In contrast to a traditional rigid wheel that moves around an axle, an elastic deformation wave develops this wheel within, causing it to move.
Simple heat flow generates the propulsion by causing thermal expansion in the material, much like the thermal convection in our atmosphere that determines our weather and climate. This thermal deformation interacts with the prescribed deformation of the ring geometry and elicits the rotation.
Dr. Falko Ziebert
With the wheel within, the researchers realized a very simple principle to set polymer materials, like a rubber band or a nylon thread, into spontaneous motion. This principle will be the foundation for the research going forward.
“Right now we are still playing with different geometries, materials, and other forms of energy flow through the system,” states Dr Kulić. One vision is to create new technical devices with strong, self-propelled elements, in the form of artificial muscles, for example. Scientists from the Swiss Federal Institute of Technology in Zurich (Switzerland) also assisted in the study.