Multifunctional high-performance porous mycelium-based composites and production method thereof

Abstract

A mycelium-based composite is provided. The mycelium-based composite comprises a 3D- printed wood-polylactic acid porous scaffold, a nutrient-rich layer coated onto inner and outer surfaces of the 3D-printed wood-polylactic acid porous scaffold, and mycelium of a fungus grown on the inner and outer surfaces of the coated 3D-printed wood-polylactic acid porous scaffold, forming a network of hyphae covering the inner and outer surfaces of the coated 3D- printed wood-polylactic acid porous scaffold, wherein the 3D-printed wood-polylactic acid porous scaffold has a porosity ranging from 50% to 90%. A method of producing the mycelium- based composite is also provided.

Description

MULTIFUNCTIONAL HIGH-PERFORMANCE POROUS MYCELIUM-BASED COMPOSITES AND PRODUCTION METHOD THEREOFCROSS REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of priority to the Singapore patent application no. 10202401441U filed on 21 May 2024, the contents of which are hereby incorporated by reference in its entirety for all purposes.TECHNICAL FIELD

[0002] This application relates to a mycelium- based composite, a method of producing the same and articles fabricated from the mycelium-based composite. In particular, the application relates to a mycelium-based composite with improved strength and multifunctionality, a method for producing the same, and articles fabricated from the mycelium-based composite.BACKGROUND

[0003] Mycelium, the roots of mushrooms, has long been acknowledged for its ability to bind and colonize organic matter by forming a dense network of hyphae. Innovators and researchers have harnessed this eco-friendly natural process to develop mycelium-based composites.

[0004] Existing methods for producing mycelium-based composites (MBCs) typically involve placing organic matter, such as agricultural waste, sawdust, coffee grounds, or various cellulosic materials, inside predefined molds for shaping. However, these methods suffer from limitations including low mechanical strength and restricted design freedom, confining the use of mycelium-based composites primarily to low-strength applications. Extensive efforts have been made to improve their mechanical performance, such as varying the type and particle-size distribution of the organic substrate, selecting different fungal species, optimizing growth conditions, or incorporating additives and reinforcements. Post-processing techniques, such ashot or cold pressing, have also been commonly employed to enhance the strength of myceliumbased composites. Despite these efforts, the highest tensile strength reported for myceliumbased composites remains at 0.72 MPa. While hot and cold pressing can significantly improve the strength of mycelium-based composites, these methods still restrict design freedom, being suitable only for simple solid geometries.

[0005] It is therefore desirable to provide a mycelium-based composite and a method for producing the mycelium-based composite that seeks to address at least one of the problems described hereinabove or at least to provide an alternative solution.SUMMARY

[0006] According to a first aspect of the present disclosure, a mycelium-based composite is provided. The mycelium-based composite comprises a 3D-printed wood-polylactic acid (PLA) porous scaffold; a nutrient-rich layer coated onto inner and outer surfaces of the 3D-printed wood-polylactic acid porous scaffold; and mycelium of a fungus grown on the inner and outer surfaces of the coated 3D-printcd wood-polylactic acid porous scaffold, forming a network of hyphae covering the inner and outer surfaces of the coated 3D-printed wood-polylactic acid porous scaffold, wherein the 3D-printed wood-polylactic acid porous scaffold has a porosity ranging from 50% to 90%.

[0007] In some embodiments, the nutrient-rich layer comprises peptone, malt and agar.

[0008] In some embodiments, the mycelium-based composite has a compressive strength ranging from 0.35 to 13.94 MPa at 90% to 50% porosity of the 3D-printed wood-polylactic acid porous scaffold.

[0009] In some embodiments, the mycelium is an inactive mycelium.

[0010] In some embodiments, the mycelium is a living mycelium.

[0011] In some embodiments, the 3D-printed wood-polylactic acid porous scaffold comprises a Triply Periodic Minimal Surface (TPMS) structure.

[0012] According to a second aspect of the present disclosure, a method of producing a mycelium-based composite is provided. The method comprises fabricating a wood-polylactic acid porous scaffold by 3D printing; coating the wood-polylactic acid porous scaffold with a nutrient-rich layer; inoculating the coated wood-polylactic acid porous scaffold with a fungal culture to facilitate mycelium growth; allowing the mycelium to grow and colonize the coated wood-polylactic acid porous scaffold to obtain a mycelium-based composite comprising the wood-polylactic acid porous scaffold coated with the nutrient-rich layer, and the mycelium grown on inner and outer surfaces of the coated wood-polylactic acid porous scaffold, forming a network of hyphae covering the inner and outer surfaces of the coated wood-polylactic acid porous scaffold, wherein the wood-polylactic acid porous scaffold has a porosity ranging from 50% to 90%.

[0013] In some embodiments, the method further comprises deactivating the mycelium by heating to obtain the mycelium-based composite with an inactive mycelium.BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various embodiments of the present disclosure are described hereinbelow in the detailed description with reference to the following drawings:FIG. 1 is a perspective view of a mycelium- based composite in accordance with an embodiment of the present disclosure.FIG. 2A is an electron micrograph of the 3D printing filament, revealing wood flakes 201 distributed in the polylactic acid (PLA) matrix 202 with some micropores (scale bar is 100 pm). FIG. 2B is a micro-computed tomography (micro-CT) reconstructed data showing the 3D distribution and percentage of different elements in the 3D printing filament in an exemplary embodiment of the present disclosure.FIG. 3 shows a CAD model of the functionally graded structure used for 3D printing of the wood-PLA porous scaffold reported in FIG. 6C (scale bar is 10 mm).FIG. 4 is a schematic illustrating the effect of the dipping time of the PMA solution on the wood-PLA.FIG. 5 shows the growth progression of the mycelium-based composite at 5% and 15% malt concentration in PMA solution over time. The figure shows morphological changes at 7, 14, and 21 days of mycelium growth (scale bar is 10 mm). The inset shows SEM images of the mycelium hyphae (scale bar is 10 pm).FIG. 6A shows the growth of mycelium with time on wood-PLA with nutrient-rich layer containing 10% w / v malt (scale bar is 10 mm). The inset shows the microscopic network of mycelial hyphae, where the thicker arrows indicate porosity, and the thinner arrows show interwoven connections and hyphae (scale bar is 10 pm).FIG. 6B are graphs showing the increase in mycelium mass (top) and the corresponding decrease in moisture (bottom) as a function of growth time.FIG. 6C is a 5x5 matrix representation of the change in average hyphae diameter and mycelium density with change in unit cell size and porosity of the porous scaffold after 21 days of growth. Lighter colour represents low mycelium density and darker represents high mycelium density.FIG. 7A illustrates the difference of the air flow in the 50% and 90% unit cell porosity gyroid scaffold from CFD simulation. Low air flow in 50% results in less oxygen supply and low carbon dioxide removal from the porous scaffold, resulting in low density mycelium, while high air flow and continuous supply of oxygen and removal of carbon dioxide results in high density mycelium (scale bar is 10 mm).FIG. 7B illustrates the air flow through 3D models of mycelium-based composites with 50% porosity (U50) and 90% porosity (U90). U90 shows more air flow.FIG. 8 illustrates mycelium growth inside the mycelium-based composite, (a) shows the internal mycelium growth of a mycelium-based composite with 80% porosity, and (b) shows the cut cross-section of the internal pores filled with mycelium of a mycelium-based composite with70% porosity (scale bar is 10 mm).FIG. 9A shows deconvolution plots of the inactive mycelium-based composites kept at three different environment conditions (IL: inside lab; OL: outside lab; OLIB: outside lab but enclosed inside a box) on Day 300.FIG. 9B are bar plots showing the percentage of different elements in the deconvolution plots of FIG. 9A.FIG. 9C shows XPS plots for the elements present in the mycelium-based composites kept at the three different conditions (IL, OL, OLIB).FIG. 9D shows Fourier Transform Infrared (FTIR) plots of active and living mycelium-based composites kept under the three different environmental conditions.FIG. 10A shows the deconvolution plots for PLA, wood-PLA and mycelium-based composite (MBC).FIG. 10B are bar plots showing the percentage of different bonding in the deconvolution plots of FIG. 10A.FIG. 10C shows XPS plots for the elements present in PLA, wood-PLA and MBC.FIG. 10D shows FTIR plots for PLA, wood-PLA and MBC samples, showing different bond stretching.FIG. 11 is a schematic diagram showing the steps for fabricating the mycelium-based composite in accordance with an embodiment of the present disclosure.FIG. 12 is a strength-density map of the mycelium-based composites (MBCs) prepared in accordance with the method of the present disclosure. The stars are the readings for the mycelium-based composites of the present disclosure; the smaller circles are the readings for the wood-PLA porous scaffold without the mycelium as well as existing materials; the bigger circles are the readings for bricks, while the big ovals are the readings for other MBCs. Conventional polymers, composites, ceramics and wood products are also represented.FIG. 13A are pictures of the scaffolds and mycelium-based composites before and after exposure to flame, showing the differences in structural integrity and char formation (scale bar is 10 mm).FIG. 13B is a bar graph showing the change in weight between before and after vertical fire testing of the wood-PLA scaffolds and the mycelium-based composites.FIG. 13C shows the electron micrographs of the melted wood-PLA (left) and char U70_my MBC (right) surfaces after flame exposure (scale bar is 10 pm).FIG. 14A shows the electron microscopy images of the mycelium developed on U50_my and U90_my samples. Arrow marks show the porosity in the skin. The images show that there are more mycelium hyphae in the sample with 90% porosity as compared to the sample with 50% porosity (scale bar is 100 pm).FIG. 14B is a graph showing the variation in porosity and average hyphae diameter with a change in porosity in the design of the mycelium-based composite.FIG. 15A is a graph showing the variation of strength in mycelium-based composites with changing malt concentration. Different zones represent the growth strategy of the mycelium.FIG. 15B is a graph showing the variation of energy absorption with malt concentration in the PMA solution.FIG. 16A are images of the porous scaffolds before (top) and after (bottom) 21 days mycelium growth for 3 different designs: uniform 70% porosity, graded porosity from 70 to 90% porosity, and graded unit cell size from 10 to 5 mm (scale bar is 10 mm).FIG. 16B is a graph showing stress-strain curves of the 3 different designs before and after mycelium growth. Inset images show the deformation of uniform 70% porosity MBC at different strains.FIG. 17 shows the force distribution mechanism in a mycelium-based composite (181), representing force carried by a wood-PLA porous scaffold (182) in the Fi(elastic + plastic) region (183) and a mycelium layer (184) in the F2 plastic region (185).FIG. 18A is a graph showing the strength (black) and improvement in strength with respect to wood-PLA porous scaffold (%, grey) of the mycelium-based composites as a function of the porosity of the uniform scaffold.FIG. 18B is a graph showing the variation of energy absorption of the mycelium-based composites with changing porosity of the wood-PLA porous scaffold samples.FIG. 19 is a graph comparing the compressive stress-strain curves of the porous scaffolds with and without mycelium. ‘G80’ represents a gyroid scaffold with 80% porosity without mycelium, while ‘G80_my’ represents a gyroid mycelium-based composite with 80% porosity. The inset in the graph shows the deformed structures at 30% strain.FIG. 20 shows the infrared thermographic images highlighting temperature distribution across various type of samples. The results show that porous mycelium-based composite has better thermal insulation. (Note that small cylindrical holes in the solid wood-PLA samples (0% porosity) are just to make sure mycelium can grow on both sides of the sample, and this should not be mistaken as porosity).FIG. 21A illustrates infrared thermographic images depicting the temperature distribution across U70_my, PG_my, and CG70_my MBCs. Inset images provide visual representation of the samples.FIG. 21B shows the average temperature change with time during heating and cooling for the wood-PLA porous scaffolds, the mycelium-based composites and commonly used polyurethane foams (HDPU and LDPU).FIG. 22 are images of the samples used for experimental thermal conductivity measurement, (a) is an image of the wood-PLA porous scaffold, and (b) are images of the uniform and graded mycelium-based composites (scale bar is 10 mm).FIG. 23 is a Finite Element Modelling (FEM) representation of the heat flux (top) and temperature (bottom) distributions for U70_my, PG_my, PG_my* and CG70_my MBCs, emphasizing the effect of the graded design in the mycelium-based composites (In PG_my MBC, heat input (source) is at the high porosity side and in PG_my*. heat input is at the low porosity side).FIG. 24 is a graph showing the thermal conductivity as a function of the scaffold porosity for the different mycelium-based composites designs, obtained by FEM. Low thermal conductivities represent the influence of mycelium integration, and the significant difference in the PG_my and PG_my* MBCs thermal conductivities represent influence of mycelium and design.FIG. 25 shows FEM thermal contour, representing the heat flux and temperature distribution in U90_my MBCs and variation with change in porosity.FIG. 26A illustrates a picture of the U70 scaffold and the U70_my MBC after t =10 s in a flame, showing the difference in flame spread.FIG. 26B is a schematic representing the difference in fire spread mechanism in wood-PLC and MBC.FIG. 27 is a graph showing the water absorbed by the samples with and without mycelium when dipped in water over time. The inset on the graph shows multiple samples immersed in the deionized water.FIG. 28A is a picture of a mycelium-based composite repelling water droplets (scale bar is 5 mm). The contact angle 9Cis measured after 30 min.FIG. 28B shows goniometer images displaying the contact angle change with time for wood- PLA and mycelium-based composite.FIG. 28C is a graph showing water absorption as a function of days for U70 scaffold and U70_my MBC.FIG. 28D is a schematic of the setup used to study water absorption of the samples.FIG. 28E is a graph showing mass decrease (water release) and increase (water uptake) as a function of time for U70 scaffold and U70_my MBC during cycling fluctuation of humidity.FIG. 29A is a graph showing the compressive strength over 300 days for U80_my MBCs left in different environmental conditions, when the mycelium is inactive.FIG. 29B is a graph showing the change in weight of the mycelium-based composites kept at different environmental conditions over 300 days.FIG. 29C shows the pictures of the U80_my MBCs left at different environmental conditions on day 0 and day 300, when the mycelium is inactive (scale bar is 10 mm).FIG. 29D is a graph showing the compressive strength of U80_my MBCs left outside the lab (OL) over 100 days, when the mycelium is still active and living.FIG. 30 depicts bar charts showing the change in compressive strength of the mycelium-based composites placed under different environmental conditions over a period of 100 days.FIG. 31A illustrates a 3D model and picture of a miniature prototype house made of myceliumbased composites (myco-house) (scale bar is 10 mm).FIG. 31B is an exploded CAD view showing different designs of the walls of the myco-house of FIG. 31 A.FIG. 31C is a picture of the myco-house of FIG. 31 A, with installed i-buttons 320.FIG. 31D is a graph showing the temperature variation recorded by sensors placed inside and outside the walls of the myco-house over 3 days. The inset shows a magnifying view of the temperature curves on Day 1 from 12 pm to 12 am (data shown arc only after the response became stable).FIG. 31E is a model illustrating the heat damping in the myco-wall made from mycelium-based composites of the present disclosure.FIG. 31F is a radar plot comparing the performance parameters of wood-PLA, the CG50_my mycelium-based composite of the present disclosure, clay brick and PU foam (Less weight is 1 / Density, and Thermal insulation is 1 / Thermal conductivity).FIG. 32 depicts a representative volume element (RVE) of the mycelium-based composite, showing a colour representation of different components.FIG. 33 depicts heat flux contour in RVE of the mycelium-based composite.DETAILED DESCRIPTION

