Novel Design of a Soft Lightweight Pneumatic Continuum Robot Arm with Decoupled Variable Stiffness and Positioning

Maria Elena Giannaccini*, Chaoqun Xiang, Adham Atyabi, Theo Theodoridis, Samia Nefti-Meziani, Steve Davis

*Corresponding author for this work

Research output: Contribution to journalArticle

19 Citations (Scopus)
3 Downloads (Pure)


Soft robot arms possess unique capabilities when it comes to adaptability, flexibility, and dexterity. In addition, soft systems that are pneumatically actuated can claim high power-to-weight ratio. One of the main drawbacks of pneumatically actuated soft arms is that their stiffness cannot be varied independently from their end-effector position in space. The novel robot arm physical design presented in this article successfully decouples its end-effector positioning from its stiffness. An experimental characterization of this ability is coupled with a mathematical analysis. The arm combines the light weight, high payload to weight ratio and robustness of pneumatic actuation with the adaptability and versatility of variable stiffness. Light weight is a vital component of the inherent safety approach to physical human-robot interaction. To characterize the arm, a neural network analysis of the curvature of the arm for different input pressures is performed. The curvature-pressure relationship is also characterized experimentally.

Original languageEnglish
Pages (from-to)54-70
Number of pages17
JournalSoft Robotics
Issue number1
Early online date30 Oct 2017
Publication statusPublished - 1 Feb 2018



  • physical human-robot interaction
  • pneumatic actuators
  • soft robot arm
  • variable stiffness

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Biophysics
  • Artificial Intelligence

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