Mycocrete: New material made of fungi hopes to replace concrete in construction projects

In an exciting step forward for sustainable construction and biofabrication, a team of scientists has developed a new material called mycocrete. Their system uses a method to create environmentally friendly building materials using knitted molds and the intricate root network of fungi.

This breakthrough, made by researchers at Newcastle University, could significantly reduce the environmental impact of the construction industry. It will also introduce an entirely new aesthetic to architectural spaces.

Previously, scientists have attempted to exploit fungi’s natural structure-forming ability but have faced challenges due to the shape and growth constraints of the organic material. The lack of versatility limited the applicability of these composites in diverse construction scenarios.

However, the research team has now addressed these limitations by using knitted molds as a flexible framework. This approach led to the creation of mycocrete, which is a stronger, more adaptable composite.

Mycocrete can be molded into diverse forms

The flexibility of the molds allows mycocrete to take diverse forms. This makes it an attractive, lightweight, and eco-friendly option for construction materials.

“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,” said Dr Jane Scott of Newcastle University, the corresponding author of the paper.

The Living Textiles Research Group carried out this innovative research. It is part of the Hub for Biotechnology in the Built Environment at Newcastle University.

How Mycocrete is made

In the process of creating mycocrete, the scientists mixed mycelium spores – part of the root network of fungi – with grains. The team uses the grains as a food source and a substrate for growth.

Researchers then pack this mixture into a mold and place it in a dark, humid, and warm environment to promote mycelium growth.

The mycelium binds the substrate together tightly. Once the composite reaches a specific density, researchers dry it out. This entire process is sustainable and could serve as a potential replacement for foam, timber, and plastic.

Using mycelium during biofabrication

One hurdle in using mycelium composites in construction is that mycelium requires oxygen for growth. This requirement has traditionally limited the size and shape of rigid molds.

To tackle this, the team used knitted textiles as oxygen-permeable molds. These molds can transition from flexible to stiff as the mycelium grows, offering a unique solution.

“Knitting is an incredibly versatile 3D manufacturing system,” explained Scott. “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.”

How to use mycocrete to build structures

The team tested their innovation by creating samples of traditional mycelium composites and mycocrete.

These samples included additional ingredients like paper powder, paper fiber clumps, water, glycerin, and xanthan gum. To improve packing consistency, researchers delivered the latter into the knitted formwork using an injection gun.

Following this, the researchers knitted tubes from merino yarn for the test structure, sterilized them, and attached them to a rigid structure. The team then filled them with the mycocrete paste.

This method ensured that changes in the fabric’s tension did not impact the performance of the mycocrete.

Building the future with fungi

Once dry, the researchers subjected these samples to various strength tests. Notably, mycocrete proved stronger than traditional mycelium composites. It even outperformed mycelium composites grown without the knitted formwork.

Also, the porous knitted fabric offered better oxygen availability and reduced shrinkage compared to most mycelium composite materials. This suggests more reliable manufacturing results.

In addition to these successes, the team constructed a larger, freestanding dome prototype known as BioKnit. Thanks to the knitted formwork, the dome was made in a single piece without joints. This process helped them avoid potential weak points.

“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.

She further highlighted that while the paper specifies particular yarns, substrates, and mycelium necessary for this goal, there is a vast opportunity to adapt this formulation for different applications.

The future of biofabricated architecture might require new machinery to bring textiles into the construction sector. But with this promising research, it seems we’re well on our way to greener construction practices.

More about biofabricated architecture

Biofabricated architecture, sometimes also referred to as biodesign or bio-architecture, refers to a rapidly growing area of architecture and construction that incorporates biological systems into the design process.

The goal is to create more sustainable, adaptive, and symbiotic built environments. This field of study exists at the intersection of biology, architecture, and engineering.

Biofabrication involves using biological substances as raw materials for construction. It leverages living organisms, such as bacteria, fungi, plants, or even animals, to produce or modify building materials.

This approach to construction has significant potential for sustainability as it often utilizes waste products or renewable resources. In addition, the organisms involved often absorb carbon dioxide. This process contributes to the mitigation of greenhouse gas emissions.

There are several key areas of focus within biofabricated architecture:

Mycelium materials

Mycelium, the root network of fungi, can be encouraged to grow around a composite of organic waste, creating a lightweight, durable material that can be used as an insulating material, or even as a form of brick or board.

Bio-concrete or Bio-bricks

Some types of bacteria are used to create bio-concrete or bio-bricks, a process in which the bacteria precipitate calcium carbonate to bind sand or other aggregates together, forming a solid mass similar to concrete. This method can also be used to repair cracks in existing concrete, extending the life of the structure.

Algae and photosynthetic organisms

Algae and other photosynthetic organisms can be used in building facades to create a dynamic, living cladding system that can produce oxygen, absorb carbon dioxide, and even potentially produce biofuels.

Bamboo and engineered wood

Although not a new building material, recent advances in manufacturing technologies have allowed for engineered wood and bamboo to be used in more structurally significant ways, creating a renewable alternative to steel and concrete.

Genetically modified organisms

As genetic modification technologies advance, there’s potential for custom-designed organisms to be used in construction. This could mean bacteria that glow when a structural fault is developing, or plants engineered to grow into specific structural forms.

Challenges in biofabricated architecture include the control of living organisms, and longevity and durability issues. Also, some have voiced concerns over ethical considerations around the use of genetically modified organisms.

The final hurdle is scaling production to a size useful for significant construction. However, research and experimentation in this field are active and ongoing.

Biofabricated architecture holds promise for a more sustainable future in construction. The concept of designing buildings and other structures that are in harmony with nature and have a positive impact on the environment is at the heart of this exciting field.