A natural material that looks and feels like real leather is taking the fashion world by storm. Scientists view mycelium—the vegetative part of a mushroom-producing fungus—as a planet-friendly alternative to animal hides and plastics.
Products crafted from this vegan leather are emerging, with others poised to hit the market soon. Among them are the Hermès Victoria bag, Lululemon's yoga accessories, Adidas' Stan Smith Mylo sneaker, and a Stella McCartney apparel collection.
The Adidas Stan Smith Mylo shoe, made with an alternative leather grown from mycelium, to be released in 2022.
Hermès has held presales on the new bag, says Philip Ross, co-founder and chief technology officer of MycoWorks, a San Francisco Bay area firm whose materials constituted the design. By year-end, Ross expects several more clients to debut mycelium-based merchandise. With "comparable qualities to luxury leather," mycelium can be molded to engineer "all the different verticals within fashion," he says, particularly footwear and accessories.
More than a half-dozen trailblazers are fine-tuning mycelium to create next-generation leather materials, according to the Material Innovation Initiative, a nonprofit advocating for animal-free materials in the fashion, automotive, and home-goods industries. These high-performance products can supersede items derived from leather, silk, down, fur, wool, and exotic skins, says A. Sydney Gladman, the institute's chief scientific officer.
That's only the beginning of mycelium's untapped prowess. "We expect to see an uptick in commercial leather alternative applications for mycelium-based materials as companies refine their R&D [research and development] and scale up," Gladman says, adding that "technological innovation and untapped natural materials have the potential to transform the materials industry and solve the enormous environmental challenges it faces."
In fewer than 10 days in indoor agricultural farms, "we grow large slabs of mycelium that are many feet wide and long. We are not confined to the shape or geometry of an animal."
Reducing our carbon footprint becomes possible because mycelium can flourish in indoor farms, using agricultural waste as feedstock and emitting inherently low greenhouse gas emissions. Carbon dioxide is the primary greenhouse gas. "We often think that when plant tissues like wood rot, that they go from something to nothing," says Jonathan Schilling, professor of plant and microbial biology at the University of Minnesota and a member of MycoWorks' Scientific Advisory Board.
But that assumption doesn't hold true for all carbon in plant tissues. When the fungi dominating the decomposition of plants fulfill their function, they transform a large portion of carbon into fungal biomass, Schilling says. That, in turn, ends up in the soil, with mycelium forming a network underneath that traps the carbon.
Unlike the large amounts of fossil fuels needed to produce styrofoam, leather and plastic, less fuel-intensive processing is involved in creating similar materials with a fungal organism. While some fungi consist of a single cell, others are multicellular and develop as very fine threadlike structures. A mass of them collectively forms a "mycelium" that can be either loose and low density or tightly packed and high density. "When these fungi grow at extremely high density," Schilling explains, "they can take on the feel of a solid material such as styrofoam, leather or even plastic."
Tunable and supple in the cultivation process, mycelium is also reliably sturdy in composition. "We believe that mycelium has some unique attributes that differentiate it from plastic-based and animal-derived products," says Gavin McIntyre, who co-founded Ecovative Design, an upstate New York-based biomaterials company, in 2007 with the goal of displacing some environmentally burdensome materials and making "a meaningful impact on our planet."
After inventing a type of mushroom-based packaging for all sorts of goods, in 2013 the firm ventured into manufacturing mycelium that can be adapted for textiles, he says, because mushrooms are "nature's recycling system."
The company aims for its material—which is "so tough and tenacious" that it doesn't require any plastic add-on as reinforcement—to be generally accessible from a pricing standpoint and not confined to a luxury space. The cost, McIntyre says, would approach that of bovine leather, not the more upscale varieties of lamb and goat skins.
Already, production has taken off by leaps and bounds. In fewer than 10 days in indoor agricultural farms, "we grow large slabs of mycelium that are many feet wide and long," he says. "We are not confined to the shape or geometry of an animal," so there's a much lower scrap rate.
Decreasing the scrap rate is a major selling point. "Our customers can order the pieces to the way that they want them, and there is almost no waste in the processing," explains Ross of MycoWorks. "We can make ours thinner or thicker," depending on a client's specific needs. Growing materials locally also results in a reduction in transportation, shipping and other supply chain costs, he says.
Yet another advantage to making things out of mycelium is its biodegradability at the end of an item's lifecycle. When a pair of old sneakers lands in a compost pile or landfill, it decomposes thanks to microbial processes that, once again, involve fungi. "It is cool to think that the same organism used to create a product can also be what recycles it, perhaps building something else useful in the same act," says biologist Schilling. That amounts to "more than a nice business model—it is a window into how sustainability works in nature."
