Annelid-inspired high-elongation origami robot using partial material removal

Abstract

With improved flexible robot elongation rate, bending angle and movement flexibility in space target acquisition, disaster search and rescue, unknown environment detection and other fields, existing soft robots face challenges. Yoshimura tubular origami shows good application performance in axial expansion ratio. However, due to the characteristics of nonrigid folding and a negative Poisson's ratio, the axial elongation length and bending angle of the Yoshimura tubular origami mechanism are limited. Annelids show high flexibility in body movement. By analyzing the main factors limiting the axial elongation rate of the Yoshimura tubular origami mechanism and imitating the morphological characteristics and motion mechanism of annelid isomic joints, we proposed a method to achieve high flexibility and large angle bending of a tubular origami mechanism based on local material removal and macroscopic negative Poisson's ratio elimination. Combined with a nickel-titanium memory alloy wire segmented driving scheme based on force constraints and geometric constraints a continuous origami robot is designed. The optimal cutting amount of origami mechanism is determined by experiments, which makes the maximum elongation ratio and bending angle of origami mechanism reach 2.5 and 3 times of those before material removal respectively, and the paper folding module unit was solved in the kinematic analysis workspace. Finally, a prototype was used to verify the performance and demonstrate the application potential of the robot in an unstructured rescue scene.