Solid interfaces have intrinsic elasticity. However, in most experiments, this is obscured by bulk stresses. Through microscopic observations of the contact-line geometry of a partially wetting droplet on an anisotropically stretched substrate, we measure two surface-elastic constants that quantify the linear dependence of the surface stress of a soft polymer gel on its strain. With these two parameters, one can predict surface stresses for general deformations of the material in the linear-elastic limit.
@article{arxiv.1711.10300,
title = {Surface Elastic Constants of a Soft Solid},
author = {Qin Xu and Robert W. Style and Eric R. Dufresne},
journal= {arXiv preprint arXiv:1711.10300},
year = {2017}
}