Carbon coated liquid crystal elastomer film for artificial muscle applications

New liquid crystal elastomer materials with properties that mimic the action of a muscle have been developed recently. Uniaxial contraction of a free standing film of the material can be achieved by heating the film through the nematic to isotropic phase transition. In this paper, carbon coating of such a material is shown to be an effective approach for enhancing the response of a free standing elastomer film to an external stimulus. The heat is generated in the carbon coating by absorption of infrared laser radiation and then conducted through the bulk. It is shown that this leads to a significant reduction in the actuation response time without substantially affecting mechanical properties. This demonstration opens up new opportunities for application of liquid crystal elastomers as actuators. (C) 2002 Elsevier Science B.V All rights reserved.