Numerical study of obstacle configuration for droplet splitting in a microchannel

•We investigate the droplet splitting in a microchannel by the use of an obstacle.•The obstacle location and length determine the droplet splitting pattern.•The obstacle inclination is used for droplet splitting with even volume distribution.•We propose the optimal obstacle configuration for droplet splitting.

The droplet splitting in a microfluidic channel by the use of an obstacle, which can be applied to lab-on-a-chip devices for biochemical testing and synthesis, is investigated numerically. The droplet deformation is calculated by a sharp-interface level-set method which is modified to treat the immersed solid surface of an obstacle. The numerical results demonstrate that obstacle configurations, such as obstacle width, length, location and inclination, in a microchannel determine the droplet splitting pattern with or without re-merging. The effects of obstacle configurations on the droplet motion are quantified to obtain the optimal conditions for droplet splitting with even volume distribution.