Shell Shocked; February 1993; Scientific American Magazine; by Gary Stix; 1 Page(s)
Should the designers of aircraft wings and crash helmets take a lesson from the walnut? Julian Vincent, co-director of the Centre for Biomimetics at the University of Reading in England, thinks so. The outer layers, cells filled with a hardened, resinous substance, efficiently resist compressive stresses, while the fibrous inner layers appear to hinder tensile fracture. Yet a walnut shell is relatively thin, relying instead on a robust design. "Nature thinks that material is difficult to come by, but finding a good structure is cheap," Vincent observes.
Vincent's straight-faced presentation was tucked away among the thousands of papers delivered at the Materials Research Society's fall conference in Boston. Despite the laconic title of "Nuts" and the fact that he also recounted how he slammed a weighted pendulum into a coconut shell to test how it might serve as a helmet for skateboarders, Vincent is hardly a crackpot.