Progress in Modeling Wetting Phenomena on Structured Substrates

Abstract

Research on wetting phenomena aims to initially understand the underlying physics and then to fabricate smart, functional surfaces with desirable wetting properties. Special attention is given to micro- and nano-textured surfaces which are expected to benefit various technological applications (e.g. drag reduction in vessels, droplet manipulation in microfluidic devices). Realizing the above applications requires an efficient methodology for predicting the behavior of droplets on such structured surfaces. The conventional modeling approaches of wetting phenomena, however, are proven to have limited applicability since either they fail to adequately describe the complicated droplet motion on a complex substrate, or demand vast computational resources for real-life applications. In this review, we initially demonstrate the conventional models for describing static and dynamic wetting phenomena. Then we present a novel, continuum-level, sharp-interface modeling approach, which has been proven particularly efficient for simulating wetting phenomena on complex (geometrically or chemically textured) solid surfaces. The efficiency of the proposed method is demonstrated by performing realistic simulations of droplets spreading and sliding on geometrically patterned substrates.