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Published Online: 19 June 2014

Soft Robotics Technologies to Address Shortcomings in Today's Minimally Invasive Surgery: The STIFF-FLOP Approach

Publication: Soft Robotics
Volume 1, Issue Number 2


Most devices for single-site or natural orifice transluminal surgery are very application specific and, hence, capable of effectively carrying out specific surgical tasks only. However, most of these instruments are rigid, lack a sufficient number of degrees of freedom (DOFs), and/or are incapable of modifying their mechanical properties based on the tasks to be performed. The current philosophy in commercial instrument design is mainly focused on creating minimally invasive surgical systems using rigid tools equipped with dexterous tips. Only few research efforts are aimed at developing flexible surgical systems, with many DOFs or even continuum kinematics. The authors propose a radical change in surgical instrument design: away from rigid tools toward a new concept of soft and stiffness-controllable instruments. Inspired by biology, we envision creating such soft and stiffness-controllable medical devices using the octopus as a model. The octopus presents all the capabilities requested and can be viewed as a precious source of inspiration. Several soft technologies are suitable for meeting the aforementioned capabilities, and in this article a brief review of the most promising ones is presented. Then we illustrate how specific technologies can be applied in the design of a novel manipulator for flexible surgery by discussing its potential and by presenting feasibility tests of a prototype responding to this new design philosophy. Our aim is to investigate the feasibility of applying these technologies in the field of minimally invasive surgery and at the same time to stimulate the creativeness of others who could take the proposed concepts further to achieve novel solutions and generate specific application scenarios for the devised technologies.

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Published In

cover image Soft Robotics
Soft Robotics
Volume 1Issue Number 2June 2014
Pages: 122 - 131


Published online: 19 June 2014
Published in print: June 2014


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Matteo Cianchetti*
The BioRobotics Institute, Polo Sant'Anna Valdera, Scuola Superiore Sant'Anna, Pontedera, Pisa, Italy.
Tommaso Ranzani*
The BioRobotics Institute, Polo Sant'Anna Valdera, Scuola Superiore Sant'Anna, Pontedera, Pisa, Italy.
Giada Gerboni
The BioRobotics Institute, Polo Sant'Anna Valdera, Scuola Superiore Sant'Anna, Pontedera, Pisa, Italy.
Thrishantha Nanayakkara
Department of Informatics, Centre for Robotics Research, NIHR Biomedical Research Centre, King's College London, London, United Kingdom.
Kaspar Althoefer
Department of Informatics, Centre for Robotics Research, NIHR Biomedical Research Centre, King's College London, London, United Kingdom.
Prokar Dasgupta
Department of Urology, King's College London, Guy's Hospital, London, United Kingdom.
MRC Centre for Transplantation, NIHR Biomedical Research Centre, King's College London, London, United Kingdom.
Arianna Menciassi
The BioRobotics Institute, Polo Sant'Anna Valdera, Scuola Superiore Sant'Anna, Pontedera, Pisa, Italy.


These two authors contributed equally to this work.
Address correspondence to:Tommaso RanzaniThe BioRobotics InstitutePolo Sant'Anna ValderaScuola Superiore Sant'AnnaViale Rinaldo Piaggio 34Pontedera (PI)Pisa 56025Italy
E-mail: [email protected]

Author Disclosure Statement

No competing financial interests exist.

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