CONTINUUM THEORY OF ELASTICITY AND PIEZOELECTRIC EFFECTS IN SMECTIC AELASTOMERS

The general continuum free energy is derived for a liquid crystalline (smectic) elastomer under small strain and orientational distortion. U sing group representation theory we obtain all invariants describing t he coupling of translational and orientational degrees of freedom. Pos sibilities of uniform rotation of the layer system under shear deforma tion are outlined. It is shown that in centrosymmetric materials (smec tic A) the only polarizational response is flexoelectric, that is in t he response to non-uniform orientational deformations. Chiral material s (rubbers of smectic A) also have a uniform piezoelectric effect in response to a shear deformation, or an extension at an angle with the layer normal. Possible experimental configurations to observe some of the predicted effects are briefly discussed.