Soft hopping and crawling robot for in-pipe traveling

Abstract Pipe inspection is of great importance from both safety and cost perspectives. Despite extensive research, in-pipe robots with multi-locomotion capability have not been fully explored. Here, we develop a multi-locomotion soft robot, with a compact yet robust structure, that can hop for speed and crawl for maneuverability in horizontal and vertical pipes for pipe inspection. The robot consists of two motors, cables, and several longitudinally arranged elastic ribbons. These ribbons, with strategically designed profiles, are 3D-printed and can be buckled into three-dimensional shapes by pulling cables, thereby achieving hopping and crawling (forward and backward) by issuing different actuation sequences and parameters of the two motors. We studied the effect of ribbon design and pulling/releasing duration on the hopping and crawling performance. Our findings may shed light on the development of in-pipe robots with new functionality and applications.