Velocity Measurements and Visualizations of the Flow Driven by Laser-Induced Cavitation Bubbles in a Blood-Like Liquid

A method for imaging and velocimetry of flows, in small volumes of blood-like liquid is presented. This method allows for imaging of fast moving blood flows (1 to 10 m/s) in volumes on the order of a cubic millimeter. A custom laser light source was developed that provides pulsed illumination at 640 nm. This light source is required by the transmission properties of the blood-like liquid and has other advantages for epi-fluorescence imaging. This custom-built PIV system was used to image the flow caused by a laser induced cavitation bubble. The measurements show the important features of this flow including the high-speed radial collapse of the bubble, the asymmetric collapse of the bubble caused by the presence of the fiber and the presence of a jet that traverses the bubble.