Liquid crystal elastomer composites for soft actuators

Liquid crystal elastomers are active materials that combine the anisotropic properties of liquid crystals with the elasticity of polymer networks. The LCEs exhibit remarkable reversible contraction and elongation capabilities in response to external stimuli, rendering them highly promising for diverse applications, such as soft robotics, haptic devices, shape morphing structures, etc. However, the predominant reliance on heating as the driving stimulus for LCEs has limited their practical applications. This drawback can be effectively addressed by incorporating fillers, which can generate heat under various stimuli. The recent progress in LCE composites has significantly expanded the application potential of LCEs. In this minireview, we present the design strategies for soft actuators with LCE composites, followed by a detailed exploration of photothermal and electrothermal LCE composites as prominent examples. Furthermore, we provide an outlook on the challenges and opportunities in the field of LCE composites.