3D printing and process optimisation of mycelium-bound composites

• Main Author: Leong, Brendon Shi Wei
• Other Authors: Hortense Le Ferrand
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/158207
• Institution: Nanyang Technological University

Mycelium composites are a new type of environmentally friendly material that has applications in construction, acoustics, thermal insulation, and packaging. These composites employ the growth of mycelium onto a nutrient-rich substrate to form a bio-composite. However, the main mode of fabrication of such materials is moulding. Direct-ink writing has been explored as a cheaper alternative that allows for more complex shaping. This project investigates the development of an extrudable paste made from readily available food waste, coffee grounds, and agar as the bio-ink. The compositions of the substrate and bio-ink within the paste are optimised to create a viscous paste that allows for maximal mycelial growth while maintaining printability. The impact of different printing parameters on printed samples are investigated and subsequently optimised to improve print quality. Rheological classification of the paste is also investigated. Finally, as a way to save material usage, machine learning was performed to predict the optimal processing window for the paste. The project shows the possibilities and feasibility of coffee grounds as a substrate and their printability. With some optimisation, Direct ink writing can be a more mainstream fabrication process for mycelium composites.