Influence of flow rate on the droplet generation process in a microfluidic chip

Droplet generation in microfluidics has attracted a great deal of attention due to the potential applications in many areas of science and technology. The understanding of the generation mechanism is still unsatisfactory and proposed models lack generality for different microchips with flow conditions and channel geometries. In this paper, we present new results of droplet generation in a PMMA microchip using flow-focusing technique. The current data are compared with existing published data obtained with similar generation microchip method. The dependence of the droplet size/slug length on the capillary number and ratio of the continuous phase and dispersed phase flow rates is investigated. A model has been proposed which explains well the data from several similar studies.