Characterization of gelatin microparticle production in a flow focusing microfluidic system

Abstract

In this study, gelatin microdroplets were generated using a PDMS square microchannel (100 ×100 µm). The flow regime map was experimentally determined, and the regimes in which is possible to obtain microdroplets, dripping and jetting, were studied in detail. The regime map was compared with maps published in the literature and it was found that the regime map depends significantly on the viscosity ratio. For each regime, a correlation to calculate the normalized size of the droplet was obtained by fitting the experimental data. The smaller microdroplets obtained had a size of 53 µm and 60 µm, for dripping and jetting regimes, respectively. The droplets generated in this microfluidic device were collected and gelled. We concluded that occurred a decrease in the size of the final microparticles during the curing process. A coefficient of variation (CV - %) between 2% and 4% was found for the microdroplets and microparticles, which demonstrates that this method can be used to produce monodispersed gelatin microparticles.