Imagine hearing a ring and rather than reaching for your pocket you roll up your sleeve and press a dot on your forearm; this was a design submitted to the Greener Gadgets Design Competition 2008, by Jim Mielke.

The device is implanted under the skin and is bio-powered. A two by four inch tattoo of a phone’s digital display materializes on your skin along with a keypad. The display animates as a digital video of the caller and then disappears when the call is over.

digital tattoo interface

The device is flat and flexible, primarily made of silicone. A pad that rolls out would be inserted through a small incision. Two tubes would then be inserted, one attaching to an artery, another to a vein. Through a complicated medical process, glucose in your blood would be converted into electricity, required to power the device.

Instead of ink, the surface tattoo would consist of clusters of microscopic spheres injected into the skin. Each sphere would contain a field sensitive material that would change from clear to black when the device is activated.

Besides functioning as a mobile phone the device could communicate with other implants around the body and could monitor for blood disorders, sugar level, toxins, etc. It would basically serve as a “human version of the check engine light.”