Reversible Photo Actuated Bulk Nanocomposite with Nematic Liquid Crystalline Elastomer Matrix

Liquid crystal elastomers (LCEs) are excellent actuator materials. However, current LCE materials are generally made in the forms with thin thickness, such as films or fibers, which have limitations in forming actuators. We have developed a bulk LCE material with the three-dimensional elastic skeleton network of polyurethane and the matrix of nematic LCE incorporating single-wall carbon nanotubes (SWCNTs). This LCE nanocomposite bulk (LCENB) exhibited sensitive and reversible photo actuation. It could evenly contract by up to 25% of the initial height under a uniform irradiation, or bend towards the incident light by up to 40° under an asymmetrical irradiation. A photo-driven scanning mirror with superior scanning angle, implementing this LCENB as the actuator, was also demonstrated.