Mycelium-based Composites Research Articles

Physical and Mechanical Properties of Indian Oyster Mushroom Mycelium/Sawdust Composites for Biodegradable Packaging Materials

Mycelium-based composite (MBC) offers an excellent sustainable alternative to hydrocarbon-based materials, especially styrofoam for packaging, due to its abundance of fungal mycelium that grows quickly on agricultural substrates, its biodegradable and its lightweight. The mycelium of a commercial mushroom species, Pleurotus ostreatus (PO), is used to fabricate MBC for packaging materials. Another species, Pleurotus pulmonarius (PP), prefers warmer weather, making it more common in tropical countries. Nevertheless, there is a lack of studies of PP mycelium-based composites and their mechanical and physical properties. This study investigated the physical and mechanical properties of PP mycelium/sawdust composite and compared to PO mycelium/sawdust composite. The results showed that the average density of PP/sawdust and PO/sawdust composites were 292.14 and 272.17 kg/m3, respectively, which fell within the range of low-density polyurethane foam. The final mass gain due to water absorption into PO/sawdust specimens was 144.04%, 1.41 times lower than PP/sawdust specimens. Furthermore, PP/sawdust composite exhibited 7.5 times faster water absorption rate than PO/sawdust composite, indicating that PO/sawdust had better water resistance. The PP/sawdust composite produced an equivalent compressive modulus to the PO/sawdust composite under compression up to 1.34 MPa of maximum value. Thus, the PP/sawdust composite showed excellent potential for substitution of biodegradable packages made from PO/sawdust composite as they contributed the equivalent strength; however, the PO/sawdust composite exhibited superior water resistance to the PP/sawdust composite. Consequently, PO/sawdust should be more advantageous if the biodegradable packaging is required to be of strength as high as the low-density polyurethane foam and of compatible water resistance.

Sustainable production of Pleurotus sajor-caju mushrooms and biocomposites using brewer’s spent and agro-industrial residues

Brazil is one of the world’s largest beer producers and also a major food producer. These activities generate a large amount of residues which, if disposed of inappropriately, can have adverse effects on the environment. The objective of this research was to evaluate the potential of using these residues for both mushroom cultivation (traditional use) and the production of mycelium-based composites (innovative use). Mushroom production (Pleurotus sajor-caju) was conducted using only brewer’s spent grains (fresh and dried) and also mixed with banana leaves (1:1) or peach palm leaves (1:1), which are residues widely available in the northern region of Santa Catarina, Brazil. The productivity of mushrooms cultivated using fresh and dried brewer’s spent grains did not exhibit a statistically significant difference, indicating that this residue can be utilized shortly after its generation in the industrial process, thereby reducing costs associated with production. Combining brewer’s spent grains with banana or peach palm leaves resulted in enhanced mushroom production (0.41 and 0.38 g day−1, respectively) compared to using the leaves as a sole substrate. The mushrooms produced contain sugars and a minimal sodium content, and are considered a source of phosphorus. In addition, no toxic elements (Hg and Pb) were present. The mycelium-based composites produced using the residual substrate (after the mushroom harvest) exhibited better mechanical properties (compressive strength = 0.04 MPa, density = 242 kg m−3, and low humidity sorption) than those produced using fresh substrate. The results demonstrate the synergistic effect of combining the two approaches under investigation. The use of brewer´s spent enhance the mushroom productivity and the residual substrate enhance the mechanical properties of mycelium-based composites. The compressive strength, density, and air humidity sorption properties are essential for determining the potential applications of mycelium-based composites. The use of brewer’s spent grains mixed with banana leaves demonstrated significant promise for mushroom production and subsequent application in the development of mycelium-based composites. These sequential approaches contribute to waste valorization and the rational utilization of natural resources, as the mycelium-based composites are considered for substitution of synthetic materials, thereby promoting sustainability for future generations.

