Hydrodynamic separation by changing equilibrium positions in contraction–expansion array channels

  • Liyan Liu
  • Linzhe Han
  • Xin Shi
  • Wei Tan
  • Wenfeng Cao
  • Guorui ZhuEmail author
Research Paper


The contraction–expansion array (CEA) channel device utilizes hydrodynamic effects, which include inertial lift forces and Dean drag forces, to manipulate particles at a very high throughput and without external forces. The equilibrium position for the particles in a CEA channel can be affected by both the particle size and the flow streamlines. Here, four focusing patterns with different particle sizes were investigated, and the force mechanism was analyzed. We present four CEA channels with different aspect ratios (\(\varphi\)) and expansion and contraction angles (\({\alpha _{\text{e}}}\) and \({\alpha _{\text{c}}}\)) based on the process of changing the particle equilibrium positions. The results show that 20 µm particles migrated to the side of the channel as the aspect ratio \((\varphi )\) increased, and the smaller expansion and contraction angles were conducive to the particle focusing. The Circle channel possesses the best focusing effect. Finally, the microfluidic system was applied for the separation of plasma, RBCs and NCI-H1299 cancer cells from blood with high efficiency and purity.



This work is supported by the Natural Science Foundation of China (21606164). The authors want to acknowledge the channels’ fabrication support from Southeast University, China.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Liyan Liu
    • 1
  • Linzhe Han
    • 1
  • Xin Shi
    • 1
  • Wei Tan
    • 1
  • Wenfeng Cao
    • 2
  • Guorui Zhu
    • 1
    Email author
  1. 1.School of Chemical Engineering and TechnologyTianjin UniversityTianjinChina
  2. 2.Tianjin Tumor HospitalTianjin Medical UniversityTianjinChina

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