Torque‐Transmitting Architected Metamaterials for Flexible and Extendable Tubular Robotics

Abstract

Soft and continuum robots commonly rely on fluid, tendon, or rod‐based power transmissions, to control robotic form and actuation. Architected geometry has enhanced robot control through tailored physical and mechanical properties based on topology. For example, twist‐actuated metamaterials, such as handed shearing auxetics (HSAs), have expanded the soft robot design space, offering varied shape changes and direct integration with simple motors. Despite these advancements, current options for torque transmission limit the successful integration of HSAs in tubular robots, especially for constructions requiring maximized interior space for passing devices or additional concentric tubes. An architected structure based on patterned straight‐line mechanisms is proposed that enables simultaneous bending, extending, and torsionally rigid (BETR) transmission. Pairing these new torque‐transmitting materials with twist‐driven materials HSAs creates new modalities for the varied actuation of tubular robots. Parameter trade offs in BETRs are analyzed, and a user operated robot is built that demonstrates feasibility for navigation, positioning, and anchoring in scaled 3D‐printed anatomies.