[0015] The following detailed description is made with reference to the accompanying drawings, showing details and embodiments of the present disclosure for the purposes of illustration. Features that are described in the context of an embodiment may correspondingly be applicable to the same or similar features in the other embodiments, even if not explicitly described in these other embodiments. Additions and / or combinations and / or alternatives as described for a feature in the context of an embodiment may correspondingly be applicable to the same or similar feature in the other embodiments.

[0016] In the context of various embodiments, the articles “a”, “an” and “the” as used with regard to a feature or element include a reference to one or more of the features or elements.

[0017] In the context of various embodiments, the term “about” or “approximately” as applied to a numeric value encompasses the exact value and a reasonable variance as generally understood in the relevant technical field, e.g., within 10% of the specified value.

[0018] As used herein, the term “and / or” includes any, and all combinations of one or more of the associated listed items.

[0019] As used herein, “comprising” means including, but not limited to, whatever follows the word “comprising”. Thus, use of the term “comprising” indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present.

[0020] As used herein, “consisting of’ means including, and limited to, whatever follows the phrase “consisting of’. Thus, use of the phrase “consisting of’ indicates that the listed elements are required or mandatory, and that no other elements may be present.

[0021] A detailed description of various embodiments will be described below with reference to the drawings.

[0022] The present disclosure provides a mycelium-based composite with improved mechanical strength and multiple functional properties, including thermal insulation, fire resistance, hydrophobicity, and durability. These properties make it suitable for variousapplications, including for use as a sustainable alternative to clay bricks currently used in construction, which contribute to pollution during processing and are typically disposed of in landfills.

[0023] Referring to FIG. 1, the present disclosure provides a mycelium- based composite 100 comprising a 3D-printed wood-polylactic acid (PLA) porous scaffold 101, a nutrient-rich layer coated onto inner and outer surfaces of the 3D-printed wood-PLA porous scaffold; and mycelium of a fungus grown on the inner and outer surfaces of the coated 3D-printed wood- PLA porous scaffold, forming a network of hyphae covering the inner and outer surfaces of the coated 3D-printed wood-PLA porous scaffold, wherein the 3D-printed wood-PLA porous scaffold has a porosity ranging from 50% to 90%.

[0024] The present disclosure leverages the design capabilities of 3D printing to fabricate a porous scaffold using fused deposition modeling (FDM) method. A filament comprising wood flakes and polylactic acid (PLA) is used for 3D-printing of the wood-PLA porous scaffold.

[0025] The term “wood flakes” as used herein refers to small, thin pieces of bio-based raw materials from low-cost discarded wood, which is the byproduct of woodworking or wood processing. In some embodiments, wood flakes may include corn. The wood flakes together with the polylactic acid (PLA) are converted into filaments for 3D printing of the porous scaffold. This filament is selected as mycelium grows well on lignocellulosic biomass, including wood, while PLA enhances the printability of the mycelium-based composite, which is also biodegradable. Due to the inherent strength of the wood-PLA composite filament, the mechanical strength of the porous scaffold is significantly higher compared to existing moldbased and 3D-printed organic structures.

[0026] FIG. 2A is an electron micrograph of the 3D printing filament, revealing wood flakes 201 distributed in the PLA matrix with some micropores 202 (scale bar is 100 pm). FIG. 2B is a micro-computed tomography (micro-CT) reconstructured dataset illustrating the 3D distribution and percentage of different elements in the 3D printing filament in an exemplaryembodiment. The figure depicts the wood-PLA filament 203, which consists of wood flakes 204 at 27.27%, PLA 205 at 53.45% and the pores 206 at 19.28%. One skilled in the art will appreciate that other combinations of the components in the wood-PLA filament may be employed without departing from the scope of the present disclosure.

[0027] In various embodiments, the wood-PLA porous scaffold comprises wood flakes and polylactic acid (PLA) in a weight ratio of 40:60.

[0028] The facile and high-quality printability achieved through the fused deposition modeling (FDM) method enables the fabrication of complex porous scaffolds. The porosity of the scaffold enhances oxygen diffusion and increases its surface area during the incubation period of the mycelium. The continuous supply of oxygen and increased surface area facilitate the growth of uniform, thick, and denser layers of mycelium throughout the scaffold. These properties render the mycelium-based composite suitable for use as a high-performance structural material.

[0029] In various embodiments, the porous scaffold comprises a Triply Periodic Minimal Surface (TPMS) structure. Suitable TPMS structures include, but are not limited to, gyroid, double gyroid, lidinoid, Schwarz D and Schwarz P structures.

[0030] In some embodiments, the TPMS structure comprises a gyroid geometry.

[0031] In the design of the porous scaffold, unit cell size in the range of 5 to 25 mm and porosity of 50% to 90% are considered (FIG. 3). The range is decided based on printability and practical application. Too small unit cell sizes are difficult to print, whereas too large ones create wide gaps that are challenging for the mycelium to bridge. Similarly, porosities above 90% are difficult to print, while below 50% result in porous scaffolds that do not align with the scope of the mycelium-based composite described in the present disclosure. Furthermore, small pore sizes may become clogged during the coating process, leading to an uneven coating of the nutrient-rich layer and preventing the internal spread of fungal hyphae.

