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MYCELIUM MATTERS - An interdisciplinary exploration of the fabrication and properties of mycelium-based materials
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Environmental pollution and scarcity of natural resources have led to an increased interest in developing more sustainable materials. The traditional construction industry, which is mostly based on the extraction of fossil fuels and raw materials, has therefore been called into question. Biological materials that are created by growing mycelium-forming fungal microorganisms on natural fibres can form a solution. In this process, organic waste streams – such as agricultural waste – are valorised, while biodegradable material is created at the end of its life cycle; a process fitting with the spirit of a circular economy. Despite this promise, these materials’ characteristics have remained mostly unexplored. More scientific insights into growing and fabrication processes are required before incorporating these biomaterials into our daily lives. Therefore, this dissertation’s main goal is to explore the principal factors affecting the biological and material properties of mycelium materials and to broaden the potential of new fabrication technologies for architectural applications using fungal organisms. Ultimately, the research provides novel insights and a comprehensive overview of several crucial aspects that come into play during the production of fungi-based lignocellulosic composites. A method for selecting fungal species that incorporates biological, chemical and mechanical performance criteria has been developed. The interaction between fungi and their feedstock and the material properties of different types of feedstocks are investigated. Then, the optimisation of mechanical properties with different types of additives is studied. A novel fabrication process to produce large-scale architectural formwork is developed. Finally, various digital additive fabrications and design strategies that improve the colonisation of the fungi in a given geometry are explored. This hybrid investigation across disciplines is guided by the motivation to explore the growth and fabrication possibilities of mycelium materials from a bioengineering, material engineering, computational fabrication and architectural perspective.
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... With this experimental work, we discovered that the deposited mycelium material's performance is directly related to the material's ability to maintain its geometry under increased weight of the next layers. An alternative additive manufacturing approach was later developed, by printing a three-dimensional bio-scaffold on a doublecurved surface, which acts as a nutritional surface for mycelium [38]. This further work shows a series of tiles that are 3D-printed in advance with a geometrical complex toolpath (S. ...
... This further work shows a series of tiles that are 3D-printed in advance with a geometrical complex toolpath (S. Fig. 5), and then inoculated with mycelium spawn [38]. In doing so, air circulation and nutrient access are accommodated all over the surface [38]. ...
... Fig. 5), and then inoculated with mycelium spawn [38]. In doing so, air circulation and nutrient access are accommodated all over the surface [38]. ...
Environmental pollution and scarcity of natural resources have led to an increased interest in developing more sustainable materials. Mycelium material fabrication is an emerging bio-based and circular technology to produce materials ranging from foam to particleboard applications. In this process, organic waste streams – such as agricultural waste – are valorised, while biodegradable material is created at the end of its life cycle; a process fitting with the spirit of a circular economy. Up to now, mycelium composites have mostly been grown in moulds, by packing a substrate of lignocellulosic fibres with a fungal strain. This fabrication method restricts not only the size and geometry of the final product, but also the access to oxygen needed for the organism to grow in the centre of the material. Additive manufacturing can potentially overcome those limitations. To establish the groundwork of 3D printing with living mycelium material, this paper provides guidance regarding the technological requirements for 3D-printing fungal material. The purpose is to generate scientific insights on all relevant challenges, processes, production steps by disentangling interdependent process variables ranging from biocompatibility with the living organism, the robotic fabrication system and hardware, the determination of the printing parameter and the sterile printing process to rheological, biological, and geometric properties. Therefore, an extrusion system is developed specifically for robotic printing living biological material. Various manufacturing processes, such as the concentration of ingredients, impact of autoclaving, and time on the viscosity, extrusion pressure, toolpath geometry, the nozzle size, printing speed and mycelium growth, are investigated in detail. These parameters, combined with the rheological and biological behaviour of living material deposition led to the emergence of an experimental fabrication methodology, using a custom robotic manufacturing set-up.
