Simulation and experimental verification of driving mechanism for a microfluidic device based on electrowetting-on-dielectric

Abstract

According to obtain the mechanism of electrowetting-on-dielectric (EWOD), the instantaneous pressure difference inside a droplet was obtained by means of a numerical simulation method in this paper, which was the root reason for EWOD. First, based upon the theory of electrowetting-on-dielectric(EWOD), a geometrical model of EWOD was established in a commercial software using VOF method. Next, deriving that two kinds of fluid which should follow the law of mass conservation and principle of momentum conservation. The experimental results show that the numerical simulation results are in good agreement with the experimental results, In one period of motion, the higher pressure region inside a droplet will keep changing and transferring along with the driving time until a steady state of pressure difference is obtained; besides, the much longer driving time is, the much larger pressure difference will be inside a droplet. The transfer of higher pressure region is the root reason for droplet establishing the velocity field which vividly illustrates how the droplet deforms.