[0032] In various embodiments, the wood-PLA porous scaffold has a porosity ranging from 50% to 90%, 70% to 90% or 70% to 80%.

[0033] In some embodiments, the mycelium-based composite has a graded porosity ranging from 50% to 90%, 70% to 90% or 70% to 80%.

[0034] In some embodiments, the mycelium-based composite has a unit cell size ranging from 5 to 25 mm, preferably 5 to 10 mm or 5 to 20 mm.

[0035] In some embodiments, the mycelium-based composite has a graded unit cell size ranging from 5 to 25 mm, preferably 5 to 10 mm.

[0036] In some embodiments, the mycelium- based composite has a graded unit cell size and a graded porosity.

[0037] In various embodiments, the wood-PLA porous scaffold is macroporous, while the mycelium-based composite is microporous. The micropores in the mycelium-based composite facilitate moisture retention via capillary action, creating an environment that supports mycelium proliferation and metabolic activity. The synergistic presence of the macroporcs from the wood-PLA porous scaffold and the micropores from the mycelium-based composite leads to multifunctional, high-strength and sustainable mycelium-based composite.

[0038] In various embodiments, the mycelium-based composite has a compressive strength ranging from 0.35 to 13.94 MPa at 90% to 50% porosity of the wood-PLA porous scaffold.

[0039] Mycelium requires a consistent supply of nutrients, optimal humidity levels, and a suitable pH environment to support efficient growth and development. Mycelium can absorb nutrients from the wood; however, the presence of polylactic acid restricts the growth. Therefore, a nutrient-rich layer is coated on the surfaces of the wood-PLA porous scaffold to provide a consistent supply of nutrients for supporting efficient mycelium growth. The surfaces include the outer surface and the inner surface of the wood-PLA porous scaffold. In some embodiments, the outer surface includes the bottom outer surface of the wood-PLA porous scaffold.

[0040] In various embodiments, the nutrient-rich layer comprises peptone (P), malt (M), and agar (A), where peptone serves as a source of micronutrients, malt provides carbohydrates, and agar helps maintain moisture and adjust rheology, creating an optimal growth environment for mycelium growth.

[0041] The nutrient-rich layer is formed by dipping the 3D-printed wood-PLA porous scaffold into a PMA solution comprising peptone, malt, and agar to form the nutrient-rich layer on the inner and outer surfaces of the wood-PLA porous scaffold. The dipping duration varies depending on the desired thickness of the nutrient-rich layer. As the dipping time increases, the thickness of the nutrient-rich layer increases. However, clogging of the wood-PLA porous scaffold may occur when the dipping time is too long.

[0042] FIG. 4 is a schematic illustrating the effect of the dipping time of the PMA solution 401 on the wood-PLA porous scaffold 402. Achieving an optimal dipping time is necessary to prevent the blockage of unit cell pores while ensuring sufficient nutrient coating. In various embodiments, the 3D-printcd wood-PLA porous scaffold is dipped into the PMA solution for a duration of 5-10 seconds. A single dip is typically sufficient to form a thin and uniform coating. However, those skilled in the art will recognize that multiple dipping steps may be employed if additional coating thickness or a longer coating time is required, particularly for more complex porous scaffolds.

[0043] Malt is the main component that influences the growth and determines the exploration (guerilla) or exploitation (phalanx) growth behaviour of the mycelium. Since it is desired to form a thick, dense, and uniform mycelium layer onto the porous scaffold, malt concentrations between 2% w / v and 20% w / v were considered, while keeping agar and peptone constant in the PMA solution. For 2 to 5% w / v malt, the mycelium still exhibits exploration behaviour, forming a fluffy and highly porous mycelium layer (FIG. 5). At 15 to 20% w / v malt, the mycelium exhibits exploitation behaviour (FIG. 15 A), with a dense but slow mycelium formation so that even after 21 days, the porous scaffold was not entirely covered. At 10%> w / vmalt, there is a balance between exploration and exploitation, resulting in a healthy and vigorous growth of the mycelium which covers the entire porous scaffold homogeneously.

[0044] In various embodiments, the nutrient-rich layer comprises 2 to 20% w / v malt. In some embodiments, the nutrient-rich layer comprises 5 to 10% w / v of malt.

[0045] In various embodiments, the nutrient -rich layer comprises 0.1% w / v peptone. 2 to 20% w / v malt and 2.4% w / v agar. In some embodiments, the nutrient-rich layer comprises 0.1 % w / v peptone, 5 to 10% w / v malt and 2.4% w / v agar. In other embodiments, the nutrient-rich layer comprises 0.1% w / v peptone, 10% w / v malt and 2.4% w / v agar.

[0046] In the embodiments described hereinbelow, 10% w / v malt was used unless otherwise stated.

[0047] In one exemplary embodiment, 10% w / v malt and 40 mm cubic uniform gyroid sample with 70% porosity was evaluated. The results show that the mycelium-based composite was completely covered with mycelium in 14 days. An addition of 7 days led to the formation of highly branched hyphae and a dense mycelium layer. FIG. 6A illustrates the growth of mycelium 601 with time on wood-PLA porous scaffold with the nutrient-rich layer 602 containing 10% w / v malt (scale bar is 10 mm). The inset shows the microscopic network of mycelial hyphae, where the thicker arrows indicate porosity, and the thinner arrows show interwoven connections and hyphae (scale bar is 10 pm). In the final week of incubation, although the mycehum mass reaches saturation, it displays active branching and expands its network without an increase in total biomass (FIG. 6B).

[0048] To achieve the desired final properties of the mycelium-based composite, the mycelium is grown on the entire 3D-printed wood-PLA porous scaffold. Without mycelium, the porous scaffold would absorb water, and its mechanical and other properties would decrease rapidly with time. Therefore, it is essential that the nutrient-rich layer covers substantially 100% of the 3D-printed wood-PLA porous scaffold surfaces, to allow the mycelium to grow on the layer and fully cover the 3D-printed wood-PLA porous scaffold. In some embodiments, thesurfaces to be coated include not only the outer and inner surfaces of the 3D-printed wood-PLA porous scaffold but also the bottrom outer surface.

[0049] The mycelium is grown from fungal species, selected from the genus Ganoderma or Pleurotus. In some embodiments, the mycelium is grown from the species Ganoderma lucidum. In other embodiments, the mycelium is grown from the species Pleurotus ostreatus.

[0050] The growth of the mycelium depends on the composition of the nutrient-rich layer, unit cell size, and the porosity of the porous scaffold.

[0051] On the porous scaffold, the hyphal diameter and density in the mycelium layer were measured from electron micrographs after 21 days of growth (FIG. 6C). Larger hyphal densities are often associated with higher unit cell porosity, suggesting a possible relation between the structure of the hyphae and the overall porosity of the scaffold. However, the hyphal diameter did not show a clear relationship with the unit cell size and porosity of the scaffold. In general, the hyphal diameter varies between 0.85 and 1.04 pm, and the mycelium has a density ranging between 41.68 and 81.43%. The high mycelium density obtained at 90% unit cell porosity results from the efficient and continuous supply of oxygen, which is necessary for mycelium growth, while it avoids carbon dioxide build-up. Real-time computational flow dynamics (CFD) simulation of the porous scaffolds with 50% and 90% unit cell porosities show higher and continuous airflow at 90% porosity and low and stagnant air flow at 50% (FIG. 7A and FIG. 7B). This is visualised by the wood-PLA brown colour (the darker area 701 shown in the top right-hand image of FIG. 7A) appearing below the mycelium on the porous scaffold with 50% porosity after 21 days growth, whereas the wood-PLA colour is not visible anymore on the porous scaffold with 90% porosity, as shown in the bottom right-hand image of FIG. 7A. Also, the connected porous network in the porous scaffold aids in the internal mycelium growth 801 (FIG. 8).

[0052] In various embodiments, the mycelium is an inactive mycelium. The inactive mycelium is prepared by heating the mycelium-based composite to kill the mycelium. In someembodiments, the mycelium is killed after 21 days of incubation. The inactive mycelium is stable and durable for 300 days or longer under standard environmental conditions.

[0053] In some embodiments, the mycelium is a living mycelium. For the living mycelium where the mycelium is not deactivated by heating, the organism is still alive. The living mycelium is stable and durable for less than 100 days under standard environmental conditions. In some embodiments, the living mycelium may be deactivated or killed any time within the 100 days.

[0054] Mycelium naturally decomposes lignocellulosic material by producing enzymes like hemicellulases, cellulases, and ligninases, which break down hemicellulose, cellulose, and lignin in wood. The weakened wood-PLA porous scaffold creates pathways for the degradation of PLA as well. This results in a synergistic effect, with the mycelium breaking down both wood and PLA components of the mycelium-based composite, ultimately aiding the decomposition of the entire structure more effectively than it would for wood or PLA alone.

[0055] The change in chemical structure and chemical bonding at day 0 and day 300 for the mycelium-based composites with inactive mycelium was studied using XPS (FIGs. 9A, 9B and 9C), which the results will be discussed in the Example section hereinbelow. FIG. 9D shows the FTIR results and the results show no change in the intensity and bonding for the inactive mycelium (samples: IL (inside lab); OL (outside lab) and GLIB (outside lab & inside a box)). However, the shift in the FTIR curve for the living mycelium (OL-active (outside lab-active)) shows a strcutural change in bond strength or chemical degradation.

[0056] The slow degradation of the mycelium-based composite while the mycelium is still active (living) presents significant advantages for sustainable construction. Its controlled biodegradability makes it suitable for temporary structures or modular buildings, allowing for eco-friendly disposal at the end of its life cycle with minimal waste. However, for long-term durability, the mycelium can be killed or deactivated after it has fully grown on the porous scaffold. The present disclsoure has thus introduces a mycelium-based composite that can beused for both short-term and long-term construction applications. Example 9 illustrates this concept with a small mycelium house (myco-house) and compares the performance of the mycelium-based composite with conventional building materials across key parameters.

[0057] It should be noted that unless specifically mentioned, references to mycelium- based composite pertain to their inactive state.