... In recent years, the exciting characteristics of filamentous fungi did not go unnoticed in the context of biodegradable materials, providing a low-cost and environmentally sustainable solution compared to the production and life cycle of petroleum-based materials [1][2][3][4][5][6][7]. These composite materials are realized by growing the fungi into lignocellulosic fibers, thereby valorizing organic waste streams, and generating dense materials with a construction material application [8]. ...
... One of the most common nanoclay forms is montmorillonite with a particle thickness of 1 nm, crosswise 70 to 100 nm [26,27]. Montmorillonite clays have a layered structure, and each layer is constructed from tetrahedrally coordinated Si atoms fused onto an edge-shared octahedral plane of either Al(OH) 3 or Mg(OH) 2 [26]. The layers exhibit excellent mechanical properties parallel to the layer direction due to the nature of the bonding between these atoms [26]. ...
... Acknowledgments: This article is based on Chapter 5 of the first author's Ph.D. thesis [2]. The authors would like to thank Svetlana Verbruggen and Frans Boulpaep of the MEMC research group for their support with the mechanical tests and the set-up of the instruments. ...
Biological materials that are created by growing mycelium-forming fungal microorganisms on natural fibers can form a solution to environmental pollution and scarcity of natural resources. Recent studies on the hybridization of mycelium materials with glass improved fire performance; however, the effect of inorganic particles on growth performance and mechanical properties was not previously investigated. Yet, due to the wide variety of reinforcement particles, mycelium nanocomposites can potentially be designed for specific functions and applications, such as fire resistance and mechanical improvement. The objectives of this paper are to first determine whether mycelium materials reinforced with montmorillonite nanoclay can be produced given its inorganic nature, and then to study the influence of these nanoparticles on material properties. Nanoclay–mycelium materials are evaluated in terms of morphological, chemical, and mechanical properties. The first steps are taken in unravelling challenges that exist in combining myco-fabrication with nanomaterials. Results indicate that nanoclay causes a decreased growth rate, although the clay particles are able to penetrate into the fibers’ cell-wall structure. The FTIR study demonstrates that T. versicolor has more difficulty accessing and decaying the hemicellulose and lignin when the amount of nanoclay increases. Moreover, the addition of nanoclay results in low mechanical properties. While nanoclay enhances the properties of polymer composites, the hybridization with mycelium composites was not successful.
... Regenerating biomass waste into new materials is an area of research being investigated through biological interactions. Microorganisms such as bacteria and fungi can use waste as a form of feedstock to grow pliable materials investigated in areas such as architecture and material innovations [5,7,12]. Because these materials are biologically derived, they seldom use landmass in their production creating a circular raw material that has been derived from waste [11,12]. ...
... Microorganisms such as bacteria and fungi can use waste as a form of feedstock to grow pliable materials investigated in areas such as architecture and material innovations [5,7,12]. Because these materials are biologically derived, they seldom use landmass in their production creating a circular raw material that has been derived from waste [11,12]. However, in order to manufacture these biomaterials into usable textile apparel, new creative manufacturing is required. ...
The need for circular textiles has led to an interest in the production of biologically derived materials, generating new research into the bioproduction of textiles through design and interdisciplinary approaches. Bacterial cellulose has been produced directly from fermentation into sheets but not yet investigated in terms of producing filaments directly from fermentation. This leaves a wealth of material qualities unexplored. Further, by growing the material directly into filaments, production such as wet spinning are made redundant, thus reducing textile manufacturing steps. The aim of this study was to grow the bio-material, namely bacterial cellulose directly into a filament. This was achieved using a method of co-designing with the characteristics of biological materials. The method combines approaches of material-driven textile design and human-centred co-design to investigate co-designing with the characteristics of living materials for biological material production. The project is part of a wider exploration of bio-manufacturing textiles from waste. The practice-based approach brought together biological sciences and material design through a series of iterative experiments. This, in turn, resulted in designing with the inherent characteristics of bacterial cellulose, and by doing so filaments were designed to be fabricated directly from fermentation. In this investigation, creative exploration was encouraged within a biological laboratory space, showing how interdisciplinary collaboration can offer innovative alternative bioproduction routes for textile filament production.
