Adhesion-Based Measurements of Strain-Dependent Surface Stress in Soft Solids

Surface stress, or surface tension, is a fundamental material property of interfaces. However, our understanding of solid surface tension and how it changes with deformation remains limited because it is difficult to measure in traditional stiff materials. Soft materials, including gels, provide a unique opportunity to measure these fundamental properties because they can be stretched elastically to very large strains. In this work, we use an adhesion-based approach to measure the solid surface stress of compliant materials as a function of applied strain. This approach is applicable to a wide range of soft materials.