9.04 – Silks

Silks are protein-based fibers produced by several arthropods, most notably silkworms and spiders. The fibers display a unique combination of high strength and extensibility, resulting in a high toughness. Silk fibers are composed of a structural hierarchy of ordered β-sheet crystallites embedded in a less organized matrix. Formation of the fibers in silkworms and spiders is performed through aqueous processing, involving complex chemical gradients and fluidic forces. Applications of silk fibers have traditionally been in textiles, but regenerated aqueous silk and genetically engineered silk-like proteins can be processed into a variety of novel materials, with applications in medical devices and biosensors.