A Hollow Shell-Lattice Soft Robot in Flexible Pipelines with Flowing Fluids.

Pipeline-crawling soft robots are increasingly preferable for effective inspection and maintenance of flexible pipes. However, most existing robots occupy the pipe cross-sections, disrupting the normal operation of the working systems. In this study, an innovative shell-lattice soft robot is designed for crawling in pipes with fluid flows. The robot features a hollow body with a pneumatic actuator in the middle and two lattice shells at the head and tail parts. It enables earthworm-like locomotion through the implementation of opposite radial deformations in the two lattice shells. The hollow body architecture ensures unimpeded fluid flow during its crawling, even when mixed with solid impurities. Moreover, the surface-to-surface contact of the robot with the pipeline walls confers superior load-carrying capability, facilitating the transport of devices necessary for inspection and maintenance tasks. The robot is also capable of traversing various pipes with different frictional coefficients, irregular cross-sectional shapes, and varying curvatures, and can support untethered operation. Finally, potential applications of this robot in obstructed concealed pipes and disturbed offshore pipes are demonstrated. By leveraging advanced fabrication techniques, smart materials, and propulsion methods, it is anticipated that the designed robot may show significant scalability and applicability across diverse domains, including healthcare, aviation, and gas-and-oil transportation.