title: A high-discernment microflow cytometer with microweir structure.
abstract: Using a simple and reliable isotropic wet etching process, we fabricated a microflow cytometer in which cells/particles are concentrated in the center of the sample stream using a 2-D hydrodynamic focusing technique and an microweir structure. Having focused the cells/particles, they are detected and counted using a LIF method. The experimental and numerical results confirm the effectiveness of the hydrodynamic sheath flows in squeezing the cells/particles into a narrow stream in the horizontal X-Y plane. Furthermore, it is shown numerically that the microweir structure results in the separation of the cells/particles in the vertical X-Z plane such that they pass through the detection region in a sequential fashion and can therefore be counted with a high degree of precision. The experimental results obtained using fluorescent polystyrene beads with diameters of 5 and 10 microm, respectively, confirm the suitability of the proposed device for microfluidic applications requiring the high-precision counting of particles or cells within a sample flow.
authors.affiliation: Department of Materials Engineering, National Pingtung University of Science and Technology, Pingtung, Taiwan.
authors.forename: Lung-Ming
authors.initials: LM
authors.lastname: Fu
authors.forename: Chien-Hsiung
authors.initials: CH
authors.lastname: Tsai
authors.forename: Che-Hsin
authors.initials: CH
authors.lastname: Lin
mesh_terms: D005434:Flow Cytometry / Q000295:instrumentation*; D007834:Lasers; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D008962:Models, Theoretical