Article

Time correlated fluorescence characterization of an asymmetrically focused flow in a microfluidic device

Microfluidics and Nanofluidics (Impact Factor: 3.22). 10(3):551-561. DOI: 10.1007/s10404-010-0689-x

ABSTRACT In this study, we explore and model the behavior of a prototype microfluidic device which employs two non-mixing fluids (sheath In this study, we explore and model the behavior of a prototype microfluidic device which employs two non-mixing fluids (sheath
and inlet fluids) displaying an asymmetric focused flow, in the presence of a fluorescent dye. Fluorescence correlation spectroscopy and inlet fluids) displaying an asymmetric focused flow, in the presence of a fluorescent dye. Fluorescence correlation spectroscopy
is employed, allowing the precise measure of flow speeds across the channels and of the concentration profile of the central is employed, allowing the precise measure of flow speeds across the channels and of the concentration profile of the central
focused flux along the flow direction. The system is modeled via a standard Navier–Stokes finite-element approach, coupled focused flux along the flow direction. The system is modeled via a standard Navier–Stokes finite-element approach, coupled
to convection–diffusion equations for the solute. Simulations reproduce accurately the shape, the position, and the width to convection–diffusion equations for the solute. Simulations reproduce accurately the shape, the position, and the width
of the velocity and concentration profiles along the central channel and across the transversal and vertical sections of the of the velocity and concentration profiles along the central channel and across the transversal and vertical sections of the
microfluidic device. The observed asymmetric flow with respect to the center of the channel is reproduced numerically with microfluidic device. The observed asymmetric flow with respect to the center of the channel is reproduced numerically with
an error in the position determination smaller than 1%. an error in the position determination smaller than 1%.

KeywordsMicrofluidics–Hydrodynamic focusing–Fluorescence correlation spectroscopy–Navier–Stokes equations KeywordsMicrofluidics–Hydrodynamic focusing–Fluorescence correlation spectroscopy–Navier–Stokes equations

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