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Mycelium-bound composites are promising materials for sustainable packaging, insulation, fashion, and architecture. However, moulding is the main fabrication process explored to date, strongly limiting the ability to design the complex shapes that could widen the range of applications. Extrusion is a facile and low energy-cost process that has not...
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... a sufficient oxygen flow is necessary to allow the mycelium to grow homogeneously in bulk and not only at the solidair interface. 42 To determine which bamboo fibre size to use in our composition, we first incubated the mycelium-enriched sawdust with chopped bamboo fibres of 1 mm, 500 µm and 200 µm-length, and studied the mycelium morphology and properties (Figure 3). ...
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... bamboo fibres promoted the growth of the mycelium, with a significant influence of their dimensions on the morphology and density of the mycelium network. This network was denser on smaller bamboo fibre sizes and appeared to grow faster, both in the bulk and in the skin formed at the surface of the substrate exposed to oxygen ( Figure 3A). The mycelium created an interconnected network with a hypha (the mycelium filaments) of diameter 1.1 ± 0.2 µm. ...
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... mycelium created an interconnected network with a hypha (the mycelium filaments) of diameter 1.1 ± 0.2 µm. This diameter was constant for all bamboo fibres, but the length between the interconnections in the network was decreasing with growth time and fibre size ( Figure 3B). The growth of the mycelium in the bulk appeared delayed in the case of the 1 mm fibre length, whereas no significant difference could be measured for the skin after 14 days. ...
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... despite the increase in the mycelium network, the overall density of the material decreased with time (Figure 3C), indicating that the fungus is consuming the substrate. [43][44][45] The higher decrease in density for the 200 µm bamboo fibres suggests that smaller fibre sizes promote more mycelium growth (see SI Figure S2). ...
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... the mycelium acts as a binder between the bamboo fibres, providing stress transfer and allowing elongation. When the composite fractured under tension, the hyphae from the mycelium J o u r n a l P r e -p r o o f appeared stretched in the tensile direction (see SI Figure S3). The mycelium-bamboo with 200 µm fibres exhibited the highest modulus. ...
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Mycelium-bound composites are promising materials for sustainable packaging, insulation, fashion, and architecture. However, moulding is the main fabrication process explored to date, strongly limiting the ability to design the complex shapes that could widen the range of applications. Extrusion is a facile and low energy-cost process that has not...
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... Formwork strategies inspired by known mouldable materials were also developed for mycelium composites in recent years: formwork-free construction with 3D printing [39][40][41], temporary formworks from single-use or recyclable sheet materials [6,42,43] and stay-in-place formworks that are 3D printed [44,45] or made of fabrics [10,13,46,47]. ...
Mycelium-based composites (MBCs) are a promising new class of environmentally friendly materials that can be produced using local materials and grown into a wide range of shapes and designs. Upscaling them to architectural scale, however, remains challenging particularly due to insufficient structural stability and the required manufacturing processes. The necessity of a formwork in the growing process often restricts designs to simple shapes, or requires costly formwork, which limits design flexibility. In preliminary research, the authors introduced 3D wood veneer lattices into MBCs as reinforcement, similar to steel reinforcement in concrete, to provide increased strength and scaffolding. This research combines robotic additive manufacturing of 3D wood lattices with a natural fibre textile, to act as a stay-in-place formwork for planar and curved architectural components. The combined lattice and textile serve as a support structure, eliminating the need for formwork and providing the required structural performance. As MBCs are often subject to large manufacturing tolerances, the fabrication steps that influence accuracy are analysed. Therefore, two prototypes of the same design are compared: one using a temporary formwork, and the other, a stay-in-place formwork. Results show that the temporary formwork provides precise shaping during growth, while the stay-in-place approach, incorporating natural fibre textiles, allows a more organic shape development. The methods are assessed via 3D scanning to compare the physical outcomes against the digital designs, highlighting trade-offs and limitations. This study contributes to sustainable biomaterials research by offering insights into the accuracy and feasibility of these approaches for future construction elements with MBCs.
