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.

It suggests different vibrations could be used to create a range of alerts.

The application lists Cambridge-based Zoran Radivojevic as the innovation's lead inventor. It was filed last week and was brought to light by the Unwired View news site.

It suggests a magnetic marking could be attached to either a user's arm, abdominal area, finger or fingernail.

"Examples of... applications may be low battery indication, received message, received call, calendar alert, change of profile, eg based on timing, change of time zone, or any other," the filing reads.

"The magnetic field may cause vibration of one short pulse, multiple short pulses, few long pulses... strong pulses, weak pulses and so on."

The filing also suggests that the magnetised marking could be used as an identity check. It says that by picking a certain shape the user could create a "specific magnetic impedance" - effectively their own magnetic fingerprint.

It says this could act as a "password" and gives the example of a laptop refusing to display content on its screen unless it verifies its user is close by.