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

**Authors:** Zhong Ouyang  
**arXiv:** [1912.04473](https://arxiv.org/abs/1912.04473)  
**Date:** 2019-12-10  
**Summary page:** https://www.summarizepaper.com/en/paper/1912.04473v1/

## Key points

- Research project aimed to design, fabricate and test a tendon-driven continuum soft robot with three modular segments
- Each segment has tunable stiffness enabled by layer jamming technology
- Modular structure allows for length of arm to be adjusted by adding extra modules/segments
- Robotic arm design supports motion within a 3-dimensional space
- Variable stiffness robotic arm with compliant main structure and layer jamming mechanism was designed and fabricated
- Connectors were designed and fabricated to integrate several link modules into one robotic arm with multiple segments
- Actuator located at the base of the arm was designed and tested
- Stiffness test conducted on one arm segment to verify load carrying capacity
- Modular design allows for greater flexibility in adjusting length of robotic arm while supporting motion in 3D space
- Results demonstrate that such robots can be used in various applications where compliance is necessary for safe interaction with humans or delicate objects while maintaining sufficient strength for practical use cases.

## Summary

This research project aimed to design, fabricate and test a tendon-driven continuum soft robot with three modular segments, each of which has tunable stiffness enabled by layer jamming technology. The robotic arm design had a modular structure that allowed for the length of the arm to be adjusted by adding extra modules/segments to the existing prototype. Additionally, it supported motion within a 3-dimensional space. To achieve these goals, the team designed and fabricated a variable stiffness robotic arm with a compliant main structure and layer jamming mechanism. They also designed and fabricated connectors to integrate several link modules into one robotic arm with multiple segments. The actuator located at the base of the arm was designed and tested as well. The team conducted a stiffness test on one arm segment to verify its load carrying capacity. They calculated the stiffness ratio of the layer jammed structure to analyze its improvement compared with an unstiffened soft robot. Compared with previous studies, this project's modular design allowed for greater flexibility in adjusting the length of the robotic arm while supporting motion in 3D space. The results demonstrate that such robots can be used in various applications where compliance is necessary for safe interaction with humans or delicate objects while maintaining sufficient strength for practical use cases.