title: A hydrodynamic focusing microchannel based on micro-weir shear lift force.
abstract: 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 99.76% 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.
authors.affiliation: Department of Engineering Science, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Ruey-Jen
authors.initials: RJ
authors.lastname: Yang
authors.forename: Hui-Hsiung
authors.initials: HH
authors.lastname: Hou
authors.forename: Yao-Nan
authors.initials: YN
authors.lastname: Wang
authors.forename: Che-Hsin
authors.initials: CH
authors.lastname: Lin
authors.forename: Lung-Ming
authors.initials: LM
authors.lastname: Fu
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