Tailoring the Mechanical Properties of Fungal Mycelium Mats with Material Extrusion Additive Manufacturing of PHBH and PLA Biopolymers

Author: mycolabadmin
12/3/2024
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Summary

Researchers developed a new way to make fungal mushroom mats stronger by printing biodegradable plastic patterns onto them using 3D printing technology. The resulting composite materials combined the sustainability of fungal products with improved strength, making them suitable for flexible applications like smart textiles and lightweight parts. Both tested polymers (PHBH and PLA) enhanced the mycelium’s mechanical properties, with PLA showing superior strength improvements while PHBH offered home compostability.

Background

Fungal mycelium-based materials are emerging sustainable alternatives to petroleum-based and animal-derived products due to their biodegradability, low carbon footprint, and cruelty-free nature. However, their mechanical properties are inherently limited, necessitating post-processing strategies. Material extrusion additive manufacturing (3D printing) has been successfully applied to combine substrates with polymeric reinforcement in various applications.

Objective

This study presents a novel approach to reinforce fungal mycelium mats by depositing defined patterns of two bio-based and biodegradable polymers—poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH) and polylactic acid (PLA)—via material extrusion additive manufacturing to create fungal mycelium-biopolymer composites with improved mechanical properties.

Results

PLA application resulted in greater improvements in ultimate tensile strength (3.11 ± 0.5 MPa) compared to PHBH (1.1 ± 0.3 MPa) relative to pure mycelium (0.65 ± 0.2 MPa). Young’s modulus increased significantly with PLA (136.0 ± 57.7 MPa) compared to PHBH (38.6 ± 19.65 MPa), though elasticity was reduced. SEM imaging revealed an unexpected additional mycelium layer between the polymer and substrate, affecting adhesion quality.

Conclusion

Material extrusion additive manufacturing successfully enhances fungal mycelium mat mechanical properties using biodegradable biopolymers. While PLA provides superior mechanical improvements, PHBH offers home compostability. Optimization of adhesion through modified printing parameters and substrate pretreatment could enhance composite quality while maintaining full biodegradability, enabling applications in smart textiles, flexible devices, and lightweight materials.

Published in:ACS Omega,
Study Type:Experimental Research,
Source: DOI: 10.1021/acsomega.4c07661, PMID: 39713613