The exercise gear of the future could be covered in living microbial cells capable of expanding and shrinking in response to changes in humidity, thus allowing an athlete’s body to cool down after sensing increases in body heat and sweat, according to a team of researchers at MIT.
In fact, Dr. Wen Wang, a former research scientist at the institute’s Media Lab and Department of Chemical Engineering, and her colleagues designed both a breathable workout suit with flaps that open and close for ventilation and running shoes with a similar breathable quality.
As they reported last week in the journal Science Advances, the moisture-sensitive cells present no danger to the individuals wearing the suit, and act as miniature sensors and actuators, causing built-in flaps to open during intense workouts and close once the body begins to cool down.
These “biohybrid wearables,” they explained in their study, demonstrate that “the hygroscopic and biofluorescent behaviors of living cells” could be combined with “a humidity-inert material” to create “a heterogeneous multilayered structure” that could quickly change shape in response to human sweat. In short, it will automatically provide ventilation when you get too hot.
In a statement, co-author Xuanhe Zhao, an associate professor in mechanical engineering at MIT, called the breakthrough “an example of harnessing the power of biology to design new materials and devices and achieve new functions,” adding that the team believes that such work “will find important applications at the interface between engineering and biological systems.”
Material experience no degradation, even after 100 moisture tests
Dr. Wang and her colleagues drew inspiration for their new biohybrid workout gear by observing how some kinds of living things are capable of altering their structures in response to changes in humidity. They hypothesized that they could harness the ability of yeast, bacteria and other kinds of natural shape-shifters to develop fabrics that could automatically respond to moisture.
First, they took cells belonging to the most common nonpathogenic strain of E. coli – cells which were found to expand or shrink in response to changing humidity. Next, they modified those cells to glow in humid conditions by expressing the green fluorescent protein, then used a technique to print parallel lines of the bacteria onto sheets of latex to create two-layered structures.
The researchers then tested the fabric by exposing it to various conditions. When placed on a hot plate, where it dried out, the bacteria cells began to shrink and the overlying latex layer started to curl up. However, then it was exposed to steam and became more moist, the cells started glowing and expanding, which caused the latex material to flatten out. The material passed 100 such tests with “no dramatic degradation” in overall performance, according to the study authors.
The flaps used in the suit were specially designed to prevent the bacteria cells from coming into contact with the skin, and placed in specific locations based on maps of where the body tends to produce the most heat and sweat, they explained. The researchers also went on to integrate their biohybrid material into the bottom of a prototype running shoe, and hope to eventually work with sportswear makers to bring their designs to the commercial market.
Image credit: MIT