Prediction of Wetting Behaviours of Femtosecond Laser Texturized Surfaces

It is well known that surface topography modification can be used to tune and control the surface wettability, and femtosecond laser ablation can be applied to modify a surface's topography with ultimate precision.However, it is not so well known how to predict the surface wettability based on the surface topography produced by femtosecond laser pulses.In this communication, a simulation tool based on previously developed Level Set Method (LSM) model is developed on the commercial multiphysics software platform, COMSOL, to evaluate the wettability of polished and ultrafast laserpatterned silicon and germanium surfaces.We demonstrate its capacity for simulation of the liquid droplet evolution on various topographies of laser-textured surface.The calculations suggest that to achieve more hydrophobic behavior on laser-textured silicon and germanium, more attention should be paid to the height of the relief, and caution should be exercised when varying the period of the relief during femtosecond laser processing.