Optimizing layout of obstacles for enhanced mixing in microchannels

Abstract

To improve mixing, obstacles have been placed in the channel to try to disrupt flow and reduce the diffusion path. The disruption to flow velocity field alters the flow direction from one fluid to another. In this way, convection may occur to enhance the mixing. Ideally, properly designed geometric parameters, such as layout and number of obstacles, improve the mixing performance without increasing the pressure drop. In this work, CoventorWareTM, a commercial computational fluid dynamics tool for microfluidics was used to study the mixing of two liquids in a 'Y' channel. The results indicate that asymmetric layout of the obstacle has more effect on the mixing than the number of obstacles. Placing obstacles in the microchannels is a novel method for mixing in microfluidic devices, and the results can provide useful information in the design of these devices.