Vortex generation in electroosmotic flow in a straight polydimethylsiloxane microchannel with different polybrene modified-to-unmodified section length ratios

  • Yongxin Song
  • Chengfa Wang
  • Jun Li
  • Dongqing LiEmail author
Research Paper


Previous studies on electrokinetically generated vortices generally involve using relatively complicated heterogeneous surface charge patterns (with zeta potentials of different polarities). In this paper, vortex formation in a straight channel with zeta potentials of two different values, but the same polarity was investigated. Particularly, the effects of the length ratio of the polybrene (PB)-modified section to the unmodified section on vortex formation in electroosmotic flow in a straight polydimethylsiloxane (PDMS) microchannel were studied numerically and experimentally. The numerical results show that for the 5% PB-modified channel (with a zeta potential of about − 5 mV), a vortex will be formed when the length ratio of the modified section to the unmodified section was larger than 4. Such results were experimentally verified with tracing particles. The critical length ratio decreases with the decrease in the absolute value of the zeta potential of PB-modified section and increases with the increased channel width. The results presented in this paper are valuable for understanding vortex formation in a straight channel which is partially modified with PB.


Electroosmotic vortex PDMS microchannel Polybrene Surface modification Length ratio 



The authors wish to thank the financial support of the National Natural Science Foundation of China (51679023) and Liaoning BaiQianWan Talents Program to Y. Song, the Fundamental Research Funds for the Central Universities (3132018261) and the Natural Sciences and Engineering Research Council of Canada through a research grant (RGPIN-03622) to D. Li is greatly appreciated.

Compliance with ethical standards

Conflict of interest

The authors have declared no conflict of interest.


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Copyright information

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

Authors and Affiliations

  1. 1.Department of Marine EngineeringDalian Maritime UniversityDalianChina
  2. 2.Department of Mechanical and Mechatronics EngineeringUniversity of WaterlooWaterlooCanada

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