Numerical Study of the Wetting Dynamics of Droplet on Laser Textured Surfaces: Beyond Classical Wenzel and Cassie-Baxter Model

Abstract

The classical wetting models, such as the Wenzel and Cassie-Baxter have been extensively used to quantify laser textured surfaces. However, these models do not provide enough explanations for wettability of femtosecond textured surfaces. In this work, we propose a continuum-level modelling to study the wetting dynamics of a water droplet on Ti-6Al-4V alloy. The calculations are performed for plain solid surfaces and surfaces with various reliefs. The calculated evolutions of the spreading parameter for both structured and non-structured surfaces not only provide explanations of several experimental results, but also underline the perspectives of using hierarchical reliefs for efficient wettability control. Thus, such simulations are shown to be useful in the relief design and laser texturing for a wide range of applications.