Microscopic images of natural fibers: Images (c) and (d) show two types of woven silk.
Growing consumer demand and market activity for sustainable materials has led to the study and application of natural fibers in biocomposites. Many composites already incorporate fibrous materials; for example, fiber-reinforced polymers can incorporate glass- or carbon-fiber strands.
Hemp and flax may be among the most studied natural fibers, but in a March 2014 report in the journal Composites Part A: Applied Science and Manufacturing, Darshil U. Shah, a post-doctoral researcher in the Department of Zoology at the University of Oxford, proposes another option: silk.
Shah and his team claim that the silk fibers of spiders and silkworms are ideal for use in composites because of their high compressibility, long thread structures, and triangular cross-sections. The resulting woven textiles offer dense, orderly structures, as opposed to the loose, disordered bundles of other natural fibers.
"Not only are silk reinforcements significantly more compressible than plant fiber reinforcements, but their compactibility exceeds that of even glass fiber textiles,” Shah told Materials Today. "Consequently, silk fiber reinforcements offer a unique opportunity in the production of high fiber volume fraction natural fiber composites.”
Despite silk fibers’ high performance, the ability to achieve large-scale biocomposite production remains an important question. Could the popularity and relatively high environmental performance of these fibers lead to the creation of factories staffed with bustling arachnids? What might such an operation look like compared to the current industrial production of glass or carbon fibers? Such a vision suggests an increasingly important role for entomologists and ecologists in the field of industrial engineering, and a novel marriage between industrial production and animal husbandry.
Blaine Brownell, AIA, is a regularly featured columnist whose stories appear on this website each week. His views and conclusions are not necessarily those of ARCHITECT magazine nor of the American Institute of Architects.
Image courtesy Oxford University.