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.

Mycelium-based composites (MBCs) are highly valued for their ability to transform low-value organic materials into sustainable building materials, offering significant potential for decarbonizing the construction sector. The properties of MBCs are influenced by factors such as the mycelium species, substrate materials, fabrication growth parameters, and post-processing. Traditional fabrication methods involve combining grain spawn with loose substrates in a mold to achieve specific single functional properties, such as strength, acoustic absorption, or thermal insulation. However, recent advancements have focused on digital biofabrication to optimize MBC properties and expand their application scope. Despite these developments, existing research predominantly explores the use of grain spawn inoculation, with little focus on liquid spawn. Liquid spawn, however, holds significant potential, particularly in digital biofabrication, due to its ease of deposition and greater precision compared with grains. This paper, part of a digital biofabrication framework, investigates the growth kinetics of Ganoderma lucidum and Pleurotus ostreatus on hemp non-woven mats, offering flexibility and mold-free fabrication using liquid inoculation. By integrating mycelium growth kinetics into digital biofabricated materials, researchers can develop more sustainable, efficient, and specialized solutions using fewer resources, enhancing the adaptability and functionality of MBCs. The experiment involved pre-cultivating P. ostreatus and G. lucidum in yeast peptone dextrose (YPD) and complete yeast media (CYM) under static (ST) and shaking (SH) conditions. Four dilutions (1:10, 1:2, 1:1, and 2:1) were prepared and analyzed through imagery to assess growth kinetics. Results showed that lower dilutions promoted faster growth with full coverage, while higher dilutions offered slower growth with partial coverage. SH conditions resulted in slightly higher coverage and faster growth. To optimize the control of material properties within the digital biofabrication system, it is recommended to use CYM ST for P. ostreatus and YPD SH for G. lucidum, as their growth curves show clear separation between dilutions, reflecting distinct growth efficiencies and speeds that can be selected for desired outcomes.

Taking the Myx Sail displayed at the Danish Design Museum as a case study, this article investigates the room acoustics of an architectural installation made of Mycelium Textiles. Mycelium Textiles represent a novel typology of mycelium-based composites (MBC). The Myx Sail absorbers are grown on a composition of different layers of plant fibres combining woven jute textile with hemp mat and loose wood wool substrate enhancing the mechanical and acoustic properties of the composite. Two complementary acoustic tests were conducted to measure the absorbing properties of the mycelium material and its effects on the acoustics of the exhibition hall. The results show that the sail acts effectively as an acoustic absorber especially in higher range of frequencies, reducing the reverberation time and improving speech intelligibility. The effect of the sail on the overall room acoustics is especially effective, if the sound source is placed directly underneath the sail. The results of a complementary survey amongst visitors on their subjective perception of comfort and well-being however indicate that the degree to which a grown surface (and by extension, a grown building) is perceived positively or negatively depends on the relationship the individual has with Nature.

The construction industry remains one of the largest contributors to global pollution, generating approximately 40% of total waste and significantly driving resource depletion and greenhouse gas emissions. Conventional construction materials—such as Expanded Polystyrene, Gypsum board, and Fiberboard—are energy-intensive to produce, with high embodied carbon that exacerbates environmental challenges. In response, the search for sustainable alternatives has intensified, particularly those that align with circular economy principles and regenerative design practices [1-3]. Mycelium-based composites (MBCs) have emerged as a promising solution, offering a biodegradable, lightweight material that can be cultivated on a range of organic substrates. While agricultural waste has been widely explored as a substrate for MBCs, there is increasing interest in leveraging post-consumer paper and cardboard waste—an underutilized resource with significant circular potential [4-6]. Paper and cardboard waste represent the largest fraction of packaging waste in the European Union, comprising 41.1% of the total packaging waste stream. In 2020, this amounted to over 32.7 million tonnes, surpassing plastic and glass packaging waste combined. Additionally, the pulp and paper industry are a major contributor to greenhouse gas emissions, with an average carbon footprint of 950 kg CO₂-equivalent per ton of paper produced [7-8]. Repurposing paper and cardboard waste into substrates for MBCs provides a dual benefit of reducing waste and producing high-value, bio-based building materials, as also demonstrated in a master thesis using waste cardboard with sample shown in Figure.1.

This study investigates the growth behavior of G. lucidum and P. ostreatus liquid spawn on non-woven hemp mats. A Complete Yeast Medium (CYM) and Yeast Peptone Dextrose (YPD) medium were used under static (ST) and shaking (SH) conditions to develop four precultures per species. Mycelium was cultured from agar plates into liquid media and incubated at 27 °C for 5 days. Non-woven hemp mats were sterilized and inoculated with 4 dilutions of each precultures. Each mat received 3 mL of liquid spawn, with biological and technical triplicates. Inoculated mats were incubated at 27 °C for 14 days and then dried at 60 °C. Daily photographs tracked growth. Using ImageJ, the surface colonization rate was quantified by calculating the mycelium-covered area as a percentage of the mat. This enabled comparison of media, fungal species, and dilution effects on growth kinetics

Mycelium-based composites (MBC) are valued for their ability to convert low-value organic materials into sustainable building resources, making them a promising solution for decarbonizing the construction sector [1-5]. MBC performance is influencing by various factors including mycelium species, substrate composition, growth conditions, and post-processing techniques [1,6]. Conventional fabrication methods involve combining grain spawn with loose organic material to achieve specific functional properties, such as strength, acoustic absorption, or thermal insulation [7,8]. Recent advancements have increasingly focused on digital biofabrication methods to enhance growth, improve material properties, and shape mycelium materials with a primary focus on additive manufacturing (AM) [9-14]. This approach integrates lignocellulosic substrates with fungal inoculation to create complex composite structures. Most experiments use an extrudable paste to construct scaffolds, with studies investigating the effects of inoculating the paste either before or after fabrication [15-20]. Liquid spawn, however, holds significant potential, particularly in AM, due to its ease of deposition and greater precision compared to grain spawn. Combining liquid spawn and AM has the potential to control localized growth within MBC, enabling more precise material customization. I propose a new digital biofabrication framework that consists of three key components: (1) computational design, which analyzes material functionalities and generates robotic actions; (2) robotic fabrication, which executes inoculation and time-dependent actions; and (3) biological material selection, encompassing mycelium species and substrate composition.