Modeling and Simulation of Electrified Droplets and Its Application to Computer-Aided Design of Digital Microfluidics

Digital microfluidics is the second-generation lab-on-a-chip architecture based upon micromanipulation of droplets via a programmed external electric field by an individually addressable electrode array. Dielectrophoresis (DEP) and electrowetting-on-dielectric (EWOD) are of dominant operating principles. The microfluidic mechanics of manipulating electrified droplets are complex and not entirely understood. This paper presents a numerical simulation method based on droplet electrohydrodynamics. First, a systematic validation study is shown comparing the simulation solution with both analytical and experimental data, quantitatively and qualitatively, and in both steady state and transient time sequences. Such comparison exhibits excellent agreement. Simulations are then used to illustrate its application to computer-aided design of both EWOD-driven and DEP-driven digital microfluidics.