Modeling the Fluid Dynamics of Electrowetting on Dielectric (EWOD)
- 7 August 2006
- journal article
- Published by Institute of Electrical and Electronics Engineers (IEEE) in Journal of Microelectromechanical Systems
- Vol. 15 (4), 986-1000
- https://doi.org/10.1109/jmems.2006.878876
Abstract
This paper discusses the modeling and simulation of a parallel-plate Electrowetting On Dielectric (EWOD) device that moves fluid droplets through surface tension effects. We model the fluid dynamics by using Hele-Shaw type equations with a focus on including the relevant boundary phenomena. Specifically, we show that contact angle saturation and hysteresis are needed to predict the correct shape and time scale of droplet motion. We demonstrate this by comparing our simulation to experimental data for a splitting droplet. Without these boundary effects, the simulation shows the droplet splitting into three pieces instead of two and the motion is over 15 times faster than the experiment. We then show how including the saturation characteristics of the device, and a simple model of contact angle hysteresis, allows the simulation to better predict the splitting experiment. The match is not perfect and suffers mainly because contact line pinning is not included. This is followed by a comparison between our simulation, whose parameters are now frozen, and a new experiment involving bulk droplet motion. Our numerical implementation uses the level set method, is fast, and is being used to design algorithms for the precise control of microdroplet motion, mixing, and splittingThis publication has 35 references indexed in Scilit:
- Electrowetting Dynamics of Microfluidic ActuationLangmuir, 2005
- PRINCIPLES OF MICROFLUIDIC ACTUATION BY MODULATION OF SURFACE STRESSESAnnual Review of Fluid Mechanics, 2005
- Electrowetting-Based Microfluidics for Analysis of Peptides and Proteins by Matrix-Assisted Laser Desorption/Ionization Mass SpectrometryAnalytical Chemistry, 2004
- Capillary Bridges in Electric FieldsLangmuir, 2004
- Liquid behavior inside a reflective display pixel based on electrowettingJournal of Applied Physics, 2004
- Digitally Tunable Microfluidic Optical Fiber DevicesJournal of Microelectromechanical Systems, 2003
- On the Relationship of Dielectrophoresis and ElectrowettingLangmuir, 2002
- Amorphous fluoropolymers as insulators for reversible low-voltage electrowettingJournal of Applied Physics, 2001
- Dynamics of Spontaneous Spreading under Electrowetting ConditionsLangmuir, 2000
- Limiting phenomena for the spreading of water on polymer films by electrowettingZeitschrift für Physik B Condensed Matter, 1999