A Soft-Rigid Tendon-Driven Continuum Robot with Multi-Curvature Actuated by a Single Set of Tendons

Abstract

This work presents a novel design of achieving multiple curvatures in a tendon-driven continuum robot (TDCR) system with only a single set of acturation tendons. The TDCR used in this work is assembled from multiple sub-sections made of low-melting point alloy (LMPA), which each of them has independent binary stiffness by localized thermal phase transitions. Through localized thermal phase transitions, the robot can dynamically "lock" or "release" specific sub-sections, enabling multi-curvature configurations, enabling independent curvature control with only one set of actuation tendons. is approach eliminates the need for additional segments or complex locking mechanisms, significantly reducing mechanical complexity and control challenges. Experimental validation confirms the system’s ability to execute complex shapes (C/J/S-shape configurations), maintain structural rigidity in locked states, as well as different spatial movements can be achieved by changing the configuration of subsegments. The SR-TDCR demonstrates potential for confined-space applications merging dexterity with actuation efficiency.