Politecnico di Torino - Corso Duca degli Abruzzi, 24 - 10129 Torino, ITALY

+39 011 090 6100 info@tech-share.it

Deformable actuating device with coaxial configuration

actuatorsbiomimesiscoaxial configurationdielectric elastomerselectroactive polymersRehabilitation


The concept developed concerns a class of actuating devices based on electroactive polymers, in particular dielectric elastomers. The actuation device of the present invention aims to mimic as much as possible the structure and behavior of muscle bundles. To obtain this result it is necessary a coaxial structure able to generate an elongation of the material as a function of the applied voltage.

Technical features

The actuator device is a fiber formed by a number N of alternated hollow cylinders respectively made of dielectric elastomer and of conductive electrode. The resulting actuation is an elongation along the axis of the device. The element of originality of the solution proposed therein is the application of different voltages on each individual layer. This operating principle puts forward the function of selective recruitment of the individual layers: controlling the number of layers electrically stimulated, as well as the voltage applied to the individual layer is possible to modulate the resulting deformation of the fiber and the intensity of the actuation force. The element of originality of the present invention is also declined in a hierarchical structure consisting of a bundle of coaxial fibers. This solution enables a hierarchical selective recruitment: by controlling the voltages applied is possible not only to modulate the activation of the individual layer in the single fiber, but also the activation of the individual fibers within the bundle.

Possible Applications

  • Artificial muscles;
  • Active prostheses;
  • Rehabilitation support;
  • Active fabrics;
  • Wearable Technologies.


  • Reduction of the applied voltages;
  • Higher actuation efficiency;
  • Actuation tuning;
  • Linear deformations and complex bending.