Origami-Based Inner Channel Securing Mechanism for Soft Growing Robots

Abstract

Soft growing robots possess unique advantages, such as the ability to navigate confined and complex environments. Although securing a stable inner channel is essential for enabling a wide range of applications, such as sensor integration, tool passage, and material transfer, the pressure required for eversion based growth imposes compressive loading on the channel, causing it to collapse by constriction. Existing approaches for channel stabilization rely on auxiliary actuation or complex control, which introduce leakage, deformation, or limited scalability. To over come these limitations, this paper presents an origami-inspired mechanism embedded into the robot membrane that inherently forms a structurally rigid inner channel without additional actuation, while preserving the intrinsic benefits of soft growing robots. The design further enables user-defined customization of channel geometry to meet application-specific requirements. A comprehensive modeling framework is developed to characterize the geometric and mechanical behavior of the mechanism, and its validity is confirmed through simulations and comparative experiments against conventional soft growing robots. Demonstrations, including inner channel visualization, steering, growth through confined paths, and parameter-dependent scalability, validate the practicality and versatility of the proposed approach.