Light-Actuated Liquid Crystal Elastomer Waveguides

The ease with which light can be spatially and temporally modulated makes it an attractive stimulus for the actuation of soft materials. However, many devices require direct line-of-sight access for deployment, severely compromising their utility in confined geometries where remote control is required. One way to circumvent these limitations is to employ actuators that act as waveguides to deliver light over distances that make flood illumination impractical. To this end, we present a method to fabricate liquid crystal elastomer fibers that can adopt defined 3D conformations in response to waveguided visible light due to localized photothermal deformation. By exploiting the photo-mediated reduction of gold salt, spatially-defined regions of nanoparticles are patterned in aligned fibers to define the location and direction of bending. Fibers are demonstrated to bend simultaneously in orthogonal directions on a characteristic time scale of seconds. Furthermore, these fibers are shown to waveguide light, thereby removing the need for line-of-sight access to achieve complex shape change.