"Vibrating magnetic tattoos may one day be used to alert mobile phone users to phone calls and text messages if Nokia follows up a patent application. The Finnish company has described the idea in a filing to the US Patent and Trademark Office. It describes tattooing, stamping or spraying "ferromagnetic" material onto a user’s skin and then pairing it with a mobile device."
BBC News - Vibrating tattoo alerts patent filed by Nokia in US

"Vibrating magnetic tattoos may one day be used to alert mobile phone users to phone calls and text messages if Nokia follows up a patent application. The Finnish company has described the idea in a filing to the US Patent and Trademark Office. It describes tattooing, stamping or spraying "ferromagnetic" material onto a user’s skin and then pairing it with a mobile device."

BBC News - Vibrating tattoo alerts patent filed by Nokia in US

BBC