Smart Skin For Your Dumb, Smelly Workout Clothes

For the most part, the clothing we wear to workout is dumb. You sweat in it, some of that sweat evaporates, and after a few months (or weeks, depending on how stinky you are), bacteria makes it unusable. The cycle begins anew.

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But it’s bacteria that make BioLogic work—an ancient one, called Bacillus Subtilis natto, which has its roots in pre-modern Japan. Natto bacteria live in rice stalks, and it was discovered that wrapping soybeans with the husks turned the beans into a delicious fermented treat. Today, that treat is known as natto, or fermented soybeans.

So Bacillus Subtilis natto has a long history, but Yao discovered something new about it. Over email, she explained to Gizmodo how while testing a dozen different types of cells, they realized natto did something unique: The bacteria grew and contracted based on how much moisture it was exposed to. To Yao and her team, this kind of behavior was fascinating; if natto’s expansion and contraction could be carefully calibrated, perhaps it could act more like a machine than an unpredictable organism. Perhaps it could act more like an actuator.

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Natto cells expanding and contracting based on humidity.

Actuators, being motors, are everywhere—in our phones, our watches, and our cars. They’re the basis for much of the modern world, turning a broad range of energy into a movement. In the Apple Watch, for example, the battery powers a linear actuator to create the vibrations you feel on your wrist.

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By definition, they’re mechanical, but Yao and her collaborators want to expand that definition and engineer actuators out of biological matter like bacteria. “A cell is typically considered a factory for producing chemicals,” says Wen Wang, the MIT scientists who oversaw the biotechnology and material science of the project, in a process video. “But its own mechanical properties is always neglected.”

These tiny biological actuators require no electronics. They’re silent. They grow exponentially overnight. They’re even edible.

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Living Things That Act Like Machines

But the process of turning those living actuators into a prototype is still complicated. The natto cells were grown in bioreactors at MIT, and their growth was carefully tracked using Atomic Force microscopes and other novel tools.

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Natto cells in the lab.

The team grew billions of the cells, cultivating them for use in a micron-resolution printer. The finished films are actually a composite of cells, sandwiched by Kapton and plastic.

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The bioprinter.

But getting the films to act the way the team hoped wasn’t as simple as simply printing them into different shapes. They actually had to develop a software to simulate the reaction of natto cells using common 3D modeling tools like Rhino and Grasshopper, helping them to speed along the process of testing different printed designs.

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They developed dozens of tests of different behaviors using different patterns and shapes of cells, ranging from folding and bending to raising a texture on a cloth.

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A sample film reacts to body temperature and moisture.

These “fresh” printed film composites were then given to designers at the Royal College of Art, who integrated them into clothing using heat maps of where the human body sweats the most and gets the hottest during exertion. The design students there created a series of garments for dancers using fin-shaped pieces of the film that raise and lower to create airflow through the clothing.

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Film panels laid out on a shirt based on anatomical maps of heat and sweating

Workout clothing is only a tiny example of what BioLogic could be used for. The team has already used it for a range of other purposes, from lampshades that adjust their shading to teabags that signal when they’re ready. It’s easy to imagine bigger industrial and architectural usages, too. Right now, Yao says the film is being tested by athletes who are hooked up to sensors to test whether the design works to cool them more efficiently.

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It won’t be hitting stores for a while, though. Yao explains this is partially because of the expense, and partially because of the regulatory rules about selling biological material.

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Will Biology Replace Mechanical Technology?

For the team at MIT, natto is just a jumping-off point. There are literally millions of other biological organisms out there to be studied. “We are very keen to unveiling and harvest responsive behaviors of microorganisms and repurpose/recompose them for design,” Yao said over email. “So far we know other microorganisms that react to light or electricity and swim in a certain pattern.”

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Yet natto is a great example of the new way the lab is thinking about living organisms, though. It’s been around for a thousand years. Generations of people have used it. Yet only now are we discovering how it could serve a totally new purpose. What other bacteria, or microorganisms, could become living actuators that involve zero electronics, need no energy, and operate completely silently?

If our mechanical world dissolves into the ancient biological one, what other mechanical devices and networks will be replaced by smarter, safer, heartier organisms?

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Contact the author at kelsey@Gizmodo.com.