The biohybrid assembly

In the field of contemporary architectural design, novel approaches have emerged to redefine the concept of sustainability through the utilization of bio-composites. One area of exploration involves investigating mycelium as an architectural material across various scales and functions. In this context, the presenting research explores the hybrid assembly combining mycelium and custom 3D printing incorporating robotic fabrication techniques. The Biohybrid Assembly project is a double-layered hybrid structure printed by FGF extruder for the inner layer and a customized mycelium extruder for the outer layer. Furthermore, the Biohybrid Assembly project demonstrates the possibility of large-scale construction, addressing challenges associated with existing mycelium applications. Various types of mycelium-based composites were tested to determine their optimal viscosity, growth, and strength, which were subsequently utilized to fabricate the desired model geometry. A specialized 3D printing extruder was designed and manufactured to nozzle the selected composite. Ultimately, a custom workflow, incorporating an industrial robotic arm, was established to fabricate the hybrid structure consisted of organic and inorganic materials. This research significantly contributes to the redefinition of sustainability by exploring biohybrid construction technology. Through establishing a system for a large-scale prototype, it reinterprets the concept of ecofriendliness in architecture and highlights the advantages and potential of innovative bio-integrated fabrication methods.

Are the mycelium-based diffusers applicable?

The use of materials based on the mycelial growth on recycled materials is widely studied. The absorbent properties of such composites can be found in a number of articles. However, this one focuses on the possibility of using mycelium-based composites for the design of sound diffusers. Diffusion parameters were determined in the form of normalized and non-normalized diffusion coefficient in a free field according to ISO 17497-2. The measured results show that the use of mycelium for the construction of diffusers is promising. However, the results are not the best, which is due to the architectural design. . For further development, the optimization of the shape of the diffusers based on acoustic requirements is expected.

Comparative Evaluation of Mechanical and Physical Properties of Mycelium Composite Boards Made from Lentinus sajor-caju with Various Ratios of Corn Husk and Sawdust.

Mycelium-based composites (MBCs) exhibit varied properties as alternative biodegradable materials that can be used in various industries such as construction, furniture, household goods, and packaging. However, these properties are primarily influenced by the type of substrate used. This study aims to investigate the properties of MBCs produced from Lentinus sajor-caju strain CMU-NK0427 using different ratios of sawdust to corn husk in the development of mycelium composite boards (MCBs) with thicknesses of 8, 16, and 24 mm. The results indicate that variations in the ratios of corn husk to sawdust and thickness affected the mechanical and physical properties of the obtained MCBs. Reducing the corn husk content in the substrate increased the modulus of elasticity, density, and thermal conductivity, while increasing the corn husk content increased the bending strength, shrinkage, water absorption, and volumetric swelling. Additionally, an increase in thickness with the same substrate ratio only indicated an increase in density and shrinkage. MCBs have sound absorption properties ranging from 61 to 94% at a frequency of 1000 Hz. According to the correlation results, a reduction in corn husk content in the substrate has a significant positive effect on the reduction in bending strength, shrinkage, and water absorption in MCBs. However, a decrease in corn husk content shows a strong negative correlation with the increase in the modulus of elasticity, density, and thermal conductivity. The thickness of MCBs with the same substrate ratio only shows a significant negative correlation with the modulus of elasticity and bending strength. Compared to commercial boards, the mechanical (bending strength) and physical (density, thermal conductivity, and sound absorption) properties of MCBs made from a 100% corn husk ratio are most similar to those of softboards and acoustic boards. The results of this study can provide valuable information for the production of MCBs and will serve as a guide to enhance strategies for further improving their properties for commercial manufacturing, as well as fulfilling the long-term goal of eco-friendly recycling of lignocellulosic substrates.

