Characterization of soft stripe-domain deformations in Sm-C and Sm-C* liquid-crystal elastomers.

The neoclassical model of Sm-C (and Sm-C*) elastomers developed by Warner and Adams predicts a class of "soft" (zero energy) deformations. We find and describe the full set of stripe domains-laminate structures in which the laminates alternate between two different deformations-that can form between pairs of these soft deformations. All the stripe domains fall into two classes, one in which the smectic layers are not bent at the interfaces, but for which--in the Sm-C* case--the interfaces are charged, and one in which the smectic layers are bent but the interfaces are never charged. Striped deformations significantly enhance the softness of the macroscopic elastic response.