[0008] Interaction and adhesion between porous scaffold and mycelium

[0059] Understanding the interaction and adhesion between the porous scaffold and mycelium is crucial to reveal changes in chemical structure during mycelium growth which impacts the composite's performance. The chemical composition and bonding structure of PLA, wood-PLA, and the mycelium-based composite (MBC) were studied using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) spectroscopy (FIGs. 10A to 10D). C-C / C-H (alkyl bonds) and C=O (carbonyl bonds) are the signature peaks for the polymer backbone in PLA. In the wood-PLA, C-0 (ether or hydroxyl bonds) intensity increases due to the lignoccllulosic components of wood. The presence of O-C=O (ester linkages) increases from the interactions between PLA and wood flakes. The C=O (carbonyl group) in the mycelium-based composite comes from the carbohydrate breakdown from the malt. FIG. 10C is a XPS plot showing the presence of nitrogen in the mycelium-based composite. It is from the nitrogen-containing functional groups, i.e., amine (C-N) and amide (N-C=O) bonds. FIG. 10D shows FTIR plots, where the broad peak is around 3200-3600 cm . and this is attributed to O- H or N-H stretching, which is more prominent in the mycelium-based composite. This increase indicates a high presence of hydroxyl (O-H) and potentially amine (N-H) groups, which are contributed by the lignocellulosic wood flakes as well as the protein or polysaccharide components present in the mycelium. Mycelium also introduces additional O-H, N-H, C-O, and possibly C-N and N-C=O bonds, suggesting a stronger and more diverse interaction between wood-PLA and mycelium, which means a more cohesive interface and better load transfer between interface. These interactions could enhance mechanical properties by promoting amore unified structure at the interface. Building on the insights into the relationship between porous scaffold design parameters (unit cell size and porosity) and the growth dynamics of mycelium, the other properties of the mycelium-based composite were examined to evaluate its structural performance. The resutlts will be discussed in greater detail in subsequent sections below.

[0060] In a second aspect, a method of preparing a mycelium-based composite is provided. Referring to FIG. 11, the method 110 comprises fabricating a wood-polylactic acid (PLA) porous scaffold by 3D printing 111; coating the wood-PLA porous scaffold with a solution comprising peptone, malt and agar 112 to obtain a nutrient-rich layer; inoculating the coated wood-PLA porous scaffold with a fungal culture 113 to facilitate mycelium growth 114; allowing the mycelium to grow and colonize 1 15 the coated wood-PLA porous scaffold to obtain a mycelium-based composite 116 comprising the wood-PLA porous scaffold coated with the nutrient-rich layer, and the mycelium grown on inner and outer surfaces of the coated wood- PLA porous scaffold, forming a network of hyphae 117 covering the inner and outer surfaces of the coated wood-PLA porous scaffold, wherein the wood-PLA porous scaffold has a porosity ranging from 50% to 90%.

[0061] In some embodiments, the 3D printing is performed using fused deposition modeling (FDM) method. Other suitable methods may be used without departing from the scope of the present disclosure.

[0062] The wood-PLA porous scaffold is 3D printed using filaments comprising wood flakes and polylactic acid. In some embodiments, the wood flakes include small, thin pieces of bio-based raw materials from low-cost discarded wood or any by-products from woodworking or wood processing. In some embodiments, the wood flakes may include corn.

[0063] In various embodiments, the wood flakes and the polylactic acid (PLA) are in a weight ratio of 40:60.

[0064] Any suitable method of coating the wood-PLA porous scaffold with the nutrient-rich layer may be employed. In some embodiments, the wood-PLA porous scaffold is coated with the nutrient-rich layer by dipping the 3D-printed wood-PLA porous scaffold into a PMA solution comprising peptone, malt and agar for a duration sufficient to fully coat the wood-PLA porous scaffold. In various embodiments, the nutrient-rich layer comprises 0.1% w / v peptone, 2 to 20% w / v malt and 2.4% w / v agar. In some embodiments the nutrient-rich layer comprises 0.1% w / v peptone, 5 to 10% w / v malt and 2.4% w / v agar. In other embodiments, the nutrientrich layer comprises 0.1% w / v peptone, 10% w / v malt and 2.4% w / v agar.

[0065] The dipping is carried out at room temperature, and the duration of dipping varies depending on the desired thickness of the nutrient-rich layer. As the dipping time increases, the thickness of the nutrient-rich layer also increases. In various embodiments, the 3D-printed wood-PLA porous scaffold is dipped into the PMA solution for a duration of 5-10 seconds. A single dip is typically sufficient to form a thin and uniform coating. However, those skilled in the art will recognize that multiple dipping steps may be employed if additional coating thickness or a longer coating time is required, particularly for more complex porous scaffolds.

[0066] After the 3D-printed wood-PLA porous scaffold is coated with the nutrient-rich layer, the coated 3D-printed wood-PLA porous scaffold is inoculated with a fungal culture to faciliate mycelium growth. The fungal culture may be prepared from one or more species belonging to genera including, but not limited to, Ganoderma, and Pleurotus. In some embodiments, the fungal culture is prepared from the species Ganoderma lucidum. In other embodiments, the fungal culture is prepared from the species Pleurotus ostreatus.

[0067] In some embodiments, the fungal culture is a liquid culture comprising a fungal inoculum prepared from the selected species, along with peptone, malt, and deionized water.

[0068] The step of inoculation comprises contacting the coated wood-PLA porous scaffold with an amount of the fungal culture sufficient to initiate mycelium growth.

[0069] The inoculated 3D-printed wood-PLA porous scaffold is then allowed to incubate for a period sufficient for the mycelium to grow and fully colonize the 3D-printed wood-PLA porous scaffold to obtain the mycelium-based composite of the present disclosure. As the rate of mycelium growth depends on various factors including the composition of the nutrient-rich layer, unit cell size and porosity of the porous scaffold, the incubation period may vary accordingly. In all cases, incubation should continue until the mycelium fully covers all surfaces of the 3D-printed wood-PLA porous scaffold, including both inner and outer surfaces. In certain embodiments, these surfaces may further include the bottom outer surface. In some embodiments, the incubation period is 21 days or longer.

[0070] In some embodiments, the method further includes killling or deactivating the mycelium to stop the mycelium growth to obtain a mycelium-based composite with an inactive mycelium. In some embodiments, the mycelium is killed on or after 21 days of incubation. The killing is performed by heating the mycelium-based composite at a temperature ranging from 45°C to 50°C, 46°C to 49°C or at 48 °C. The mycelium-based composite comprising the inactive mycelium is stable and durable for 300 days or longer under standard environmental conditions.

[0071] In some embodiments, the mycelium is a living mycelium where no heating is performed. Under these conditions, the mycelium-based composite remains stable and durable for up to 100 days or lesser under standard environmental conditions. The mycelium may be killed or deactivated at any time within the 100-day period to halt further growth.

[0072] The mycelium-based composite of the present disclosure can be produced on-site using low-energy drying. The method is customizable and the resulting mycelium-based composite is fully compostable. In certain embodiments, the wood-PLA porous scaffold can be3D-printed first, followed by on-site coating with the nutrient-rich layer and subsequent inoculation with the fungal culture.[0073 J The method described in the present disclosure facilitates mycelium growth on the 3D-printed wood-PLA porous scaffold. This growth significantly enhances the strength of the 3D-printed wood-PLA porous scaffold while also imparting other functional properties such as thermal insulation, fire resistance, hydrophobicity, and durability, which will be discussed in the following sections.

[0074] Mechanical properties

[0075] Example 6 analysed the influence of the scaffold design (unit cell size, porosity, functional grading) on the mechanical properties of the mycellium-based composite to assess their structural performance. The results show that the mycellium-based composite provides an excellent balance of strength and density, making it a suitable material for lightweight and sustainable construction applications. Indeed, the mycellium-based composite has properties comparable to existing wood products with a tunability easily achievable through design (FIG. 12 and Table 1 in Example 5). In particular, the present disclsoure demonstrates that it is possible to obtain mycellium-based composite with strength comparable to that of bricks, which confirms its capability to be used for low-load bearing applications, such as false walls, decorative features, or insulation panels. In comparison to other mycellium-based composites, the approach presented here fabricates a stronger mycellium-based composite than ever reported. Measurements of functional properties such as thermal insulation and fire resistance were also taken to further assess the suitability of the mycellium-based composite for building applications.

[0076] Thermal insulation and fire-resistance

[0077] Thermal insulation and fire resistance are key properties for application in the building environment. The thermal property of the mycelium-based composite can be tailored through the design of the porous scaffold while the presence of the dense mycelium layer provides fire resistance. Example 7 presents the results of tests evaluating the thermal insulation and fire-resistant properties of the mycelium-based composite.

[0078] The mycelium-based composite demonstrates improved thermal insulation, as indicated by their slower heating and cooling rates compared to the porous scaffolds alone and high-density polyurethane (HDPU) and low-density polyurethane (LDPU) foams. The thermal insulation performance of the mycelium-based composite was further extended experimentally and numerically, which will be discussed in Examples 7 and 10 in the sections below.

[0079] The fire resistance also depends on the design of the mycelium-based composite, as quantified from a change in weight between before and after fire testing. FIG. 13A shows images of the porous scaffolds and mycelium-based composites before and after exposure to flame, highlighting differences in structural integrity and char formation (scale bar =10 mm). FIG. 13B is a bar graph showing the change in weight between before and after vertical fire testing of the wood-PLA porous scaffolds and the mycelium-based composites. Uniform mycelium-based composite has the highest change in weight, suggesting poorer fire resistance than the graded samples. Fire spread in the wood-PLA porous scaffold melts the polymer, compromising the structural integrity, while char in the mycelium-based composite prevents melting. FIG. 13C shows the electron micrographs of the melted wood-PLA 131 and char U70_my MBC 132 surfaces after flame exposure (scale bar is 10 pm). The inset shows the condition of mycelium 133 after flame exposure.

[0080] The thermal insulation and fire resistance analysis in mycelium-based composite is backed by infrared imaging. Experiment and numerical analysis of heat transfer and fire resistance of the mycelium-based composites, showcase their exceptional performance and underscore the potential for property customization through design optimization. Building on these advantages, the hydrophobicity and durability of mycelium-based composite are critical factors that further determine their suitability and extended functionality in the built environment.[0081 J Hydrophobicity and durability

[0082] This section and Example 8 illustrate the hydrophobicity and durability tests of the mycelium-based composite, highlighting water and humidity absorption, and durability under various environmental conditions for inactive and living mycelium-based composites. In the inactive mycelium-based composite, mycelium was killed after 21 days of inoculation and in living mycelium-based composite, mycelium was still active when the samples were placed in different environment conditions. Further details will be elaborated herein below in Example 8.

