Inventor creates wood-like material with unique environmentally friendly properties
A nine-month volunteer experience in Ecuador dramatically demonstrated to Gabe Tavas the importance of sustainable materials.
Gabe Tavas got a world of education before college, when he was living in an indigenous community in Ecuador.
He envisioned a career in industrial design—until residents told him of their concerns about their lack of sustainable products and deforestation. “I saw how they had to burn plastic garbage in piles near their homes to avoid accumulation,” he said.
Before long he was learning about biodesign, a field that uses living organisms to grow materials for products. This was the inspiration for Pyrus—a petroleum-free, wood-like material sustainably produced with repurposed bacterial cellulose waste from the kombucha industry that is the winning entry in the 2021 U.S. James Dyson Award competition.
Pyrus fights deforestation by replacing exotic woods that are disappearing from rainforests such as the Amazon. It has the versatility of wood with ability to be laser cut, CNC machined, and sanded to a smooth finish to create jewelry or other small products.
Sourcing wood
After his nine-month volunteer experience in Ecuador ended in August 2018, he visited New York City to meet biodesign practitioners and refine the formula for Pyrus in the Genspace laboratory.
To achieve his goal, Tavas said he had to fully understand the makeup of wood.
“Every piece of wood has two essential ingredients: cellulose, which provides its basic shape and framework, and lignin, which acts as a glue for all the other components. These are the most common organic molecules on Earth, and trees and other plants are not the only way to source them.
“There are certain bacteria, especially Gluconacetobacter xylinus, used by some companies to produce acidic drinks like kombucha which produce coherent (and slimy) sheets of cellulose on top of any liquid they are living within. All they need is some space, air, and sugar, which can be sourced from food waste like rotten fruits and bread.”
To make Pyrus, the sheets of cellulose are blended to an even consistency and then embedded in an algae-based gel. As the gel dries, it hardens significantly and is placed under a mechanical press to form a flat sheet of wood. This material can then be sanded, cut, and coated with resins just like its tree-based counterparts.
Blending cultures
After learning about bacterial cellulose, Tavas began growing a supply of it using cultures bought online, water from his local “Fab Lab” at the University of Illinois at Urbana-Champaign, and apple slices from his university’s dining halls.
“Over two weeks, the bacteria fed off the apples in several small water containers to create cellulose sheets at the surface. I often grabbed these sheets, dried them, and then exposed them to several different ingredients such as food dyes, resins, salts and oils to see if they could become more rigid, water-resistant, and colorful like wood.
“Many days were full of just sheer experimentation. The breakthrough came after I did casual readings on pykrete, a fancy name for sawdust frozen in water. Under the right conditions, pykrete rivals concrete’s impact resistance and strength, and was even considered for projects by the U.S. military.
“Freezing cellulose in water though is a short-lived approach, so I decided to suspend cellulose in a gel instead. The result was the first samples of Pyrus.”
Multiple advantages
Tavas’s invention has advantages over other wood substitutes. It does not trace any origins back to trees, or use any petroleum-based or toxic chemicals.
Other materials, such as medium-density fiberboard (MDF) or oriented strand board (OSB), reduce waste by gluing sawdust and shards together. But they still ultimately depend on tree cutting to exist. In addition, the binders for some of them contain formaldehyde, which can be released during cutting and endanger woodworkers.
Plastic woods are non-biodegradable, release greenhouse gases during production, and might also contain dangerous chemicals.
Other materials try to mimic wood by using other plants such as flax rather than trees. But those plants could be expensive to harvest and may require retting that adds excessive nutrients to the environment. Companies making this kind of wood also tend to produce thin veneers combined with other materials, not dense standalone sheets.
What’s next
Tavas wants to remain a difference maker in a sustainability movement that is more than sustainable: It’s crucial.
His priority is to put Pyrus into environmentally friendly product forms that meet consumer needs and are commercially viable.
“My team and I are currently using laser cutters at local design studios to make items like jewelry and coasters sold through the retail store of The Plant, a business incubator in Chicago focused on recycling waste,” he said.
