Fig. 1. （a） Thermal responsiveness of LCE actuators： schematics of the deformation of LCE actuators with （i） in-plane uniaxial alignment， （ii） twisted nematic alignment and （iii） splay alignment； （b） Photothermal responsiveness and （c） photochemical responsiveness of monodomain LCE actuators.

Fig. 2. （a） Schematic of the photochemical-mechanical negative feedback loop； （b） （i） Schematic of a photochemical LCE self-oscillator and its self-oscillation under （ii） different air pressures and （iii） light intensities^［54］. （c） AZO-LCE self-oscillator generating continuous mechanical waves under constant UV light （10° from the left）^［60］. （d） Schematic diagram of the photothermal-mechanical negative feedback. Photothermal LCE self-oscillators with （e） Striped ^［62］ and （f） fibrous structures ^［63］.

Fig. 3. （a） （i）Assembly diagram of an omnidirectional LCE self-oscillator with a lampshade structure and （ii） images of structures with different sizes^［68］； （b） （i） Schematic of the preparation of the self-rotating seifert ribbon actuator and （ii） its application as artificial muscles^［69］； （c） （i） Schematic of nonlinear self-oscillatory motion based on a superimposed double- negative-feedback-loop and （ii） cilia-inspired coupled motion pattern^［70］.

Fig. 4. （a） Schematic of thermo-mechanical negative feedback loop of the LCE self-walker； （b） Structural design of the LCE self-walker and its （c） self-sustained crawling motion^［73］； （d） Self-walking of a photothermal-responsive LCE actuator on a horizontal hair^［74］； （e） Schematic and （f） photograph of a light-driven self-walker achieved through autonomous waving motion^［75］ .

Fig. 5. （a） Mechanism of thermally induced self-rolling motion of rod/fiber-shaped LCE actuators^［75］； （b） Effects of thermal expansion coefficient （α_//）， stimulus and （c） twisted-and-coiled structures on correlated self-rolling and curvature directions^［76-77］； （d） Self-rolling direction controlled through pre-set and post-induced curvature^［78］.

Fig. 6. Twisted-and-coiled LCE actuators with light-induced self-rolling on （a） sand and （b） a palm， and （c） ability to pass through a narrow gap by large contraction^［77］.

Fig. 7. （a） Maze-escaping capability of twisted LCE strips ^［82］； （b） Self-rolling of asymmetric twisted-helical LCE actuator along a ‘Z’ -shaped path and it’s self-escaping capability in dynamic maze^［83］.

Fig. 8. （a） LCE film with patterned alignment structure and （b） its multimodal self-rolling and self-jumping motion capabilities^［84］

Fig. 9. （a） Thermally induced deformation of a 4D-printed LCE film with 45°/-45° dual-alignment layers （top） and its self-rolling capability on flat and inclined surfaces （bottom）^［86］； （b） Light-induced autonomous step-climbing capability of a 45°/-45° twisted nematic AZO-LCN actuator^［87］.

Fig. 10. （a） Schematic of gait-like motion in a bistable LCE self-flipping ring^［89］； （b） Autonomous flipping-spinning-orbiting motion of a defected twisted LCE ring and its terrain mapping capability in enclosed spaces^［90］.

Fig. 11. （a）Schematic of （i） assembly of LCE for self-sustained transportation and （ii） photograph of its transportation process^［91］； （b） LCE actuator dolphin bionic continuous swimming （i） schematic，（ii） photograph and （iii） light-induced steering movement^［92］.

Fig. 12. Self-sustained LCE actuators applied to （a） an intelligent optical tuning device^［94］ and （b） a microgenerator^［95］