Measurement of a microchamber flow by using a hybrid multiplexing holographic velocimetry

A hybrid multiplexing holographic velocimetry used for characterizing three-dimensional, three-component (3D-3C) flow behaviors in microscale devices was designed and tested in this paper. Derived from the concept of holographic particle image velocimetry (HPIV), a new experimental facility was realized by integrating a holographic technique with a state-of-the-art multiplexing operation based on a microPIV configuration. A photopolymer plate was adopted as an intermedium to record serial stereoscopic images in the same segment. The recorded images were retrieved by a scanning approach, and, afterwards, the distributions of particles in the fluid were analyzed. Finally, a concise cross-correlation algorithm (CCC) was used to analyze particle movement and, hence, the velocity field, which was visualized by using a chromatic technique. To verify practicability, the stereoscopic flow in a backward facing step (BFS) chamber was measured by using the new experimental setup, as well a microPIV system. The comparison indicated that the photopolymer-based velocimetry was practicable to microflow investigation; however, its accuracy needed to be improved.