Life cycle assessment of mycelium based composite acoustic insulation panels

Mycelium-based composites (MBC) have gained attention in research and industry as environmentally favorable substitutes for materials in various applications, including packaging inserts, textiles, automotive and even electronics. As construction materials, MBCs show promising characteristics as fully bio-based thermoacoustic insulation. To investigate the potential environmental impacts of the production, use and end-of-life of MBC acoustic insulation panels and their mounting system, we conducted a cradle-to-grave life cycle assessment (LCA) based on real-world production planning data and supplementary literature data. Life cycle modules and system boundaries were chosen following EN 15804. A life cycle impact assessment was carried out based on select impact categories from the Environmental Footprint (EF 3.1) framework. Uncertainties and sensitivities were examined based on a Monte-Carlo simulation and contribution to variance. Energy use for incubation and drying during the manufacturing stage is the most important contributor in most impact categories, including global warming potential. This is further underlined by the large sensitivity of the results to uncertainties related to energy-use. Overall, the manufacturing stage is the dominant life-cycle stage in terms of potential environmental impacts. Generally, our results agree with literature values of LCA studies on similar materials, when normalized for mass and volume. Tracing biogenic carbon throughout the product system shows an early release of over 10 % of the stored biogenic carbon during the manufacturing stage as opposed to a release of all remaining stored carbon during disposal and energetic recycling.

Knit-Mycelium Hybrids: Textile Design Strategies for Biofabrication Systems Based on Mycocrete Injection in 3D Knitted Tubular Formworks

This paper investigates the design potential of monolithically grown Mycelium-based Composites (MBCs), focusing on integrating 3D knitted formworks within the fabrication process. Mycelium has gained attention as a sustainable, biodegradable construction material with insulating and self-healing capabilities. While there have been advancements in MBC, challenges remain regarding geometrical complexity and design potential at scale through in situ practices. Recent interest has emerged in digital fabrication methods and mould creation using textile logic and CNC knitting. However, fabricating mycelium within tubular soft moulds present a lack of stability and uneven growth distribution. The novel technique using injection filling of Mycocrete, a viscous mycelium paste, overcomes this structural disintegration. This method enables the creation of complex designs within a two-staged fabrication process while providing high structural performance. The paper presents three case studies demonstrating the impact of hanging, draping, and internal shape integration as fabrication steps as design tools for geometrical possibilities and diversity of expressions. It examines the relationship between knitted soft preform design and biofabrication parameters in relation to design expression, scale and mycelium growth. The paper concludes by emphasising the significance of 3D knitted formworks in scaling up MBCs in the built environment and its potential for implementing textile design parameters in MBC expressions and geometries. The fabrication steps provide newfound design opportunities, opening possibilities for aesthetical, material-saving and functionally graded design approaches. Further research in this area holds promise for advancing sustainable construction and textile design practices.

Characterization of Uncoated and Coated Fungal Mycelium-Based Composites from Water Hyacinth

Characterization of Uncoated and Coated Fungal Mycelium-Based Composites from Water Hyacinth

Functionality of production processes in mycelium-based composites

The current study, the mechanical and structural properties of mycelium-based composites, focusing on impact bending strength (IBS), Brinell hardness (BH), and tensile strength (TS), were investigated. The specimens were prepared with three degrees of densification (0, 30, and 50 %) and followed the curing time (4 and 12 days). The finding reveals that densification and curing time significantly influence the mycelium board properties. At a curing time of 4 days, the highest values of IBS, BH, and TS were observed at 30 to 50 % densification, while at 12 days, the densification results on the mechanical properties were less pronounced. SEM analysis indicated the presence of air gaps, mycelial binders, and a network of fibers that contribute to the material’s thermal insulation and mechanical properties.Additionally, the presence of the chlamydospores suggests the’mycelium’s adaptive survival mechanism under adverse environmental conditions. The obtained results were supported by density profile analysis and SEM analysis. The results of the work point to the possibility of applying alternative methods to create products whose mission is to satisfy consumers’ requirements.

