Design of lightweight and extensible tendon-driven continuum robots using origami patterns

Tendon-driven continuum robots (TDCR) have been researched to utilize their slender structure, compliance, large workspace, and follow-the-leader deployment capabilities. Improving the performances of TDCR by increasing its length and extensibility is however challenging due to the need of guiding the tendons along the backbone. A standard design uses rigid spacer disks, which mass may cause stability issues in the case of robots with long length. In this paper, we propose a design of lightweight and extensible TDCR taking advantage of extensible paper-based origami structures to guide the tendons along a superelastic nitinol backbone. The four tendons and the backbone control the three degrees of freedom of the robot, yaw, pitch, and axial translation. The robot is composed of multi-segments, and the manufacturing process with water-based ink printing provides fast, easily customizable, and scalable fabrication of the robots. The design allows for a reduction of up to 95% of the robot mass with respect to a standard design of TDCR. The prototype demonstrates the extension ratio of more than 10 times and ±167 degrees yaw/pitch angle with 21.9 g weight. The proposed robot design can be applied for search and rescue missions and minimally invasive surgical applications.