Climbing drops

A drop of liquid on a substrate will often remain pinned in place even if the substrate is inclined vertically. Such is the case of drops on a window after the rain. This gravity-defying behavior is due to imperfections in the surface which make the motion of the contact-line energetically costly. Naively, one might expect that if the incline is shaken up and down, the drop will come loose and slide downward. We showed that a drop on an incline can climb up the surface when the substrate is vibrated harmonically in the vertical direction.

Publications

P. Brunet, J. Eggers, & R.D. Deegan, "Triggering the motion of a sessile drop by substrate vibrations", to appear in European Physical Journal.

P. Brunet, J. Eggers, & R.D. Deegan, “Vibration-induced climbing drops”, Phys. Rev. Lett. 99, 144501 (2007)

News Coverage

"Mechanics: A defiant droplet", Nature 449, 758-759 (18 October 2007)

"Liquid drops defy gravity, travel uphill", LiveScience

Updated May 14, 2008