Futuristic Body Armor Could Be Based on This Weird Mushroom, Study Finds

The flimsy mushrooms served atop your burger or the delicate, bouncy mushroom caps adorning logs in the forest are not known for their strength or tough exteriors. But their fungal distant cousin, Fomes fomentarius, may just hold the keys to producing new materials that could replace today’s plastic, according to new research.

This horse hoof-shaped fungi can be found on continents around the world and gloms onto the damaged bark of trees as a pathogen responsible for diseases like white rot. F. fomentarius has long been used as a source of tinder and even planted-based leather, but now a team of researchers from Finland have found that this resilient fungi can offer a path toward bio-derived plastics that mimic its structure. 

With its unique combination of traits, the team believe that  F. fomentarius “could offer a great source of inspiration for producing multifunctional materials with superior properties for diverse medical and industrial applications in the future,” they wrote in the study. It could be used to design rugged products like body armor, exoskeletons for aircraft, or surface coatings for windshields, according to a press release. 

“There is a huge variety of solutions to different material engineering problems in nature, and not all of them have yet been properly explored,” Pezhman Mohammadi, a senior author on the paper and scientist at VTT Technical Research Centre of Finland, told Motherboard in an email. “We were interested in the origin of the good material properties of the Fomes fomentarius fungus.”

Research into the application of F. fomentarius may be fresh, but the study of fungi components like mycelium—a network of fungal threads—or chitin, which is a component of fungi cell walls, are well underway. Mycelium is being studied for its potential as a building material on Earth and chitin has been studied for its potential as a building material on Mars. 

To determine how F. fomentarius could remain lightweight yet strong enough to resist being knocked down by debris in the forest, the researchers used chemical and mechanical analysis tools, such as computed-tomography, X-ray diffraction, and infrared spectroscopy, to look inside the fungus to determine how it was constructed. Their findings were published Wednesday in the journal Science Advances.

In their analysis, the team discovered that the fungus is made of three distinct layers: a hard, outer crust, a foam-like layer called ‘context’, and a section of tightly packed hollow tubes called hymenophore tubes (H. tubes).

Despite all three layers being largely composed of mycelium and other similar chemical components, the difference in microstructure and density of the layers creates distinct mechanical properties. This characteristic is crucial, Mohammadi said, because it shows how small tweaks to a fungus-inspired material might create diverse properties without needing to engineer new materials from scratch to achieve them.

Another uncommon feature the team uncovered while studying the fungus was its ability to remain lightweight while still providing strength on par with much heavier materials.

“To increase the strength of materials, compromises usually have to be made, for example by increasing the density,” Mohammadi said. “[Yet] when comparing the material properties of F. fomentarius structures, it is important to consider how light they are compared to hard plastic or wood. For example, hymenophore tubes are comparable in strength to wood, but are much lighter than wood.”

A crucial first step towards a mushroom-coated future will be for scientists to understand how the fruiting body—the part of the fungus we can see—is created from spores. Right now, this hasn’t yet been studied under laboratory conditions.

Until then, Mohammadi hopes that these new findings will continue to stoke interest in living materials like fungi.

“Collaboration will allow these discoveries to be used to develop, for example, the next generation of programmable materials capable of sensing, learning, self-repairing and adapting to different situations,” he said.