Abstract: Entanglement of slender elements by interlacing or growing in place offers unique routes to manufacturing composite structural systems with properties that exceed the constituent materials. In this talk, we explore this theme across two systems: woven baskets and mycelium-bound composites.

First, we show how weaving thin ribbons into three-dimensional basket shapes creates structures and metamaterials with high stiffness and a remarkable resilience to damage. Experiments and simulations show that woven corners can be as stiff as continuous counterparts made with the same amount of material, yet under large deformations they remain elastic and can fully recover their initial shape, because the interlaced ribbons permit segmented local buckling that deconcentrates stresses. We then show that introducing traditionally unwanted 'snags' into woven systems can engineer the spatial curvature of the thin-sheet system, and that modular assemblies of woven corners can be used to fabricate functional robots that locomote while carrying loads much larger than their self-weight.

Second, we turn to mycelium-bound composites, a low-cost, renewable, and biodegradable material made by growing filamentous fungi on lignocellulosic waste. Here, the entanglement is grown rather than woven, and we use pull-out experimental tests to explore the bonding behavior of mycelium. Our results show that mycelium bonds well with all tested materials, including woods, ceramics, metals, polymers, and textiles. Surprisingly, the bonding with Copper, Zinc, Nickel, Iron, and their alloys is particularly strong, as ions from these metals encourage enhanced growth of the mycelium network.

Contact: Ian Tobasco