Measurement of Viscoelastic Fluid Flow in the Curved Microchannel Using Digital Holographic Microscope and Polarized Camera

Abstract

This paper aims to develop a threedimensional (3D) measurement approach to investigate the flow structures of viscoelastic fluid in the curved microchannel by using digital holographic microscope (DHM). The measurement system uses offaxis holographic/interferometric optical setup for the moving target, and the realtime threedimensionalthreecomponents (3D3C) particle tracking velocimetry (PTV) can be achieved based on the analysis of phase information of holograms. To diagnose the irregular flow inside the microchannel, the 3D temporal positions of tracer particles in the volume of 282 خ¼m أ— 282 خ¼m أ— 60 خ¼m have been detected and velocity field was calculated based on the PTV algorithm. Moreover, to explain the flow field inside the curved microchannel, for the first time the polarized highspeed camera was utilized to identify the strong elongation in the viscoelastic fluid. The DHM is proven to be successful for the measurements of microfluidic flow, especially for the truly realtime 3D motions.