Multimodal breakup of a double emulsion droplet under an electric field†
We investigate the hydrodynamic deformation and breakup of double emulsion droplets under a uniform DC electric field. Based on comprehensive experiments, we observe four different breakup modes for the double emulsion droplet by varying the viscosity of shell liquid, and conductivity, permittivity or volume fraction of the core liquid. The breakup modes are classified as a unidirectional breakup mode, two different bidirectional breakup modes, and a tip-streaming breakup mode. We performed scaling analysis and numerical simulation to explain the experimental observations. We believe that this study could provide insight for the comprehension of double emulsion droplet functionalities in various applications, including drug delivery, materials science, biological and chemical engineering, and lab-on-a-chip applications.