... Most experiments in the literature employ the direct ink writing technique, where an extrudable paste made of lignocellulosic material is used to fabricate scaffolding structures. These studies explore inoculating the paste either before or after the fabrication process [20][21][22][23][24][25]. However, no fabrication techniques have yet investigated the direct deposition of liquid spawn onto or within non-printed substrate material. ...
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.
... Most experiments in the literature employ the direct ink writing technique, where an extrudable paste made of lignocellulosic material is used to fabricate scaffolding structures. These studies explore inoculating the paste either before or after the fabrication process [20][21][22][23][24][25]. However, no fabrication techniques have yet investigated the direct deposition of liquid spawn onto or within non-printed substrate material. ...
Mycelium-based composites (MBC) are valued for converting low-value organic materials into high-performance building materials, offering significant potential for decarbonizing the construction sector. MBC properties are influenced by mycelium species, substrate materials, and fabrication growth parameters. In traditional applications, grain spawn is combined with loose particle substrates to achieve specific functional properties, such as strength, acoustic absorption, or thermal insulation, tailored to a single purpose. However, recent advancements have shifted toward creating graded materials—materials in which properties vary gradually throughout the structure. This approach allows for multiple local optimized properties to be incorporated within a single material. As a result, graded materials can support applications that require complex, multifunctional performance, making them ideal for fields like construction where multiple properties are often needed within a single component. This study, part of a digital biofabrication framework, explores controlling mycelium growth via liquid spawn. While liquid spawn has improved mechanical properties, its effects on growth performance have not been fully studied. Non-woven mats, offering flexibility and mold-free fabrication, are proposed as substrates. This paper investigates the growth kinetics of Ganoderma lucidum and Pleurotus ostreatus on hemp non-woven mats using liquid inoculation, comparing it to traditional grain spawn inoculation. By integrating graded properties into digital biofabricated materials, researchers can develop more sustainable, efficient, and specialized solutions using fewer resources, enhancing the adaptability and functionality of MBC.The experiment involved pre-cultivating P. ostreatus and G. lucidum in yeast peptone dextrose (YPD) and complete yeast (CYM) media under static (ST) and shaking (SH) conditions. Four mycelium dilutions (1:10, 1:2, 1:1, and 2:1) were prepared and analyzed through imagery to assess growth kinetics, aesthetics, and potential material properties. Results showed that lower dilutions promoted faster growth with full coverage, while higher dilutions offered slower growth with partial coverage, providing more control during incubation. Shaking conditions resulted in slightly higher coverage and faster growth. CYM medium resulted in G. lucidum and P. ostreatus closely matching the grain spawn growth curve across all dilutions, compared to YPD medium. 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. P. ostreatus should be preferred for acoustic absorption qualities due to its thin, fibrous growth, while G. lucidum is ideal for strength and aesthetic properties, thanks to its dense growth and color-changing characteristics.
... In these composite materials, the biomass particles (made from agricultural waste such as hemp hurd) act as the substrate, and a network of fungal hyphae grow through and bind the biomass particles together. [1,2]. These biomass-fungi composite materials, serving as sustainable alternatives to petroleum-based plastics, find applications in packaging [3][4][5][6], furniture [7], and construction industries [8]. ...
... 3D printing of biomass-fungi composite materials could facilitate the manufacturing of parts with complex shapes (such as sandwich and topology-optimized structures) in art, architecture, interior design, and construction that cannot be easily produced using molding-based or hot-pressing based methods [2,16,17]. The use of additive manufacturing has the potential to leverage in situ resources on the Moon and Mars, with the minimal amounts (less than 1 mg) of fungi transported from the Earth to serve as an inoculum for continuous production locally [18][19][20][21]. ...
... Understanding the relationship between geometry and mycelium growth is crucial for enhancing the design and material properties of MBCs building elements. While it is acknowledged that other factors such as the growth environment, fungal species, and nutrient substrates also impact growth, this study primarily focuses on elucidating the influence of geometry (Soh et al., 2020). ...
