Fig. 1. Preparation of LCE-PI soft actuator.（a）Molecular structure of LCE chemical composition；（b）Schematic diagram of fabrication process of LCE strip；（c）DSC curve of the LCE strip；（d）Structure diagram of the soft actuator.

Fig. 2. Influence of factors on the heating performance of the electrothermal film.（a）Influence of wire widths on the performance of the electrothermal film；（b）Influence of separation distance on the performance of the electrothermal film；（c）Influence of applied voltages on the performance of the electrothermal film.

Fig. 3. Characterization of LCE.（a）Actual strain of the LCE strip and the fitting line；（b）LCE-PI actuator simulation and experimental comparison.

Fig. 4. Characterization of controllable deformation of LCE-PI actuator；（a）Curvature-time curve of the LCE-PI actuator；（b）Representative images of the deformation of the LCE-PI actuator.

Fig. 5. Schematic diagram of inchworm movement gait

Fig. 6. Structure and the motion gait diagram of the robot.（a）Overall structure diagram of the robot；（b）ABAQUS simulation of the robot’s motion gait；（c）Motion gait of the robot；（d）Thermal imaging diagram of the actual motion gait of the robot.

Fig. 7. Robot motion experiment.（a）Movement on 30° acrylic plate；（b）Movement on rough ground；（c）Movement in smooth pipe；（d）Movement in a pipe filled with debris.