#  Braided Sheath 

 



 ##  

  expand\_more  

 
  

 

The external sheath is fabricated starting from a commercial one.

1\. Cut about 1.5 m of the expandable braided sheath (a).

2\. Insert a metallic cylinder of 30 mm in diameter and 250 mm in length inside the sheath.

3\. Push down and force the sheath by hand sliding over the cylinder, in order to create crimps (b).

4\. Heat with a heating gun at 350 °C for 2-3 min until a permanent deformation is obtained (b).

5\. Let the sheath cool down and remove the internal cylinder (c).

 ![guaina_fabbricaz](/sites/g/files/omnuum4601/files/2024-11/guaina_fabbricaz.jpg)

 

The sheath fabrication is based on a simple procedure. Remember that the development of the crimps has to ensure the necessary space to insert the module and the right distance between the crimps. These features ensure the right behavior of the module when the chambers are inflated. The sheath has the function to limit the radial expansion of the silicone when the chambers are inflated, avoiding the “balloon effect” showed in Design Section. Close crimps improve the expansion of the silicone along the motion direction optimizing the bending and the elongation movements. In addition, particular care is needed when heating the sheath because an overheating could degrade the material.

### Contributors

Iris De Falco

### Bibliography

Cianchetti et al. (2013) [STIFF-FLOP Surgical Manipulator: mechanical design and experimental characterization of the single module. ](/publications/stiff-flop-surgical-manipulator-mechanical-design-and-experimental)

De Falco et al. (2014) [A soft and controllable stiffness manipulator for minimally invasive surgery: preliminary characterization of the modular design](/publications/soft-and-controllable-stiffness-manipulator-minimally-invasive-surgery).

De Falco et al. (2014) [STIFF-FLOP surgical manipulator: design and preliminary motion evaluation*.*](/publications/stiff-flop-surgical-manipulator-design-and-preliminary-motion-evaluation)

De Falco et al. (2015) [Design and fabrication of an elastomeric unit for soft modular robots in minimally invasive surgery.](/publications/design-and-fabrication-elastomeric-unit-soft-modular-robots-minimally)

Ranzani et al. (2013) [A modular soft manipulator with variable stiffness.](/publications/modular-soft-manipulator-variable-stiffness)

Elsayed et al. (2014) [Finite Element Analysis and Design Optimization of a Pneumatically Actuating Silicone Module for Robotic Surgery Applications.](/publications/finite-element-analysis-and-design-optimization-pneumatically-actuating-0)

L. Vyas et al. (2011) [Flexible Robotics.](/publications/flexible-robotics)

Laschi et al. (2014) [Soft Robotics: new perspectives for robot bodyware and control.](/publications/soft-robotics-new-perspectives-robot-bodyware-and-control)

Cheng et al. (2012) [Design and Analysis of a Robust, Low-cost, Highly Articulated Manipulator Enabled by Jamming of Granular Media.](/publications/design-and-analysis-robust-low-cost-highly-articulated-manipulator-enabled)

Allen et al. (2014) [Robotic Granular Jamming: Does the Membrane Matter?](/publications/robotic-granular-jamming-does-membrane-matter)