Mycelium-Based Composites: Surveying Their Acceptance by Professional Architects

Mycelium-based composites (MBCs) are biomaterials with scientifically proven potential to improve sustainability in construction. Although mycelium-based products are not entirely new, their use in engineering presents challenges due to the inherent properties of this fungal material. This study investigated professional architects’ and interior designers’ perceptions of MBCs, focusing on familiarity, aesthetic appeal, and willingness to use. The first phase of the survey explored respondents’ views on material-related ecological design principles. In the second phase, respondents evaluated ten small architectural objects crafted from MBCs, focusing on form, detail, and visual appeal. The last phase of the survey measured their interest in using mycelium in their design work. The results revealed that MBCs were relatively unknown among the surveyed professionals; only every second respondent knew this material. Despite this, 90% found MBCs visually appealing after seeing the examples. Interestingly, the natural, unprocessed appearance of the material was assessed as less aesthetically pleasing, with thermal treatment improving its perceived value. Architects were more receptive to using MBCs in their professional projects for customers than for personal use. This observation points to a ‘double standard’: professional architects are more open to using MBCs in projects not intended for their own use.

A study on the thermal performance of Pleurotus Ostreatus/Straw mycelium composites and its application in building envelopes

Most conventional construction materials are non-degradable, putting huge burden on our environment at disposal. Mycelium-based composites are formed by aggregating some forestry and agricultural residues with networks of filamentous hyphae, and they are degradable and environmentally friendly. The paper examines the thermal property of Pleurotus Ostreatus/Straw (PO/S) mycelium composites and explores the possibility of using it for building insulation application. Samples of PO/S mycelium composites of different composition and density were prepared. The thermal conductivity was measured by a steady-state thermal measurement approach. It was found that incubation time, preparation method, and composition are important factors for the thermal performance of the material. The lowest thermal conductivity was 0.12 W/m‧K, with the sample (FMC 04) consisting of 75 % Pleurotus Ostreatus primary spawn and 25 % straw substrate and prepared without pressure. With this composition, a series of mycelium-based façade and roof sandwich insulation panels were designed in details. The U-values of the panels were calculated using THERM software, and required panel thickness was investigated. It was found that when the panel thickness reaches 240 mm, two types of wall panels (W1 and W2) and two types of roof panels (R1 and R2) satisfy the energy efficiency requirements of Class A public building in the “hot summer and cold winter” climate zone in China. A cost-benefit analysis shows that implementation of this novel insulation panel is financially sustainable for at least 10 years from now on, if it is sold at a price 5 % more than normal panels.

PRODUCTION OF MYCELIUM-BASED COMPOSITE MATERIALS AND EVALUATION OF THERMAL INSULATION PERFORMANCE

ABSTRACT Increasing awareness of the adverse effects of materials used in the construction industry on the environment and health increases the tendency towards bio-based products based on principles such as circular economy and sustainability. Meanwhile, there is a tendency to solve the post-use waste problem and reduce carbon emissions by extending the service life of building materials or making recyclable materials widespread. Mycelium-based composites (MBC) constitute an innovative natural building material interface with the potential to be used as building insulation material. In producing MBC, a substrate is used because of the significant growth provided by lignocellulosic biomass. In this study, MBCs were produced by growing Pleurotus ostreatus on 16 substrates during a 28-day incubation period. Consequently, two composites with the best performance were selected from the preliminary research on the produced samples. It was aimed to determine the thermal, mechanical, physical properties, microstructure characterization and longterm performance of the selected composites. For this reason, thermal conductivity coefficient measurement, water absorption values, water vapor permeability, ultrasound velocity determination, mechanical strength tests and durability tests were carried out. The findings showed that composites containing beech sawdust and pulp paper had better properties than other substrates. Advanced research results showed that MBCs are promising as thermal insulation materials.

