Development of a three-dimensional scanning microparticle image velocimetry system using a piezo actuator

A technique for measuring the full field (x,y,z,u,v,w) velocity distribution of fluid flow at a micrometer scale spatial resolution has been developed. To investigate three-dimensional (3D) flow structures on a microscopic scale, a 3D scanning microparticle image velocimetry system was developed by combining a high-speed camera, an epifluorescent microscope, a cw laser, and a piezo actuator. Both numerical simulations and an experiment were carried out in order to validate the measurement accuracy of the system. Optimum measurement conditions were determined by numerical simulations using synthetic images under epifluorescent microscope observation. As a demonstration, the three-dimensional velocity distribution of water flow inside a microround tube having a diameter of 95 mu m was measured at a spatial resolution of 5.4x2.7x4.2 mu m.