Nonlinear buckling instabilities of free-standing mesoscopic beams

Abstract

We review our observations of a rather striking change in the static equilibrium shape of free-standing mesoscopic buckled beams as a function of the length-to-width aspect ratio. For low values of the aspect ratio the beams exhibit the classical mechanical bifurcation known as Euler buckling, while at higher values the shapes become surprisingly complex. The data are consistent with a nonlinear Ginsburg-Landau elastic field theory that incorporates asymmetry in higher-order buckling modes. Results of mechanical and electromechanical actuation of the beams are discussed with respect to the theory. The observed effects may have an impact on the emerging technology associated with bistable nanomechanical systems. © 2009 Springer-Verlag Berlin Heidelberg.