Size-selective separation of magnetic nanospheres in a microfluidic channel

  • Jie Wu
  • Qifan Yan
  • Shouhu Xuan
  • Xinglong GongEmail author
Research Paper


This paper reported an efficient method to size-selective separate magnetic nanospheres using a self-focusing microfluidic channel equipped with a permanent magnet. Under external magnetic field, the magnetophoresis force exerted on particles leads to size-dependent deflections from their laminar flow paths and results in effective particles separation. By adjusting the distance between magnet and main path of channel, we obtained two monodisperse nanosphere samples (Ca. 90 nm, Ca. 160 nm) from polydispersing particles solution whose diameters varied from 40 to 280 nm. Based on the magnetostatic and laminar flow models, numerical simulations were also used to predict and optimize the nanospheres migrations. Two thresholds of particles diameters were obtained by the simulations and diverse at each position of magnet. Therefore, appropriate position of the magnet could be determined at a certain particle sizes’ range when the flow rate of the two inlets remains unchanged.


Microfluidic channel Magnetic nanospheres Permanent magnet Numerical simulations Size-selective separate 



Financial support from the National Natural Science Foundation of China (Grant Nos. 11572309, 11572310), the Strategic Priority Program of the Chinese Academy of Science (Grant No. XDB2204502) and the Fundamental Research Funds for the Central Universities (WK2480000002) are gratefully acknowledged. This work was also supported by Collaborative Innovation Center of Suzhou Nano Science and Technology.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2017

Authors and Affiliations

  1. 1.CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern MechanicsUniversity of Science and Technological of ChinaHefeiPeople’s Republic of China

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