Sure, fitness trackers or a heart rate monitors are technically "wearables." But a new breakthrough in electronic textiles gives us a glimpse at truly wearable electronics—and they look a lot like the shirt you're wearing right now. Except woven with circuit board thread instead of cotton.

In a study published yesterday in Proceedings of the Royal Society A, Hong Kong Polytechnic researchers Qiao Li and Xiao Ming Tao introduced a whole new type of circuit: FCB, or fabric circuit boards. These electronics are woven out of a mixture of copper and elastic threads using computerized knitting technologies. They're just like your average textiles—except they can carry a current and communicate.

These Washable Fabric Circuit Boards Can Even Survive Being Shot

What makes these wearable circuits so cool—and potentially groundbreaking—is how durable they are. Each of these insulated threads can carry a current, but thanks to their elastic content, they're also extremely stretchable. According to New Scientist, you can stretch them 20 percent up to a million times before they'll fail. Crucially, they can also endure water and intense wear—which means that throwing them in the washer repeatedly is fine. You certainly can't say as much for the other fragile, gadget-like wearables out there.

And while fabric like this could be a boon for your average consumer—who just wants to know how many calories they burned during their yoga class, damn it—the team in Hong Kong has their sights set on a far more impactful application. Quite literally. As part of a durability test, they actually shot bullets at the fabric, sewn underneath a layer of kevlar, simulating what a soldier or cop might endure in the field.

These Washable Fabric Circuit Boards Can Even Survive Being Shot

It turns out their wired fabric survived—and it could still communicate after being shot. A fitness-tracking shirt is cool and all, but a vest that lets a central base know if a soldier's been wounded could be groundbreaking. [New Scientist]