Looks can be deceiving when it comes to the bleeding edge of technology research.
It may look like a piece of burnt paper but this is an ultra-thin superconductor developed by scientists at Saarland University. Image credit: Saarland University
What appears as just a charred black piece of paper may, in fact, be an ultra-thin superconductor capable of withstanding harsh conditions up to negative 200 degree Celsius and conducts electricity without loss, levitates magnets and can screen magnetic fields.
The research comes from Saarland University in Germany where scientists have developed a way to create superconducting nanowires that can be woven into an ultra-thin film that is flexible. The new technology may usher in new ways to coat applications from aerospace to medical technology.
Superconductors have zero electrical resistance and can conduct electric current without loss. The electrons in the material flow unrestricted through the cold immobilized atomic lattice. If a magnet is brought up close to a cold superconductor, the magnet effectively “sees” a mirror image of itself in the superconducting material—offering the ability to levitate magnets when they come in contact with liquid nitrogen.
Scientists say most common superconducting materials are rigid, brittle and dense, a combination that makes them heavy and unusable in most applications. By packing superconducting properties into a flexible film, the material can cling to other objects allowing it to be possibly coated on various applications.
“Theoretically, the material can be made to any size. And we need fewer resources than are typically required to make superconducting ceramics, so our superconducting mesh is also cheaper to fabricate,” says Uwe Hartmann, professor of nanostructure research and nanotechnology at Saarland University.
Because the material weighs about 100 times less than conventional superconductors, it might be extremely important in space technology, where lighter objects are always a benefit, or in medical technology as some sort of smart clothing. The material could also be used to provide low-temperature screening from electromagnetic fields or used in flexible cables or to facilitate friction-free motion, scientists say.
How They Did It
Saarland University made use of a technique known as electrospinning, a process used to make polymeric fibers, in order to weave the material. A liquid material is forced through a very fine nozzle called a spinneret to which a high electrical voltage is applied.
This produces nanowire filaments that are much thinner than a strand of human hair—about 300 nanometers or less. These filaments are then heated so superconductors of the right composition are created. The superconducting material is typically an yttrium-barium-copper-oxide or similar compound, the university says.
The team is currently looking for commercial and industrial partners in order to develop a practical use for the ultra-thin superconducting film.
