Encoding and controlling of two droplet trains in a microfluidic network with the loop-like structure

Abstract

A theoretical model is derived mathematically for the encoding and controlling of the navigating of two droplet trains in a microfluidic network with a loop-like structure. The model reveals the relationship between the new outlet droplet train's arrangement information (output signals) and the parameters including the two droplet trains' input signals (droplet intervals), tuning flow rates, etc. The theoretical results are compared with the experimental results and they agree with each other. We find that every tuning flow rate corresponds to a certain output signal and a new droplet train can be obtained accurately. The generation orders of the successive droplets of the new droplet train remain unchanged within a certain range of the tuning flow rates. This work can be a useful reference for traffic controlling of two or more droplet trains in many microfluidic networks including the loop structure; the output signal of this work can be the input one for the next level which makes the multilevel studies possible. In addition, this study can help to promote the effective fusion of droplets and further the biological and chemical applications on droplet microfluidics.