of different multiport toggle switches. Such a multiport switch can be used in the compact designs of switching matrices, routing networks, or phase shifters. One application range is the creation of electronically steerable antenna arrays, which can be used for radar applications and satellite communication. The miniaturized switches are based on the single pole single throw (SPST) toggle switch and, in addition to their small size, they have an increased RF performance regarding losses and operation bandwidth (DC to 50 GHz). A 3D FDTD field solver has been used for the electromagnetic design of all the switches. © 2004 Wiley Periodicals, Inc. Int J RF and Microwave CAE 14: 329,337, 2004. [source]

Correlating Raman peak shifts with phase transformation and defect densities: a comprehensive TEM and Raman study on silicon

JOURNAL OF RAMAN SPECTROSCOPY, Issue 6 2009
Thomas Wermelinger
Abstract Silicon is the most often used material in micro electromechanical systems (MEMS). Detailed understanding of its mechanical properties as well as the microstructure is crucial for the reliability of MEMS devices. In this paper, we investigate the microstructure changes upon indentation of single crystalline (100) oriented silicon by transmission electron microscopy (TEM) and Raman microscopy. TEM cross sections were prepared by focused ion beam (FIB) at the location of the indent. Raman microscopy and TEM revealed the occurrence of phase transformations and residual stresses upon deformation. Raman microscopy was also used directly on the cross-sectional TEM lamella and thus microstructural details could be correlated to peak shape and peak position. The results show, however, that due to the implanted Ga+ ions in the lamella the silicon Raman peak is shifted significantly to lower wavenumbers. This hinders a quantitative analysis of residual stresses in the lamella. Furthermore, Raman microscopy also possesses the ability to map deformation structures with a lateral resolution in the submicron range. Copyright © 2009 John Wiley & Sons, Ltd. [source]