Nokia’s patent application describes a system that could work in two ways. The first concept uses a detachable electronic material that could peel off your skin, much like these, that you could pair with a phone. The peelable circuitry could detect a magnetic field and cause a vibration, probably through piezoelectrics. When someone calls your phone, the phone sends a signal to the haptic material, which would vibrate in a certain pattern…

The second concept would use a ferromagnetic ink to permanently imprint this material into your skin. You could get whatever image you’d want, just like a regular tattoo, and after it’s applied it would be magnetized so it, too, could recognize a magnetic field from your phone. Unwired View breaks down Nokia’s patent application in greater detail.