Research on the Effect of Geometric Parameters of a Six-Way Junction Microchannel on the Formation of a Double Emulsion Droplet

As a typical microdroplet, double emulsion droplet, has received much attention and been widely used in recent years. For a simplified double-cross-shaped microchannel, the process of preparing double emulsion droplets is numerically simulated in this paper. The mechanism of droplet forming was analyzed, and the effects of the angles of the inner-, middle-, and outer-phase channels of the microchip, length of the focusing hole, and expansion angle on the process and quality of the double emulsion droplet formation were investigated. The variation in angles between each inlet channel affects the droplet area; the change in expansion angle affects the flow pattern of droplets; the change in each geometric parameter affects the monodispersity of droplets. The droplet area is fitted to the microchannel geometric parameters and the functional expressions that represent their relationship are derived. The work in this paper provides a reference for the practical production and research of double emulsion droplets.