A study on the mixing characteristics in a hybrid type microchannel with various obstacle configurations

Micromixer can be classified into two categories: active and passive mixers. An active mixer uses an external force, typically an electric power input, to stir the samples in the microchannel. Passive mixers, on the other hand, have either small protrusion in the microchannel or rough surfaces on the microchannel wall to enhance mixing without requiring any external energy input. In this study, we numerically investigated the mixing phenomena in the hybrid type microchannel combined both active and passive function. The modeling of passive type microchannel with different shaped obstacles (rectangular, triangular and cylindrical configurations, respectively) is conducted, which were mounted on top and bottom walls with groove pitch to height ratio. Also, we have accorded active effects as applied to electric fields and compared mixing performance with both types of microchannel. The incompressible Navier-Stokes equation is solved in this model, and the convection-diffusion equation was used to describe the concentration of the dissolved substances in the fluid. The concentration, flow and electric fields in the channel were calculated and the results were graphically depicted for various flow and electric conditions. (C) 2012 Elsevier Ltd. All rights reserved.