Out-of-plane bending tests are here used to
experimentally validate some numerical models of microbeams
actuated by the electric field. Out-of-plane bending
microcantilevers and clamped–clamped microbeams often
suffer the presence of residual strain and stress, respectively,
which affect their static and dynamic behaviour and
pull-in voltage. In case of microcantilever an accurate
modelling has to include the effect of an initial curvature
due to microfabrication process, while in double clamped
microbeams constraints may impose a pre-loading caused
by a tensile stress. So-called geometrical nonlinearity
sometimes occurs, when microcantilever exhibits large
displacement, or because of the mechanical coupling
between axial and flexural behaviours in double clamped
microbeams. Modelling this kind of nonlinearity is an
additional goal of this study. Experiments demonstrated a
good agreement with results of FEM approaches proposed.
In the case of microbridges numerical models are used to
identify the residual stress. A reverse analysis is
implemented, the axial pre-stress is calculated by means of
the measured pull-in voltage.
