Characterization of soft stripe-domain deformations in SmC and SmC* liquid-crystal elastomers

The neo-classical model of SmC (and SmC*) 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 SmC* 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.