Quasi-buckling of micromachined beams

Buckling of structures with imperfections, quasi-buckling (QB), is studied. At the bifurcation load, these structures show a smooth transition into one of the stable postbuckling equilibrium states, instead of the traditional sudden change in deflection characteristics. QB structures can show the classical snap-through buckling behaviour, i.e., a sudden change of postbuckling equilibrium state. The QB is described with a generalized temperature, T_g, representing the compression of the structure. Imperfections and distributed deflection loads are represented by a generalized pressure, p_g. Experiments on micromachined beams, exposed to heating (T_g) and to a Lorentz force (p_g), verify that the QB phenomena can efficiently transfer a longitudinal stress into a transversal deflection, with a scale-factor depending on both T_g and p_g.