Mycelium-based materials
[2] It was popularized by Eben Bayer and Gavin McIntyre through their work developing mycelium packaging while founding their company, Ecovative, during their time at Rensselaer Polytechnic Institute.
“Mycelium” is a term referring to the network of branching fibers, called hyphae, that are created by a fungus to grow and feed.
[5][4] Commonly used species of fungi to grow mycelium are aerobic basidiomycetes, which include Ganoderma sp., Pleurotus sp., and Trametes sp.
[6] Basidiomycetes have favorable properties as fungi for creating mycelium based composites because they grow at a relatively steady and quick pace, and can use many different types of organic waste as substrates.
For most man-made materials there is a high degree of control in the processing methods of the final product leading to normalized properties.
[7] Their process begins with introducing the mycelium to calcium and carbohydrates in a filter patch bag where it is allowed to grow over the course of 4–6 days.
The mycelium is then packed into molds with more growth nutrients that are left for 4 days with special adjustments to temperature, humidity, oxygen, and other factors.
[5] According to another company, Grown Bio, mycelium based packaging also has advantages because of the versatility of design shapes as well as having a high shock absorbance and insulation properties.
[4] They use a 3D printed reusable mold made from a biopolymer to template their products which are then filled with agricultural waste, water, and lastly the mycelium.
To fabricate these mycelium based composites outside of natural processes, options for substrates include common “left-over” materials such as wood and straw.
[12] Recycling waste products contributes to the mycelium based composites' low cost and environmental-friendliness over the current methods and materials.
The results found that composites with a higher density were slightly affected by the levels of humidity, but remained mechanically sound by the standard necessary for construction materials.
[7] To construct a panel of acoustic dampening material, the fungus can be mechanically suspended within a rigid chamber, and allowed to grow to fill the space.
[7] Studies have found that the resultant paneling, when compared to conventional acoustic dampening materials like foam, cork, felt, cotton and ceiling tiles, displayed comparable acoustic absorption in frequencies around 3000 Hz and above, while falling short in performance at frequencies below 3000 Hz.
[17][8] Performance of any given panel is highly dependent on the mix of substrate, species and other previously mentioned variables, and yield varying absorbance profiles.
[8][18] Within the contemporary fashion industry there has been a push for more ethically sourced materials in order to alleviate environmental concerns.
[19] To fulfill these needs, companies like Mycoworks and Ecovative have developed sustainable materials to substitute for leather of varying thicknesses and applications.
