Fig. 1. Schematic diagram of the transition from ordered to disordered states in liquid crystal elastomers， elicited by external stimuli， culminating in macroscopic deformation.

Fig. 2. Liquid crystal elastomer material manufactured based on the origami and kirigami. （a） Kirigami and origami structure actuator realized by fast photocuring^［37］； （b） Reversible Miura folding actuator^［39］； （c） Kirigami structure-based liquid crystal elastomer material actuator， whose functionality is achieved through prestress applied to the base substrate^［40］； （d） Kresling structure-based actuator embedded with photoresponsive materials^［42］.

Fig. 3. Liquid crystal elastomer mechanical metamaterials based on laser cutting. （a） Negative Poisson’s ratio metasurface of grid-like kirigami structure^［44］； （b） Negative thermal expansion grid structure^［45］.

Fig. 4. Fabrication of liquid crystal elastomer metastructures through diverse 3D printing techniques. （a） Preparation of exquisitely precise latticework via melt electrowriting^［53］； （b） Employment of digital light processing to construct complex 3D metastructures^［55］； （c） Spatial architecting of liquid crystal elastomer lattice structures through laser direct ink writing^［56］； （d） Crafting of microscale three-dimensional metastructures through two-photon polymerization enhanced by electro-orientation^［57］.

Fig. 5. Two-dimensional phononic crystal and lattice. A denotes a lattice composed of oriented liquid crystal elastomer arrays， configured in a square arrangement， while B denotes the cylindrical inclusions. These inclusions can comprise materials possessing physical characteristics distinct from those of the liquid crystal elastomers or can alternatively embody a vacuum.

Fig. 6. Composite structural metamaterials： （a） Kirigami structural metamaterials with liquid crystal elastomer serves as rotary hinges^［68］； （b） An electronics-free soft robots， with the liquid crystal elastomer functioning as an intricate response modulation unit^［69］； （c） A terahertz-frequency optical steering metasurface underpinned by a liquid crystal elastomer substrate^［70］； （d） A liquid crystal elastomer metastructure that fulfills a critical function in the dissipation and absorption of energy with high efficacy^［73］.