By mixing the fungus’ filament-like hyphae with natural waste byproducts, the scientists were able to develop a new material that, once 3D printed, yields objects with noise-absorbing qualities. In future, the team aims to fabricate a new line of sustainable acoustic prototypes, that outperform conventional products.

Julia Krayer, project manager at Fraunhofer UMSICHT in Oberhausen says: “There’s currently a focus on vegetal substrates and mycelium for the development of new materials.”

The potential applications for this mycelial material are not limited to acoustics. “The end products could probably be used as insulating material, but this would require more intensive research,” says Krayer.

Mycelium consists of a fine network of filament-like hyphae. In its natural habitat, mycelium grows underground, where it may span more than a square kilometre.

For the current project, Krayer and colleagues are growing hyphae in the lab. This mycelium is first mixed with a vegetal substrate consisting of straw, wood and waste from food production, and then printed into the desired shape by means of a 3D printer.

“The mycelial hyphae spread throughout the substrate and create a solid structure,” says Krayer.

Once the mycelium has permeated the fine-grained substrate, the product is dried in a kiln in order to kill the fungus. The cell walls of the resulting material are open, meaning that it will absorb sound. With its open cells and 3D-printed porous structure, it is ideal for soundproofing purposes.

Sound absorbers made of fungus-based materials have a range of advantages – they are effective, sustainable and help conserve resources.

Moreover, as Roman Wack, a project partner from Fraunhofer IBP in Stuttgart, explains: “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.”

Similarly, the use of a 3D printer enables the creation of a predefined porous structure within the absorber. The printer is programmed to produce this structure, which can then be progressively enhanced as research advances.

This will help developers perfect their design. In other words, they can reasonably expect this method to deliver a sound absorber that is made of renewables yet outperforms today’s conventional products.

Their priority right now is the fabrication of sustainable sound absorbers. At present, employees at Fraunhofer UMSICHT are producing a range of prototypes for a sustainable sound absorber, which will then be tested at Fraunhofer IBP.

The prospects of using mycelium as a base material for fungal faux leather, fabric and plastic also look promising. In the future, fungus-based materials could be used not only to produce sound absorbers and insulating materials, but also clothing, furniture and housings for electrical appliances. Research is already underway to make this possible.