It's the world's only man-made 2D material, and physicists believe it could change the way we live. Graphene, a line of carbon that's a mere atom thick, is several times stronger than steel and 100 times more conductive than copper. But this wonder material has yet to find a breakout application. As the New Yorker put it in 2014, "Graphene may be the most remarkable substance ever discovered. But what is it for?"
Now, we might know. Rice University researchers have successfully used a commercial laser to transform the surface carbon in foods–like toast, coconuts shells, potatoes, and Girl Scout cookies–into graphene. Without using any special vacuums or clean rooms, graphene can be patterned into an impossibly thin, edible circuit–including fuel cells to store power, radio hardware to transmit data, glowing elements to light up, and even all sorts of sensors, too. These circuits resemble a dark, inky tattoo, a bit like very burnt toast.