If concrete were a country, it would be will be Third largest emitter of greenhouse gases on Earth. We need better and more sustainable building materials, and researchers are exploring unconventional options. Now, an international team of scientists has discovered a way to grow building materials using woven molds and the root networks of fungi.
Previous studies Attempts were made to create composites based on mycelium, which is part of the root network of fungi, but the material’s shape and growth limits made it difficult to create applications. Some fungus-based materials are already used commercially in packaging and insulation panels due to their thermal and acoustic properties.
But using them in manufacturing is a whole new ball game.
To accomplish this, researchers use woven molds as a flexible framework or ‘formwork’ to produce a composite known as ‘mycocrete’. This innovative material is stronger and more adaptable in shape and form, enabling scientists to cultivate lightweight and environmentally friendly construction materials.
The building sector’s energy consumption and greenhouse gas emissions hit an all-time high last year. A UN report. The UN said the sector accounts for 34% of energy demand despite increased energy efficiency investment and reduced energy intensity.
“Our ambition is to transform the look, feel and well-being of architectural spaces by using mycelium combined with bio-based materials such as wool, sawdust and cellulose,” study author Jane Scott of Newcastle University said in a statement. The study was published in Frontiers in Bioengineering and Biotechnology Journal.
Simply put, our existing materials just don’t cut it. We need something better.
To create mycelium compounds, scientists combine mycelium spores with nutrient-rich grains and growth medium. This mixture is then packed into a mold and placed in a dark, warm, moist environment to allow the mycelium to flourish. After achieving the desired density, before expanding the mushroom, the compound is dried.
This process can be a cheap and sustainable alternative to foam, wood and plastic. However, mycelium requires oxygen for growth, presenting limitations in size and shape of traditional rigid molds and restricting current applications. Woven fabrics using oxygen-permeable molds that can change from flexible to rigid as the mycelium grows offer a way.
But fabrics can be overly flexible, making it challenging to achieve consistent packing of molds. With this in mind, the researchers embarked on a mission to create a mycelium mixture and a production system that could effectively utilize the advantages offered by woven forms. “Weaving is an incredibly versatile 3D manufacturing system,” said Scott.
A way forward
In their study, the scientists prepared samples of conventional mycelium composite as controls and cultivated them alongside samples of myconrate. It includes other ingredients like paper powder, paper fiber clumps, water, glycerin and xanthan gum. This paste is designed to be injected in a knitted form using an injection gun.
After drying, the samples were subjected to rigorous strength tests in tension, compression and flexion. It showed that the mycocrete samples had better strength than the conventional mycelium composite samples. Additionally, mycocrete outperformed mycelium composites grown without the use of woven formwork.
After the tests, the researchers built a proof-of-concept prototype structure known as BioNit. This freestanding dome is constructed as a single unit, with no joints that could serve as weak points. This was made possible by taking advantage of the flexibility and adaptability of woven formwork, she explained.
“The mechanical performance of mycocrete used in combination with sustainable woven formwork is a significant result and a step towards the use of mycelium and textile biohybrids within construction,” said Scott.