A hydrodynamic focusing microchannel based on micro-weir shear lift force

Ruey-Jen Yang, Hui Hsiung Hou, Yao Nan Wang, Che Hsin Lin, Lung-Ming Fu

Research output: Contribution to journalArticlepeer-review

16 Citations (Scopus)


A novel microflow cytometer is proposed in which the particles are focused in the horizontal and vertical directions by means of the Saffman shear lift force generated within a micro-weir microchannel. The proposed device is fabricated on stress-relieved glass substrates and is characterized both numerically and experimentally using fluorescent particles with diameters of 5 μm and 10 μm, respectively. The numerical results show that the micro-weir structures confine the particle stream to the center of the microchannel without the need for a shear flow. Moreover, the experimental results show that the particles emerging from the micro-weir microchannel pass through the detection region in a one-by-one fashion. The focusing effect of the micro-weir microchannel is quantified by computing the normalized variance of the optical detection signal intensity. It is shown that the focusing performance of the micro-weir structure is equal to 99.% and 99.57% for the 5-μm and 10-μm beads, respectively. Overall, the results presented in this study confirm that the proposed microcytometer enables the reliable sorting and counting of particles with different diameters.

Original languageEnglish
Article number034110
Issue number3
Publication statusPublished - 2012 Jul 18

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Materials Science(all)
  • Genetics
  • Condensed Matter Physics
  • Physical and Theoretical Chemistry


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