RF-MEMS beam components : FEM modelling and experimental identification of pull-in in presence of residual stress

Alberto Ballestra (1) , Eugenio Brusa (2) , Giorgio de Pasquale (2) , Mircea Gh. Munteanu (2) , Aurelio Somà (1)

1 Mechanical Department
2 Department of Electrical, Management and Mechanical Engineering

In this paper an experimental validation of numerical approaches aimed to predict the coupled behaviour of microbeams for out-of-plane bending tests is performed. This work completes a previous investigation concerning in plane microbeams bending. Often out-of-plane microcantilevers and clamped-clamped microbeams suffer the presence of residual strain and stress, which affect the value of pull-in voltage. In case of microcantilever an accurate modelling includes the effect of the initial curvature due to microfabrication. In double clamped microbeams a preloading applied by tensile stress is considered. Geometrical onlinearity caused by mechanical coupling between axial and flexural behaviour is detected and modelled. Experimental results demonstrate a good agreement between FEM approaches proposed and tests. A fairly fast and accurate prediction of pull-in condition is performed, thus numerical models can be used to identify residual stress in microbridges by reverse analysis from the measured value of pull-in voltage.

Domaines: Autre [cs.OH]

Alberto Ballestra, Eugenio Brusa, Giorgio de Pasquale, Mircea Gh. Munteanu, Aurelio Somà. RF-MEMS beam components : FEM modelling and experimental identification of pull-in in presence of residual stress. DTIP 2008, Apr 2008, Nice, France. pp.232-235. ⟨hal-00277714⟩