... The determining factors of 3D-printed mycelium-based composites can be divided into two main categories: (1) factors associated with the material itself, including material particle size, viscosity, and ingredient concentration; (2) factors associated with the printing environment and printing equipment, such as extrusion pressure, extrusion speed, nozzle diameter, toolpath geometry, and the 3D printer [26]. ...
The construction industry makes a significant contribution to global CO2 emissions. Material extraction, processing, and demolition account for most of its environmental impact. As a response, there is an increasing interest in developing and implementing innovative biomaterials that support a circular economy, such as mycelium-based composites. The mycelium is the network of hyphae of fungi. Mycelium-based composites are renewable and biodegradable biomaterials obtained by ceasing mycelial growth on organic substrates, including agricultural waste. Cultivating mycelium-based composites within molds, however, is often wasteful, especially if molds are not reusable or recyclable. Shaping mycelium-based composites using 3D printing can minimize mold waste while allowing intricate forms to be fabricated. In this research, we explore the use of waste cardboard as a substrate for cultivating mycelium-based composites and the development of extrudable mixtures and workflows for 3D-printing mycelium-based components. In this paper, existing research on the use of mycelium-based material in recent 3D printing efforts was reviewed. This review is followed by the MycoPrint experiments that we conducted, and we focus on the main challenges that we faced (i.e., contamination) and the ways in which we addressed them. The results of this research demonstrate the feasibility of using waste cardboard as a substrate for cultivating mycelia and the potential for developing extrudable mixtures and workflows for 3D-printing mycelium-based components.
... One of the forerunners of such explorations are mycelium-based composites (MBCs). MBCs are gaining momentum in recent years, with an increased number of publications appearing each year [1,2] Production of the material using fungi is researched in many fields of application. Flexible fungal materials (utilizing either fruiting bodies of fungi or pure mycelium are finding their way as fungal leather, foams, or paper-like materials [3]. ...
The paper discusses how characteristics of the mycelium growth process—namely different growth effectiveness depending on the nutrition content of the substrate, gradual solidification of the inoculated substrate, and bio-welding—can be a driving force for developing sustainable biofabrication processes of mycelium based composites (MBC) for architectural application. To explore this potential one-semester (12 weeks) seminar and one block seminar (2 weeks) with master-level students were held at the University of Stuttgart, and independent work within the Institute IBK2 was performed. The free experimentation with fabrication tactics resulted in the emergence of different investigation paths, tested with small-scale demonstrators, from which the most interesting three this paper presents in detail. The first is the two-phase printing process of mycelium substrate and subsidiary reusable support materials. It applied tests with the small, inorganic, loose substances (plastic pellets) extractable mechanically and meltable substances (wax) extracted by heating. The second path of investigation followed lost formworks created from hemp strings positioned inside the material. Finally, the third path is a particular case of lost formwork approach utilizing different tubular bandages stuffed with MBC and utilizing it later as a thick filament for other different form-giving deposition practices: layering, hanging, braiding, and knotting. All three investigation paths prove feasible, although their upscaling potential correlates strongly with the successful automation of the processes using CNC machines, which could provide the precision and sterility needed for this highly heterogenous and sensitive material. In addition, further developments in the material cultivation protocols are indispensable to provide a higher repetition of the results.
... This increases the chance of obtaining a material exhibiting comparable properties over the entire material volume. In the case of incomplete substrate sterilization, the produced biocomposite may exhibit various physical properties differing from those assumed [135]. The colonization of dead wood by fungi under natural conditions takes the form of microbial succession. ...
