This paper studies the collapse of a void in an elastomer caused by osmosis. The void is filled with liquid water, while the elastomer is surrounded by unsaturated air.  The difference in humidity motivates water molecules to permeate through the elastomer, from inside the void to outside the elastomer, leaving the liquid water inside the void in tension.  When the tension is low, the void reduces size but retains the shape, a mode of deformation which we call breathing.  When the tension is high, the void changes shape, possibly by two types of instability:  buckling and creasing.  The critical conditions for both types of instability are calculated.  A tubular elastomer collapses by buckling if the wall is thin, but by creasing if the wall is thick.  As the tension increases, a thin-walled tube undergoes a buckle-to-crease transition.

This paper can be found at http://www.seas.harvard.edu/suo/papers/233.pdf

When a block of an elastomer is bent, the compressed surface may form a crease. This paper analyzes the critical condition for creasing by comparing the elastic energy in a creased body and that in a smooth body. This difference in energy is expressed by a scaling relation. Critical conditions for creasing are determined for elastomers subject to general loads and gels swelling under constraint. The theoretical results are compared with existing experimental observations.