Investigation of pressure profile evolution during confined microdroplet formation using a two-phase level set method

The formation of droplets at a T-junction in a microchannel network is primarily influenced by the pressure difference across the interface in the squeezing regime. Accurate measurements of droplet velocity and pressure profiles are difficult to obtain experimentally, yet these are the basic parameters required for understanding the physics governing the droplet formation process and for shaping the optimum design of microfluidic devices. The current work presents predictions from two dimensional numerical simulations of microdroplet generation at a T-junction. The simulation results are validated with the experimental observations. Detailed profiles of the predicted pressure evolution across the channel upstream of the T-junction indicate that the pressure variation is sensitive to small changes in the wetting properties of the continuous phase. (C) 2013 Elsevier Ltd. All rights reserved.