Fabrication and characterization of mycelium-based composites from Lentinus squarrosulus and Pleurotus ostreatus with improved physico-mechanical properties for versatile applications

This study explores the potential of fungal mycelium-based plate-like composites as sustainable and cost-effective alternatives for synthetic materials. Locally available lignocellulosic waste and fungi isolated locally were used to fabricate mycelium composites. The medium primarily consists of Albizia sawdust and the fungi Lentinus squarrosulus and Pleurotus ostreatus were used. All the composites identified here were subjected to analyses based on scanning electron microscopy, moisture content, dry density, water absorption, flammability, thermal stability, and compression strength following ASTM and ISO standards. The mycelium plates produced with L. squarrosulus mycelium (ASL) exhibited lower dry density and less water absorption. The ASL mycelium plates exhibited a soft and foamy appearance, whereas the P. ostreatus material (ASP) appeared dense mycelium growth only in the top and bottom parts of the plate. The UL-94 rating demonstrated that both samples exhibited superior flame retardancy properties (rated as V1) compared to commercially used expanded polystyrene (EPS). These variations were due to the difference between mycelium density. Therefore, these new bio-composites have the potential to replace conventional packaging or interior construction materials.

Life cycle assessment of mycelium-based composite materials

Mycelium-based composites (MBCs) show promising acoustic and thermal insulation, fire safety, and mechanical strength properties and are suitable for multiple applications in the construction, packing or furniture industry. A life cycle assessment confirmed climate change and fossil energy demand benefits in a laboratory scale production modelled for Germany. MBC are associated with 0.3668 kg CO2e / kg MBC (EN 15804 + A2). The electricity required to run MBC production and hemp cultivation, if used as a substrate, contribute significantly to the environmental impact categories considered. Compared to conventional insulation materials, environmental advantages of MBC can be confirmed. Particularly, MBC has a better climate change impact than extruded polystyrene, quadcore sandwich panel, foam concrete and rockwool. However, since the end-of-life is not assessed, the wood-fiber and straw panels perform better regarding climate change. Moreover, MBC has lower fossil energy demand than all conventional insulation materials. Land-use and water demand are higher than for conventional materials.

Mycelium-Based Composites as a Sustainable Solution for Waste Management and Circular Economy.

The global population is expected to increase by nearly 2 billion individuals over the next three decades, leading to a significant surge in waste generation and environmental challenges. To mitigate these challenges, there is a need to develop sustainable solutions that can effectively manage waste generation and promote a circular economy. Mycelium-based composites (MBCs) are being developed for various applications, including packaging, architectural designs, sound absorption, and insulation. MBCs are made by combining fungal mycelium with organic substrates, using the mycelium as a natural adhesive. Mycelium, the vegetative part of fungi, can be grown on various organic feedstocks and functionalized into a range of diverse material types that are biobased and thus more sustainable in their production, use, and recycling. This work aims to obtain mycelium-based composites with acoustic absorption properties, using coffee grounds and agricultural waste as raw materials. The topic approached presents a new method of recovering spent coffee grounds that does not involve high production costs and reduces two current environmental problems: noise pollution and abundant waste. Measurements of the normal-incidence sound absorption coefficient were presented and analyzed. Mycelium-based composites offer an innovative, sustainable approach to developing bio-composite sound-absorbing surfaces for interior fittings. The material by Ganoderma lucidum exhibits exceptional sound-absorbing properties at frequencies below 700 Hz, which is a crucial aspect of creating sound-absorbing materials that effectively absorb low-frequency sound waves. The modular construction system allows for a high degree of flexibility to adapt to short-term changes in the workplace.

Procena fundamentalnih faktora koji utiču na karakteristike materijala na bazi micelijuma - pregled

The mycelium-based materials (MBMs) are produced by growing the vegetative part of the mushroom-forming fungi-from Dikarya group: phylum Basidiomycota and Ascomycota, on different organic substrates, mostly due to containing important mycelium characteristics: septa and anastomosis. Moreover, function of these composites can be further tuned by controlling the species of fungus, the growing conditions, and the processing methods to meet a specific mechanical requirement in their further applications. The material formed after full colonization of the substrate, needs to be exposed to dry heating in order to remove the moisture content and to inactivate the mycelium, giving us the lightweight, and biodegradable material with great potential to replace fossil-based and synthetic materials such as polyurethane and polystyrene. Their low carbon footprint, low energy and processing cost, biodegradability, low heat conductivity, high acoustic absorption, and fire safety qualities were some of the main characteristics that encouraged the use of mycelium based composites (MBCs) in the construction and building sector, especially as paneling, insulation, and furniture materials. Since mycelium products are quite new and there is limited industry peer-reviewed testing data available, there is a need for standardized mechanical properties, universal testing requirements and published standards (ISO, ASTM) to ensure that qualification and testing programs can be developed to support the manufacture and use of MBCs.

