SOFT ELASTICITY - DEFORMATION WITHOUT RESISTANCE IN LIQUID-CRYSTAL ELASTOMERS

Polymeric nematic liquid crystals crosslinked into elastomers (solid l iquid crystals) are shown to display novel and complex elasticity. The internal (nematic) direction can experience a barrier to its rotation which couples to standard elasticity. We predict a new phenomena uniq ue to anisotropic rubber - a ''soft elastic response''; uniaxial strai n is developed without resistance below a critical deformation lambda due to the relaxation of related shear strains and reorientation of t he nematic director. We discuss possible experiments to verify this pr ediction and interpret the existing experimental observation in terms of the concept of ''soft elasticity''.