Instant fabrication and selection of folded structures using drop impact

Proc Natl Acad Sci U S A. 2011 Jun 28;108(26):10400-4. doi: 10.1073/pnas.1101738108. Epub 2011 Jun 13.

Abstract

A drop impacting a target cutout in a thin polymer film is wrapped by the film in a dynamic sequence involving both capillary forces and inertia. Different 3D structures can be produced from a given target by slightly varying the impact parameters. A simplified model for a nonlinear dynamic Elastica coupled with a drop successfully explains this shape selection and yields detailed quantitative agreement with experiments. This first venture into the largely unexplored dynamics of elastocapillary assemblies opens up the perspective of mass production of 3D packages with individual shape selection.