Multi-objective optimization of mycelium-based bio-composites based on mechanical and environmental considerations

Mycelial materials, the biodegradable lightweight composites derived from the colonization of fungi on organic wastes, present a promising alternative to the traditional methods of material procurement. This study aims to identify the substrate composition and production methodology that not only maximize the mechanical strength but also minimize the environmental footprint of mycelium-based bio-composites (MCBs) for construction applications. A statistical experiment was designed with one numeric and two categoric factors, leading to 27 combinations, for all of which compressive and three-point bending tests were conducted and single-score weighed environmental impacts extracted from life-cycle analysis. Upon the development of predictive models and investigation of interactions between the design factors, an optimizing desirability analysis was carried out, revealing that MBCs containing up to 37% fine bamboo fibers can satisfy most target criteria with relatively high levels of desirability. In the scenario where equal weights and importance were assigned to environmental impact and mechanical performance, materials made of 11% fine bamboo and no pre-compression were identified as the optimal choice. The results highlight how meticulous modifications in composition and production framework can yield a range of MBCs with different characteristics, allowing for the fulfillment of various needs based on the intended applications.