Engineered mycelium-based composite materials: Comprehensive study of various properties and applications

The need for increased development in sustainable materials has grown over the past few years due to the high cost and large carbon footprint of conventional materials in its production. This study highlights the possible use of mycelium as an alternative for common construction and packaging materials. Mycelium is the vegetative part of a fungi or the roots of the mushroom which can be used in producing bio-composite materials with agricultural waste (substrates) called mycelium-based composite material (MBC), whereby the mycelium acts as a natural glue binding the substrates. The oyster mushroom mycelium was used in producing MBCs with three different substrate types namely, bagasse (B + RH), coconut husk (CH + RH) and a mixture of coconut husk plus bagasse (CH + B + RH). Rice husk (RH) was added to all substrates for mycelium nutrients. Readymade and fully mycelium colonized oyster mushroom spawn in juncao grass (JG) was used as well. Four different combinations of MBCs of standard size according to ASTM D1037 standard were prepared to conduct the flexural, compressive and fire resistance tests. The results showed that B + RH and JG mycelium composites have better mycelium growth density and better flexural strength, 63.4 and 399.39 kPa, and compressive strength, 13.81 and 78.34 kPa, respectively. However, the dispersion of results for JG indicated that it had a non-homogenous growth of mycelium. Furthermore, based on the fire resistance test, B + RH performed the best as total heat penetration took more than 16 min, indicating it had low thermal conductivity than other composites and can be used as an insulating material. Other suitable end-applications have been derived for the best performing MBC, which were JG and B + RH.