Elastocapillary deformation of thin elastic ribbons in 2D foam columns

TL;DR

This paper investigates how liquid foam structures can shape thin elastic ribbons through capillarity and elasticity, combining experiments and theory to understand equilibrium shapes and potential applications in miniaturization.

Contribution

It introduces a model system of a 2D foam column with an embedded elastic ribbon, analyzing the shape formation through experimental and theoretical methods, advancing elastocapillarity understanding in complex liquids.

Findings

Quantified equilibrium shapes of elastic ribbons in foam columns.

Analyzed the ribbon profile and deformation amplitude.

Demonstrated potential for shaping UV-curable structures using foam techniques.

Abstract

The ability of liquid interfaces to shape slender elastic structures provides powerful strategies to control the architecture of mechanical self assemblies. However, elastocapillarity-driven intelligent design remains unexplored in more complex architected liquids - such as foams. Here we propose a model system which combines an assembly of bubbles and a slender elastic structure. Arrangement of soap bubbles in confined environments form well-defined periodic structures, dictated by Plateau's laws. We consider a 2D foam column formed in a square section cylinder in which we introduce an elastomer ribbon, leading to architected structures whose geometry is guided by a competition between elasticity and capillarity. In this system, we quantify both experimentally and theoretically the equilibrium shapes, using X-ray micro-tomography and energy minimisation techniques. Beyond the understanding of the amplitude of the wavy elastic ribbon deformation, we provide a detailed analysis of the profile of the ribbon, and show that such setup can be used to grant a shape to a UV-curable composite slender structure, as a foam-forming technique suitable to miniaturisation. In more general terms, this work provides a stepping stone towards an improved understanding of the interactions between liquid foams and slender structures.