Commun. Comput. Phys., 7 (2010), pp. 1076-1094. Numerical Simulation for a Droplet Fission Process of Electrowetting on Dielectric Device Dongdong He 1, Huaxiong Huang 2*, Yongji Tan 31 School of Mathematical Sciences, Fudan University, Shanghai, China; and Department of Mathematics and Statistics, York University, Toronto, Canada. 2 Department of Mathematics and Statistics, York University, Toronto, Canada. 3 School of Mathematical Sciences, Fudan University, Shanghai, China. Received 3 January 2009; Accepted (in revised version) 25 September 2009 Available online 6 January 2010 doi:10.4208/cicp.2009.09.012 Abstract Electrowetting has been proposed as a technique for manipulating droplets surrounded by air or oil. In this paper, we discuss the modeling and simulation of the droplet fission process between two parallel plates inside an electrowetting on dielectric (EWOD) device. Since the gap between the plates is small, we use the two-phase Hele-Shaw flow as a model. While there are several high order methods around, such as the immersed interface methods [1, 2], we decide to use two first-order methods for simplicity. A ghost-fluid (GF) method is employed to solve the governing equations and a local level set method is used to track the drop interface. For comparison purposes, the same set of two-phase Hele-Shaw equations are also solved directly using the immersed boundary (IB) method. Numerical results are consistent with experimental observations reported in the literature. AMS subject classifications: 76T99, 65M06 Notice: Undefined variable: pac in /var/www/html/issue/abstract/readabs.php on line 164 Key words: Electrowetting, ghost fluid method, Hele-Shaw equations, immersed boundary method, local level set method, microfluidics, moving interface, two-phase flow. *Corresponding author. Email: 061018014@fudan.edu.cn (D. He), hhuang@yorku.ca (H. Huang), yjtan@fudan.edu.cn (Y. Tan)