Sculpting liquids with ultrathin shells

TL;DR

This paper demonstrates how ultrathin elastic shells with negligible bending rigidity can shape liquid interfaces into their original forms, enabling new optical and material manipulation techniques.

Contribution

It introduces the concept of using curved shells to control liquid interfaces, expanding beyond traditional planar elastocapillarity studies.

Findings

Ultrathin shells can impose their shape on liquid surfaces.

The pressure difference inflates shells into their original shape.

The method is suitable for optical applications due to transparency and wrinkle-free surfaces.

Abstract

Thin elastic films can spontaneously attach to liquid interfaces, offering a platform for tailoring their physical, chemical, and optical properties. Current understanding of the elastocapillarity of thin films is based primarily on studies of planar sheets. We show that curved shells can be used to manipulate interfaces in qualitatively different ways. We elucidate a regime where an ultrathin shell with vanishing bending rigidity imposes its own rest shape on a liquid surface, using experiment and theory. Conceptually, the pressure across the interface "inflates" the shell into its original shape. The setup is amenable to optical applications as the shell is transparent, free of wrinkles, and may be manufactured over a range of curvatures.