A product can be called "sustainable" if it's biodegradable, leaves a minimal carbon footprint during production, and is also profitable, says Preeti Arya, an assistant professor at the Fashion Institute of Technology in New York City and faculty adviser to a student club of the American Association of Textile Chemists and Colorists.
On the opposite end of the spectrum, products composed of petroleum-based polymers don't biodegrade—they break down into smaller pieces or even particles. These remnants pollute landfills, oceans and rivers, contaminating edible fish and eventually contributing to the growth of benign and cancerous tumors in humans, Arya says.
Commending the steps a few designers have taken toward bringing more environmentally conscious merchandise to consumers, she says, "I'm glad that they took the initiative because others also will try to be part of this competition toward sustainability." And consumers will take notice. "The more people become aware, the more these brands will start acting on it."
A further shift toward mycelium-based products has the capability to reap tremendous environmental dividends, says Drew Endy, associate chair of bioengineering at Stanford University and president of the BioBricks Foundation, which focuses on biotechnology in the public interest.
The continued development of "leather surrogates on a scaled and sustainable basis will provide the greatest benefit to the greatest number of people, in perpetuity," Endy says. "Transitioning the production of leather goods from a process that involves the industrial-scale slaughter of vertebrate mammals to a process that instead uses renewable fungal-based manufacturing will be more just."
The "Making Sense of Science" podcast features interviews with leading medical and scientific experts about the latest developments and the big ethical and societal questions they raise. This monthly podcast is hosted by journalist Kira Peikoff, founding editor of the award-winning science outlet Leaps.org.
This month, our guest is JPL's Dr. Suzanne Smrekar, who will be pushing the boundaries of knowledge about the planet Venus during the upcoming VERITAS mission set to launch in 2028. Why did Earth's twin planet develop so differently than our own? Could Venus ever have hosted life? What is the bigger purpose for humanity in studying the solar system -- is it purely scientific, or is it also a matter of art and philosophy? Hear Dr. Smrekar discuss all this and more on the latest episode.
Watch the 30-Second Trailer:
Listen to the Episode:
Each year the world releases around 33 billion tons of carbon dioxide into the atmosphere. What if we could use this waste carbon dioxide to make shirts, dresses and hats? It sounds unbelievable. But two innovators are trying to tackle climate change in this truly unique way.
Chemist Tawfiq Nasr Allah set up Fairbrics with material scientist Benoît Illy in 2019. They're using waste carbon dioxide from industrial fumes as a raw material to create polyester, identical to the everyday polyester we use now. They want to take a new and very different approach to make the fashion industry more sustainable.
The Dark Side of Fast Fashion
The fashion industry is responsible for around 4% of global emissions. In a 2015 report, the MIT Materials Systems Laboratory predicted that the global impact of polyester fabric will grow from around 880 billion kg of CO2 in 2015 to 1.5 trillion kg of CO2 by 2030.
Professor Greg Peters, an expert in environmental science and sustainability, highlights the wide-ranging difficulties caused by the production of polyester. "Because it is made from petrochemical crude oil there is no real limit on how much polyester can be produced...You have to consider the ecological damage (oil spills, fracking etc.) caused by the oil and gas industry."
Many big-name brands have pledged to become carbon neutral by 2050. But nothing has really changed in the way polyester is produced.
Some companies are recycling plastic bottles into polyester. The plastic is melted into ultra-fine strands and then spun to create polyester. However, only a limited number of bottles are available. New materials must be added because of the amount of plastic degradation that takes place. Ultimately, recycling accounts for only a small percentage of the total amount of polyester produced.
Nasr Allah and Illy hope they can offer the solution the fashion industry is looking for. They are not just reducing the carbon emissions that are conventionally produced by making polyester. Their process actually goes much further. It's carbon negative and works by using up emissions from other industries.
"In a sense we imitate what nature does so well: plants capture CO2 and turn it into natural fibers using sunlight, we capture CO2 and turn it into synthetic fibers using electricity."
Experts in the field see a lot of promise. Dr Phil de Luna is an expert in carbon valorization -- the process of converting carbon dioxide into high-value chemicals. He leads a $57-million research program developing the technology to decarbonize Canada.
"I think the approach is great," he says. "Being able to take CO2 and then convert it into polymers or polyester is an excellent way to think about utilizing waste emissions and replacing fossil fuel-based materials. That is overall a net negative as compared to making polyester from fossil fuels."
