Droplet dynamics in a microfluidic bifurcation

Authors: Carlson, A.C., Do-Quang, M., Amberg, G.A.
Document Type: Conference
Pubstate: Published
Journal: Proc. of the 1st European Conference on Microfluidics - Microfluidics
Volume:    µFLU08-130
Year: 2008


Numerical experiments with the phase field method are presented about the generic phenomenon of droplet dynamics in a microfluidic bifurcation. Two distinct flow regimes were observed; splitting and branching, that have also been reported in experiments in a similar geometry [3, 16, 22]. These different phenomena are dictated by the relative importance of the governing forces in the flow. Mapping of the results in non-dimensional space of the Ca number and the normalized droplet area shows the relation between the two regimes. We propose a numerical fit in order to characterize the boundary between the parameter regimes. The splitting regime generates a symmetric flow and distribution of the dispersed phase in the channels daughter branches. The branching regime on the other hand generates an asymmetric mass flow through the channels junction. Thus, we show the deterministic nature such droplets have on the flow phenomena as it lodges in one of the channels daughter branches. Its resulting dynamics is highly responsive to any disturbance, showing the unstable character of the flow in the branching regime.