This study explores the potential impact of geometric configurations on the growth and mechanical properties of 3D-printed Mycelium-Based Composites (MBCs). Through a combination of digital exploration, physical experimentation, and data analysis, the study examines how geometrical parametric manipulation may affect MBCs growth and mechanical properties. Material preparation involves a combination of Ganoderma Tsugae mycelium with hemp and straw substrate, followed by 3D-printing and incubation in controlled growth conditions. Structural testing and digital image processing techniques are employed to analyse growth patterns and material behaviour. The study reveals significant correlations between geometric parameters and MBCs growth, underscoring the potential for geometry to optimise mycelium growth and structural performance. These findings contribute valuable insights for informed design and the utilisation of MBCs in sustainable architectural applications, emphasising on further exploration in biomaterial systems research.
... There have been other reported studies on 3D printing-based manufacturing methods using biomass-fungi composite materials. Bamboo fibers and chitosan were included in biomass-fungi composite materials to improve the printability and mechanical properties of 3D printed parts [20]. Shredded cardboard and natural gums were used to maintain the structural integrity of printed parts [21]. ...
Petroleum-derived plastic materials are used to manufacture a wide range of products [...]
... Also, making these materials involves moulding: the nutritional substrate and mycelium spores were combined, put into a mould, and allowed to expand until the mycelium development was halted by heating. 4 The mycelium multiplies rapidly and generates a large number of self-assembling connections in the form of minute threads known as hyphae, which cover the source completely, decompose it, and combine it into an enduring and organic substance. The primary elements of the mycelium are natural biopolymers like cellulose, chitin, various proteins, etc. Lignin, cellulose, pectin, various compounds from microbes or medicinal plants, protein products from both animals and plants, etc. are essential resources to create biopolymers among the various natural sustainable resources. ...
In healthcare and human life, and with the growing need for environmentally friendly materials to replace synthetic ones, biomaterials are essential. Desirable biomaterials may now be created using a wide range of extracted natural polymers. Mycelium-based biomaterials are being developed into more adaptable, inexpensive, and self-replicating products. Some fungal species, like Pleurotus ostreatus and Ganoderma lucidum, have been recognised as excellent sources of biomaterials with unique morphological, mechanical, and hydrodynamical characteristics. Thermomyces lanuginosus and Purpureocillium lilacinum are two fungal strains that may be used to create biomaterials. This article seeks to introduce these strains and use experimentation to identify their distinctive characteristics. The fungus was cultivated in a lab, and the growth kinetics of the fungus were estimated. The strains of P. lilacinum and T. lanuginosus had maximum specific growth rates (μmax) of 1.34 ± 0.024 and 3.09 ± 0.019 L⁻¹ d⁻¹, respectively. Decellularization of the fungal biomass was performed using 0.1% SDS solution, after which the scaffolds were created by drying the biomass in plastic moulds. Following that, analysis using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and Fourier transform infrared spectroscopy (FT-IR) was carried out. The porosity and swelling ratio were also determined and hydrodynamic characterization was performed for the samples. The results show that mycelia have the potential to serve as inexpensive, all-natural bio-scaffolds and T. lanuginosus-prepared materials have a larger swelling ratio and increased porosity, which makes them better myco-materials than those formed from P. lilacinum.
... The mycelium binds the substrate particles together to form a cohesive composite. MBCs are most commonly produced by growing fungi on substrates of lignocellulosic residues to obtain an easily sourced and cheap, sustainable material [2,3]. Different fungi and substrates can directly influence the functional properties of an MBC and ultimately alter its potential in different applications [4]. ...
Mycelium-based composites are a promising avenue for innovating sustainable materials from the hyphae of fungi. This study focuses on the use of fibers from four local fungal species, namely, Pleurotus ostreatus, Pleurotus sajor-caju (Fr. Singer), Auricularia auricula-judae, and Schizophyllum commune Fr., to produce mycelium-based composites from water hyacinth. An inoculum of each of the mushroom species was cultivated on PDA medium at 25 and 30 °C to determine the optimal temperature based on the growth rate. The obtained optimal condition was used to grow the fungi on water hyacinth (WH) mixed with rice bran in different proportions (100% WH, 70% WH, and 50% WH) with various numbers of fungal inocula (10, 20, and 30 plugs). The obtained composites were coated with a solution of either starch, chitosan, or epoxy resin. Schizophyllum commune Fr. exhibited the highest growth rate and fiber density, with a growth rate of 1.45 ± 1.92 mm/day at 30 °C. Ten inocula of Schizophyllum commune Fr. incubated at 30 °C for seven days on a mixture of 50% WH and 50% rice bran gave the optimal composite. Coating the obtained composite with chitosan improved its mechanical properties, but coating it with epoxy resin improved its water absorbency. Buried in soil, the composite coated with a chitosan solution decomposed within 30 days. The results indicate that Schizophyllum commune Fr. can be used as a binder to produce mycelial composites on a substrate of WH mixed with rice bran. The implications of these results will enable the further development and tuning of mushroom-based materials, especially for the production of sustainable bio-construction materials derived from local mushrooms and bio-waste.
