Microsystem Technologies

, Volume 19, Issue 4, pp 493–501 | Cite as

Investigations into mixing of fluids in microchannels with lateral obstructions

  • Pankaj Kumar Sahu
  • Aakash Golia
  • Ashis Kumar SenEmail author
Technical Paper


This work presents a study of a passive micromixer with lateral obstructions along a microchannel. The mixing process is simulated by solving the continuity, momentum and diffusion equations. The mixing performance is quantified in terms of a parameter called ‘mixing efficiency’. A comparison of mixing efficiencies with and without obstructions clearly indicates the benefit of having obstructions along the microchannel. The numerical model was validated by comparing simulation results with experimental results for a micromixer. An extensive parametric study was carried out to investigate the influence of the geometrical and operational parameters in terms of the mixing efficiency and pressure drop, which are two important criteria for the design of micromixers. A very interesting observation reveals that there exists a critical Reynolds number (Re cr  ~ 100) below which the mixing process is diffusion dominated and thus the mixing efficiency is reduced with increase in Re and above which the mixing process is advection dominated and mixing efficiency increases with increase in Re. Microchannels with symmetric and staggered protrusion arrangements were studied and compared. The mixing performance of the staggered arrangement was comparable with that of symmetric arrangement but the pressure drop was lower in the case of staggered arrangements making it more suitable.


Pressure Drop Microfluidic Chip Critical Reynolds Number Active Mixer Symmetric Arrangement 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to acknowledge the Science and Engineering Research Council (SERC), Department of Science and Technology (DST), India for providing financial support for the project.


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Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Pankaj Kumar Sahu
    • 1
  • Aakash Golia
    • 1
  • Ashis Kumar Sen
    • 2
    Email author
  1. 1.Department of Mechanical EngineeringIndian Institute of Technology GuwahatiGuwahatiIndia
  2. 2.Department of Mechanical EngineeringIndian Institute of Technology MadrasChennaiIndia

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