Fungus in Your Ears: Fraunhofer 3D Prints Mycelium as Sound Absorber

We’re in an urgent need of shifting not just our energy sources from fossil fuels to renewables, but in replacing the source of our plastics from petroleum to biopolymers. Much of the research dedicated to this field is occurring in Europe, in part due to the fact that the E.U. has placed a ban on single-use plastics that will begin this year. Among the alternatives are cellulose, chitin, keratin, lignin, PHA, and PLA.

Now, the Fraunhofer Institute for Building Physics (IBP) and Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT are proposing the use of fungus for supplanting mineral fibers or synthetic foams for manufacturing sound-cancelling components. Because traditional materials are not typically sustainable or easily recycled, the team is exploring the use of mycelium as a 3D printing material. Similar to the root network beneath a tree, mycelium is the underlying body of fungi that can give rise to mushrooms. Made up of a network of filament-like hyphae, mycelium can span over a square kilometer underground.

To 3D print with it, Fraunhofer UMSICHT and Fraunhofer IBP have combined the mycelium with a vegetable base made up of straw, wood, and food waste. Once printed, the mycelium spreads throughout the vegetable material, resulting in a solid structure. The fabricated object is then dried in a kiln, killing the fungus and resulting in open cell walls that absorb sound. This porous structure, made up of open cells, can be ideal for soundproofing.

3D printing of a sample based on mycelium. Image courtesy of Fraunhofer IBP.

Obviously, the use of 3D printing means that complex, custom geometries can be created from this sustainable material. Roman Wack, a project partner from Fraunhofer IBP, adds, “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.” This means that, as the groups’ research continues, they may be able to 3D print sound absorbing devices that work better than existing counterparts.

The Fraunhofer UMSICHT team, led by project manager Julia Krayer, are currently testing a variety of prototype sound absorbers that will be tested at Fraunhofer IBP. However, the researchers believe that mycelium could be used for other applications. With the fungal material able to mimic leather, fabric and plastic, they suggest that it could be applied to clothing, furniture and electrical appliance housings.

In fact, we’ve already seen a number of projects deploy mycelium as a printing material, the earliest of which was probably the mycelium chair from Dutch artist Eric Klarenbeek. Klarenbeek combined the fungus with straw to create his work. This led the artist to initiate a mushroom-based product startup. Kai Parthy even came out with a mycelium filament. One shoe designer has explored the use of fungus for producing shoes. If these projects ultimately launch into more widespread initiatives, we may even see BMW realize its concept for a mycelium car.