Hallam, Jonathan M.Rigas, EvangelosCharrett, Thomas O. H.Tatam, Ralph P.2020-04-092020-04-092020-03-27Hallam JM, Rigas E, Charrett TO, Tatam RP. (2020) 2D spatially-resolved depth-section microfluidic flow velocimetry using dual beam OCT. Micromachines, Volume 11, Issue 4, March 2020, Article number 3512072-666Xhttps://doi.org/10.3390/mi11040351https://dspace.lib.cranfield.ac.uk/handle/1826/15391A dual beam optical coherence tomography (OCT) instrument has been developed for flow measurement that offers advantages over microscope derived imaging techniques. It requires only a single optical access port, allows simultaneous imaging of the microfluidic channel, does not require fluorescent seed particles, and can provide a millimetre-deep depth-section velocity profile (as opposed to horizontal-section). The dual beam instrument performs rapid re-sampling of particle positions, allowing measurement of faster flows. In this paper, we develop the methods and processes necessary to make 2D quantitative measurements of the flow-velocity using dual beam OCT and present exemplar results in a microfluidic chip. A 2D reference measurement of the Poiseuille flow in a microfluidic channel is presented over a spanwise depth range of 700 μm and streamwise length of 1600 μm with a spatial resolution of 10 μm, at velocities up to 50 mm/s. A measurement of a more complex flow field is also demonstrated in a sloped microfluidic section.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/particle image velocimetry (PIV)flow measurementmicrofluidicsinterferometryoptical coherence tomography (OCT)Article26703844