Helical Kirigami-Inspired Centimeter-Scale Worm Robot With Shape-Memory-Alloy Actuators

The worm-like robots are capable of imitating the amazing locomotion of the long and thin creature. This paper presents a novel centimeter-scale worm robot inspired by a kirigami-fold which is a variation of origami with helical motion. The body structure is extracted from the kirigami structure and its motion characteristics are analyzed in terms of kinematic principles. This leads to identification of the capability of the segmented worm robot with integrated parallel kirigami structures to imitate contracting motion, omega-shaped bending motion and twisting motion of the locomotion in nature. A prototype of the worm robot with three segments is fabricated with paper-made body structure and actuated by shape-memory-alloy (SMA) coil springs. The robot is lightweight and can be used in confined environments for detection and inspection. The study creates a new approach of integrating SMA actuators in origami-enabled parallel kinematic structures for the development of compliant and miniaturized robots including the presented worm robot.