title: Time-resolved fluorescence imaging of solvent interactions in microfluidic devices.
abstract: We present the application of wide-field time-resolved fluorescence imaging methods for the study of solvent interactions and mixing in microfluidic devices. Time-resolved imaging of fluorescence polarization anisotropy allows us to image the local viscosity of fluorescence in three dimensions in order to directly monitor solvent mixing within a microfluidic channel. This provides a viscosity image acquisition time of the order of minutes, and has been applied to a steady-state laminar flow configuration. To image dynamic fluid mixing in real-time, we demonstrate high-speed fluorescence lifetime imaging at 12.3 Hz applied to DASPI, which directly exhibits a solvent viscosity-dependant fluorescence lifetime. These two methods facilitate a high degree of quantification of microfluidic flow in 3-D and/or at high speed, providing a tool for studying fluid dynamics and for developing enhanced microfluidic assays.
authors.forename: Richard
authors.initials: R
authors.lastname: Benninger
authors.forename: Oliver
authors.initials: O
authors.lastname: Hofmann
authors.forename: James
authors.initials: J
authors.lastname: McGinty
authors.forename: Jose
authors.initials: J
authors.lastname: Requejo-Isidro
authors.forename: Ian
authors.initials: I
authors.lastname: Munro
authors.forename: Mark
authors.initials: M
authors.lastname: Neil
authors.forename: Andrew
authors.initials: A
authors.lastname: Demello
authors.forename: Paul
authors.initials: P
authors.lastname: French