The demand for building materials has been constantly increasing, which leads to excessive energy consumption for their provision. The looming environmental consequences have triggered the search for sustainable alternatives. Mycelium, as a rapidly renewable, low-carbon natural material that can withstand compressive forces and has inherent acoustic and fire-resistance properties, could be a potential solution to this problem. However, due to its low tensile, flexural and shear strength, mycelium is not currently widely used commercially in the construction industry. Therefore, this research focuses on improving the structural performance of mycelium composites for interior use through custom robotic additive manufacturing processes that integrate continuous wood fibers into the mycelial matrix as reinforcement. This creates a novel, 100% bio-based, wood-veneer-reinforced mycelium composite. As base materials, Ganoderma lucidum and hemp hurds for mycelium growth and maple veneer for reinforcement were pre-selected for this study. Compression, pull-out, and three-point bending tests comparing the unreinforced samples to the veneer-reinforced samples were performed, revealing improvements on the bending resistance of the reinforced samples. Additionally, the tensile strength of the reinforcement joints was examined and proved to be stronger than the material itself. The paper presents preliminary experiment results showing the effect of veneer reinforcements on increasing bending resistance, discusses the potential benefits of combining wood veneer and mycelium’s distinct material properties, and highlights methods for the design and production of architectural components.

Office and retail interior fittings have a relatively short service life of 5-7 years. In this context, composite materials are often used, hindering possibilities of reuse or recycling. This research explores novel bio-composite materials and subsequently a construction method for CO2-neutral, circular interior fittings for office spaces. Based on the potential of fungal mycelium as a rapidly renewable, regenerative, affordable, low-carbon building material, bio-composite construction methods are explored in conjunction with timber-based additive manufacturing using continuous fibres. As mycelium has potentially excellent sound-absorbing properties but low load-bearing capacity, composite construction of timber veneer and mycelium allows to increase the structural capabilities of resulting components, while relying entirely on bio-based value chains. We describe the production process as well as the material development, including robotically aided processes for additive manufacturing of veneer reinforcement grids and compatibility studies of different mycelial species and substrates, and their bonding capabilities with veneer. We further present initial results on the mechanical characterization of the composite material, and its comparison to conventional mycelium composites. Minimal structural, acoustic, and functional requirements for different interior fitting elements are studied and compared to the characteristics of the proposed composite, highlighting the range of applications of the presented wood-mycelium composites.