Biomedical Microdevices

, Volume 10, Issue 5, pp 739–748

Mixing behavior of the rhombic micromixers over a wide Reynolds number range using Taguchi method and 3D numerical simulations


DOI: 10.1007/s10544-008-9185-4

Cite this article as:
Chung, C.K., Shih, T.R., Chen, T.C. et al. Biomed Microdevices (2008) 10: 739. doi:10.1007/s10544-008-9185-4


A planar micromixer with rhombic microchannels and a converging–diverging element has been systematically investigated by the Taguchi method, CFD–ACE simulations and experiments. To reduce the footprint and extend the operation range of Reynolds number, Taguchi method was used to numerically study the performance of the micromixer in a L9 orthogonal array. Mixing efficiency is prominently influenced by geometrical parameters and Reynolds number (Re). The four factors in a L9 orthogonal array are number of rhombi, turning angle, width of the rhombic channel and width of the throat. The degree of sensitivity by Taguchi method can be ranked as: Number of rhombi > Width of the rhombic channel > Width of the throat > Turning angle of the rhombic channel. Increasing the number of rhombi, reducing the width of the rhombic channel and throat and lowering the turning angle resulted in better fluid mixing efficiency. The optimal design of the micromixer in simulations indicates over 90% mixing efficiency at both Re ≥ 80 and Re ≤ 0.1. Experimental results in the optimal simulations are consistent with the simulated one. This planar rhombic micromixer has simplified the complex fabrication process of the multi-layer or three-dimensional micromixers and improved the performance of a previous rhombic micromixer at a reduced footprint and lower Re.


Micromixer Rhombic microchannel Turning angle 

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • C. K. Chung
    • 1
    • 2
    • 3
  • T. R. Shih
    • 1
  • T. C. Chen
    • 2
  • B. H. Wu
    • 3
  1. 1.Department of Mechanical EngineeringNational Cheng Kung UniversityTainanRepublic of China
  2. 2.Institute of Nanotechnology and Microsystems EngineeringNational Cheng Kung UniversityTainanRepublic of China
  3. 3.Center for Micro/Nano Science and TechnologyNational Cheng Kung UniversityTainanRepublic of China

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