Frequency analysis of porous nano-mechanical mass sensors made of multi-phase nanocrystalline silicon materials

Abstract

Nanocrystalline materials (NcMs) are multi-phase composites containing nanograins, nanovoids and interface. Dynamic behavior of nanocrystalline silicon mass sensors on an elastic substrate is analyzed based on a two-variable refined plate model. Due to the experimental observation of grains micro-rotation and strain gradients near interfaces, the strain gradient based couple stress theory is employed to describe the size-dependent behavior of the nanocrystalline sensors. A micromechanical model is employed to incorporate the effects of inclusions and their surface energies. Galerkin’s method is implemented to obtain the frequency shifts of the nanocrystalline mass sensor with different boundary conditions. One can see that the nanoparticle mass, nanograins size, nanograins surface energy, nanovoids size, void percentage, interface region, scale parameter, foundation constants and boundary conditions have a great influence on the frequency shifts of nanocrystalline mass sensors.