Liquid Crystal Elastomers Based Soft Robots

As a hot robot research direction, soft robots have potential applications in many fields, such as the operation of small objects in limited space, due to the advantages including many degrees of freedom, excellent adaptability and flexible contact. As a classical smart material, liquid crystal elastomers (LCEs) are very promising to be the suitable candidate for preparing the soft robots owing to the large and reversible shape deformations in response to external stimuli (heat, light, electric or magnetic field, humidity, etc.). Due to the changes of microscopic orders or molecular structures of uniaxial-aligned mesogens, the whole LCE materials can execute very large and reversible macroscopic actuation during the LC-to-isotropic phase transition process. At present, according to different driving modes, the research of LCE-based soft robots mainly focuses on the thermal-driven soft robots, light-driven soft robots, electro-driven soft robots, magnetic-driven soft robots and humidity-driven soft robots. This article reviews the developments of LCE-based soft robots, and also introduces the main different driving modes and related LCE-based soft robot systems in detail. Besides, the article further provides a view of prospective development in the future for LCE-based soft robots.