Modeling microdrop motion between covered and open regions of EWOD microsystems

摘要

EWOD Microsystems are now widely used in digital microfluidics. Two different types of EWOD Microsystems are developped: open systems - in which a sessile drop is sitting freely on a horizontal substrate - and covered systems - where the droplet is confined between two horizontal plates. In order to combine the advantages of the two systems, a dual open/covered system has been developed. The concept relies on the fact that motion between a covered and open region - and back - is possible under electrowetting actuation. In this work, the mechanism of such a motion is analyzed by using a numerical model based on energy minimization, and a domain of possible droplet motion is defined by an analytical model based on a simplification of the numerical model. The validity of the models is checked against experimental results.