Electrowetting-Induced Droplet Movement in an Immiscible Medium

This paper describes and characterizes the electrowetting-induced movement of droplets in an immiscible medium. When an aqueous droplet undergoes electrowetting-induced motion in a continuous phase of olive oil, the droplet glides through the olive oil at a much higher velocity than is possible in the absence of oil and is able to travel greater than 10 times the electrode separation distance. To describe this behavior, a simple hydrodynamic model is developed to predict the droplet speed and to elucidate the mechanism of droplet movement. On the basis of this model, we also discuss a strategy to reduce droplet splitting.