DYNAMIC MEASUREMENT OF NANOLITER PER MINUTE FLOW BY SCALED DOSAGE OF FLUORESCENT SOLUTIONS
Gregory A. Cooksey, Paul N. Patrone, James R. Hands, Stephen E. Meek, Anthony J. Kearsley
This work describes a new method for continuous measurement of flow in a microchannel from 1 nL/min to 1000 nL/min using an optofluidic device with waveguides that deliver and collect light from small regions of a microfluidic channel. By relating the fluorescence intensity of a photobleachable dye to the energy it receives, our device extrapolates the measurement of a calibrated flow meter to a regime where the latter has large or unknown uncertainties. Coupled to a new way to determine zero flow, we demonstrate a first-of-its kind ability to accurately measure 20 nL/min with uncertainties on the order of 5 %.