Swelling-induced microchannel formation in nonlinear elasticity

We study the effect of swelling on the axisymmetric deformation of a circular cylinder. A continuum description of swelling is established on the basis of a specific generalization of nonlinear elasticity for incompressible materials. This theory is used to analyse microchannel formation and channel growth. We show that certain kinds of material constitutive laws in conjunction with certain types of variable swelling fields are capable of inducing this formation and growth process without the aid of an externally applied traction. The solutions are presented as a bifurcation from the standard solution that involves no channel formation. The channel formation solution is found to be energetically preferable to the standard solution.