Inertial particle focusing and spacing control in microfluidic devices

  • Chao Wang
  • Sifan Sun
  • Ying Chen
  • Zhengdong Cheng
  • Yuxiu Li
  • Lisi Jia
  • Pengcheng Lin
  • Zhi Yang
  • Riyang Shu
Research Paper


Focusing particles into a tight stream is usually a necessary step prior to counting, detecting and sorting them. Meanwhile, particle spacing control in microfluidic devices could also be applied in the field of accurate cell detection, material synthesis and chemical reaction. To achieve simultaneous particle focusing and spacing control, a novel microchannel composed by Dean and sheath flow section was proposed and fabricated according to the elaborated design principle with its manipulating performance in situ visualized. Using microspheres with a few microns as a template, the trajectory of the particles was discovered to follow lateral migration and reach certain equilibrium positions at the end of the designed Dean section. After being focused, the streamline was further concentrated and centralized with a controllable interparticle distance in sheath flow section. For sheath flow section, the angle between symmetrical tributaries and the mainstream channel and abrupt constriction/expansion structure of mainstream channel as important channel geometric features were investigated to minimize the focusing streamline width and optimize spacing control. An modified analytical model for sheath flow with different tributary angles was derived and proved to well describe the microsphere spacing control process.


Microfluidics Sheath flow Dean flow Enhancing inertial focusing Spacing control 



This work was supported by Natural Science Foundation of China (No. 51606046), Research and Development Project for Application supported by Guangdong (2016B020243010) and International Scientific and Technological Cooperation Project by Guangzhou city (2016201604030063).

Compliance with ethical standards

Conflict of interest

The authors declared that they have no conflict of interest.

Supplementary material

10404_2018_2035_MOESM1_ESM.docx (19 kb)
Supplementary material 1 (DOCX 19 kb)


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Chao Wang
    • 1
  • Sifan Sun
    • 1
  • Ying Chen
    • 1
  • Zhengdong Cheng
    • 2
  • Yuxiu Li
    • 1
  • Lisi Jia
    • 1
  • Pengcheng Lin
    • 1
  • Zhi Yang
    • 1
  • Riyang Shu
    • 1
  1. 1.Guangdong Provincial Key Laboratory on Functional Soft Condensed Matter, School of Materials and EnergyGuangdong University of TechnologyGuangzhouChina
  2. 2.Artie McFerrin Department of Chemical EngineeringTexas A&M UniversityCollege StationUSA

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