Stitched mushrooms build strong
A new engineering solution sounds like it could come from the story of the three little pigs.
An international team of researchers has combined wool and fungus to potentially revolutionise the construction industry's environmental impact.
Their breakthrough involves the development of mycocrete, a paste made from the root networks of fungi known as mycelium, which is seamlessly integrated into a knitted merino textile framework to create a versatile and consistent material.
The scientists harnessed the power of mycelium by mixing its spores with grains that serve as nourishment, combined with a knitted merino textile acting as a nurturing surface for growth.
This innovative mixture was then carefully packed into a mould and placed in an optimal environment - dark, humid, and warm - facilitating controlled growth.
To prevent the formation of mushrooms, the material was dried at a specific density.
The team confidently claims that this process could ultimately provide an inexpensive, sustainable alternative to traditional construction materials such as foam, timber, and plastic.
Dr Jane Scott of Newcastle University, the lead author of the study, shared their ambitious vision, stating; “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”.
The research was conducted by a collaborative team of designers, engineers, and scientists within the Living Textiles Research Group, part of the Hub for Biotechnology in the Built Environment at Newcastle University, with funding from Research England.
Until now, the shape and growth constraints of organic materials have hindered the development of diverse applications.
However, by employing knitted moulds as flexible frameworks or “formwork”, the scientists overcame these challenges.
The resulting composite, aptly named “mycocrete”, surpasses its predecessors in strength and versatility, making it ideal for constructing lightweight, environmentally friendly buildings.
Mycelium, the vital network of fungi, forms the basis of these composites. By blending mycelium spores with nourishing grains and a suitable growth substrate, researchers achieved a tightly bonded material.
However, conventional rigid moulds limited the size and shape due to the oxygen requirements for mycelium growth.
Enter knitted textiles: the team discovered that oxygen-permeable moulds created with knitted fabrics addressed the oxygen supply issue while allowing flexibility and stiffness adjustment during growth.
The researchers capitalised on the extraordinary versatility of knitting technology, which enables the creation of 3D structures and forms without seams or waste.
The team devised a specialised mycelium mixture and production system, injecting a unique paste consisting of mycocrete, paper powder, paper fibre clumps, water, glycerin, and xanthan gum into the knitted formwork using an injection gun.
This ensured consistent packing while maintaining the paste's desired shape. To test their creation, tubes made of sterilised merino yarn were employed as the formwork, securely attached to a rigid structure before being filled with the mycocrete paste.
The fabric's tension fluctuations had no detrimental effect on the mycocrete's performance, minimising the risk of structural weak points.
Upon drying, the mycocrete samples exhibited superior strength in tension, compression, and flexion compared to conventional mycelium composite samples.
The use of knitted formwork allowed for enhanced oxygen availability, resulting in less shrinkage during the drying process, thus ensuring more reliable and consistent manufacturing outcomes.
Perhaps the most astonishing achievement was the construction of a large proof-of-concept prototype structure called BioKnit - a complex freestanding dome built seamlessly in a single piece without any joins that could potentially weaken its integrity. This was made possible thanks to the flexible knitted form used.
More details are accessible here.