The fibers could make identifying friendly soldiers on a confusing, smoky, dusty, dark battlefield easier. Shine a laser designator on someone you don’t recognize. If she’s wearing the same uniform as you, the functional microfibers sewn into it would sense the laser and send a data signal back to your shirt. Same with someone’s voice. Heat-sensitive fibers show potential for battlefield medicine: the shape and rate of change of a heat pattern pressed up against the shirt indicate where and how severely someone’s been wounded.

“Your uniform would transit that information. You wouldn’t be talking, it would transmit information: who you are, what time you went down, where the wounds are, what is the estimated severity of the wound, et cetera,” Joannopoulos says. “The idea with these fibers is that eventually, we’d like to enable full-body sensing for the soldier.”