From Spores to Skyscrapers: New Technology Uses Fungi to Create Sustainable Building Materials

The earth’s population is inevitably expanding, and so is the need for more structures to support our rising numbers. However, constructing these buildings requires large quantities of natural resources like wood, concrete, steel, and sand. While these materials are great at creating sound, solid establishments, they are often sourced through ecologically harmful processes that greatly disturb natural habitats and deforest the land. 

In a move to reduce the environmental impact of the construction industry, a group of scientists has teamed up to create a groundbreaking solution that not only addresses the urgent need for sustainable building materials but also uses the potential of nature’s very own recycling system: fungi.

The collaboration between researchers from Newcastle University and Vrije University Brussels has led to the development of an eco-friendly material known as BioKnit mycocrete. The novel construction material, comprised of fungal mycelium and organic waste products, is set to revolutionize the building industry with a durable and eco-friendly alternative to conventional building materials.

Mycelium: nature’s building block

Mycelium is the root-like structure of fungi made up of a network of tiny filamentous threads called hyphae. While mycelium’s main role is to break down organic matter and provide nutrients to fungi, scientists have been harnessing its unique properties to create a wide variety of products and materials. 

Because mycelium is made from all-natural sources, it is the perfect bio-based solution for developing alternatives to more environmentally taxing products. Yet despite its biodegradable nature, mycelium can be produced as heavy-duty and versatile materials. Previous applications have determined that mycelium composites are excellent construction materials due to their thermal and acoustic properties, making them a great choice for insulation and soundproofing. These composites could be used to make inexpensive materials as a replacement for timber, plastics, and foams (1).

To create these composites, specialized fungal spores are grown on a substrate of organic material such as sawdust or straw. This mixture is tightly packed in a mold and kept under controlled conditions for 7 to 14 days, allowing the mycelium to bind the materials together and take form. Once the mycelium composite is done growing, it is dried or heat treated to harden it further and stop its growth. 

Mycelium composites have been successfully used to construct 100% bio-based structures. However, this technique of using mycelium blocks to assemble buildings can limit the creation of more complex and lightweight shapes. 

The development of BioKnit mycocrete marks a significant advancement in biobased building, as scientists have figured out how to use digital fabrication strategies like 3D printing or textile-based formwork to design more complex building forms better tailored for larger-scale production and applications.

Breakthroughs in mycocrete

The newly developed BioKnit mycocrete material is significantly stronger and more versatile than prior mycelium construction attempts. BioKnit mycocrete goes through a production process similar to standard mycelium products but with a major innovation: the incorporation of knitted textile formworks that allow for greater design flexibility and structural integrity. 

“Knitting is an incredibly versatile 3D manufacturing system,” said Dr. Jane Scott of Newcastle University, corresponding author of the study. “It is lightweight, flexible, and formable. The major advantage of knitting technology compared to other textile processes is the ability to knit 3D structures and forms with no seams and no waste.”

During the mycelial growth stage, a paste made from paper, water, glycerin, and xanthan gum was applied in a knitted formwork explicitly designed for the intended structure. These formworks are created using digital fabrication techniques, allowing for precise control over the shape and size of the final mycocrete structures. The flexibility of the knitting enables the formwork to adapt as the mycelium grows, ensuring that the structure expands uniformly without compromising the integrity of the design (2).

BioKnit mycocrete has demonstrated several unique properties that make it an attractive option for sustainable construction. Compared to prior attempts at mycocrete, the new material allows for more complex, seamless 3D structures that can be difficult to achieve with traditional molds. 

Future prospects in construction

Although the new mycocrete is still being perfected, it has been used to create its first proof-of-concept build: a 6-foot, freestanding arched dome made with a single piece of the flexible material in tube form. As this new technology continues to adapt, researchers can ensure its long-term durability under environmental conditions and develop ways to scale up production to meet commercial demands.

“The mechanical performance of the mycocrete used in combination with permanent knitted formwork is a significant result, and a step towards the use of mycelium and textile biohybrids within construction,” said Scott. “In this paper we have specified particular yarns, substrates, and mycelium necessary to achieve a specific goal. However, there is extensive opportunity to adapt this formulation for different applications. Biofabricated architecture may require new machine technology to move textiles into the construction sector.”

References

1. Jones Mitchell, Andreas Mautner, Stefano Luenco, Alexander Bismarck, and Sabu John. 2020. “Engineered Mycelium Composite Construction Materials from Fungal Biorefineries: A Critical Review.” Materials & Design 187 (108397): 108397. https://doi.org/10.1016/j.matdes.2019.108397.
2. Romy Kaiser, Ben Bridgens, Elise Elsacker, and Jane Scott. 2023. “BioKnit: Development of Mycelium Paste for Use with Permanent Textile Formwork” 11 (July). https://doi.org/10.3389/fbioe.2023.1229693.