Liquid-crystalline elastomers

Recent experimental and theoretical work shows that liquid-crystalline elastomers and gels have a highly mobile axis of anisotropy. Despite being nominally elastic solids, they also show features of fluids, such as the effect of soft elasticity. Work over the last few years is reviewed and some of the most important discoveries, as well as the outstanding problems in this field, are highlighted. We examine the unusual mechanical properties of nematic and smectic rubbers, their randomly disordered equilibrium textures, some aspects of dynamics and mechanical relaxation and the effect of uniform chiral piezoelectricity in amorphous polymer networks.