Mycelium-Based Composites (MBCs) are innovative engineering materials made from lignocellulosic by-products bonded with fungal mycelium. While some performance characteristics of MBCs are inferior to those of currently used engineering materials, these composites nevertheless prove to be superior in ecological aspects. Improving the properties of MBCs may be achieved using an adequate substrate type, fungus species, and manufacturing technology. This article presents scientifically verified guiding principles for choosing a fungus species to obtain the desired effect. This aim was realized based on analyses of scientific articles concerning MBCs, mycological literature, and patent documents. Based on these analyses, over 70 fungi species used to manufacture MBC have been identified and the most commonly used combinations of fungi species-substrate-manufacturing technology are presented. The main result of this review was to demonstrate the characteristics of the fungi considered optimal in terms of the resulting engineering material properties. Thus, a list of the 11 main fungus characteristics that increase the effectiveness in the engineering material formation include: rapid hyphae growth, high virulence, dimitic or trimitic hyphal system, white rot decay type, high versatility in nutrition, high tolerance to a substrate, environmental parameters, susceptibility to readily controlled factors, easy to deactivate, saprophytic, non-mycotoxic, and capability to biosynthesize natural active substances. An additional analysis result is a list of the names of fungus species, the types of substrates used, the applications of the material produced, and the main findings reported in the scientific literature.
... There are publications on biomass-fungi composites [22][23][24][25][26][27] and their applications [28][29][30][31]. These publications report the effects of fungal species, nutrient substrates, environmental growth conditions (e.g., light or dark and CO2 concentration) on mycelium-based biocomposites, biocomposite fabrication methods [25,32,33], and their effects on the mechanical properties of fabricated samples [34]. ...
Biomass–fungi composites, an emerging class of sustainable materials, have potential applications in the construction and packaging industries. Molding-based manufacturing methods are typically employed to make products from these composites. Recently, a 3D printing-based method was developed for biomass–fungi composites to eliminate the need for making molds and to facilitate customized product design compared with manufacturing methods based on molding and hot-pressing. This method has six stages: biomass–fungi material preparation; primary colonization; mixture preparation; printing; secondary colonization; and drying. This paper reports a study about the effects of waiting time between the mixture preparation and 3D printing using biomass–fungi composites. As the waiting time increased from 0.25 to 3 h, the hardness and compressibility of the prepared mixture increased. As the waiting time increased from 0.25 to 8 h, the shear viscosity showed a decreasing trend; the yield stress of the prepared mixture increased at the beginning, then significantly decreased until the waiting time reached 3 h, and then did not significantly vary after 3 h. As the waiting time increased, the storage modulus and loss modulus decreased, the loss tangent delta increased, and the minimum required printing pressure for continuous extrusion during extrusion-based 3D printing increased. The print quality (in terms of layer-height shrinkage and filament-width uniformity) was reasonably good when the waiting time did not exceed 4.5 h.
... To address the problems of textile distortion and difficulties with filling, the substrate mixture was replaced with a paste. The paste, originally developed for 3D printing mycelium, combines beechwood sawdust with paper clay, xanthan gum, glycerine, and water (Elsacker, 2021) to produce a smooth texture suitable for extrusion rather than hand packing. The extrusion technique was adapted to a filling technique, enabling ease of filling knitted tubes and a reduction in the distortion caused by the bulky substrate (figure 3). ...
The BioKnit prototype is a free-standing architectural construction fabricated using knitted fabric, mycelium, and bacterial cellulose. This paper documents the experimental work that underpins the development of BioKnit and presents a new methodological approach; the Living Textiles strategy that combines biological experimentation with parametric modelling and knit programming. Using knitted fabric, this fabrication system is capable of easily achieving complex, curvaceous architectural forms, as well as providing an integrated scaffold and mould to guide biomaterial growth and expression. This paper highlights specific aspects of the Living Textile Strategy to enable scalability, biocompatibility and material expression to extend and enhance the range of qualities achievable in architectural bio-construction.
