Surface sulci in squeezed soft solids
Tallinen, T., Biggins, J. S., & Mahadevan, L. (2013). Surface sulci in squeezed soft solids. Physical Review Letters, 110, 024302. doi:10.1103/PhysRevLett.110.024302
Published inPhysical Review Letters
© 2013 American Physical Society. Published in this repository with the kind permission of the publisher.
The squeezing of soft solids, the constrained growth of biological tissues, and the swelling of soft elastic solids such as gels can generate large compressive stresses at their surfaces. This causes the otherwise smooth surface of such a solid to become unstable when its stress exceeds a critical value. Previous analyses of the surface instability have assumed two-dimensional plane-strain conditions, but in experiments isotropic stresses often lead to complex three-dimensional sulcification patterns. Here we show how such diverse morphologies arise by numerically modeling the lateral compression of a rigidly clamped elastic layer. For incompressible solids, close to the instability threshold, sulci appear as I-shaped lines aligned orthogonally with their neighbors; at higher compressions they are Y-shaped and prefer a hexagonal arrangement. In contrast, highly compressible solids when squeezed show only one sulcified phase characterized by a hexagonal sulcus network.