[0083] In a further aspect of the present disclosure, an article comprising the myceliumbased composite of the present disclosure is provided.

[0084] In yet another aspect, a construction article comprising a plurality of the myceliumbased composites of the present disclosure is provided. In some embodiments, the construction article includes, but are not limited to, structural walls for use in building permanent structures or non-load-bcaring structures such as partition walls, panel walls, false walls, decorative feature walls, or insulation panels.

[0085] The present disclosure offers several advantages over existing composites and their fabrication methods. Traditional mould-based methods lack design freedom and are limited primarily to simple bio-composite geometries. Although direct ink writing (DIW) 3D printing allows for moderately complex designs, it is generally limited to smaller-scale mycelium-based composites. As print height increases, the possibility of buckling due to self-load increases, a common problem in DIW-based methods This limits their applicability for larger structures.

[0086] Furthermore, the present disclosure uses porous structures that increase oxygen diffusion during incubation. The high strength obtained from the wood-PLA porous scaffold in the present disclosure cannot be obtained from the traditional organic matter inside the meld. As mycelium growth is dependent on the porosity of the wood-PLA porous scaffold, the density of the mycelium can be controlled through designs with graded porosity.

[0087] 3D printing, porous scaffold design, and mycelium growth can be leveraged synergistically to obtain advanced and sustainable functional bio-composites. The growth dynamics and metabolic activity of the mycelium can be tailored within the porous scaffold. The high mechanical properties and exceptional durability of these mycelium-based composites are part icul arly noteworthy, as they address the typical challenges faced by bio-based materials, which often struggle to achieve the robustness required for broader industrial adoption.

[0088] Though the current work considered wood-PLA scaffold, a similar approach can be used for other types of biopolymers. Additionally, utilising discarded wood to produce 3D printing filaments reduces waste and offers a sustainable alternative to conventional plasticbased materials. The functionalization of mycelium-based composites through the method of the present disclosure shows significant potential for diverse applications, ranging from sustainable construction materials with enhanced mechanical and thermal properties, to substitutes in packaging and product design. Advancements in 3D printing have revolutionised the construction industry by enabling efficient, sustainable, and complex structural designs and facilitating the integration of innovative materials such as mycelium-based composites. The capability to engineer these composites with optimized mechanical stability and biological properties represents a promising step toward next-generation sustainable and functional materials, paving the way for a future in which materials are not only structurally engineered but also inherently possess bio-inspired characteristics.

[0089] The current approach also considers the reduction in costs in transportation (due to the mycelium-based composite’s lightweight material), low-temperature process, customization, and final composting of the mycelium-based composite, in addition to its performance while in application.

[0090] To facilitate a better understanding of the invention, the following examples of specific embodiments are given. In no way should the following examples be read to limit ordefine the entire scope of the invention. One skilled in the art will recognize that the examples set out hereinbelow are not an exhaustive list of the embodiments of this invention.EXAMPLESExample 1

[0091] 3D Printing of Wood-PLA Porous Scaffold

[0092] A gyroid triply periodic minimal surface (TPMS) structure was selected due to its highest surface area and strength among commonly used TPMS structures. An industrial-grade fused deposition modeling (FDM) printer. Flashforge Creator 3 Pro, was used to 3D print the porous scaffold with a 0.6 mm size tungsten carbide nozzle.

[0093] The printing was carried out using wood-PLA filament made from recycled materials comprising 40% wood and 60% PLA composition. The filament has a diameter of about 1.7 mm, and it can be synthesised by a plastic compounding process or obtain from commercially available filament. The printing parameters used for the wood-PLA filament were kept the same as the commercial printing parameters used for PLA filament. However, in the present disclosure, the temperature for the printhead can be increased to 240 °C if a darker finish of the print is desired.Example 2

[0094] Preparation of Nutrient-Rich Solution

[0095] In this example, a PMA solution comprising 0.1% w / v peptone, 10% w / v malt, and 2.4% w / v agar in de-ionized water was selected for optimal growth of the mycelium. All the chemicals used were sourced from Sigma-Aldrich. To avoid contamination during the incubation period, the PMA solution was sterilised in an autoclave at 120 °C for 1 hour, followed by 1 hour of warming at 50 °C.Example 3

[0096] Preparation of a Liquid Mycelium Culture

[0097] Firstly, a master agar plate (MAP) was prepared. It was prepared by adding 2.5% w / v agar in deionized water, followed by sterilization at 121 °C for one hour and 30 min of warming at 50 °C in an autoclave (Hirayama, HG-80). Sterilized agar solution was poured into 90 mm petri dishes. A small piece of fungal spawn from the species Ganoderma lucidum was used as an inoculum and placed at the center of the petri dish. Ganoderma Lucidum spawn was obtained from a commercial farm, Malaysian Redmills Farms Ltd. This fungus was chosen for its robust growth due to its natural tendency to thrive on woody substrates and properties, but other strain of fungi can also be used without departing from the present disclosure. The complete process was conducted in a bio-safety cabinet (BSC) (Gelman, BH Class II) under ultraviolet light to avoid contamination. MAPs were stored in a dark enclosed cabinet for 21 days.

[0098] Liquid mycelium culture (LMC) was prepared by adding 0.3% w / v peptone and 1.7% w / v malt, in deionized water. Similar steps (like MAP) were followed to sterilize the solution. A small inoculum from the MAP plate was placed in the sterilized solution to inoculate the solution. The liquid mycelium culture was stored for 14 days at 23 °C and 80% relative humidity in a dark enclosed cabinet before being used to inoculate the porous scaffolds. LMC was sub-cultured by 1 ml solution from the previous batch every 2-3 weeks.Example 4

[0099] Preparation of a Mycelium-based Composite

[0100] Though the FDM printed wood-PLA porous scaffold samples were sterilized at the printing stage, still to avoid contamination, the porous scaffolds were UV sterilized for 30 min in a BSC.

[0101] The PMA solution prepared in Example 2 was coated onto the porous scaffolds using the dip coating method. A one-time dip of 10 s was enough to form a thin and uniform coating.From the experiments, it was observed that the PMA solution at temperatures between 40 °C to 50 °C was perfect, i.e., it is not too viscous to pass through the pores of samples and not too thin to stick on the samples. Once again, the PMA-coated porous scaffold samples were UV sterilized.

[0102] The samples were inoculated at the top surface with 1 ml of the liquid mycelium culture prepared in Example 3 using a micropipette. All the experiments were conducted in the BSC. Each inoculated sample was stored in a parafilm- sealed container and placed at 23°C and 80% relative humidity in a dark enclosed cabinet for 21 days for the mycelium to grow to obtain a mycelium-based composite. To ensure that the mycelium- based composite does not undergo any further biological changes and remained stable, mycelium growth was stopped by heating the samples overnight in an oven (IKA, Malaysia) at 48 °C; these samples are called inactive samples. For those samples that did not undergo heating, the mycelium growth was not stopped; these samples are called living samples. Pictures of the samples taken on different days of the incubation period are shown in FIG. 6A.Example 5

[0103] The improvement in mechanical and functional properties of the wood-PLA porous scaffold due to the formation of mycelium is validated using experimental data. The shape and size of the samples were selected according to the established standards. To differentiate between different designs, a generalized notation has been defined, i.e., G70 means gyroid wood-PLA porous scaffold with 70% porosity and G70_my means the gyroid mycelium-based composite with wood-PLA porous scaffold. Similar notation will be used for structures with other porosities.

[0104] Composition Analysis

[0105] To enhance the electrical conductivity of the samples for electron microscopy, a sputter coating of 5 nm gold was applied using a mini sputter coater (Quorum SC7620). A field emission scanning electron microscope (JEOL JSM-6360) was utilized to obtain electronmicrographs. The resulting micrographs were analysed with ImageJ software to assess the density of the mycelium layer, employing a threshold method to differentiate mycelium from pores, as well as to measure the diameters of the hyphae. The microstructure of the 3D printing filament was measured using the micro-CT scanning method (Zeiss Xradia 620 Versa). A 1 cm long filament was cut out from the spool and vertically mounted on the rotating X-ray stage. X- rays were then emitted and captured as 2D projection images while the sample rotates, typically through 360 degrees. Finally, these images were processed using open-source SLICER software to reconstruct high -resolution 3D images of the internal structure. The parameters used for capturing the images and doing the 3D reconstruction are provided in Table 1 below.

[0106] Table 1: Parameters used in micro-CT of the wood-PLA filament.[00107J Fourier Transform Infrared (FT1R) spectrometry (Perkin Elmer Frontier) was used to describe functional groups. The samples were analysed for surface chemistry using X-rayphotoelectron spectroscopy (XPS Kratos AXIS Supra). The data from the XPS machine were further analysed using (Casas’s v2.3.26).

[0108] Mycelium growth

[0109] Mycelium needs a continuous oxygen supply to extract nutrients from the organic matter and grow. It has been observed that the presence of porosity in the porous scaffold diffuses more oxygen and mycelium grows thicker, more uniform, and denser. Such a comparison has been shown in FIG. 14A. FIG. 14A shows the electron microscopy images of sample (a) U50_my; and (b) U90_my. The images show that there are more mycelium hyphae in the sample with 90% porosity as compared to the sample with 50% porosity.

[0110] The quantification of the hyphae diameter and mycelium density is shown in FIG. 14B. These results show that the porosity and design of the porous scaffold indeed play a major role in the growth and development of the mycelium-based composite.

