Influences of a longitudinal and tilted vibration on stability and dewetting of a liquid film

TL;DR

This paper investigates how high-frequency longitudinal and tilted vibrations affect the stability and dewetting behavior of thin liquid films on substrates, revealing conditions for stabilization and destabilization.

Contribution

It introduces a multiscale analysis of vibrating thin films, deriving an amplitude equation that accounts for various forces and shows how vibrations influence film stability.

Findings

Longitudinal vibration destabilizes the film but can also produce stable deflected states.

Tilted vibration can either stabilize or destabilize the film depending on parameters.

Vibration-induced stabilization of dewetting films is demonstrated and discussed.

Abstract

We consider the dynamics of a thin liquid film in the attractive substrate potential and under the action of a longitudinal or a tilted vibration. Using a multiscale technique we split the film motion into the oscillatory and the averaged parts. The frequency of the vibration is assumed high enough for the inertial effects to become essential for the oscillatory motion. Applying the lubrication approximation for the averaged motion we obtain the amplitude equation, which includes contributions from gravity, van der Waals attraction, surface tension, and the vibration. We show that the longitudinal vibration leads to destabilization of the initially planar film. Stable solutions corresponding to the deflected free surface are possible in this case. Linear analysis in the case of tilted vibration shows that either stabilization or destabilization are possible. Stabilization of the dewetting film by mechanical action (i.e., the vibration) was first reported by us in PRE 77, 036320 (2008). This effect may be important for applications.