actuated beams; nano-structured materials; nanocrystalline silicon; pull-in voltage; modified couple stress theory

The effects of the material structure on the pull-in instability of nano-actuated beams made of nanocrystalline silicon (Nc-Si) and subjected to a distributed electrostatic force are investigated. Nc-Si is represented as a multi-phase material composed of nano-sized grains, nano voids, and an amorphous-like interface to consider the effects of the interface, grain size, porosity, and the inhomogeneities surface energies on the elastic properties of the composite material.