Numerical Investigation of Double Emulsion Droplets using Modified Flow Focusing Microfluidic Device for Drug Delivery

Double emulsion droplets generation is convenient for drug delivery applications since the core-shell template has the ability to increase the success of the target and release of the drug. In this study, the modified flow-focusing microfluidics device is proposed to generate double emulsion droplets with high monodispersity and high throughput, satisfying industrial needs. The W/O/W (water-in-oil-in-water) encapsulation template is a common combination in drug delivery. The research aims to analyze double emulsion droplets generation using the 2D Volume of Fluid (VoF) VoF approach, which is able to visualize flow regime, droplets average diameter, Coefficient of Variation (CoV), and droplets generation rate. Combination of water-in-olive oil-in-water was used as the working fluids. The diameter of the droplets, CoV, and generation rate was obtained using image processing. The simulation results showed that the injection model and the sudden expansion in the modified flow-focusing device successfully produced double emulsion droplets with two dripping instabilities. The narrowing jetting flow regime is obtained, including its droplets evolution. The average diameter for both outer and inner droplets were achieved with their CoV, including the generation rate. The outer and inner droplet's diameter generated can potentially be implemented for drug delivery, although the inner droplet's monodispersity must be further investigated. Nevertheless, the proposed device and the flow control were able to generate high-throughput double emulsion droplets.