Force measurements using capillary instabilities

Abstract

This article reviews some recent experimental studies on film instabilities. Since surface instabilities of planar films are driven by destabilizing interfacial pressures, the patterns that form in thin films are a signature of these interfacial forces. The direct correspondence of pattern selection and the underlying destabilizing pressures provides a way to quantitatively determine these interface potentials. This principle is documented for three different film destabilization mechanisms: van der Waals forces, forces caused by an applied electric field, and forces that arise from the confinement of thermal molecular motion in the film. © 2005 Wiley Periodicals, Inc.