From Harmful Waste to Useful Raw Material
It all started with Nasr Allah's academic research, primarily at the French Alternative Energies and Atomic Energy Commission (CEA). He spent almost 5 years investigating CO2 valorization. In essence, this involves breaking the bonds between the carbon and oxygen atoms in CO2 to create bonds with other elements.
Recycling carbon dioxide in this way requires extremely high temperatures and pressures. Catalysts are needed to break the strong bonds between the atoms. However, these are toxic, volatile and quickly lose their effectiveness over time. So, directly converting carbon dioxide into the raw material for making polyester fibers is very difficult.
Nasr Allah developed a process involving multiple simpler stages. His innovative approach involves converting carbon dioxide to intermediate chemicals. These chemicals can then be transformed into the raw material which is used in the production of polyester. After many experiments, Nasr Allah developed new processes and new catalysts that worked more effectively.
"We use a catalyst to transform CO2 into the chemicals that are used for polyester manufacturing," Illy says. "In a sense we imitate what nature does so well: plants capture CO2 and turn it into natural fibers using sunlight, we capture CO2 and turn it into synthetic fibers using electricity."
The Challenges Ahead
Nasr Allah met material scientist Illy through Entrepreneur First, a programme which pairs individuals looking to form technical start-ups. Together they set up Fairbrics and worked on converting Nasr Allah's lab findings into commercial applications and industrial success.
"The main challenge we faced was to scale up the process," Illy reveals. "[It had to be] consistent and safe to be carried out by a trained technician, not a specialist PhD as was the case in the beginning."
They recruited a team of scientists to help them develop a more effective and robust manufacturing process. Together, the team gained a more detailed theoretical understanding about what was happening at each stage of the chemical reactions. Eventually, they were able to fine tune the process and produce consistent batches of polyester.
They're making significant progress. They've produced their first samples and signed their first commercial contract to make polyester, which will then be both fabricated into clothes and sold by partner companies.
Currently, one of the largest challenges is financial. "We need to raise a fair amount to buy the equipment we need to produce at a large scale," Illy explains.
How to Power the Process?
At the moment, their main scientific focus is getting the process working reliably so they can begin commercialization. In order to remain sustainable and economically viable once they start producing polyester on a large scale, they need to consider the amount of energy they use for carbon valorization and the emissions they produce.
The more they optimize the way their catalyst works, the easier it will be to transform the CO2. The whole process can then become more cost effective and energy efficient.
De Luna explains: "My concern is...whether their process will be economical at scale. The problem is the energy cost to take carbon dioxide and transform it into these other products and that's where the science and innovation has to happen. [Whether they can scale up economically] depends on the performance of their catalyst."
They don't just need to think about the amount of energy they use to produce polyester; they also have to consider where this energy comes from.
"They need access to cheap renewable energy," De Luna says, "...so they're not using or emitting CO2 to do the conversion." If the energy they use to transform CO2 into polyester actually ends up producing more CO2, this will end up cancelling out their positive environmental impact.
Based in France, they're well located to address this issue. France has a clean electricity system, with only about 10% of their electric power coming from fossil fuels due to their reliance on nuclear energy and renewables.
Where Do They Get the Carbon Dioxide?
As they scale up, they also need to be able to access a source of CO2. They intend to obtain this from the steel industry, the cement industry, and hydrogen production.
The technology to purify and capture waste carbon dioxide from these industries is available on a large scale. However, there are only around 20 commercial operations in the world. The high cost of carbon capture means that development continues to be slow. There are a growing number of startups capturing carbon dioxide straight from the air, but this is even more costly.
One major problem is that storing captured carbon dioxide is expensive. "There are somewhat limited options for permanently storing captured CO2, so innovations like this are important,'' says T. Reed Miller, a researcher at the Yale University Center for Industrial Ecology.
Illy says: "The challenge is now to decrease the cost [of carbon capture]. By using CO2 as a raw material, we can try to increase the number of industries that capture CO2. Our goal is to turn CO2 from a waste into a valuable product."
For Nasr Allah and Illy, fashion is just the beginning. There are many markets they can potentially break into. Next, they hope to use the polyester they've created in the packaging industry. Today, a lot of polyester is consumed to make bottles and jars. Illy believes that eventually they can produce many different chemicals from CO2. These chemicals could then be used to make paints, adhesives, and even plastics.
The Fairbrics scientists are providing a vital alternative to fossil fuels and showcasing the real potential of carbon dioxide to become a worthy resource instead of a harmful polluter.
Illy believes they can make a real difference through innovation: "We can have a significant impact in reducing climate change."