The buckling of a swollen thin gel layer bound to a compliant substrate

TL;DR

This paper investigates the buckling behavior of swollen thin gel layers on compliant substrates, combining experiments with a simplified theoretical model to understand the resulting fold patterns.

Contribution

It introduces a semi-quantitative model that captures the buckling and folding phenomena of swollen gel layers on substrates, aligning with experimental observations.

Findings

Measured buckling wavelengths and amplitudes

Observed cusp-like folds in experiments

Model reproduces fold patterns semi-quantitatively

Abstract

Gels are used to design bilayered structures with high residual stresses. The swelling of a thin layer on a compliant substrate leads to compressive stresses. The post-buckling of this layer is investigated experimentally; the wavelengths and amplitudes of the resulting modes are measured. A simplified model with a self-avoiding rod on a Winkler foundation is in semi-quantitative agreement with experiments and reproduces the observed cusp-like folds.