... These bio-based materials, with their ability to fully biodegrade, are potential replacements for less-sustainable materials, such as bioplastics for petroleum-based plastics and SCOBY leather for animal leather. While bio-based materials have achieved visual similarity to their conventional counterparts, research is still in progress to improve their physical properties, durability, and fabrication processes so that bio-based materials will be viable alternatives [15]. In this regard, recent research suggests a need to move for biomaterials beyond artistic domains, such as bioart and biodesign, by characterizing the materials for broader applications. ...
Each new material developed opens a broader pallet of aesthetic and functional possibilities for designers. This paper introduces DIS to biofoam, a material that is water-soluble, biodegradable, and can be made conductive. We describe the material in detail: the process of making the material from scratch, the material’s fabrication into forms with hand-craft techniques, and present two HCI specific applications of the biofoam. The biofoam can be cooked, molded, layered, extruded, dissolved, or recooked opening up possibilities to consider the entire life cycle of the material in the design process. We contribute design considerations to allow designers to “tune” the biofoam to the desired quality, as well as a characterization of many aspects of the biofoam such as compression, spring back time, water permeability, and electrical conductivity. Finally, we discuss the unique opportunities this material and its life cycle bring to the design and HCI communities.
Traditional wood composites are produced with synthetic, formaldehyde-based
adhesives, commonly made from fossil-derived constituents, such as urea, phenol,
melamine, etc. Along with their undisputable advantages, these adhesives are
characterized by certain problems, connected with the emission of hazardous volatile organic compounds (VOCs), including free formaldehyde emission from the finished wood composites, which is carcinogenic to humans and harmful to the environment. The growing environmental concerns, connected with the adoption of circular economy principles, and the new, stricter legislative requirements for the emission of harmful VOCs, e.g., free formaldehyde, from wood composites, have posed new challenges to researchers and industrial practice, related to the
development of sustainable, eco-friendly wood composites, optimization of the available lignocellulosic raw materials, and use of alternative resources.
This reprint presents a collection of 10 high-quality original research and review papers providing examples of the most recent advances and technological developments in the fabrication, design, characteristics, and applications of eco-friendly wood and wood-based composites.
Living building materials (LBMs) were engineered that are capable of both biological and structural functions. LBMs were created by inoculating an inert structural sand-hydrogel scaffold with Synechococcus sp. PCC 7002, a photosynthetic cyanobacterium. The scaffold provided structural support for Synechococcus, which toughened the hydrogel matrix via calcium carbonate biomineralization. Temperature and humidity switches were utilized to regulate the metabolic activity of the microorganisms and achieve three successive regenerations of viable LBMs from one parent generation. Microbial viability in LBMs maintained in at least 50% relative humidity for 30 days was 9%–14%, which far exceeded literature values of microorganisms encapsulated in cementitious materials for similar timeframes (0.1%–0.4%). While structural function was maximized at ultradesiccated conditions, prolonged dehydration compromised microbial viability. Despite this tradeoff in biological-structural function, LBMs represent a platform technology that leverages biology to impart novel sensing, responsive, and regenerative multifunctionality to structural materials for the built environment.
Significant efforts exist to develop living/non-living composite materials—known as biohybrids—that can support and control the functionality of biological agents. To enable the production of broadly applicable biohybrid materials, new tools are required to improve replicability, scalability, and control. Here, the Hybrid Living Material (HLM) fabrication platform is presented, which integrates computational design, additive manufacturing, and synthetic biology to achieve replicable fabrication and control of biohybrids. The approach involves modification of multimaterial 3D-printer descriptions to control the distribution of chemical signals within printed objects, and subsequent addition of hydrogel to object surfaces to immobilize engineered Escherichia coli and facilitate material-driven chemical signaling. As a result, the platform demonstrates predictable, repeatable spatial control of protein expression across the surfaces of 3D-printed objects. Custom-developed orthogonal signaling resins and gene circuits enable multiplexed expression patterns. The platform also demonstrates a computational model of interaction between digitally controlled material distribution and genetic regulatory responses across 3D surfaces, providing a digital tool for HLM design and validation. Thus, the HLM approach produces biohybrid materials of wearable-scale, self-supporting 3D structure, and programmable biological surfaces that are replicable and customizable, thereby unlocking paths to apply industrial modeling and fabrication methods toward the design of living materials.