[0111] Mycelium proliferation

[0112] The overall weight of the samples decreases during the incubation period. This is caused by the loss of water from the PMA solution which is more than the gain in mycelium mass. Sacrificial samples were prepared to subtract the loss of moisture from the reading. The sample preparation for these samples followed the same steps as the mycelium-based composites except for no mycelium inoculation. They were also stored in the same environment conditions. When moisture loss is subtracted from the reading, overall increasing trend of mycelium mass was observed.[001 13] Compression test

[0114] Compression tests were conducted using an MK-2100S universal testing machine by the ASTM D1621 standard. The average of three samples was considered as final reading. A loading rate of 2 mm / min was chosen to ensure a steady and controlled compression process.The yield strength (of) is the stress value corresponding to first peak in the stress-strain curve and peak strength (of) is the stress value at the densification point, i.e., the point where all thepores are completely compressed and the porous structure starts behaving like a solid material.The energy absorption (EA) is the area under the stress-strain curve and is calculated using Equation 1.Example 6

[0115] Mechanical Properties

[0116] The influence of scaffold design (unit cell size, porosity, functional grading) on the mechanical properties of the mycelium-based composites was analyzed to assess their structural performance.

[0117] The peak strength (c^) and energy absorption EA) of the mycelium- based composites grown on a gyroid scaffold with 70% porosity increase with increasing malt concentration up to 10 wt% which corresponds to a dense and homogeneous mycelium layer (FIG. 15A, FIG. 15B).[001 18] Next, PMA coating with 10 wt% malt was used to grow the mycelium on different scaffold designs: uniform (U), porosity -graded (PG), and unit cell size graded (CG) (see FIG. 16A). The stress-strain curves of the mycelium-based composites and the bare scaffolds (without mycelium) were measured under compression. The readings arc as shown in FIG. 16B. Pictures during the test also show the layer by layer deformation mechanism of the uniform 70% porosity MBC (U70_my). All the curves present an elastic, a plateau, and a densification region, which is typical of porous structures. In the elastic region, the stress values are the same for the mycelium-based composites and the porous scaffold alone since the load is mostly carried by the walls of the porous scaffold. Beyond the yield stress, the cell walls start to collapse, and the mycelium layer acts as a foam inside the porous scaffold (FIG. 17), ultimately increasing the stress values in the mycelium-based composites as compared to the bare scaffolds. For the designs explored here, the mycelium-based composites with graded cell sizeshowed the highest crpand EA. However, the highest improvement in <7Pand EA after mycelium growth as compared to wood-PLA porous scaffold was observed in the porosity-graded mycelium-based composites, with an increase in strength up to 300%. For uniform designs, the apand EA decrease when the porosity increases because the unit cell wall thickness decreases. Nevertheless, the improvement in cr>due to mycelium increases with increasing porosity (FIG. 18A, FIG. 18B). The highest mechanical properties for graded unit cell size were observed for the CG50_my MBCs are elastic modulus (£’) = 385.02 MPa, yield strength (tty) = 13.94 MPa, (jp= 14.01 MPa, an

[0119] The mycelium-based composites obtained provide an excellent balance of strength and density, making them suitable materials for lightweight and sustainable construction applications. Indeed, the mycelium-based composites have properties comparable to existing wood products with a tunability easily achievable through design. See FIG. 12 and Table 2 below.

[0120] Table 2: Density and peak strength of the different materials and mycelium-based composites used to plot the Ashby chart in FIG. 12.

[0121] In particular, the tests demonstrate that it is possible to obtain mycelium-based composites with strength comparable to that of bricks, which confirms their capability to be used for low-load bearing applications, such as false walls, decorative features, or insulation panels. In comparison to other mycelium-based composites, the approach presented here fabricates mycelium-based composites stronger than ever reported. Measurement of functional properties such as thermal insulation and fire resistance are conducted to further assess the suitability of the mycelium-based composites for building applications.

[0122] The traditional methods of mycelium development generally result in myceliumbased composites that are not suitable for use in construction settings. Quasi-static compressive tests were conducted on the cube-shaped samples with an edge length of 40 mm according to the ASTM D695 standard. The present disclosure developed mycelium-based composites with peak strength as high as 3.17 MPa at 70% porosity. Also due to the mycelium, the energy absorption of the wood-PLA porous structure increased by 2 times. The compressive strcssstrain curves of the G80_my and G80 structures are shown in FIG. 19. The deformation behaviours are divided into three zones, initially, the applied load is mostly carried by the porous scaffold, and as the unit cell walls start to yield, accompanied by local buckling of the walls, the stress value becomes stable. Once the cell walls collapse and start touching each other, the stress value increases sharply, and this is the point where the material starts behaving as a solid material. The deformation mechanisms of both the wood-PLA and mycelium-based composites are similar. However, the presence of mycelium increases the stress value, especially when the cell walls start touching each other, resulting in an increased peak strength and energy absorption in the mycelium-based composites. The mechanical properties of the porous scaffold with different porosities arc showm in Table 3.

[0123] Table 3: Mechanical properties of uniform porosity samples with and without mycelium, obtained from compressive tests (mean ± standard deviation).Improvement in mechanical properties with mycelium:Compressive strength = 1.11-1.5 timesPeak strength = 1.46-3.18 timesEnergy absorption = 1.44-2.8 timesExample 7

[0124] Thermal insulalion

[0125] Thermal insulation is one of the key properties for applications in the built environment. The thermal properties of the mycelium-based composite can be tailored through the design of the scaffold.

[0126] The low thermal conductivity (Kt) of mycelium, reported to be of 0.03-0.05 W / mK, makes it suitable for thermal insulation. Relatively high Ktof wood-PLA of 0.2 W / mK should decrease the overall Ktof the mycelium-based composites, but can be further reduced by introducing porosity, as low Ktfrom the air in the pores reduces conductive heat transfer. The combination of a porous scaffold, mycelium, and wood-PLA greatly improves thermal insulation properties, surpassing the performance of traditional polyurethane (PU) foams (FIG.20). Thermal insulation can be further modulated through the functional grading of the scaffolds. By varying the porosity and material distribution within the scaffold, it is possible to tailor the Ktto meet specific insulation requirements. FIG. 21A shows the comparison between thermographic images of uniform MBC (U70_my) with 70% porosity and 20 mm unit cell size, porosity graded from 70-90% MBC (PG_my) with 20 mm unit cell size, and unit cell size graded from 20-40 mm MBC (CG70_my) with 70% porosity. The results show that functional grading the MBCs improves thermal insulation. This is further confirmed by the heating and cooling behavior of different samples as illustrated in FIG. 21B. Mycelium-based composites demonstrate improved thermal insulation, as indicated by their slower heating and cooling rates compared to the porous scaffolds alone and high-density polyurethane (HDPU) and low-density polyurethane (LDPU) foams. The thermal insulation performance of the mycelium-based composites was further extended experimentally and numerically. The thermal conductivity of the samples tested are as shown in Table 4.L00127 J Table 4: Experimental thermal conductivities of the wood-PLA porous scaffolds and the mycelium-based composites measured using a hot wire thermal conductivity meter.

[0128] (Samples pictures arc shown in FIG. 22).

[0129] Finite Element Modelling (FEM) simulations help reveal the heat flux and temperature distributions throughout the uniform and graded mycelium- based composites. FIG. 23 depicts the FEM representation of heat flux (top) and temperature (bottom) distributions for U70_my and PG_my and PG_my* and CG70_my MBCs. U70_my and PG_my* exhibit higher heat flux, means more heat transfer and lower thermal insulation, while functionally gradedMBCs CG70_my and PG_my show lower heat flux and more effective thermal insulation. Furthermore, the insulation performance in the case of the graded mycelium-based composites can be engineered by changing the hot (source) and cold (sink) sides of the mycelium-based composites. For instance, in PG_my where the source has 90% porosity and the sink has 70% porosity, the Kt= 0.24 W / mK, whereas in PG_my* the hot and cold sides axe reversed, and the Kt= 0.06 W / mK (FIG. 24). Ktalso depends on the porosity of the mycelium-based composites, where higher porosity yields lower Kt(FIG. 25). These findings highlight that functional grading tailors heat flow and temperature distribution effectively, offering enhanced design flexibility for different types of infrastructure.

[0130] Experiment

[0131] The room temperature experimental thermal conductivity of the mycelium-based composites was measured under transient heat transfer conditions following ASTM D5930-17 standard using Biotech TC3000E transient hotwire thermal conductivity meter (see FIG. 22 for the images of the samples). The average of three measurements was considered for the final value. The infrared thermal images of the mycelium-based composites were captured using a thermal imaging system (FLIR, ETS320), and each sample was recorded at least three times. The constant emissivity of 0.95 was applied to all mycelium-based composites. Each sample was recorded for 5 minutes of heating and 5 minutes of cooling. During heating, the sample was placed on a heated plate (Torrey Pines Scientific Hot Plate HP50) at 100 °C and recorded for 5 minutes; the same sample was shifted to a plate at 25 °C and recorded for another 5 minutes during the cooling stage. DS1921H-F5 Thermochron i-buttons were used to measure the temperature in real-time (see FIG. 31C for the details of the i-button arrangement in myco- house). The logging rate was set at 10 (one reading in 10 minutes).

[0132] Fire resistance

[0133] Wood catching fire in buildings poses a significant safety hazard, risking property damage and endangering the lives of occupants. Without appropriate fire-prevention measures,flames can rapidly spread, leading to catastrophic outcomes in both residential and commercial structures. Mycelium-based composites exhibit inherent fire-resistant properties, making them promising candidates for constructing structures with enhanced fire safety. Comparative burning characteristics of the wood-PLA and mycelium-based composite were evaluated using a vertical fire test conducted according to ASTM D3801 -20a. The sample dimensions and test procedures were also considered based on the same standard

[0134] For fire testing, samples of size 12x12x120 mm were prepared and tests were carried out in a dark cabinet of size 0.5 m3according to ASTM D3801-20a standard. Butane gas with torch setup was placed vertically at 10 mm from the bottom head of the sample and a blue flame of length 20 nun was used to burn the samples. Each test was performed for 10 seconds of flaming time and fire was put out at the 20thsecond. Every test was repeated three times, and the average value was considered.

[0135] Fire-resistant performance is characterized by the speed by which the sample catches fire and how slowly the fire travels from the bottom end to the top end, which is also noted as the burning rate. Mycelium-based composites showed excellent resistance to fire due to char forming tendency of the mycelium.

