A Diffuse Interface Model for Electrowetting with Moving Contact Lines

TL;DR

This paper develops a comprehensive diffuse interface model for electrowetting that captures complex phenomena like droplet splitting and coalescence, integrating physical effects such as electrostatics, incompressibility, and dynamic contact lines.

Contribution

It introduces a new coupled system of equations for electrowetting that accounts for multiple physical parameters and provides discretization techniques and numerical experiments.

Findings

Model captures droplet splitting and coalescence.

Coupled equations integrate electrostatics and fluid dynamics.

Numerical experiments demonstrate model's effectiveness.

Abstract

We introduce a diffuse interface model for the phenomenon of electrowetting on dielectric and present an analysis of the arising system of equations. Moreover, we study discretization techniques for the problem. The model takes into account different material parameters on each phase and incorporates the most important physical processes, such as incompressibility, electrostatics and dynamic contact lines; necessary to properly reflect the relevant phenomena. The arising nonlinear system couples the variable density incompressible Navier-Stokes equations for velocity and pressure with a Cahn-Hilliard type equation for the phase variable and chemical potential, a convection diffusion equation for the electric charges and a Poisson equation for the electric potential. Numerical experiments are presented, which illustrate the wide range of effects the model is able to capture, such as splitting and coalescence of droplets.