Fungal adhesive - insulation materials based on fungal mycelium

Biointelligent building materials created by replacing chemical bonding processes with biological ones

Fungal adhesive prototype made from cattail
© Fraunhofer IBP
Fungal adhesive prototype made from cattail (lat. Typha) bound by the Ganoderma fungus.

To achieve a biological transformation, material flows must be considered as a whole and biointelligent solutions found for them. Closed material cycles are essential.

The idea of applying biological principles to create construction products rather than using petroleum-based raw materials has been almost completely neglected. In contrast to medical applications, this potential is still being wasted in the building industry. However, the sheer volume of materials used in this sector demonstrates the need to close material cycles in a sustainable, biointelligent manner. Furthermore, by using bio-based materials, the subsequent costs of recycling petroleum-based materials can be avoided.

Project goals

The aim of the project was to develop a biohybrid insulating material in which the conventional chemical binding processes are replaced by biological ones. To this end, the extent to which fungal mycelium can be used as a substitute for conventional fossil or inorganic binders in building materials was explored. Biological raw materials as well as residual materials were used as structural building materials, which were bonded together by mycelial growth.

Project results

In preliminary pilot tests, the potential of various material combinations of nutrient, fungus and building material was investigated. Based on these findings, larger prototypes measuring 25 x 25 x 3 cm³ were produced and their material properties determined in the laboratory. It was found that the prototypes consistently exhibited very low diffusion resistance. The resulting thermal conductivity ranges from 0.049 to 0.068 W/(mK), depending on the fungal species, substrate and aggregates. This is quite high compared to conventional insulation materials. The experiments demonstrate a fundamental potential of myco composites as substitutes for mineral oil-based products. Further studies are required.

Project partners