New Accurate 3-D Finite Element Technology for Solving Geometrically Complex Coupled-Field Problems
I. Avdeev, M. Gyimesi, M. Lovell and D. Ostergaard
University of Pittsburgh, US
Keywords: strong coupling, 3-D modeling, MEMS, FEA
Increased functionality of microelectromechanical systems (MEMS) has lead to the development of micro-scale devices that are geometrically complex. These complex configurations require the development of new and more efficient finite element (FE) techniques for modeling MEMS devices. This is primarily due to the fact that lumped modeling and semi-analytical approaches are not applicable for complicated geometries where fringing electrostatic fields are dominant. In the present investigation, a novel strongly coupled 3-D tetrahedral transducer element is introduced for modeling the quasi-static behavior of analog electrostatic MEMS devices. This new transducer element, which can be utilized for a broad range of micro-system applications (i.e. combdrives, micromirrors, and electrostatic motors), is compatible with conventional electrostatic and structural 3-D finite elements. The element is capable of efficiently modeling interaction between deformable or rigid conductors that generate an electrostatic field. Strong coupling between the electrostatic and mechanical domains allows the static element formulation to be extended to transient and full harmonic analyses. Therefore, in many respects, the element is the most sophisticated FEA tool available for modeling MEMS problems where dominant fringing fields develop. The new technology is also very efficient in determining the pull-in parameters of complicated multi-electrode microdevices.
Nanotech 2004 Conference Technical Program Abstract