The title character of Ray Bradbury’s book The Illustrated Man is covered with moving, shifting tattoos. If you look at them, they will tell you a story.

New LED tattoos from the University of Pennsylvania could make the Illustrated Man real (minus the creepy stories, of course). Researchers there are developing silicon-and-silk implantable devices which sit under the skin like a tattoo. Already implanted into mice, these tattoos could carry LEDs, turning your skin into a screen.

The silk substrate onto which the chips are mounted eventually dissolves away inside the body, leaving just the electronics behind. The silicon chips are around the length of a small grain of rice — about 1 millimeter, and just 250 nanometers thick. The sheet of silk will keep them in place, molding to the shape of the skin when saline solution is added.

These displays could be hooked up to any kind of electronic device, also inside the body. Medical uses are being explored, from blood-sugar sensors that show their readouts on the skin itself to neurodevices that tie into the body’s nervous system — hooking chips to particular nerves to control a prosthetic hand, for example.

Chips are already used inside bodies, most notably the tiny RFID tags injected into pets. But the flexible nature of these “tattooed” circuits means they can move elastically with the body, sitting in places that a rigid circuit board couldn’t.

The first displays are sure to be primitive, but likely very useful for the patients that receive them. You won’t be getting the full-color, hi-res images that come with ink, but functional displays. This doesn’t mean that the commercial and artistic possibilities are being ignored. Philips, the electronics giant, is exploring some rather sexual uses.

Source: http://www.wired.com/gadgetlab/2009/11/the-illustrated-man-how-led-tattoos-could-change-the-face-of-humanity