Google and Levi's Project Jacquard is already imagining a future of wearables built right into our clothing. But when all our clothes are smart, how will they be powered? And just as importantly, how will they go through the wash?
Right now, the answer is removable battery packs. But a new textile created by engineers at Georgia Tech could allow tomorrow's smart clothes to harvest energy on their own. The new fabric boasts soft interwoven pastel fibers (very much in vogue right now) that collect energy from two sources: the sun, and movement.
Just rustling this fabric around is enough to generate minute amounts of power, thanks to the fact that it is partially made up of fiber-based triboelectric nanogenerators. You know the feeling of shuffling your wool socks against the carpet and hitting the next person you touch with a static charge? That's the triboelectric effect in action, and triboelectric nanogenerators use it to generate small amounts of power every time they move. The power it generates isn't necessarily much—think of how much electricity a static shock produces—but it's electricity that is being generated constantly. It adds up.
But that's not the only place this fabric draws power from. Georgia Tech's textile can also harvest power from the sun, thanks to solar cells that are woven together with the nanogenerators, augmenting its power generating abilities even more. The result is a textile that could keep a low-power wearable juiced up indefinitely without recharging. And it's thin, too. The resulting strands are just 320 micrometers thick, and can be woven together with other fabrics, such as wool. Tests also suggest that the fabric can stand up to abuse, will continue to work if ripped, and could even be waterproof with proper encapsulation to protect the electrical components from moisture.
"This hybrid power textile presents a novel solution to charging devices in the field from something as simple as the wind blowing on a sunny day," writes Georgia Tech professor Zhong Lin Wang, who co-authored the paper on the new textile. Better yet, the textile seems cheap enough for mass production. ""The backbone of the textile is made of commonly-used polymer materials that are inexpensive to make and environmentally friendly," Wang added. "The electrodes are also made through a low cost process, which makes it possible to use large-scale manufacturing."
Since the fabric is still in the academic research phase, it's going to be a few years before we see real-world applications. Still, such a fabric certainly opens up a number of interesting possibilities. You could charge your smartwatch just by using a textile watchband, or your smartphone by attaching it to a little triboelectric sail. Tomorrow's sneakers could track your steps, or your pants could have a multitouch patch that pairs with your iPhone, all without external power sources.
[All Photos: courtesy Georgia Tech]