Design of an inchworm-inspired crawling robot based on dielectric elastomers

Soft crawling robots have advantages in environmental adaptability and safe interaction, but existing systems often rely on rigid-flexible hybrid structures or adhesion mechanisms, which limit their bidirectional stable motion under fully flexible conditions. This paper proposes a pure flexible forward-backward crawling robot (OA-FBCR) composed of obtuse and acute dielectric elastomer minimal energy structure (DEMES) units. This robot does not require a rigid frame, mechanical joints, or electrostatic adhesion, and achieves bidirectional crawling solely through the electroactive. The voltage-deformation coupling model was established and validated through finite element simulation, and experiments were conducted to optimize structural parameters and gait strategies. The results show that under optimal conditions, the robot achieved stable motion at a speed of 5-8 mm s^-1and demonstrated good environmental adaptability and repeatability under different surface and slope conditions. Further structural expansion experiments indicate that adding more drive units does not improve performance, thereby validating the effectiveness of the simplified structure. This study provides a theoretical and experimental foundation for the structural design and performance optimization of DEMES soft robots.