Stereoscopic observation and its application to three-dimensional flow measurement in a microchannel

This paper describes development of a stereoscopic observation system for three-dimensional (3-D) flow in a microchannel. The ultimate objective is construction of a particle tracking velocimetry (PTV) system to measure 3-D flows. There are several crucial points to developing the system: the requirement for a lens, darkness of images, and a calibration method. Using two lenses of long working distance and focal length along with high-speed cameras, we obtained two different angular images at 200 frames/s. A 3-D microchannel was fabricated from polydimethylsiloxane (PDMS). Distilled water with 2-μm-diameter fluorescent particles was used as the test liquid. Stereoscopic observation was performed. Then, 3-D particle motions in the microchannel were calculated.