Session: MNS-02-02 Dynamics of M/NEMS

Paper Number: 67179

Start Time: August 18, 03:20 PM

67179 - Tristable Properties in Electrostatically Actuated Initially Curved Coupled Micro Beams 

A limit point behaviour analysis of a metastructure, composed of two double clamped, initially curved beams, and coupled via a rigid truss at their respective centres, is carried out when subjected to a distributed electrostatic load. The analysis is based on a reduced order (RO) model, resulting from Galerkin's decomposition, with symmetric buckling modes used as the base functions, for wither beam. All solutions employed the usage of the implicit arc-length ``Riks'' method, to accommodate for winding equilibrium paths, while validation of the said results were carried out against a finite differences (FD) direct solutions. The analysis has shown that the double beam metastructure is able to become bistable and even tristable, provided that it meets certain geometrical parameters, pertaining to the elevation of each beam and their thickness. Several variations of tristability are disclosed in the study, providing insight to intrinsic capabilities such a structure possesses. The analysis indicates that a model with at least three degrees of freedom (DOF) is needed to predict tristability, as well as the various critical thresholds, with reasonable errors of around one percent. In so doing, the model can be used for the design of various applications, where tristability is a favourable outcome.

Presenting Author: Lior Medina University of Cambridge

Authors:

Lior Medina University of Cambridge
Ashwin A. Seshia University of Cambridge