Design and Fabrication of a Microfluidic Droplet Generating System for Microgels Production

Droplet-based microfluidics technique is one of the advancing subcategories of microfluidics capable of generating highly stable, controlled, and monodispersed emulsion particles. The conventional methods, such as bulk emulsification, lack exquisite control over size distribution, uniformity, and morphology of produced droplets. Microfluidic droplets play important role in generating templates to produce advanced microparticles and microgels, which has developing applications in biochemical and biomedical fields. A major challenge in on-chip generation of mirogels is separation of emulsification and gelation steps. The main goal of this research is to propose a new microfluidic droplet generating platform to overcome this challenge. Here, a new scheme was developed to shield an aqueous precursor solution by using two streams of oil phase before a typical flow focusing nozzle where monodispersed droplets are formed. It was observed that complete shielding of aqueous phase could be obtained by optimizing the flow rates of the streams. Occurrence of shielding was confirmed by pictures taken through experiments. Also the ability of presented scheme to produce monodisperse droplets was shown by image processing

Keywords:

Microfluidic , Droplet , Flow focusing , Shielding