Dynamics of sessile droplets deformation under electric fields in microgravity

Abstract

An experimental study of the dynamics of the deformation and breakup of a sessile droplet placed on a plane electrode made out of polished brass or aluminum is described. The breakup was filmed with a high-speed camera at 2000 frames per second. Film frames are presented, showing, at definite intervals, the apex and resting angles of the Taylor cone formation, the gradual deformation of the Taylor cone leading to breakup, the oscillation of the sessile droplet after the breakup of the Taylor cone tip, and some unusual deformations of the Taylor cone tip. Most of the experiments were carried out with tap water. The authors also present a series of photographs showing the dynamics of droplet breakup in the case of a highly viscous, dielectric liquid. Mathematical modeling exhibited the breakup and the oscillation frequency of the sessile droplet under electric fields below the intensity required for breakup.<>