Creases on the interface between two soft materials.

Soft matter

PubMedID: 24651667

Jin L, Chen D, Hayward RC, Suo Z. Creases on the interface between two soft materials. Soft Matter. 2014;10(2):303-11.
THEORY
and experiment are presented to show that an interface between two soft materials under compression can form creases, a type of bifurcation distinct from wrinkles.While creases bifurcate from a state of flat interface by a deformation localized in space and large in amplitude, wrinkles bifurcate from a state of flat interface by a deformation nonlocal in space and infinitesimal in amplitude. The interfacial creases set in at a lower critical compression than interfacial wrinkles, but higher than surface creases. The condition for the onset of interfacial creases is scale-free, and is calculated in terms of elastic moduli, pre-strains and applied strains.