Streaming and ring formation from the equator of a drop in a uniform DC electric field
Electrohydrodynamic streaming and jet formation from the conical tips formed at the poles of a highly conducting drop in strong electric field is a well known phenomenon. We have discovered a novel streaming-like instability occurring with drops less conducting than the suspending medium. In a uniform DC electric field, the drop deforms into a flattened oblate (pancake-like) shape with cusped rim around the equator. The rim emits concentric threads which subsequently break up into tiny droplets forming a Saturn-like rings of droplets around the mother drop. The rate of droplet production is much larger than the classical tip-streaming and suggest a potential new route for electroemulsification.
Reference: Q. Brosseau and P. M. Vlahovska, “Equatorial streaming of a drop in an electric field” Physical Review Letters 119: 034501 (2017)