Robust design of an active micro-mixer based on the Taguchi method

Microfluidic analysis of an active micro-mixer with an oscillating stirrer in a straight micro-channel was performed. The effects of molecular diffusion and disturbance by the stirrer for mixing were examined. The mixing was calculated by the lattice Boltzmann method using the D2Q9 model. In this study, the time-averaged mixing index was used to estimate the mixing performance of time-dependent flow. From the results, it was found that the mixer with an oscillating stirrer was much more enhanced and stabilized. Therefore, an optimum design for an active micro-mixer with an oscillating stirrer was performed based on the Taguchi method in order to obtain a robust solution. The design parameters were selected as the reduced frequency, the length and the rotation angle of the stirrer, and the optimal values were determined as 2, 0.8 D and +/- 75 degrees, respectively. It was found that the mixing index of the optimal design was improved by up to 84.59% compared to that of the initial design. (C) 2007 Elsevier B.V. All rights reserved.