Fungi spores and knitting combine to make a durable and sustainable building material

The fascinating, complex world of fungi is enabling breakthroughs in everything from mushroom-powered motherboards to kombucha-derived bioplastics, but the latest achievement could one day form the very buildings in which researchers continue such experiments.

As detailed in a new paper published on Friday in Frontiers in Bioengineering and Biotechnology, a team of scientists, engineers, and designers from Newcastle University’s Hub for Biotechnology in the Built Environment have developed a method to literally grow building materials from mycelium—aka fungi roots.

[Related: Inside the lab that’s growing mushroom computers.]

“Our ambition is to transform the look, feel and wellbeing of architectural spaces using mycelium in combination with biobased materials such as wool, sawdust and cellulose,” explains corresponding paper author Jane Scott.

Conventional mycelium composites can be created by first combining spores with structures to grow on and grain food sources. Researchers then pack the mixture into a desired mold and leave it in a warm, dark, humid environment; i.e., a prime habitat for growing fungi. As the mycelium grows, it tightly binds the material around it, but the mycelium is dried out before actual mushrooms begin to sprout. Unfortunately, this method is severely limited by the amount of oxygen that mycelium needs to actually grow.

To solve this, researchers turned to textile knitting, producing molds that are far more permeable for oxygen. According to Scott, textile knitting results in “incredibly versatile” three-dimensional structures that are flexible and lightweight. Another advantage compared to existing mycelium composite methods is that the knitted 3D structures can be created with “no seams and no waste.”

After creating a new composite known as “mycocrete” from a paste of mycelium, paper powder and fiber clumps, glycerin, xanthan gum, and water, researchers injected the substance into a “knitted formwork” made from sterilized merino yarn stretched across a rigid frame. As the mycocrete dried, it strengthened and adhered to the shape to create promising building materials. During subsequent stress tests, the mycocrete proved stronger than existing mycelium composite materials.

[Related on PopSci+: How to use the power of mushrooms to improve your life.]

As a proof-of-concept, the team created a prototype structure called BioKnit, a nearly six-foot-tall, freestanding three-dimensional dome constructed as a single piece without any joins. Although new machine tech will be needed to integrate knitted textiles into construction industry, the “biofabricated architecture,” according to Scott, could soon be a promising alternative for building projects.