Modeling the Fluid Dynamics of Electro-Wetting on Dielectric (EWOD)
S. Walker and B. Shapiro
University of Maryland, US
Keywords: 2-phase flow, electrowetting, micro-fluidics, modeling, control
By applying voltages across a liquid droplet and an underlying dielectric, it is possible to make dielectric forces compete with surface tension forces, and to thereby cause the liquid droplet to change shape. This effect has been used to successfully move, mix, split, and join droplets in micro-fluidic devices. In our past research we have developed models for the equilibrium deformation of electrically actuated liquid droplet. In this paper, we present a model for the fluid dynamics that can capture the time-varying velocity fields inside the liquid and which can predict the dynamics of droplet splitting and joining. The model runs in minutes, is implemented in Matlab, and is being used to design controllers for precise control of droplet motion and droplet splitting.
Nanotech 2004 Conference Technical Program Abstract