A dancer breaks a sweat and small, triangular scales on his tightly-fitted shirt curl up, making holes to allow for some airflow. Called bioLogic, the workout gear does what athletes, until now, could only hope for. It recognizes when the wearer is heating up, and it actually breathes.
The secret to the ventilating garment is bacteria. Bacillus subtilis natto, a bacteria found in soil, is traditionally used in Japanese cooking to ferment soybeans. But researchers from MIT Media Lab’s Tangible Media Group teamed up with New Balance to apply a film of natto bacteria, which expand and contract based on relative humidity, to fabric.
According to Lining Yao, the project's lead researcher, the team had been looking at ways that various bacteria change when they’re exposed to humidity and studying how they could take advantage of those properties. “There’s a group of microorganisms, like baker’s yeast, that all react to humidity,” she says. They chose natto, in part, because the bacteria is non-toxic and FDA approved.
The researchers had been studying the ways the different parts of the natto cells moved, to see if they could use them, like tiny motors, to lift flaps of fabric open. They found that the cells' protein, DNA and cellulose all react to humidity and that, on a micron level, the cells' structure allows for these parts to expand and contract.
Representatives from New Balance, a Media Lab partner, came through the lab. Excited about the work, the company expressed an interest in teaming up to make breathable clothing. “Human sweat is one type of humidity change,” Yao says.
To incorporate the bacteria into fabric, the group printed what Yao calls a bi-layer biohybrid film. “We print one layer of inert film, like natural latex, then we load billions of cells into a printer and this printer deposits those cells line by line on the thin film,” she says. “The cells are printed in a certain pattern, where they can expand."
They then put that film into clothing, in the places where people get the sweatiest. The New Balance designers biomapped where the fabric should open up, and they’ve started testing the clothes with company-sponsored athletes.
Working with a living medium, Yao says, has its challenges. Bacteria can be finicky, and it can die early in the cell-growing process. Then there is making the bacteria-infused clothing work on a large scale. The cells are one-micron long, so it takes billions of them to make a shirt.
That said, the bacteria could be used in a number of ways. While the strongest application is in garments, Yao and her colleagues have experimented with other projects, such as transformable lamp shades that would let out increasing amounts of light.
“Nothing is really technically impossible, and we’re looking at daily objects,” Yao says. “For instance, it would be amazing if your daughter’s favorite shoe grew bigger as she did.”
Now, the MIT group is researching ways to make the natto cells multifunctional. What if they could make biking gear ventilate and glow, for instance, for use at night? The researchers are also looking at ways to make the bacteria react to other chemical changes, such as the presence of carbon dioxide.
“You can empower an object to be more adaptive and responsive. It’s nature’s approach and an engineering approach," says Yao. “For me, personally, it’s the future.”