Modeling of H2O adsorption-induced curvature of a nanocantilever

In this paper, a simulation model is proposed to describe H₂O adsorption-induced curvature of a nanocantilever, based on the energy transfer between potential energy of adsorbates and elastic energy of the bending cantilever. For most cantilever sensors, the basic structure is a silicon beam coated with a metal layer on the top, and aluminum is chosen in this paper. Because the native oxide is usually formed during the fabrication of silicon beams, it is the first time to describe the effect of native oxide on the elastic modulus of the silicon nano-beam in this model based on the semi-continuum method. This model gives a way to predict the curvature of the composite cantilever with native oxide when adsorbing a single layer of H₂O molecules, and meanwhile, the basic principle of the model in this paper could be used to calculate other Si cantilevers with different sensitive materials and different adsorbates.