67th Annual Meeting of the APS Division of Fluid Dynamics (November 23, 2014 — November 25, 2014)

V0091: Wrapping a drop with a flat sheet

Authors

• Joseph D Paulsen, University of Massachusetts Amherst
• Vincent Démery, University of Massachusetts Amherst
• Benny Davidovitch, University of Massachusetts Amherst
• Chris Santangelo, University of Massachusetts Amherst
• Thomas P Russell, University of Massachusetts Amherst
• Narayanan Menon, University of Massachusetts Amherst

DOI: https://doi.org/10.1103/APS.DFD.2014.GFM.V0091

Many objects in nature and industry are enclosed in protective wrappings. A liquid drop on a thin sheet (~60 μm) can wrap itself up, by balancing surface tension with bending forces [1]. Here, we place an ultrathin (79 nm) circular polystyrene sheet on a water drop that is immersed in oil. The volume of the drop is controlled by a needle inserted from below. As the radius of the drop is reduced, the sheet forms wrinkles, crumples [2], and folds. These patterns form when the cost of bending is much smaller than surface energies. Folds can grow quasistatically, or they can propagate at a finite speed. 

[1] Py et al, PRL 98, 2007.
[2] King, Schroll, Davidovitch, & Menon, PNAS 109, 2012.