Drop dynamics on Liquid Infused Surfaces: The Role of the Wetting Ridge

TL;DR

This study uses a lattice Boltzmann method to analyze how a liquid drop moves on a textured, liquid-infused surface, highlighting the effects of contact line pinning and viscous dissipation at the lubricant ridge.

Contribution

It introduces a detailed numerical analysis of drop dynamics on liquid-infused surfaces considering partial wetting lubricants and the influence of the wetting ridge shape and viscosity ratios.

Findings

Pinning and viscous dissipation dominate at different angles.

Viscous dissipation depends on viscosity ratio.

Wetting ridge shape influences drop motion.

Abstract

We employ a free energy lattice Boltzmann method to study the dynamics of a ternary fluid system consisting of a liquid drop driven by a body force across a regularly textured substrate, infused by a lubricating liquid. We focus on the case of partial wetting lubricants and observe a rich interplay between contact line pinning and viscous dissipation at the lubricant ridge, which become dominant at large and small apparent angles respectively. Our numerical investigations further demonstrate that the relative importance of viscous dissipation at the lubricant ridge depends on the drop to lubricant viscosity ratio, as well as on the shape of the wetting ridge.