Temperature Imaging for Thermal Fluid Flow in Microchannels with Luminescent Polymer Nanosheets

The paper describes microscopic temperature imaging with luminescent polymer nanosheets. Europium complexes were incorporated in ultrathin polymer film prepared by the Langmuir-Blodgett (LB) technique for temperature sensing in microchannels. Straight and T-shaped microchannels were fabricated so that the bottom surface of the microchannels served as the temperature sensing plane. This set-up allows a two-dimensional temperature mapping of the thermal fluid flow in the microchannel. Both steady-state and dynamic processes of temperature distribution was clearly imaged by using a fluorescence microscope equipped with a digital CCD camera with good spatial and time resolution of 1.9 mu m and 0.3 K. The results indicate that the polymer nanosheets prepared by the LB technique are a good candidate to develop the fundamental understanding of microfluidic systems.