How would you like to be able to sense magnetic fields? It could come in handy, given that some animals navigate and maintain their spatial orientation by doing so. Well, we've now come one step closer to humans having that ability, too. Scientists from Germany's Leibniz Institute for Solid State and Materials Research, along with colleagues from the University of Tokyo and Osaka University, have developed a thin, flexible magnetoresistive sensory foil that can be applied to a person's own natural skin.
Each piece of the foil consists of an array of magneto-sensitive elements, embedded on one side of a PET (polyethylene terephthalate) substrate measuring just 1.5 micrometers thick. The material weighs only 3 grams per square meter (10.8 sq ft), although it likely wouldn't be used in sheets that large.
It is envisioned that the foil could be temporarily applied to an appendage such as a finger, allowing users to sense the proximity of both static and dynamic magnetic fields. Presumably the material could be tweaked to deliver a tactile response, which the wearer would feel in their own skin – in lab tests, its responses were indicated on a nearby electronic display.
Because the foil detects magnetic fields even through non-magnetic objects such as walls or glass, it could conceivably be used to read magnetic "messages" sent by electronic devices. It could also be used to add a magneto-sensory system to soft robotics, or for medical implants that respond to magnetic stimuli.
For any of those applications to work, however, the material needs to be robust ... and it is.
When laminated onto an elastomer surface, pieces of the foil maintained their functionality after being stretched more than 1,000 times by over 270 percent. The material also survives being scrunched up in a ball, like a piece of paper.
A paper on the research was recently published in the journal Nature Communications.
Source: Leibniz Institute for Solid State and Materials Research (IFW Dresden)