BioChip Journal

, Volume 10, Issue 1, pp 16–24 | Cite as

Design and validation of on-chip planar mixer based on advection and viscoelastic effects

  • Lourdes Albina Nirupa Julius
  • Veerendra Kalyan Jagannadh
  • Issac J. Michael
  • Rajesh Srinivasan
  • Sai Siva GorthiEmail author
Original Article


Mixing at low Reynolds number is usually due to diffusion and requires longer channel lengths for complete mixing. In order to reduce the mixing lengths, advective flow can be induced by varying the channel geometry. Additionally, in non-newtonian fluids, appropriate modifications to channel geometry can be used to aid the mixing process by capitalizing on their viscoelastic nature. Here we have exploited the advection and viscoelastic effects to implement a planar passive micro-mixer. Microfluidic devices incorporating different blend of mixing geometries were conceived. The optimum design was chosen based on the results of the numerical simulations performed in COMSOL. The chosen design had sudden expansion and contraction along with teeth patterns along the channel walls to improve mixing. Mixing of two different dyes was performed to validate the mixing efficiency. Particle dispersion experiments were also carried out. The results indicated effective mixing. In addition, the same design was also found to be compatible with electrical power free pumping mechanism like suction. The proposed design was then used to carry out on-chip chemical cell lysis with human whole blood samples to establish its use with non-newtonian fluids. Complete lysis of the erythrocytes was observed leaving behind the white blood cells at the outlet.


Microfluidics Lab-on-a-chip Planar micromixer Advection Viscoelastic effect Cell lysis 


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Copyright information

© The Korean BioChip Society and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  • Lourdes Albina Nirupa Julius
    • 1
  • Veerendra Kalyan Jagannadh
    • 2
  • Issac J. Michael
    • 1
  • Rajesh Srinivasan
    • 1
  • Sai Siva Gorthi
    • 1
    • 2
    Email author
  1. 1.Incubated at Robert Bosch Centre for Cyber Physical Systems (RBCCPS)IIScBangaloreIndia
  2. 2.Department of Instrumentation and Applied PhysicsIndian Institute of Science (IISc)BangaloreIndia

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