(298e) Electrohydrodynamic Deformation of Thin Liquid Films Near Surfaces with Topography

Motivated by the use of electrostatic assist to improve liquid transfer in gravure
printing, we use theory and experiment to understand how electric fields deform thin
liquid films near surfaces with cavity-like topographical features. Lubrication theory
is used to describe the film dynamics, and both perfect and leaky dielectric materials
are considered. For sinusoidal cavities, we apply asymptotic methods to obtain
analytical results that relate the film deformation to the other problem parameters.
For trapezoidal-like cavities, we numerically solve evolution equations to study the
influence of steep topographical features and the spacing between cavities. Results
from flow visualization experiments are in qualitative agreement with the theoretical
predictions. In addition to being relevant to printing processes, the model problems
we consider are also of fundamental interest in and represent novel contributions to
the areas of electrohydrodynamics and thin-liquid-film flows.