Plastic microchip flow cytometer based on 2- and 3-dimensional hydrodynamic flow focusing

This paper deals with design and fabrication of 2- and 3- dimensional microchip type flow cytometers hydrodynamically driven. Flow rate and pressure distrubution have been calculated from Poiseuille flow theory and results were confirmed by computational fluid dynamics. The flow focusing has been evaluated in 2- and 3-dimensional microchip type flow cytometers fabricated with Polydimetylsiloxane molding process. The shape of focused flow was detected with a laser scanning microscope and favourably compared with calculations based on Poiseuille flow assumptions and CFD (Computational Fluid Dynamics) simulation. Simulation and calculation results showed good correlations to each other, and also to the visualized shape of focused flow in microchip. The 3-dimensional focused flow showed the more stable focusing status in laser induced fluorescence measurements than that in 2-dimensional case.