الفهرس 
TitleOnly 14 pages are availabe for public view
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Abstract
Hydrodynamic focusing inside microfluidic devices has the main role in precisely directing the particles flow into a single stream carrying one particle at a time for cell sorting and medical diagnosis. Among various physical mechanisms used in flow cytometers, it has proven to be the most effective technique used for aligning sample stream into a single film without rupturing or changing the characteristics of samples.
The results of the simulations of two studies were presented. First, simultaneous design was compared with successive design and the effect of different parameter on the successive design was studied. Second, the study of the conical shaped channel was investigated and also the effect of different parameter on it was studied.
from the first study, the effect of location of vertical side channels on focusing width, identity of focusing and ion concentration distribution using two proposed microchannel designs is presented. Simulations showed that the focusing width in the successive design is narrower than the simultaneous one with lower concentration profile peak value and slightly wider horizontal focusing width than the vertical focusing width.
from the second study, numerical simulations are performed using COMSOL program to investigate the effect of a microchannel design on hydrodynamic focusing behavior, shape and value of focused width. from obtained results, it can be concluded that using a conical shaped side channel permitting entrance of sheath with an axial angle less than 90 degree to sample stream moving inside a cylindrical shaped channel produces narrower circular shaped focused stream with high concentration peak value.