Room acoustics of Mycelium Textiles: the Myx Sail at the Danish Design Museum

Abstract 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.

Valorization and biorefinery of local agricultural and textile wastes through mycelium composites for structural applications

Abstract Manufacturing of mycelium-based composites is an emerging biorefinery technology toward the development of environmentally positive materials within the circular economy: it benefits from waste and industrial by-products upcycling while excelling in biodegradability. This study investigates the compressive behavior of materials repurposed from local agricultural wastes (tree nuts and crop wastes in California’s Central Valley), using the fungal mycelium of Pleurotus ostreatus and Ganoderma lucidum, well-known edible and medicinal species. We also explore the hybridization of these mycelium-based composites with local textile waste fibers as reinforcements. Following guidelines from several ASTM standards, the compressive behavior of these composites is analyzed to determine the impact of biomass processing, composition, fungal species used, and post-processing strategy. We propose a post-processing strategy based on a short exposure to sodium chloride solutions in ambient conditions, to de-activate mycelium and prevent its fruiting, replacing the established energy-intensive heat-based post-processing. This work aims at contributing to the decarbonization of the built environment and the construction industry in particular, through materials designed with upcycled waste (agricultural and textile), fungal mycelium and low-carbon footprint processes.

Bacteria–fungi interaction for material formation

Abstract This paper describes an early-stage research and experiments exploring methods of co-cultivation of the fungal strain Ganoderma lucidum and the bacterial strain Sporosarcina pasteurii within the field of architecture. Co-cultivating these species within a bio-based compound, forming a living material, shows that the binding abilities of both microbial partners can be harnessed through multistep production techniques. As the mycelial network of the fungus spreads through the inoculated wood substrate, bacterial cells disperse and multiply on this same network and release the enzyme urease throughout the now-forming compound bound by the fungus. The enzyme is one of the key actors in the biocementation process, which is activated with the addition of a calcium source to the material. Calcium carbonate minerals form and attach on the hyphae, as well as in between the network, inside the wood sawdust pieces and around void spaces within the composite. While additional data collection is required, the current state of this research suggests that properties of both living materials can be expanded, for example, fire resistance and compressive strength compared to traditional mycelium-based composites, as well as the increased ability of the bacteria to homogeneously distribute and exist in unfavorable environments compared to mono-cultured bacterial communities.

Fabrication of mycelium (oyster mushroom)-based composites derived from spent coffee grounds with pineapple fibre reinforcement

ABSTRACT Mycelium-based composites (MBCs) are eco-friendly materials made by combining mushroom mycelia with lignocellulosic biomass, offering diverse applications such as packaging and construction. The specific characteristics of MBCs can be significantly influenced by the choice of substrates and reinforcing materials during myco-fabrication. This study aims to improve MBCs sourced from Pleurotus ostreatus (oyster mushroom) using spent coffee grounds (SCGs) as the main substrate, combined with natural pineapple fibres (NPFs). NPFs are incorporated to SCGs in different proportions (10% to 30%) to explore their potential in improving the material properties of MBCs. The findings demonstrate that the mechanical properties of MBCs, as well as the physical and chemical properties, can be altered by manipulating the proportion of NPFs. The MBCs reinforced with 10% NPFs exhibit the highest density and compressive strength, while the MBC with 30% NPFs outperforms others in terms of bending strength, water absorption, swelling, and sound absorption. Furthermore, a fire resistance test affirms the non-combustible properties of the MBC made of SCGs and NPFs, thereby demonstrating its safety features. These MBCs, made from oyster mushroom, embody a hopeful substitute for product creation and production in relation to practical usage, eco-friendly manufacturing techniques, and recyclability throughout its lifecycle.