A numerical technique to simulate display pixels based on electrowetting

Journal article (2015)

Authors

I Roghair External organisation
M. Musterd ChemE/Transport Phenomena - AS
D van den Ende External organisation
C.R. Kleijn ChemE/Transport Phenomena - AS
M.T. Kreutzer ChemE/Product and Process Engineering - AS
F Mugele External organisation
Research Group
ChemE/Transport Phenomena (AS) (TU Delft)
More Info
expand_more

Published Date

2015

Language

English

Reuse Rights

Other than for strictly personal use, it is not permitted to download, forward or distribute the text or part of it, without the consent of the author(s) and/or copyright holder(s), unless the work is under an open content license such as Creative Commons.

Faculty

Applied Sciences

Department

ChemE/Chemical Engineering

Research Group

ChemE/Transport Phenomena

Abstract

We present a numerical simulation technique to calculate the deformation of interfaces between a conductive and non-conductive fluid as well as the motion of liquid¿liquid¿solid three-phase contact lines under the influence of externally applied electric fields in electrowetting configuration. The technique is based on the volume of fluid method as implemented in the OpenFOAM framework, using a phase fraction parameter to track the different phases. We solve the combined electrohydrodynamic problem by coupling the equations for electric effects¿Gauss¿s law and a charge transport equation¿to the Navier¿Stokes equations of fluid flow. Specifically, we use a multi-domain approach to solving for the electric field in the solid and liquid dielectric parts of the system. A Cox¿Voinov boundary condition is introduced to describe the dynamic contact angle of moving contact lines. We present several benchmark problems with analytical solutions to validate the simulation model. Subsequently, the model is used to study the dynamics of an electrowetting-based display pixel. We demonstrate good qualitative agreement between simulation results of the opening and closing of a pixel with experimental tests of the identical reference geometry. © 2015 The Author(s)