[0136] The low Ktof mycelium-based composites enhances their fire resistance by slowing heat transfer, thereby delaying ignition and reducing the flame spread as compared to the porous scaffolds alone (FIG. 26A). The uniform wood-PLA scaffold U70 has poor fire resistance as it burns rapidly, while the corresponding U70_my MBC burns slowly, suggesting better fire resistance. The better fire resistance of the mycelium-based composite as compared to the porous scaffold is due to their char production ability without significant flaming combustion, which restricts the further spread of fire (FIG. 26B). The fire resistance also depends on the design of the mycelium- based composite, as quantified from a change in weight between before and after fire testing (FIG. 13A, FIG. 13B). Uniform mycelium-based composites have the highest change in weight, suggesting poorer fire resistance than the graded samples. Fire spreadin the wood-PLA porous scaffold melts the polymer, compromising the structural integrity, while char in the mycelium-based composite prevents melting (FIG. 13C).

[0137] The thermal insulation and fire resistance analysis in mycelium-based composites is backed by infrared imaging. Experiment and numerical analysis of heat transfer and fire resistance of the mycelium-based composites showcase their exceptional performance and underscore the potential for property customization through design optimization. Building on these advantages, the hydrophobicity and durability of mycelium-based composites are also critical factors that further determine their suitability and extended functionality in the built environment.Example 8

[0138] Hydrophobicity

[0139] This section illustrates the hydrophobicity and durability tests of mycelium-based composites, highlighting water and humidity absorption, and durability under various environmental conditions for inactive and living mycelium-based composites. In the inactive mycelium-based composites, mycelium was killed after 21 days of inoculation and in living mycelium-based composites, mycelium was still active when the samples were placed in different environment conditions.

[0140] As normally seen in the monsoon season, traditional bricks absorb water, resulting in water marks on the building walls which are not only aesthetically unpleasant but also could harm the structural integrity of the buildings. The natural hydrophobicity of mycelium is a solution to this problem Two types of tests were conducted:

[0141] Firstly, the contact angle (ft) was optically measured by placing a 1 ml drop of deionised water on the flat surface of samples using a Goniometer (Theta Flex, Biolin Scientific).

[0142] Water absorption test: Water absorption tests were conducted according to ASTMD570 standards by dipping complete mycelium and without mycelium samples in the water andrecording the weight of the samples after 1 day, 1 week, 2 weeks, 3 weeks, and 14 weeks until the weight became saturated.

[0143] NORD test: The moisture uptake and release were measured using the NORD test. It uses two humidity levels per day. In this example, 53% (16 hours) and 75% (8 hours) were selected. The objective of the test is to evaluate the compatibility of mycelium-based composites within an office environment. Similar test criteria have been widely used for natural woods. Weight is measured twice a day and plotted vs time. This test was also conducted for 96 hours until the moisture uptake became saturated.

[0144] For tests carried out on G80 and G80_my samples, the graph in FIG. 27 shows a reduction in water absorption due to the presence of mycelium and mycelium-based composites became water-saturated after 7 days which is not the case with normal wood-PLA samples. Similarly, NORD test data also show more moisture uptake and release in the case of wood- PLA samples in comparison to mycelium-based composites. High moisture absorption in wood items like furniture, doors, and windows can lead to structural instability and decay, compromising their strength and durability over time. Excessive moisture also promotes mould and fungal growth, further degrading the wood's quality and appearance.

[0145] Another way of characterizing the hydrophobic nature of the material is a measurement of the contact angle. Images captured by the goniometer during contact angle are shown in FIG. 28B. The high contact angle in the case of mycelium-based composite shows it is hydrophobic and no change in the contact angle shows that mycelium-based composite do not absorb water.

[0146] Further tests were also conducted on the uniform (70%) and uniform (70%) with mycelium samples. Water absorption problems could be more severe in porous materials because of the internal cavities and high surface area. The contact angle (ft) of the wood-PLA scaffolds increased from 85.51° to 130.93° after mycelium growth (FIG. 28A and FIG. 28B). The increasing ft and its stability over time indicate the enhancement in hydrophobicity due tothe mycelium layer, making the mycelium-based composite more resistant to moisture. Furthermore, the water absorption of the wood-PLA porous scaffolds (uniform (70%)) and the mycelium-based composite (uniform (70%) with mycelium) shows a rapid increase over the first 7 days, with higher absorption in the wood-PLA porous scaffolds (FIG. 28C, FIG. 28D). Overall, mycelium decreases water absorption by 2.5 times.

[0147] Construction materials may expand and contract under fluctuating and high-humidity environmental conditions, potentially leading to crack formation and compromised structural integrity of the building. Moisture uptake and release were evaluated using the NORD test, wherein samples were exposed to two humidity levels to assess their hydrophobicity and overall resilience. At the low humidity of 53%, the mass of both the wood-PLA porous scaffolds and the mycelium-based composites decreased, suggesting moisture release. Conversely, at high humidity of 75%, the sample mass increased, signifying moisture uptake. Compared to the porous scaffolds, the mycelium-based composites exhibited a higher rate of moisture release and a lower rate of moisture uptake, as shown by the slopes of the corresponding curves in FIG. 28E. The higher release rate means the moisture absorption in the mycelium-based composites is low, as mycelium prevents the capillary intake of the water. This could avoid any structural change in the mycelium-based composites due to moisture absorption.

[0148] Durability

[0149] To study the durability of mycelium-based composites, mycelium-based composites were left for 300 days under three environmental conditions: inside lab (IL), outside lab (OL), and outside lab but enclosed inside a box (GLIB). Durability was measured from mechanical test data, change in weight, FTIR, and XPS analysis of the mycelium-based composites.

[0150] The durability of the samples was studied for inactive and living mycelium.

[0151] The inactive mycelium- based composites were left for 300 days under the three environmental conditions. The durability of the mycelium-based composites was accessed by measuring the strength and weight on different days (FIG. 29A, FIG. 29B). The results showno significant change in the aforementioned properties for all three conditions. The myceliumbased composites are in perfect condition even after 300 days despite some colour alteration due to ambient dust (FIG. 29C).

[0152] For the living mycelium- based composites where the mycelium was not deactivated by drying, the organism was still alive. These living mycelium-based composites were left outside the laboratory. The results show that the strength increased for the first 25 days, but suddenly started to decrease after that (FIG. 29D). After 100 days, the strength of the myceliumbased composites was reduced by 2.82 times from the maximum strength on the Day 25. The decrease in strength is due to the degradation of the wood-PLA by the living mycelium. Electron micrographs of the cell walls of the living mycelium-based composites on different days show the colonization of wood-PLA by the mycelium in the mycelium-based composites. Mycelium naturally decomposes lignocellulosic material by producing enzymes like hemicellulases, cellulases, and ligninases, which break down hemicellulose, cellulose, and lignin in wood. The weakened wood-PLA scaffolds create pathways for the degradation of PLA as well. This results in a synergistic effect, with the mycelium breaking down both wood and PLA components of the mycelium-based composites, ultimately aiding the decomposition of the entire structure more effectively than it would for wood or PLA alone.

[0153] The change in chemical structure and chemical bonding at day 0 and day 300 for the mycelium-based composites with inactive mycelium was studied using XPS (FIG. 9A, FIG. 9B, FIG. 9C). Deconvolution plots show no change in the bonding type. However, the percentage of C=O bonding decreases, with less change in inside samples (IL) and more in the outside samples (OL and GLIB). This could be due to prolonged exposure to the sunlight, which causes photo-oxidative degradation and breaks down C=O bonds. FTIR results (FIG. 9D) show no change in the intensity and bonding for inactive mycelium-based composites. However, the shift in the FTIR curve for OL_active (living) mycelium-based composite shows a structural change in bond strength or chemical degradation.

[0154] The slow degradation ability of the mycelium-based composites while mycelium is living presents significant advantages for sustainable construction. The controlled biodegradability could be used for temporary structures or modular buildings, which allows eco-friendly disposal at the end of the life cycle with minimal waste. However, for long-term durability, the mycelium can be killed after it is fully grown on the porous scaffold. The new method of the present disclosure has developed mycelium-based composites which can be used for both short and long-term construction practices. Example 9 presents a proof-of-concept small mycelium-based house (myco-house) and compares the performance of mycelium-based composites with conventional building materials across key parameters.

[0155] Environmental Degradation

[0156] The environmental degradation of the samples that were not oven-heated was also studied, which means mycelium was still alive when the samples were placed outside the lab.

[0157] Testing mycelium-based composites for environmental degradation is crucial, safeguarding against structural vulnerabilities amidst changing climates. It ensures longevity and shields our infrastructure from the erosive forces of nature's relentless march. To check the resilience of the mycelium-based composites to environmental degradation, three testing conditions were selected; that is, inside the laboratory (IL) with controlled humidity and temperature, outside the laboratory (OL) with uncontrolled humidity and temperature, and outside the laboratory with uncontrolled humidity and temperature but the samples are placed inside closed containers (OLIB).

[0158] The quantification of environmental resilience is carried out by measuring mechanical strength on different days, i.e., Day 0, 7, 30, and 100. Bar charts in FIG. 30 show the compressive strength of the mycelium-based composites placed under different environmental conditions on different days. The data shows a small decrease in the strength on Day 7, which is due to the evaporation of the moisture from the mycelium-based composites.No significant change in the mechanical strength was measured on Day 30 and 100 days, wTiichproves the mycelium-based composites are resilience to different environmental conditions and could be used in the construction of buildings.Example 9

[0159] Applications

[0160] The improved mechanical strength and multifunctional characteristics of the mycelium-based composite of the present disclosure highlight its potential as sustainable and high-performance alternatives to conventional construction materials. To illustrate this, aproof- of-concept sample was created, and its performance was compared with existing construction materials.

[0161] As a proof-of-concept example, a miniature house (myco-house) was developed (FIG. 31A). Referring to FIG. 31B, the miniature house 310 consists of a dome 31 1 as the ceiling, a solid (S) 312, a uniform base (U) 313, a uniform wall (U) 314, and graded myceliumbased composite walls including porosity graded (PG) wall 315 and unit cell graded (CG) wall 316. The miniature house is also installed with i-buttons 320 as shown in FIG. 31C. DS1921H- F5 Thermochron i-buttons were used in this example to measure the temperatures in real-time. The temperatures inside and outside the house were recorded for three consecutive days using several of these i-buttons and temperature sensors. The recorded temperatures fluctuate cyclically following the day-night cycles, although it displayed a lower temperature due to rainy weather on Day 2 (FIG. 31D). For solid (porosity = 0%) and the uniform mycelium-based composites, the temperature gradient (AT = Outside wall temperature - Inside wall temperature) is high, indicating low thermal inertia and high heat transfer, which is less suitable for thermal insulation. Both graded walls have lower AT, which means better insulation and low heat transfer. The lag between the peaks (At) of the external and internal temperatures for each wall design reflects their thermal inertia (inset in FIG. 31D). It allows the wall to dampen the effects of external temperature changes (FIG. 31E), providing a more stable indoor climate and reducing the need for active heating or cooling.

