The researchers used simple materials, such as a superconductor, and ferromagnetic materials that are freely available on the market to create an invisibility field that can effectively hide contents from the prying eyes of magnetic fields. The results of the study were presented in the journal Science.
Scientists from the Institute of Electrical Engineering of the Slovak Academy of Sciences in Slovakia and from the Universitat Autònoma de Barcelona (UAB) in Spain described the device as a cylinder they created using a high temperature superconductor material, which was later refrigerated with liquid nitrogen and covered in a layer of iron, nickel and chrome. When the cylinder was subsequently placed directly in the path of a magnetic field, the researchers observed that the device had no impact on the path of the magnetic field lines. Specifically, magnetic ‘waves’ did not bounce off, create a shadow or generate any sort of reflection. As a result, anything placed inside the device could not be detected.
This special feature is an important breakthrough as there are security scanners and other devices that are used to detect hidden objects, such as concealed weapons. In fact one of the lead researchers, UAB’s Àlvar Sánchez said he envisions their research can be used in a variety of fields ranging from military to medical. ‘There are many applications – for some cars, ships or a submarine,’ Dr Sánchez is quoted as saying. ‘For the submarine, you have to make a shell around the submarine that will make the submarine magnetically undetectable.’
At the moment, some patients have difficulty using magnetic resonance imaging (MRI) in due to pacemakers or reconstructive surgery, this device however could be employed so that the image created by the MRI is not distorted. ‘This could also be used to protect some (military and medical) equipment against electromagnetic disturbances,’ Dr Sánchez explained.
Researchers at UAB initially designed the mathematical formula for the device in what the university says it believes is ‘an extraordinarily simple equation’. In theory, this formula would allow a cylinder to be undetectable to magnetic fields from the outside, while maintaining everything inside completely isolated from these fields.
With their equation, the researchers at the UAB needed the expertise of a laboratory specialising in the precise measurement of magnetic fields. Enter the Institute of Electrical Engineering of the Slovak Academy of Sciences in Bratislava. Working in conjunction, the team was able to create positive results after just a few months. The cylinder they created consists of two concentric layers. The inner layer is made up of superconducting material that repels magnetic fields, while the outer layer has a ferromagnetic material that attracts the same magnetic fields. The cylinder was made invisible to magnetic fields and, according to the UAB, represents a step towards the invisibility of light – an electromagnetic wave.