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.