The photoelectrochemical (PEC) production of syngas from water and CO2 represents an attractive technology towards a circular carbon economy. However, the high overpotential, low selectivity and cost of commonly employed catalysts pose challenges for this sustainable energy-conversion process. Here we demonstrate highly tunable PEC syngas production by integrating a cobalt porphyrin catalyst immobilized on carbon nanotubes with triple-cation mixed halide perovskite and BiVO4 photoabsorbers. Empirical data analysis is used to clarify the optimal electrode selectivity at low catalyst loadings. The perovskite photocathodes maintain selective aqueous CO2 reduction for one day at light intensities as low as 0.1 sun, which provides pathways to maximize daylight utilization by operating even under low solar irradiance. Under 1 sun irradiation, the perovskite–BiVO4 PEC tandems sustain bias-free syngas production coupled to water oxidation for three days. The devices present solar-to-H2 and solar-to-CO conversion efficiencies of 0.06 and 0.02%, respectively, and are able to operate as standalone artificial leaves in neutral pH solution.
The construction industry faces severe problems resulting from low productivity and increasing shortages of skilled labor. The purposeful digitalization and automation of all relevant stages, from design and planning to the actual construction process appears to be the only feasible solution to master these urgent challenges. Additive concrete construction has a high potential to be a key part of the solution. In the first place, technologies are of interest which would enable large-scale, on-site manufacturing of concrete structures in accordance with the demands of contemporary architectural and structural design. The article at hand evaluates the state-of-the-art with respect to these requirements and presents the CONPrint3D concept for on-site, monolithic 3D-printing as developed at the TU Dresden. This concept is driven by the demands and boundary conditions of construction practice. It complies with common architectural norms, valid design codes, existing concrete classes and typical economic constraints. Furthermore, it targets the use of existing construction machinery to the highest possible extent. The interdisciplinary team of authors illuminates various perspectives on the new technology: those of mechanical engineering, concrete technology, data management, and construction management. Some representative results of completed work in these fields are presented as well.
This paper describes how 3D-printed formwork can be used to facilitate the integration of functional features in structurally optimised concrete slabs. The weight of concrete slabs represents the largest portion of the weight of a concrete framed, multi-storey building. Despite this significant share, slabs are usually designed as monolithic, oversized boxes due to various construction constraints. Optimised design alternatives, featuring funicular shapes, differentiated ribs, profiled soffits and hollow sections use significantly less material and can moreover integrate building services within the thickness of the slab, such as heating, cooling and ventilation. Nevertheless, both the optimised external geometry and the internal network of functional voids present very complex fabrication challenges for concrete. This is because standard commercial formwork systems are not suitable for bespoke designs. To address this limitation, this research demonstrates how fused-deposition 3D printing can be used for the fabrication of custom formwork for a functionally integrated concrete slab. The resulting prototype efficiently uses material and integrates provisions for an active beam ventilation system within the standard structural depth of the slab. All these intricate geometric features are achieved with an ultra-lightweight 3D-printed formwork, which weighs less than 15 kg for the 660 kg concrete slab.
