Earthworm-Like Planar Locomotion Robot Based on Yoshimura-Origami Structure

Abstract Inspired by the biological characteristics of the earthworm and the prominent deformability of origami structure, this research proposes an origami-based earthworm-like robot to achieve effective planar locomotion. Origami is attractive for building earthworm-like robots’ ‘body’ because it can exhibit excellent compliance and reduce the cost of fabrication. In this paper, we choose Yoshimura structure incorporated with hybrid actuators and anchoring mechanisms to construct the robot segment. The Yoshimura structure is composed of multiple layers and each layer is assumed to have uniform deformation. Kinematic analysis indicates that the Yoshimura structure has excellent axial and bending deformability, and the deformability is closely related to the number of layers. To control the axial and bending deformation of the robot segment individually, each segment contains two types of actuators: pneumatic balloon and SMA spring. The balloon is used to actuate the expansion and contraction of the segment, while the SMA spring is used to actuate the bending behavior of the segment. The experiment is performed to verify that the robot can achieve rectilinear and planar locomotion. Our results could lead to the development of origami-based locomotion robots and deepen our understanding of them.