| Medical ultrasound is a favorable imaging modality poised for improvement and future application in drug delivery through microfluidics, which offers a platform for fine-tuning the creation and manipulation of micro particles. This dissertation presents the development of a microfluidic module capable of producing monodisperse dual-layer microbubbles using flow-focusing generation that is scalable to clinically relevant volumes.;A PDMS chip with a planar multi-channel array containing 4 or 8 bubble generating orifices enables parallel production, which feed into a common reservoir. Gas is introduced into the chip by a single bifurcating inlet located outside a circular array, while aqueous lipid solution, constituting the continuous phase, and oil are supplied to each orifice through vertical passages originating from two separate PDMS layers. Dual-layer microbubbles are generated as all three fluids come together at each orifice through fixed geometric channels and shear individually forming a single-file stream of bubbles. Such microbubbles could potentially be applied clinically as ultrasound contrast agent and drug delivery vehicles for cancer therapies. |
