title: Application of fluorescence correlation spectroscopy for velocity imaging in microfluidic devices.
abstract: In this paper we present and demonstrate a technique for mapping fluid flow rates in microfluidic systems with sub-micrometer resolution using confocal microscopy in conjunction with fluorescence correlation spectroscopy (FCS). Flow velocities ranging from approximately 50 microm/s to approximately 10 cm/s can be recorded using fluorescent polymer nanospheres as fluid motion tracers. Velocity profiles and images of the flow in poly(dimethylsiloxane)-glass microchannels are presented and analyzed. Using the method, velocity images along the horizontal (top view) and vertical planes within a microdevice can be obtained. This is, to our knowledge, the first report of FCS for producing velocity maps. The high-resolution velocity maps can be used to characterize and optimize microdevice performance and to validate simulation efforts.
authors.affiliation: Chemical Engineering Department, FAMU-FSU College of Engineering, Tallahassee, Florida 32306, USA.
authors.forename: Kalyan K
authors.initials: KK
authors.lastname: Kuricheti
authors.forename: Volker
authors.initials: V
authors.lastname: Buschmann
authors.forename: Kenneth D
authors.initials: KD
authors.lastname: Weston
mesh_terms: D002626:Chemistry, Pharmaceutical / Q000379:methods; D044085:Microfluidics / Q000379:methods*; D018613:Microscopy, Confocal / Q000379:methods; D008856:Microscopy, Fluorescence; D012212:Rheology / Q000379:methods*; D013050:Spectrometry, Fluorescence / Q000379:methods*