High-speed micro-PIV measurements of transient flow in microfluidic devices

This paper reports a new technique of micro-resolution particle image velocimetry (PIV). To investigate transient phenomena in a microfluidic device, a high-speed micro-PIV technique was developed by combining a high-speed camera and a continuous wave (CW) laser. The technique was applied to a micro counter-current flow, consisting of water and butyl acetate. The velocity fields of water in the micro counter-current flow were visualized for a time resolution of 500 mus and a spatial resolution of 2.2 x 2.2 mum(2). Using the micro-PIV technique, the vortex-like motions of fluorescent particles around the water-butyl acetate interface were captured clearly.