Fig. 1. Process of inflating a traditional soft pneumatic actuator^［55］

Fig. 2. （a） Schematic diagram of preparing liquid crystal elastomer soft pneumatic actuators by template method^［57］； （b） Process of inflating the liquid crystal elastomer soft pneumatic actuator， scale bar： 2 cm^［57］.

Fig. 3. Under different magnitude axial loads， （a） the variation of inflation pressure versus chamber length^［57］， （b） relationship between inflation pressure and chamber diameter^［57］， （c） relationship between inflation pressure and chamber volume change^［57］， the points in （a~c） represent the actual experimental data， and the curves are the predictions of the theoretical model； （d） Inflated axial contraction of the chamber， which is evenly divided into five short segments by rigid rings （red）^［57］； （e） Inflatable axial contraction of the same chamber， divided into three segments of different lengths^［57］； （f） Inflation of the chamber induces axial contraction^［57］.

Fig. 4. （a） Schematic diagram of the mechanical response of a liquid crystal elastomer， where the direction of stress is perpendicular to the direction of the initial liquid crystal orientation^［58］， ①，②，and ③ represent the corresponding change in the liquid crystal mesogen in a liquid crystal elastomer with the passage of time when the strain is applied； （b） Schematic diagram of the strain-stress curve of the model in Fig.4（a）^［58］.

Fig. 5. （a） Schematic diagram of preparing LCE hollow tubes by rotational 3D printing method^［59］； （b） On the left is a photograph of the LCE hollow tube^［59］， on the right is the polarized images of an axially oriented LCE hollow tube； Schematic diagram of the orientations of LCE soft pneumatic actuators and their image after inflation： （c） an axially oriented actuator^［59］， （d） a circumferentially oriented actuator^［59］ and （e） a spiral-oriented actuator^［59］； （f） LCE soft pneumatic actuators loads lifting heavy loads^［59］， on the left is a picture of an axially oriented drive lifting a 33 g weight after inflation， on the right is a picture of a circumferentially oriented actuator lifting a 12 g weight after deflation； （g） Picture of a soft gripper assembled from three LCE soft pneumatic actuators catching and lifting a basket containing grain^［59］； （h） A stirrer assembled from a spiral-oriented LCE soft pneumatic actuator stirred the ink and purified water mixture in the beaker at a frequency of 0.5 Hz under the air pressure of 80 kPa^［59］.

Fig. 6. （a） Chemical structure of RM257 as mesogen， DODT as spacer and PETMP as crosslinker； （b） Schematic diagram of preparing LCE hollow fibers by solvent evaporation-assisted template method^［60］.

Fig. 7. Formation and diffusion of a gas bubble pathway in the LCE mixture^［61］

Fig. 8. （a） Photograph of an artificial arm bent by a LCE soft pneumatic actuator at different temperatures and air pressures^［61］； （b） Bending angle curves of an artificial arm composed of LCE soft pneumatic actuators under different air pressures and temperatures^［61］， the longitudinal axis is the change in the bending angle of the artificial arm， the horizontal axis is the air pressure difference between the inside and outside of the chamber， and the curves of different colors represent different temperature conditions； （c） Changes in the bending angle of the artificial arm over time when the fibrous LCE soft pneumatic actuator is pneumatically actuated at different temperatures^［61］. The enlarged images show the bending angle of the artificial arm overtime at 60 °C， 80 °C， and 100 °C， respectively.

Fig. 9. Schematic diagram of a pixelated structural coloring platform consisting of a PDMS base with an air channel and an MCLCE membrane that is reversibly pneumatically actuated after inflation and deflation^［62］

Fig. 10. （a） Optical display application demonstration^［62］， the building consists of 7 air channels and 28 identical small coloring units manufactured， where every 4 coloring units are connected to an air channel； （b） Demonstration of the optical camouflage application^［62］， the material is colored to match the background with different color dots.