Pancake droplet breakup in a microfluidic constriction

Whether or not a droplet breaks up as it passes through a pore is important in applications ranging from oil recovery to filtration. This problem has been studied in different configurations such as complex three-dimensional porous media as well as simpler cases involving single pores. In this talk, we focus on non-wetting pancake droplets passing through a single constriction inside a microfluidic channel. Our experiments reveal that for a given pore geometry, droplet breakup depends the most on the size of the initial droplet and the capillary number. However, while some previous studies show that droplets break up at low capillary numbers, we observe the opposite trend: droplets break up at higher capillary numbers in our experiments. We aim to explain this discrepancy between our observation and existing studies using mathematical modeling.