Multiscale interfacial mechanics of soft solids Bain, Nicolas Wilen, Lawrence A. Gerber, Dominic Zu, Mengjie Goodrich, Carl Peter ; https://orcid.org/0000-0002-1307-5074 Duraivel, Senthilkumar Varma, Kaarthik Koganti, Harsha Style, Robert W. Dufresne, Eric R. ddc:530 Soft solids and their surface deformations control the response of many natural and artificial systems. Yet, their underlying properties are vigorously debated, particularly for polymer networks. While molecular-scale theories predict no interfacial changes with macroscopic deformation, multiple experiments suggest otherwise. To settle this issue, we measure displacement fields near the interface of a silicone gel, in the limit of small deformations. We discover an unexpected multiscale response. The shear modulus decreases smoothly by half with 20  μ⁢m of the interface. At the same time we observe a surface excess elasticity, that depends on history and outer medium composition. These results reveal the fundamentally multiscale nature of polymeric surfaces, and call for further experimental and theoretical investigations into the basic understanding of soft solid interfaces. American Physical Society 2026 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/22288 https://research-explorer.ista.ac.at/download/22288/22309 Bain N, Wilen LA, Gerber D, et al. Multiscale interfacial mechanics of soft solids. <i>Physical Review X</i>. 2026;16(2). doi:<a href="https://doi.org/10.1103/8msx-l8s7">10.1103/8msx-l8s7</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1103/8msx-l8s7 info:eu-repo/semantics/altIdentifier/issn/2160-3308 info:eu-repo/semantics/altIdentifier/arxiv/2410.09158 https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess