It’s not such much a literal tattoo as an electronic interface implanted beneath the skin:

The basis of the 2×4-inch “Digital Tattoo Interface” is a Bluetooth device made of thin, flexible silicon and silicone. It´s inserted through a small incision as a tightly rolled tube, and then it unfurls beneath the skin to align between skin and muscle. Through the same incision, two small tubes on the device are attached to an artery and a vein to allow the blood to flow to a coin-sized blood fuel cell that converts glucose and oxygen to electricity. After blood flows in from the ...

Read the whole story on Neatorama