Tendon-Based Stiffening for a Pneumatically Actuated Soft Manipulator

Ali Shiva, Agostino Stilli, Yohan Noh, Angela Faragasso, Iris De Falco , Giada Gerboni, Matteo Cianchetti, Arianna Menciassi, Kaspar Althoefer, Helge A. Würdemann

Research output: Contribution to journalArticlepeer-review

147 Citations (Scopus)
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There is an emerging trend toward soft robotics due to its extended manipulation capabilities compared to traditionally rigid robot links, showing promise for an extended applicability to new areas. However, as a result of the inherent property of soft robotics being less rigid, the ability to control/obtain higher overall stiffness when required is yet to be further explored. In this letter, an innovative design is introduced which allows varying the stiffness of a continuum silicon-based manipulator and proves to have potential for applications in Minimally Invasive Surgery. Inspired by muscular structures occurring in animals such as the octopus, we propose a hybrid and inherently antagonistic actuation scheme. In particular, the octopus makes use of this principle activating two sets of muscles-longitudinal and transverse muscles-thus, being capable of controlling the stiffness of parts of its arm in an antagonistic fashion. Our designed manipulator is pneumatically actuated employing chambers embedded within the robot's silicone structure. Tendons incorporated in the structure complement the pneumatic actuation placed inside the manipulator's wall to allow variation of overall stiffness. Experiments are carried out by applying an external force in different configurations while changing the stiffness by means of the two actuation mechanisms. Our test results show that dual, antagonistic actuation increases the load bearing capabilities for soft continuum manipulators and thus their range of applications.
Original languageEnglish
Article number7394145
Pages (from-to)632-637
Number of pages6
JournalIEEE Robotics and Automation Letters
Issue number2
Early online date28 Jan 2016
Publication statusPublished - Jul 2016


  • manipulators;pneumatic actuators;actuation mechanisms;antagonistic actuation scheme;continuum silicon-based manipulator;innovative design;longitudinal muscles;manipulation capabilities;manipulator wall;minimally invasive surgery;muscular structures;pneumatic actuation;pneumatically actuated soft manipulator;rigid robot links;robot silicone structure;soft continuum manipulators;soft robotics;structure complement;tendon-based stiffening;transverse muscles;Electron tubes;Manipulators;Muscles;Pneumatic systems;Surgery;Tendons;Biologically-Inspired Robots;Biologically-inspired robots;Soft Material Robotics;Tendon/Wire Mechanism;hydraulic/pneumatic actuators;soft material robotics;tendon/wire mechanism


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