[0162] The radar chart in FIG. 31F compares the performance of the wood-PLA porous scaffold and mycelium-based composite with clay bricks and PU foam. The mycelium-based composites produced in this work demonstrate the most balanced (high strength-to-weight ratio, high insulation, and durable) performance overall, indicating their potential as the most efficient material for construction applications, requiring high insulation and temperature stability. Clay bricks and PU foam display a trade-off between strength and insulation, making them low- performing choices as compared to mycelium-based composites. The findings suggest that mycelium-based composites of the present disclosure are ideal for applications in climates with significant temperature fluctuations due to their strong insulating properties and ability to maintain indoor temperature stability.Example 10

[0163] Numerical analysis

[0164] Numerical analysis were carried out in some of the Examples described hereinabove.

[0165] Computational fluid dynamic simulation

[0166] To visualize the flow of air inside the porous scaffold, CREO parametric software was used. The live flow simulation was carried out in CREO Parametric 1 1 software. Porous scaffold were prepared in the software by selecting porosity and unit cell size. The porosity in the porous scaffold was defined as fluid domain with viscosity and density of room temperature air. The inlet velocity and outlet pressure were defined as a boundary conditions. In the simulation wizard, steady state flow condition was selected.

[0167] Homogenization

[0168] Analytical effective thermal conductivity for RVE (FIG. 32) was calculated bythe Maxwell-Garnett model for three-phase composites using Equations 2-4.

[0169] VAB = VA + VB (4)

[0170] Where kA, ks, kc are the thermal conductivities and VA, VB, Vc are the volume fractions of the mycelium, wood-PLA and air, respectively. Sec Table 5 below.

[0171] Table 5: Different parameters and values used in the homogenization technique.

[0172] From the before mentioned equations and data, ka= 0.059 W / mK.

[0173] Finite element modeling

[0174] Numerical effective thermal conductivity (kn) by finite element modeling.

[0175] (5) 11

[0176] q is heat flux (W)

[0177] k is thermal conductivity (W / m-K)

[0178] A is a cross-section area (m2)

[0179] dT / dx is temperature gradient (K / m)

[0180] From the before mentioned equations kn- 0.066 W / mK.

[0181] Both Kaand K„ arc almost similar, suggesting accuracy of the RVE method (FIG.33).

[0182] Thermal heat transfer

[0183] The thermal heat transfer conditions were modeled in ABAQUS software.

[0184] Knwas used to perform transient heat transfer analysis in Abaqus 6.14. The .STL files of the porous mycelium-based composites were generated using MS Lattice software.Mesh lab software was used to refine the mesh size in the .STL files. The solid geometries from .STL files were created using Abaqus plugin ‘convert geometry from mesh’. Finally, STP files were used to define material properties. Second-Order (Quadratic) tetrahedral element (DC3D10) of size 1 / 10 of the unit cell wall were used to discretize the geometry. In the boundary condition, 100 °C was given as inlet temperature and 0 °C as outlet temperature. Postprocessing was carried out to analyze the results. Temperature distributions, time-dependent thermal profiles, and heat transfer efficiency across the mycelium-based composites were extracted.

[0185] All examples described herein, whether of apparatus, methods, materials, or products, are presented for the purpose of illustration and to aid understanding, and are not intended to be limiting or exhaustive. Modifications may be made by one of ordinary skill in the art without departing from the scope of the claimed invention.

Claims

Claims1. A mycelium-based composite, comprising: a 3D-printed wood-polylactic acid (PLA) porous scaffold; a nutrient-rich layer coated onto inner and outer surfaces of the 3D-printed wood- polylactic acid porous scaffold; and mycelium of a fungus grown on the inner and outer surfaces of the coated 3D-printed wood-polylactic acid porous scaffold, forming a network of hyphae covering the inner and outer surfaces of the coated 3D-printed wood-polylactic acid porous scaffold, wherein the 3D-printed wood-polylactic acid porous scaffold has a porosity ranging from 50% to 90%.

2. The mycelium-based composite of claim 1, wherein the nutrient-rich layer comprises peptone, malt and agar.

3. The mycelium-based composite of claim 2, wherein the nutrient-rich layer comprises 2 to 20% w / v of malt.

4. The mycelium-based composite of claim 2, wherein the nutrient-rich layer comprises 5 to 10% w / v malt.

5. The mycelium- based composite of claim 2, wherein the nutrient-rich layer comprises 0.1% w / v peptone, 10% w / v and 2.4% w / v agar.

6. The mycelium- based composite of claim 1, wherein the mycclium-bascd composite has a compressive strength ranging from 0.35 to 13.94 MPa at 90% to 50% porosity of the 3D- printed wood-polylactic acid porous scaffold.

7. The mycelium-based composite of claim 1, wherein the mycelium is an inactive mycelium.

8. The mycclium-bascd composite of claim 7, wherein the mycelium-based composite comprising the inactive mycelium is stable and durable for 300 days or longer under standard environmental conditions.

9. The mycelium-based composite of claim 1, wherein the mycelium is a living mycelium.

10. The mycelium-based composite of claim 9, wherein the mycelium-based composite comprising the living mycelium is stable and durable for less than 100 days under standard environmental conditions.

11. The mycelium-based composite of claim 1, wherein the 3D-printed wood-polylactic acid porous scaffold comprises a Triply Periodic Minimal Surface (TPMS) structure.

12. The mycelium-based composite of claim 11, wherein the TPMS structure is selected from the group consisting of a gyroid, a double gyroid, a lidinoid, a Schwarz D, and a Schwarz P structure.

13. The mycelium-based composite of claim 1 or 12, wherein the mycelium-based composite has a unit cell size ranging from 5 to 25 mm.

14. The mycelium-based composite of claim 1 or 12, wherein the mycelium-based composite has a graded unit cell size.

15. The mycelium-based composite of claim 1, wherein the mycelium-based composite has a graded porosity.

16. The mycelium-based composite of claim 1, wherein the 3D-printed wood-polylactic acid porous scaffold comprises wood flakes and polylactic acid in a weight ratio of 40:60.

17. The mycelium-based composite of claim 1, wherein the fungus is a species selected from the group consisting of species of the genus Ganoderma and species of the genus Pleurotus.

18. The mycelium-based composite of claim 17, wherein the species is Ganoderma lucidum.

19. The mycelium-based composite of claim 17, wherein the species is Pleurotus ostreatus.

20. A method of producing a mycelium-based composite comprising: fabricating a wood-polylactic acid porous scaffold by 3D printing; coating the wood-polylactic acid porous scaffold with a nutrient-rich layer; inoculating the coated wood-polylactic acid porous scaffold with a fungal culture to facilitate mycelium growth; allowing the mycelium to grow and colonize the coated wood-polylactic acid porous scaffold to obtain a mycelium-based composite comprising the wood-polylactic acid porous scaffold coated with the nutrient-rich layer, and the mycelium grown on inner and outer surfaces of the coated wood-polylactic acid porous scaffold, forming a network of hyphae covering the inner and outer surfaces of the coated wood-polylactic acid porous scaffold, wherein the wood- polylactic acid porous scaffold has a porosity ranging from 50% to 90%.

21. The method of claim 20, further comprising: deactivating the mycelium by heating to obtain the mycelium-based composite with an inactive mycelium.

22. The method of claim 21, wherein the mycelium is deactivated on or after 21 days of incubation.

23. The method of claim 22, wherein the mycelium-based composite comprising the inactive mycelium is stable and durable for 300 days or longer under standard environmental conditions.

24. The method of claim 20, wherein the mycelium is a living mycelium.

25. The method of claim 24, wherein the mycelium-based composite comprising the living mycelium is stable and durable for less than 100 days under standard environmental conditions.

26. The method of claim 20 or 21, wherein the wood-polylactic acid porous scaffold is 3D printed using filament comprising wood flakes and polylactic acid.

27. The method of claim 26, wherein the wood flakes and the polylactic acid are in a weight ratio of 40:60.

28. The method of claim 20 or 21, wherein the wood-polylactic acid porous scaffold comprises a Triply Periodic Minimal Surface (TPMS) structure.

29. The method of claim 28, wherein the TPMS structure is selected from the group consisting of a gyroid, a double gyroid, a lidinoid, a Schwarz D, and a Schwarz P structure.

30. The method of claim 20 or 29, wherein the mycelium-based composite has a unit cell size ranging from 5 to 25 mm.

31. The method of claim 20 or 30, wherein the mycelium-based composite has a graded unit cell size.

32. The method of claim 20 or 21, wherein the mycelium-based composite has a graded porosity.

33. The method of claim 20 or 21, w'hcrcin the wood-polylactic acid porous scaffold is coated w'ith the nutrient-rich layer by dipping the wood-polylactic acid porous scaffold in a PMA solution comprising peptone, malt and agar, for a duration sufficient to fully coat the wood-polylactic acid porous scaffold.

34. The method of claim 20 or 21, wherein the fungal culture is prepared from a fungus selected from the group consisting of species of the genus Ganoderma, and species of the genus Pleurotus.

35. The method of claim 34, wherein the species is Ganoderma lucidum.

36. The method of claim 34, wherein the species is Pleurotus ostreatus.

37. The method of claim 34, wherein the fungal culture is a liquid culture comprising a fungal inoculum prepared from the said fungus, along w'ith peptone, malt and deionized water.

38. The method of claim 37, wherein the step of inoculation comprises contacting the coated wood-polylactic acid porous scaffold with an amount of the fungal culture sufficient to initiate mycelium growth.

39. The method of claim 20 or 21, wherein the mycelium-based composite has a compressive strength ranging from 0.35 to 13.94 MPa at 90% to 50% porosity.

40. An article comprising the mycelium-based composite of any one of claims 1 to 19.

41. A construction article comprising a plurality of the mycelium-based composite of any one of claims 1 to 19.

Images