At the 'Hannover Messe', Festo for the first time showed its research platforms dealing with superconductivity: SupraLinearMotion, SupraHandling and SupraPicker. In all three displays, objects were transported in a floating state in order to demonstrate possible automation applications. But what is behind this technology and how does it make objects float in air?
What are superconductors?
Superconductors are metals, metal compounds or ceramic materials which abruptly lose their electrical resistance below a certain transition temperature. In the case of modern high-temperature superconductors, this point is around 100 Kelvin (-173°C). If a flow of current is started in a superconductor material, it will continue to flow without losses in a closed loop.
Floating thanks to a magnetic field
Below its transition temperature, a superconductor not only changes its conductivity but is also able to store or "freeze" the magnetic field of a permanent magnet at a predefined distance. If, for example, we place a piece of wood or styrofoam between a magnet and a superconductor, cool the superconductor down to its transition temperature and remove the wood or styrofoam spacer, the superconductor will then float over the magnet in a stable state. If we then try to push the superconductor to one side, it will always return to the stored position.
Superconductor technology and its cooling methods are still at the research stage. Conceivable applications include friction-free, stable and energy-efficient bearings which are able to operate without complex instrumentation and control technology. It would also be possible to control the movement of objects in sealed rooms from outside the room at all angles of inclination. These applications were illustrated by the research platforms which Festo showed at the 2013 'Hannover Messe':