Photothermal Actuation of Liquid Crystal Elastomer Nanocomposites

Photoactive liquid crystal elastomers are a powerful platform for generating work from light. Material systems incorporating azo-based dyes and carbon nanomaterials into liquid crystal elastomers have been shown to drive actuation upon light illumination through isomerization and photothermal heating, respectively. However, little work has been done on the incorporation of metallic nanoparticles into liquid crystal networks for photothermal actuation. Here we demonstrate the preparation of nanorod-containing liquid crystal elastomers by post-synthesis doping of aligned networks. Upon illumination with visible light, these materials generate up to 30% strain due to photothermal heating. An investigation of optical properties, mechanical properties, deformation kinetics, and a simple heat transfer model are also presented. Finally, we discuss opportunities for the use of these materials in deformable optics and future avenues for development.