geluidsabsorberend materiaal gedrukt met 3D-printer, Foto Fraunhofer
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Green sound barriers along highways and green walls to improve air quality are now the most normal things in the world. But indoor sound insulation often still uses less environmentally friendly plastic materials such as foam panels and mineral wool.

However, if it is up to the German Fraunhofer Institute, this is going to change over the coming years. Two departments of the institute are working on a new building material composed of green waste and fungal threads.


The idea came from Julia Krayer, a project manager at Fraunhofer UMSICHT in Oberhausen, Germany. She has been working on materials based on fungi for a couple of years now. In this case, it mainly concerns the fungal threads, also known as mycelium.

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All mushrooms have a system of fungal threads under the ground that they use to extract nutrition from soil, photo Pixabay

The principle is not very complicated. First of all, a specific amount of mycelium is grown in the laboratory. These fungal threads are then mixed in with a mixture of straw, wood waste, and food waste. Then a malleable mass is created which is sprayed into a particular shape using a 3D printer, e.g. an insulation wall.

The fungal threads feel quite at home in this nutrient-rich environment and begin to spread rapidly. When the material is completely overgrown with the threads, it’s time for the final step: The killing of the fungi, in a kiln.

According to Krayer, what remains is a light, solid and fully vegetal material with excellent sound-absorbing properties.

Furniture and other plastic substitutes

At UMSICHT and the Fraunhofer Institute for Building Physics IBP, they are now researching how this process can be optimized and what mixture of materials can achieve the best results.

Julia Krayer says that the research focuses mainly on sound insulation, but she certainly does not rule out any other applications. For example, she is also thinking of environmentally friendly clothing, furniture, and other potential replacements for plastics.

You can also read our stories about coffins and clothing made of fungal threads.