Strongest fibre

Spider silk is one of the strongest fibres in nature and is composed of two types of proteins: a sheet type (beta sheet nanocrystals, 2D structure) and a strand type (beta strands, 1D structure). In 2011, a team of scientists from Hanyang University in South Korea mimicked this natural fibre by combining a Poly Vinyl Alchohol polymer (PVA) with sheets of reduced graphene oxide flakes (RGOFs) and carbon nanotubes (CNTs). The resulting yarns are much cheaper than those using CNTs on their own, and produce fibres that can be sewn like threads. One type of fibre made using this process possessed strength of up to 870 Joules/gram (J/g) – far stronger than spider silk (at 165 J/g) and the synthetic fibre Kevlar (at 78 J/g) that is commonly used in body armour. Different proportions of CNTs and RGOFs have been tried, and optimised alignment of the spinning process led to fibres with strengths up to 970 J/g. This far exceeds any material seen in nature or in a lab to date. The yarns can be twisted without breaking, or can be sewn like thread, as well as coiled into spring shapes, which are fixed by heating the material and which return to their original shape after elongation or compression. Uses for ultra-strong body armour, as well as strong engineering materials, are currently being investigated.