The current physical goods economy produces materials by extracting finite valuable resources without taking their end of the life and environmental impact into account. Mycelium-based materials offer an alternative fabrication paradigm, based on the growth of materials rather than on extraction. Agricultural residue fibres are inoculated with fungal mycelium, which form an interwoven three-dimensional filamentous network binding the feedstock into a lightweight material. The mycelium-based material is heat-killed after the growing process. In this paper, we investigate the production process, the mechanical, physical and chemical properties of mycelium-based composites made with different types of lignocellulosic reinforcement fibres combined with a white rot fungus, Trametes versicolor. This is the first study reporting the dry density, the Young's modulus, the compressive stiffness, the stress-strain curves, the thermal conductivity, the water absorption rate and a FTIR analyse of mycelium-based composites by making use of a fully disclosed protocol with T. versicolor and five different type of fibres (hemp, flax, flax waste, softwood, straw) and fibre processings (loose, chopped, dust, pre-compressed and tow). The thermal conductivity and water absorption coefficient of the mycelium composites with flax, hemp, and straw have an overall good insulation behaviour in all the aspects compared to conventional materials such as rock wool, glass wool and extruded polystyrene. The conducted tests reveal that the mechanical performance of the mycelium-based composites depends more on the fibre processing (loose, chopped, pre-compressed, and tow), and size than on the chemical composition of the fibres. These experimental results show that mycelium-composites can fulfil the requirements of thermal insulation and have the potential to replace fosile-based composites. The methology used to evaluate the suitability and selection of organic waste-streams proved to be effective for the mycelium-material manufacturing applications.
A kind of novel sustainable mycelium/cotton stalk composite were prepared in laboratory by growing white rot fungus of Ganoderma lucidum on cotton stalk and stored in a block mold followed by hot-pressing process. To improve the mechanical properties, the composites were, respectively, subject to water immersion prior to hot-pressing at various water uptake (20%, 30%, 40% and 50%). The mechanical properties including flexural and internal bonding properties were tested. The results showed that with increasing water uptake, the mechanical properties of the composites increased at first after reaching the maximum at water uptake of 30 wt% in accordance with the saturation point of cotton stalk. Therefore, the water contributed to the good interface between mycelium and cotton stalk particles, where the flexural and internal bonding strength met the standard for non-load bearing particleboard listed in ANSI A208.1-2016. However, at water uptake higher than 30 wt%, no further improvement occurred due to the excessive water located in cell lumen rather than in the cell wall.
Recent convergence of biotechnological and design tools has stimulated an emergence of new design practices utilizing natural mechanisms to program matter in a bottom-up approach. In this paper, the fibrous network of mycelium—the vegetative part of fungi—is employed to produce sustainable alternatives for synthetic foams. Current research on mycelium-based materials lacks essential details regarding material compositions, incubation conditions, and fabrication methods. The paper presents the results of ongoing research on employing mycelium to provide cleaner architecture and design products with sustainable lifecycles. The paper opens with a critical review of current projects, products, and scientific literature using mycelium in design and architecture. In the second section, material properties of varied fungi-substrate compositions and fabrication methods are evaluated and compared through changes in essential chemical parameters during fermentation, visual impression, water absorbency, and compression strength tests. Then, potential architecture and design implications related to the material properties are discussed. Results indicate a clear correlation between fungi, substrate, mold properties, and incubation conditions on final material characteristics, depicting a clear effect on material density, water absorbency, and the compressive strength of the final bio-composite. Finally, two primary case studies demonstrate implications for mycelium-based composites for circular design and architectural applications. The study shows that in order to produce desirable designs and performance within an inclusive circular approach, parameters such as material composition and fabrication conditions should be considered according to the target function of the final product throughout the design process.
A novel sustainable mycelium/cotton stalk composite was prepared in laboratory by growing cotton stalk with white rot fungus of Ganoderma lucidum in a block mold followed by hot-pressing process. The effects of pressing temperature (160, 180, and 200 °C) on physical, mechanical, and thermal properties of the composites were investigated. The results showed that with increasing pressing temperature, most properties of the composites increased significantly owing to the improved interfacial bonding at high temperature. However, it showed slight negative effect to the thermal decomposition resistance, while with increasing hot-pressing temperature, the thermal decomposition resistance of the composites was improved. After cultivation of mycelium, the structure of the cotton stalk particles was destroyed and main components, such as hemicelluloses and lignin degraded. However, after hot-pressing, the structures of the composites became compact and new chemical bonds between mycelium and cotton stalk particles occurred. The optimal group of this study was achieved under 200 °C hot-pressing, where the flexural and internal bonding strength was comparable to non-load bearing fibreboard.