Design, characterization and optimization of a soft fluidic actuator for minimally invasive surgery

  • Gilles DecrolyEmail author
  • Benjamin Mertens
  • Pierre Lambert
  • Alain Delchambre
Original Article



In minimally invasive surgery and endoscopy, the rise of soft robotics, using materials of similar softness as biological soft tissues, opens many new opportunities. Soft actuated catheters could become an alternative to current steerable catheters, by minimizing the risk of damage to surrounding tissues while enhancing the possibilities to navigate in confined space and to reach remote locations. Fluidic actuators present the advantage to be safe, since they do not require rigid parts nor voltage, to be lightweight, and to allow the reduction of the number of parts needed for a given movement. This work presents the design, development and characterization of a soft fluidic bending actuator for a steerable catheter.


A silicone prototype of 5 mm diameter has been designed. It has one degree of freedom in bending and achieves a radius of curvature below 10 mm. A numerical model has been developed and compared to the experimental results.


Despite an overestimation of the bending, the numerical model properly captures the behaviour of the actuator. This allowed to identify and validate the key design parameters of the actuator, namely the ratio between the pressure channel surface and the actuator cross-section surface. Based on the results, an optimized design has been developed and numerically implemented. The miniaturization and the potential to carry devices with non-negligible bending stiffness have also been discussed.


In this work, a proof of concept of a soft fluidic actuator for a steerable catheter has been designed, developed and characterized. It showed promising results concerning the feasibility of a miniaturized actuator with two degrees of freedom.


Soft robotics Fluidic actuator Steerable catheter Minimally invasive surgery Finite element modelling 



This work was made possible by the support of Boston Scientific and the Michel Cremer Foundation. This work is also supported by the FNRS (Fonds National de la Recherche Scientifique) through the funding of a FRIA Grant.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors.

Informed consent

This article does not contain patient data.


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Copyright information

© CARS 2019

Authors and Affiliations

  1. 1.BEAMS DepartmentUniversité libre de BruxellesBrusselsBelgium
  2. 2.TIPs DepartmentUniversité libre de BruxellesBrusselsBelgium

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