In this wicked video from Philips corporation we see a concept of LED tattoos embedded in human skin that come alive when touched. This concept is based on real work done at the University of Pennsylvania. Scientists there are working on silicon-and-silk implantable devices that would act like a LED screen sitting just under the surface of the skin. The images would appear as a tattoo and be fully customizable. 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. These displays could be hooked up to any kind of electronic device (inside or outside the body). It has already been successfully demonstrated in mice.
Would you want to turn your body into a screen like this?