Fabrication

This section presents the steps required for the fabrication of the robot, as well as the list of materials and tools needed. The CAD files of each part of the prototype can be found at the end of each sub-section.

List of Tools and Materials

Dragon Skin 10A silicone rubber

The pneumatic actuators and the end-effector are made of Dragon Skin 10A silicone rubber by Smooth-On, which has a good compromise between elasticity and tear strength.

OpenBeam

12 beams of 30cm long are required to build the frame of the base of the manipulator. In order to join the beams together, some A-brackets and bolts are needed as well.

Wooden plank

A wooden plank of 30cm x 30cm was used on top of the beam frame as a fixation platform for the manipulator and the servos.

Polyethylene tube

Polyethylene tube of Ø4mm  is used to connect the pneumatic actuators to the valves.

Fishing line

Fishing line of Ø.35mm functions as our cable-tendons. It is very resistant and thin.

Bolts and nuts

We used 4 bolts of Ø4mm to fix the manipulator to the wooden plank. The required length of these bolts depend on the thickness of the wooden plank selected., A total of 22 bolts of Ø2.5mm and 10mm long and 3 bolts of Ø2.5mm and 30mm long are used in the assembly of the manipulator.

Scissors

We used scissors to remove silicone excess from the actuators.

Cardboard cutter

Same as the scissors, the cutter is use to clean and detail silicone and plastic parts.

Dremel tool

The Dremel tool is used to detail the plastic parts in case the 3D printer left some plastic residue. Since we are working with silicone rubber, it is important to check for plastic edges that can puncture the silicone or prevent any other piece to fit in place.

Electric drill

Same as above, the drill is used to finish the holes in the plastic pieces and to make some holes in the wooden plank

Ultimaker 3D printer

A Ultimaker 3D printer was used in the fabrication of all the rigid parts of the manipulator.

ProJet 460 plus 3D printer

We had the fortune of having access to a ProJet plus 3D printer. With it, we were able to print plaster molds for the silicone parts, since the plastic molds are quite difficult to handle.

Bibliography

Robinson et al. (1999) Continuum robots-a state of the art

Walker et al. (2013) Continuous backbone “continuum” robot manipulators

McMahan et al. (2005) Design and implementation of a multi-section continuum robot: Air-Octor

Neppalli et al. (2007) Design, construction, and analysis of a continuum robot

Bosman et al. (2015) Domain decomposition approach for FEM quasistatic modeling and control of Continuum Robots with rigid vertebras

Duriez, et al. (2008) Contact skinning

Duriez et al. (2013) Control of elastic soft robots based on real-time finite element method

Contributors

Thor Bieze

Frédérick Largillière

Sandra Hage Chehade

Mario Sanz Lopez

Christian Duriez