Dewetting of a droplet

When a droplet spreads into a film, but what if a film dewets into a single droplet? Is it a video in reverse?

Dewetting of a liquid film into a single macroscopic droplet.

Our experiments use liquid dielectrophoresis to induce a droplet into an initial static film state on a surface which would not normally allow the liquid to form the film. When the voltage is removed (quenched), the droplet then re-gathers (dewets) into a single macroscopic droplet. The dewetting process has an initial stage where a dimple forms and the rim retracts, followed by a second stage which is a spherical cap droplet approaching its equilibrium shape. This starkly contrasts with the spreading of small a droplet into a film which follows a smooth sequence of spherical cap shapes. Dewetting is not a video in reverse of wetting.

Publication

  • Not spreading in reverse: The dewetting of a liquid film into a single drop
    A.M.J. Edwards, R. Ledesma-Aguilar, M.I. Newton, C.V. Brown and G. McHale
    Science Advances 2 (9) (2016) e1600183.
    View open access version
    See also popular explanation