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Pyrus

Pyrus is a petroleum-free wood-like material sustainably produced with repurposed bacterial cellulose waste from the kombucha industry.

  • This is a collection of jewelry, functional guitar picks, and a coaster made from Pyrus wood.

  • This video clip explains the progress of Symmetry Wood, the venture producing Pyrus.

    This video clip explains the progress of Symmetry Wood, the venture producing Pyrus.

  • After being CNC machined to a certain thickness, Pyrus glows brilliantly under bright light

  • This was a candle box laser cut from Pyrus. Wood glue maintained well on the material

  • These were very early prototypes. Colors varied to mimic different exotic woods.

What it does

Pyrus combats deforestation by replacing exotic woods that are disappearing from rainforests such as the Amazon. Maintaining the versatility of wood, it can be laser cut, CNC machined, and sanded to a smooth finish to create jewelry or other small products.


Your inspiration

Right before college, I became more attuned to environmental issues after living in an indigenous community in Ecuador. The people there told me about their worries over climate change and deforestation, and I saw how they had to burn plastic garbage in piles near their homes to avoid accumulation. Afterwards, I shifted my focus away from *industrial* design and looked for solutions to those problems. My research led me to learn about biodesign, a field using living organisms to grow materials for products. I then visited New York City to meet some of its practitioners and began refining the formula of Pyrus in the Genspace laboratory.


How it works

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.


Design process

After I learned about bacterial cellulose, I started growing a supply of it using cultures bought online, water from my local Fab Lab, and apple slices from my 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. Since they were hand-sized, bumpy, and curled, my team and I had to use much of the following months to grow the size of the molds, determine an optimal drying temperature, and improve the flattening process. Now, samples are large and flat enough to create jewelry, guitar picks, and coasters.


How it is different

Pyrus is a dense wood equivalent that does not trace any origins back to trees and does not use any petroleum-based or toxic chemicals. Other materials like medium-density fiberboard (MDF) or oriented strand board (OSB) might reduce waste by gluing sawdust and shards together but they still ultimately depend on tree cutting to exist. Plus, the binders for some of them contain formaldehyde, which can be released during cutting and endanger woodworkers. Meanwhile, 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 like flax rather than trees. The issue is that those other 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.


Future plans

The top priority is to put Pyrus into various 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 ("the circular economy"). Eventually, we hope to turn any customer interest into revenue streams that will sustain a formal company, Symmetry, and fund improvements for the material that will let it work at larger scales like furniture and even buildings.


Awards

This invention was one of four finalist entries for the 2020 Illinois Innovation Prize, which was open to students from all departments and years of the University of Illinois (50,000+) with a faculty nomination. Pyrus was also part of the university’s first-ever finalist entry in the international Biodesign Challenge.


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