title: Photobleaching absorbed Rhodamine B to improve temperature measurements in PDMS microchannels.
abstract: Rhodamine B based fluorescence thermometry is commonly used in microfluidics to measure fluid temperatures in microchannels. Notable absorption of Rhodamine B into PDMS channel walls, however, causes difficulties in obtaining accurate temperature measurements due to a steady increase in the overall fluorescent signal. A simple and effective technique is reported that removes the fluorescent signal from absorbed Rhodamine B dye by means of photobleaching with a high intensity light source before taking images for thermometry analysis. The temperature field at the convergence of hot and cold streams in a Y-channel fabricated in PDMS/glass microfluidic chip is studied to demonstrate the execution of the photobleaching technique.
authors.affiliation: Department of Mechanical and Mechatronics Engineering, University of Waterloo, Waterloo, Canada.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Glawdel
authors.forename: Zeyad
authors.initials: Z
authors.lastname: Almutairi
authors.forename: Shuwen
authors.initials: S
authors.lastname: Wang
authors.forename: Carolyn
authors.initials: C
authors.lastname: Ren