Soft Robotic Snake Locomotion on Curved Surfaces

Snakes possess an extraordinary ability to traverse diverse terrains, thanks to their continuous bending and distributed surface contacts. While robotic snakes have replicated some of these locomotion capabilities, most existing designs rely on a rigid, articulated approach. However, the discrete nature of rigid-bodied construction poses challenges in maintaining a uniform distributed force, particularly when traversing curved surfaces. This article explores the locomotion potential of soft robotic snakes (SRSs) made primarily from soft, elastic materials, focusing on their ability to navigate curved surfaces. We introduce a novel locomotion gait specifically tailored for curved terrain, with parameterized movements to accommodate varying degrees of steepness. Recognizing the critical role of surface grip in locomotion on curved surfaces, we also present a mathematical model to adjust the gripping force exerted by distributed contacts, enhancing stability. Extensive experiments with our SRS prototype validate the effectiveness, viability, and robustness of the proposed locomotion strategies. Our findings pave the way for SRS applications in challenging environments such as cylindrical ducts, pipelines, and confined spaces, where traditional robotic systems may face limitations.