Actuators based on liquid crystalline elastomer materials

Liquid crystalline elastomers (LCEs) exhibit a number of remarkable physical effects, including the unique, high-stroke reversible mechanical actuation when triggered by external stimuli. This article reviews some recent exciting developments in the field of LCE materials with an emphasis on their utilization in actuator applications. Such applications include artificial muscles, industrial manufacturing, health and microelectromechanical systems (MEMS). With suitable synthetic and preparation pathways and well-controlled actuation stimuli, such as heat, light, electric and magnetic fields, excellent physical properties of LCE materials can be realized. By comparing the actuating properties of different systems, general relationships between the structure and the properties of LCEs are discussed. How these materials can be turned into usable devices using interdisciplinary techniques is also described. Direct sun-driven artificial heliotropism for solar energy harvesting based on photo-thermo-mechanical liquid-crystal elastomer nanocomposite actuators.