Substrate-based mycelium materials for applications in building insulation: Investigation of mechanical properties

Substrate-based mycelium materials are a potential alternative to insulation materials, which are currently dominated by petroleum-based and mineral materials. Mycelium materials are based on resource-efficient manufacturing processes: suitable substrates can be obtained from agricultural and forestry residues, for example, and the production also requires less energy than conventional insulation materials. In this study, substrate-based mycelium materials (fungal species Trametes versicolor) with different densities were produced by using substrates with different fiber lengths (wheat straw pellets and wheat straw chaff) and two levels of compaction. Materials with densities from 0.115 g cm-3 to 0.274 g cm-3 were obtained. The compressive strengths (0.032 MPa to 0.148 MPa) and flexural strengths (0.043 MPa to 0.123 MPa) obtained reach the range of commercially available insulation materials (with low densities) such as mineral wool, foamed polystyrene, or wood fiber-based materials.