by A team of Vancouver academics is merging the fields of microbiology and architecture to create living building materials made from oyster mushrooms and other edible mushrooms.
They say their research into “designed living materials” could help curb the high energy and environmental impact of the construction industry, replace traditional insulation or even help regulate indoor temperatures as the climate warms.
One day, it could even help filter air pollutants like wildfire smoke, according to a postdoctoral fellow at the University of BC.
“This idea of engineered living materials is a very new concept,” said Nicholas Lin, an engineer with a background in microbiology.
“These materials are assembled by combining raw materials with living cells and exhibit certain properties of living systems,” explained Lin, whose research spans UBC’s schools of microbiology and architecture.
His teammates at UBC’s Biogenic Architecture Laboratory are creating several building materials filled with mycelium—the fuzzy-looking network of tiny pale underground strands, or hyphae, that serve a similar function to plant roots. .
But fungi, one of the oldest organisms on the planet at more than a billion years old, are neither plants nor animals.
The research team works mainly with edible species, such as oyster, reishi and turkey tail mushrooms.
“The oyster is probably the most popular because we know it’s edible, its toxicity is not known, and it grows very fast,” Lin said.
‘Dynamic, tunable’
One of his supervisors is associate professor of architecture Joseph Dahmen.
Dahmen said his main inspiration during his years of research into what he calls “mycelium biocomposites” was to reduce the energy and environmental impact of building materials.
“Most of the energy that goes into buildings is in the materials themselves,” he told CBC News. “Mycelium biocomposites offer a type of biodegradable material to replace them.”
To make engineered living materials, whether bricks, gels that can take any shape, insulation or drywall-like boards, he said researchers mix fungal spores with something high in cellulose, often a recycled material or byproduct like sawdust, wheat straw. or rice husks.
A 3D printer at the University of BC creates layers of a hydrogel solution infused with reishi mushroom mycelium, a network of fine strands known as hyphae that are equivalent to the roots of the fungus. (Presented by the UBC Biogenic Architecture Laboratory)
Although this has been done for years around the world with both fungi and bacteria, he explained, the final product is often “cooked” to kill the organisms.
“We didn’t invent the process,” he said. “But what we’re really interested in is the potential of these materials if they remain alive.
“So you could imagine a material that then becomes dynamic and adjustable. We can make it with different strengths. It keeps growing.”
Oyster mushrooms grow from bricks molded with mycelium. They were used to construct a wall for an art installation created by AFJD, the design studio of Joe Dahmen and his wife Amber Frid-Jiminez. (AFJD)
‘Grows like mushrooms’
While Lin’s doctoral research led him to kill microorganisms by creating antibacterial surfaces, he is now using 3D printers to help create a gel full of them.
“Actually, it’s something similar: killing something and raising it,” he mused. “Some parts are quite similar in the way a pure culture is maintained.
“But one thing that’s always really interesting is that if we neglect the mushrooms or if we forget to control them, sometimes it will result in a little oyster mushroom.”
The speed with which oysters and other fungi spread allows researchers to test new ideas quickly.
And that led the UBC lab to develop everything from a mushroom-based composting toilet to solid sawdust benches and bricks.
“The expression ‘grows like mushrooms’ is really true,” Dahmen jokes. “They are growing very quickly and tend to be hydrophobic, so they can repel water.
“We can tailor them to the unique environmental considerations of where we want to employ them.”
A microscope image shows how mycelium, the equivalent of mushroom roots, is spread or inoculated into a growth bag in a laboratory at the University of BC. (Presented by the UBC Biogenic Architecture Laboratory)
Dahmen said that currently an entire house made of live, 3D-printed mushrooms is purely hypothetical.
“I would say we are probably still a few years away from incorporating it into conventional buildings,” he said. “But we are just beginning to understand some of the potentials of these materials.”
Built-in climate control
Lin said there are some even more complex functions that the future may hold for living building materials, based on what he called the “environmental responsiveness” of fungal hyphae.
A study published in the journal proceedings of the National Academy of Sciences This year it was discovered that fungi could reduce their temperature by an average of 3C below their surroundings, which Lin said could indicate climate control applications as the climate warms.
And with climate change worsening wildfire seasons in Canada, fungal-filled living materials could one day help clean the air in our homes.
“Could we engineer these fungi so that if there’s a lot of wildfire smoke, they can recognize it and produce more of these fibrous, diffuse materials to capture these particles?” he speculated.
That’s an idea that’s still mostly science fiction, but Lin thinks it requires more research.
“In the very, very distant future, these biological tools could give us new ways and new knowledge to produce materials that are faster, better, cheaper and, in the long term, more ecologically sound,” he said.
An architectural artist’s rendering of a hypothetical house built from 3D-printed biocomposite materials filled with microscopic networks of fungal mycelium. (Presented by the UBC Biogenic Architecture Laboratory)
