2005 Volume 25 Issue Supplement1 Pages 301-304
This paper presents a novel scalar field measurement for microfluidic devices; "2-Color Laser-induced Fluorescence (2-Color LIF)". In general, a conventional method (1-Color LIF) strongly depends on the excitation intensity distribution, which is generated by spatio-temporal intensity fluctuation of light itself and configuration of microchannel. In contrast, the proposed method can eliminate the undesirable influence using a ratio-metric technique with two fluorescence images, because fluorescence intensity can be approximately a linear function of the excitation light intensity. Therefore, it is possible to measure the scalar distribution quantitatively and simplify its calibration. In this experiment, this was applied to calibrate between either temperature or pH and normalized ratio value by dividision between two fluorescence images. Consequently, spatial intensity error can be reduced to about 95% as compared with 1-Color LIF image. The scalar distribution in microchannel was visualized with high resolution 0.24um×0.24μm.
