Fungus-based materials are being investigated by researchers in Germany for the fabrication of eco-friendly sound absorbers.
According to the Fraunhofer Institute, soundproofing panels used in walls or room fittings are made of mineral fibres or synthetic foams that are not sustainable or easily recycled. In a bid to bring to market an eco-friendlier and more effective alternative, Fraunhofer UMSICHT is working with Fraunhofer IBP to develop more sustainable sound-absorbing materials.
“There’s currently a focus on vegetal substrates and mycelium for the development of new materials,” said Julia Krayer, project manager at Fraunhofer UMSICHT in Oberhausen. Mycelium consists of a network of filament-like hyphae which grow underground and can span over a square kilometre.
For this project, Krayer and colleagues are growing hyphae in a lab. This mycelium is mixed with a vegetal substrate consisting of straw, wood, and waste from food production, and then printed into the desired shape with a 3D printer that enables the creation of a predefined porous structure within the absorber.
“The mycelial hyphae spread throughout the substrate and create a solid structure,” Krayer said in a statement. Once the mycelium has permeated the fine-grained substrate, the product is dried in a kiln to kill the fungus. The cell walls of the resulting material are open and will absorb sound. With its open cells and 3D-printed porous structure, it is claimed to be ideal for soundproofing purposes.
Roman Wack, a project partner from Fraunhofer IBP in Stuttgart, said: “The material, which is permeated by mycelium, has a solid structure. This means that much thinner layers of it could be used to make sound absorbers.”
A team at Fraunhofer UMSICHT is currently producing a range of prototypes for a sustainable sound absorber, which will then be tested at Fraunhofer IBP.
The prospect of using mycelium as a base material for fungal faux leather, fabric and plastic is also said to look promising and research is underway to investigate this.