Capillary Collapse and Adhesion of a Micro Double Cantilever Beam

• Author / Creator

  Lavoie, Shawn

• High aspect ratio microelectromechanical structures have been found, in the literature, to collapse due to capillary forces of liquids. In this dissertation, mathematical models are developed to study (i) the collapse of a microstructure represented by a double cantilevered beam (DCB) with a free end liquid droplet, and (ii) post-collapse DCB adhesion. Formulations are presented using the classical Bernoulli-Euler beam theory as well as an analysis that accounts for geometrical nonlinearity. The models introduce rigorous coupling between the DCB deformation, the capillary forces and meniscus position, and have predicted interesting nonlinear behaviours that previous models could not. Parameters governing the capillary collapse and adhesion of the DCB are identified and their influence is discussed. A single dimensionless number that controls the condition for collapse is proposed. Comparison between the linear and nonlinear beam analyses shows that linear analysis generally suffices in description of capillary collapse and adhesion of microelectromechanical systems.

• Subjects / Keywords

  • Cantilever
  • Surface tension
  • Beam
  • Adhesion
  • MEMS
  • Capillary forces
  • NEMS
  • Capillary collapse

• Graduation date

  Fall 2011

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3JT50

• License

  This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.