title: Selective spreading and jetting of electrically driven dielectric films.
abstract: We study the electrically driven spreading of dielectric liquid films in wedge-shaped gaps across which a potential difference is applied. Our experiments are in a little-studied regime where, throughout the dynamics, the electrical relaxation time is long compared to the time for charge to be convected by the fluid motion. We observe that at a critical normal electric field the hump-shaped leading edge undergoes an instability in the form of a single Taylor cone and periodic jetting ensues, after which traveling waves occur along the trailing thin film. We propose a convection-dominated mechanism for charge transport to describe the observed dynamics and rationalize the viscosity dependence of the self-excited dynamics.
authors.affiliation: Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: Pilnam
authors.initials: P
authors.lastname: Kim
authors.forename: Camille
authors.initials: C
authors.lastname: Duprat
authors.forename: Scott S H
authors.initials: SS
authors.lastname: Tsai
authors.forename: Howard A
authors.initials: HA
authors.lastname: Stone