Nokia has filed a patent for "a material attachable to skin" that will be able to detect a magnetic field and transfer a perceivable stimulus to the skin. (Shutterstock)

In the future, people could sport magnetic tattoos that vibrate when they get an alert on their phones.

At least, that's Nokia's vision of the future. The company has filed a patent for "a material attachable to skin, the material capable of detecting a magnetic field and transferring a perceivable stimulus to the skin, wherein the perceivable stimulus relates to the magnetic field."

According to tech writer Jaime Condliffe, that means vibrating tattoos.

"Basically, that means a magnetic field would cause a tattoo to vibrate in a specific way. The tattoos, the patent suggests, would have to use 'ink enriched by ferromagnetic or paramagnetic compounds' -- not too tricky, given that tattoos already contain metallic compounds," he wrote on the blog Gizmodo. "Then, different magnetic fields could be used to provide different sensations, allowing the tatt-wearer to discern between different callers, or different kinds of alerts."

Wall Street Journal tech reporter Ben Rooney compared it to ring tones.

"Nokia's thinking is that in much the same way that you can have different ring tones for different callers, so too a future phone could emit a different magnetic field depending who is calling, or if your battery is running low, or you receive an SMS, for example," he wrote.