Development of an Extrudable Paste to build Mycelium-bound Composites

TL;DR

This paper introduces an extrudable, sustainable mycelium-based composite material made from agricultural waste, bamboo, and chitosan, enabling complex shapes and structural applications with low energy costs.

Contribution

It develops a novel extrudable mycelium composite using common agricultural materials, expanding design possibilities beyond traditional moulding methods.

Findings

Optimal bamboo fibre size and chitosan concentration for growth and stiffness

Materials exhibit low energy costs and high sustainability

Shapeable composites suitable for structural applications

Abstract

Mycelium-bound composites are promising materials for sustainable packaging, insulation, fashion, and architecture. However, moulding is the main fabrication process explored to date, strongly limiting the ability to design the complex shapes that could widen the range of applications. Extrusion is a facile and low energy-cost process that has not been explored yet for mycelium-bound composites with design freedom and structural properties. In this study, we combine cheap, easily and commonly available agricultural waste materials, bamboo microfibres, chitosan, and mycelium from Ganoderma Lucidum, to establish a composite mixture that is workable, extrudable and buildable. We study the impact of bamboo fibre size, chitosan concentration, pH and weight ratio of bamboo to chitosan to determine the optimum growth condition for the mycelium as well as highest mechanical stiffness. The resulting materials have thus low energy costs, are sustainable and can be shaped in diverse forms easily. The developed composition is promising to further explore the use of mycelium-bound materials for structural applications using agricultural waste.