A Comparison of 2-D Molecular Tagging Velocimetry (MTV) and Micro Particle Image Velocimetry (µPIV) for Microscale Flows

A 2-D scanning molecular tagging velocimetry technique is presented. The described MTV technique utilizes a scanning laser system enabling two-dimensional flow velocity measurements. The laser scanning system allows the tagging of molecules seeded in the flow of any desired pattern. This array of small dot markers in the region of interest is visualized using an epi-fluorescent optical imaging system. The scanning system facilitates the convenient maneuvering of the laser beam allowing the tagging of either a single point or a pattern. The laser beam is focused onto a single point leading to a more efficient tagging process. A standard particle tracking velocimetry (PTV) approach is used to resolve the two components of the flow velocity. Results obtained show the capability of the designed system to tag a region in the centre of the field of view. The tagging laser will be moved to any desired location within the field of view to tag the desired region.