Dynamic simulation of MEMS switches using Simulink
David J Combes, Kevin M Brunson, R John T Bunyan
QinetiQ Ltd, UK
Keywords: MEMS, switch, dynamic, forces, stiction
A nodal model is implemented in Simulink and used to investigate the dynamics of electrostatically actuated MEMS switches. The model is based on reduced order 4DOF beam elements, with electrostatic forces based on simple parallel plate approximations at each node. Hard stops and contact stiction conditions are implemented. Using this model, the role of dynamic forces in overcoming contact stiction in MEMS switches is investigated. For an example MEMS switch, the relationship between the design of the switch, the strain energy under actuation and the dynamic restoring force are discussed. Dynamic forces are found to play a highly significant role in overcoming contact stiction, therefore the design paradigm for MEMS switches should be altered to include more detailed consideration of dynamics.
NSTI Nanotech 2003 Conference Technical Program Abstract