The visualization study of breakup of drops in T-shaped micro-fluidic devices

In this paper, the experimental system was set up to study the symmetrical passive breakup of micro-droplet in T-shaped micro-fluidic chip. The process of the breakup of micro-droplet was observed and the mechanism was studied. In the experiment, the cross section of the micro-channel is 200 μm×100 μm or 100 μm×100 μm. Silicone oil and peanut oil were used as continuous phase, while deionized water was used as dispersed phase. For Ca number ranging from 0 to 0.1, four types of droplets' symmetrical breakup, breakup with tunnels, breakup with discontinuous obstruction, breakup with permanent wall obstruction, non-breakup were captured. Finally, the phase diagram was drawn and empirical correlations about critical Ca number and the non-dimensional length of micro-droplet were obtained to predict the conditions of weather the micro-droplet will breakup in different structure and sizes of micro-fluidic chips.