A Pneumatically-Driven Soft Robot Biologically Inspired by Earthworms

We present the design, fabrication and feedback control of an earthworm-inspired soft robot capable of locomoting inside pipes. The bodies of natural earthworms are composed of repeated deformable structural units, actuated by axial and longitudinal muscles, employed to generate the body motions required for limbless locomotion, such as burrowing. Following this basic notion, we propose a new pneumatically-driven soft robotic system, built by integrating together two radial actuators with an axial actuator, which mimics the motion and functionality of one body segment of a natural earthworm. The suitability of the proposed approach is demonstrated experimentally through three basic locomotion tests: horizontal motion, vertical motion and oblique motion inside a varying-angle transparent pipe.