Superconductors work by hovering, are resistance-free and energy efficient. While they have been used in medical technology for two decades and are currently making their mark in large-scale systems with high power density, Festo is looking into how the technology can be applied to sustainable production of the future.
Superconductors are metals, metal compounds or ceramic materials which abruptly enter a superconducting state below a certain transition temperature. When this happens, they lose their electrical resistance. Once the transition temperature is reached, mutually repulsive electrons bind to form what are called Cooper pairs. Once paired, they can no longer interact with the atomic lattice that surrounds them, and as a result conduct the electrical current without any resistance. Once the electrical current is put into motion in the superconducting material below the transition temperature, it flows in a closed circuit without any losses. The superconductor technology is still in the research stage but has great potential in material development and cooling systems. The cost of cooling the material to extremely low temperatures stood in the way of widespread industrial applications for a long time. High-temperature superconductors whose transition temperature is above 100 Kelvin were discovered in 1986. These superconductors are ceramic materials. Since then, it has become possible to cool materials directly using liquid nitrogen or electrically, which is much cheaper and more practical.
Superconducting magnetic bearings in automation
If a superconductor is cooled to below the transition temperature under the influence of the external magnetic field of a permanent magnet, it loses its electrical resistance and changes its characteristics as well: The superconductor can store the magnetic field of the permanent magnet at a predefined distance, enabling a stable hovering condition. The superconductor responds to any attempt to move it by returning to the stored position. Research projects demonstrate this characteristic of frictionless, stable bearing without the need for complex measurement and control technology.
A Suprapicker is a magnetic gripper with superconducting bearing system which for example completes a handling operation, first outside of an hermetically sealed room and then inside. The gripper, which hovers thanks to superconductivity, picks up a vial magnetically, conveys it through a lock into a hermetically sealed room and places it in the designated position. This example shows the benefits of the non-contacting, stable, superconducting bearing system, which opens up new opportunities for handling applications. pb