Generation and dispersion of monodisperse microbubbles

Optical measurements of monodisperse microbubbles dispersed by a cross flow in a quiescent environment are presented. The dispersion is controlled by injecting the bubbly train exiting a microfluidic T-junction into a 1 mm diameter cross flow. Near range microscopy is used to obtain an effective field of view for dual-shot shadowgraphy measurements. The air and water pressures of the microfluidic T-junction, along with the shear flow velocity, are varied to determine the effect these parameters have on the microbubble size, spacing, production frequency and velocity. Suitable operating parameters are established based on the microbubble size and consistency of the measurements for application to the development and calibration of optical measurement techniques.