... Biomass-fungi composite materials comprise two primary constituents: biomass particles sourced from agricultural residues (such as corn stover, beechwood sawdust, and hemp hurd) and a network of fungal hyphae binding the biomass particles [1]. These composite materials can be used to fabricate products traditionally manufactured from petroleum-based plastics. ...
Biomass–fungi composite materials primarily consist of biomass particles (sourced from agricultural residues) and a network of fungal hyphae that bind the biomass particles together. These materials have potential applications across diverse industries, such as packaging, furniture, and construction. 3D printing offers a new approach to manufacturing parts using biomass–fungi composite materials, as an alternative to traditional molding-based methods. However, there are challenges in producing parts with desired quality (for example, geometric accuracy after printing and height shrinkage several days after printing) by using 3D printing-based methods. This paper introduces an innovative approach to enhance part quality by incorporating ionic crosslinking into the 3D printing-based methods. While ionic crosslinking has been explored in hydrogel-based bioprinting, its application in biomass–fungi composite materials has not been reported. Using sodium alginate (SA) as the hydrogel and calcium chloride as the crosslinking agent, this paper investigates their effects on quality (geometric accuracy and height shrinkage) of 3D printed samples and physiochemical characteristics (rheological, chemical, and texture properties) of biomass–fungi composite materials. Results show that increasing SA concentration led to significant improvements in both geometric accuracy and height shrinkage of 3D printed samples. Moreover, crosslinking exposure significantly enhanced hardness of the biomass–fungi mixture samples prepared for texture profile analysis, while the inclusion of SA notably improved cohesiveness and springiness of the biomass–fungi mixture samples. Furthermore, Fourier transform infrared spectroscopy confirms the occurrence of ionic crosslinking within 3D printed samples. Results from this study can be used as a reference for developing new biomass–fungi mixtures for 3D printing in the future.
... The rate of colonization, the thickness of the hyphae, the tendency to branch, and the topography of the surface vary depending on the selected fungus species [16][17][18][19][20][21][22][23][24][25][26]. ...
... The substrate mixes described in the literature usually consist of ground waste from agricultural crops, such as cotton, straw, wheat, hemp or sawdust [16][17][18][19][20][21][22][23][24][25][26]. The type, size and processing of the substrate particles directly affects the various properties of the final biocomposite. ...
... The type, size and processing of the substrate particles directly affects the various properties of the final biocomposite. A detailed description of the substrate composition and processing method is essential for further understanding of mycelium colonization trends and their impact on the final material properties [16][17][18][19][20][21][22][23][24][25][26]. ...
Mycelium materials represent a new class of environmentally friendly materials for structural applications that can grow on low‐cost organic waste while achieving satisfactory thermal or acoustic insulation properties. The aim of this study is to grow a biocomposite of mycelium on flax tows and then use it as a reinforcement with a geopolymer matrix. To achieve this, three species of mycelium were selected, a culture process was carried out, and then samples of the composite were synthesized with a geopolymer matrix. To determine the utility in terms of structural applications, the density, compressive strength, and thermal conductivity of the samples were tested. Scanning electron microscope images were also taken to observe the microstructure. The results indicate that it is possible to produce a mycelium composite with a geopolymer matrix. A lower density was achieved for all samples than for the geopolymer without reinforcement. The coefficient of thermal conductivity was reduced only for the sample with one of the mycelia. The compressive strength for biocomposites was between 12.1 MPa–14.2 MPa, this value is enough for some engineering applications.
