A Fractal Analysis of Stiction in Microelectromechanical Systems

[+] Author and Article Information
K. Komvopoulos, W. Yan

Department of Mechanical Engineering, University of California, Berkeley, CA 94720

J. Tribol 119(3), 391-400 (Jul 01, 1997) (10 pages) doi:10.1115/1.2833500 History: Received February 27, 1996; Revised June 28, 1996; Online January 24, 2008


The strong adherence (stiction) of adjacent surfaces is a major design concern in microelectromechanical systems (MEMS). Advances in micromachine technology greatly depend on basic understanding of microscale stiction phenomena. An analysis of the different stiction micromechanisms and the elastic deformation of asperities at MEMS interfaces is developed using a two-dimensional fractal description of the surface topography. The fractal contact model is scale independent since it is based on parameters invariant of the sample area size and resolution of measuring instrument. The influence of surface roughness, relative humidity, applied voltage, and material properties on the contributions of the van der Waals, electrostatic, and capillary forces to the total stiction force is analyzed in light of simulation results. It is shown that the effects of surface roughness and applied voltage on the maximum stiction force are significantly more pronounced than that of material properties. Results for the critical pull-off stiffness versus surface roughness are presented for different material properties and microstructure stand-free surface spacings. The present analysis can be used to determine the minimum stiffness of microdevices required to prevent stiction in terms of surface roughness, apparent contact area, relative humidity, applied voltage, and material properties.

Copyright © 1997 by The American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.





Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In