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Design of Microswitch Systems Avoiding Stiction due to Surface Contact

  • Ling Wu
  • L. Noels
  • V. Rochus
  • M. Pustan
  • J. C. Golinval
Conference paper
Part of the Conference Proceedings of the Society for Experimental Mechanics Series book series (CPSEMS)

Abstract

Stiction which results from contact between surfaces is a major failure mode in micro electro-mechanical systems (MEMS). Increasing restoring forces using high spring constant allows avoiding stiction but leads to an increase of the actuation voltage so that the switch’s efficiency is threatened. A statistical rough surfaces interaction model, based on Maugis’ and Kim’s formulations is applied to estimate the adhesive forces in MEMS switches. Based on the knowledge of these forces, the proper design range of the equivalent spring constant, which is the main factor of restoring force in MEMS switches, can be determined. The upper limit of equivalent spring constant depends mainly on the expected actuator voltage and on the geometric parameters, such as initial gap size and thickness of dielectric layer. The lower limit is assessed on the value of adhesive forces between the two contacting rough surfaces. It mainly depends on the adhesive work of contact surfaces and on the surfaces’ roughness. In order to study more complicated structures, this framework will be used in a multiscale model: resulting unloading micro adhesive contact-distance curves of two rough surfaces will be used as contact forces in a finite-element model. In this paper the extraction of these curves for the particular case of gold to gold micro-switches is pursued.

Keywords

Contact Force Adhesive Contact Asperity Height Total Contact Force Major Failure Mode 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science + Business Media, LLC 2011

Authors and Affiliations

  • Ling Wu
    • 1
    • 2
  • L. Noels
    • 1
  • V. Rochus
    • 1
  • M. Pustan
    • 1
    • 3
  • J. C. Golinval
    • 1
  1. 1.Aerospace and Mechanical Engineering DepartmentUniversity of LiegeLiegeBelgium
  2. 2.School of AeronauticsNorthwestern Polytechnical UniversityXi’anChina
  3. 3.Technical University of Cluj-NapocaCluj-NapocaRomania

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