Worm-Like Soft Robot for Complicated Tubular Environments

This article describes a worm-like soft robot capable of operating in complicated tubular environments, such as the complex pipeline with different diameters, water, oil, and gas environments, or the clinical application in natural orifice transluminal endoscopic surgery. The robot is completely soft and robust, and consists of one multidegree of freedom (DoF) extension module and two clampers for locomotion and steering. The multi-DoF extension module is able to adjust the heading direction in the three-dimensional space. The clamper has a basic expansion module structure and detachable sucking module structure. The combined clamping principle for sticking to the inner wall can be reconfigurable to adapt the tubes with multiple tubular scales and super elastic materials. For fabrication of the mechanical structure, a low-cost and time-efficient method is proposed in this article. Based on our proposed robot, a series of phantom and application experiments are performed. The results demonstrate that the soft robot can freely bend and elongate with the entire soft body, and pass through tubes with changing diameters or branches, dry tubes, liquid environments, hard surfaces, and even soft deformable tubes. It has the ability to remove a load of >10 times its own weight. In addition, an additional visualization unit, biopsy, and electromagnetic sensor are mounted on the robot tip for the real-time image inspection, manipulation, and robot tracking. The proposed worm-like soft robot is compact, flexible-actuated, and sufficiently safe, as well as extensible. Its ability to move in the complex unstructured environment shows a great potential for search and medical applications.