Development of a Tendon Driven Variable Stiffness Continuum Robot with Layer Jamming

TL;DR

This paper presents a modular, tendon-driven continuum robot with variable stiffness enabled by layer jamming, capable of 3D motion and adjustable length, with successful fabrication and stiffness testing.

Contribution

It introduces a novel modular design for a variable stiffness continuum robot with layer jamming, supporting 3D motion and adjustable length, which was not previously available.

Findings

Successful fabrication of the modular robot prototype

Verified load carrying capacity through stiffness testing

Quantified stiffness improvement with layer jamming

Abstract

The purpose of this research is to design, fabricate and test a tendon driven a continuum soft robot with three modular segments, each of which has a tunable stiffness enabled by layer jamming technology. Compared with previous studies, the robotic arm design of this project has a modular structure, which means the length of the robotic arm can be adjusted by addition of extra arm modules/segments to the existing robotic prototype. Furthermore, the new arm prototype supports motion within a 3-dimensional space. To achieve the goals, the design and fabrication for the variable stiffness robotic arm with compliant main structure and layer jamming mechanism has already been finished. Design and fabrication of the connector has also been finished to integrate several link modules into one robotic arm with multiple segments. The actuator located at the base of the arm has already been designed and tested. Finally, a stiffness test of one arm segment was conducted to verifying the load carrying capacity of the variable stiffness robotic arm, then the stiffness ratio of the layer jammed structure was calculated to analyze the stiffness improvement compared with unstiffened soft robot.