Living Tattoo

Science Daily: Engineers 3-D print a 'living tattoo' - New technique 3-D prints programmed cells into living devices for first time.

summary - Engineers have devised a 3-D printing technique that uses a new kind of ink made from genetically programmed living cells. The cells are engineered to light up in response to a variety of stimuli. When mixed with a slurry of hydrogel and nutrients, the cells can be printed, layer by layer, to form three-dimensional, interactive structures and devices.