Numerical study of microdrops sorting by microfluidic device

Recently, numerical simulations have been used to study important physical phenomena in microfluidics application. A topic of great interest in this field is that of microdrops manipulation, which is applied to lab-on-a-chip devices for biomedical testing and synthesis. Computational fluid dynamics (CFD) analysis of microdrops flow was performed to simulate the design channel of Yung-Chieh et al. (2008) [1]. In order to produce water in oil micodrops, the channel design is connected with T-junction geometry, where a continuous phase in one channel is sheared off by a dispersed phase in the perpendicular channel. A numerical solution of the Navier´ Stokes equation using a volume-of-fluid (VOF) technique was carried out to model the process. As a main advantages, without moving part in this passive device, microdrops sorting was achieved in microchannel through controlling of applying pressure on T-junction. In this paper, the influence of surface tension on microdrops dispersion is investigated. In addition, microdrops sorting frequency across the range of low Reynold number is also discussed. The results are compared with available experimental results and indicate a good agreement, which demonstrate the accuracy of our model.