She’s not talking up the joys of sauce moutarde. Goldberg is trying to replicate the glue that allows these bivalves to stick to rocks in even the roughest seas. Chemists have yet to synthesize an adhesive that can withstand such conditions, but a glue that works in water would do wonders for shipbuilding, to say nothing of dentistry. Last week Goldberg was in Boston, along with 3,800 other material boys and girls, for the annual meeting of the Materials Research Society. That wasn’t unusual-MRS meets in Boston every year. The surprise was that sprinkled among the usual metallurgists, ceramics mavens and plastics gurus were geneticists and zoologists. They had come to preach the wonders of biomimetics, the science of mimicking biological materials. “Nature comes up with solutions that are very novel and clever,” says molecular biologist John Cordingley of the University of Wyoming. Its successes have survived millions of years of natural selection. Its failures are extinct. Says geneticist Steven Case of the University of Mississippi, “You can make something from scratch, or steal something that’s already out there.”
Even wood, edged out of skis and kitchen counters, may be poised for a comeback. Zoologist Julian Vincent of Reading University in England has created a fiberglass-resin composite inspired by wood. It’s lightweight but tough enough to absorb high-energy’ impacts from things like speeding bullets. Vincent thinks it would make a dandy material for bulletproof vests, now made from Kevlar. (Kevlar is derived from nylon, which comes from oil or coal.) Unlike Kevlar, this George’s Wood can stop a bullet without bruising the body. Vincent is also studying the morphology of potatoes. He thinks that may serve as a model for a new kind of “hydraulic actuator,” a machine that uses fluid pressure to produce movement without friction-prone and easily snapped pistons.
Ever tried to shoot an abalone? Its shell is mostly chalk–calcium carbonate-which, as every school janitor knows, is not exactly shatterproof. The abalone shell’s strength comes from the way the calcium is arranged. Crystals of chalk are held together with a sticky polymer that acts as glue. This brick-and-mortar arrangement is stronger and more resistant to fractures than solid chalk. Researchers at the University of Washington have imitated this design, with polypropylene for the glue, to produce an armor for tanks that resists impacts better than anything today. The army is testing it.
The rag trade long ago recognized the profits to be made from imitating silk, and now materials scientists have caught on. Silk still inside a spider dissolves in water-not a very useful property if the spider wants to catch flies on a rainy day. But spinning the silk into a web somehow makes it resist rain and snow like the toughest twine. Christopher Viney and colleagues at the University of Washington hope to perform the same sort of alchemy. The idea is to figure out how to make a fabric as strong and stiff as silk using simple water as the solvent (most fancy materials, like Kevlar, require a solution of red-hot sulfuric acid). Viney thinks this sort of silk-inspired synthetic could be useful as cables for suspension bridges or for protective clothing.
Other researchers have found inspiration for ultrastrong aircraft composites in the crisscrossing fibers of the common bess beetle’s outer skeleton, and for the skin of tomorrow’s aerospace plane (two hours from New York to Tokyo) in the light but strong covering of the homed beetle. At Reading, Vincent has been shattering walnuts-not for snacks but to understand what makes their shells so strong. Contrary to man’s tendency to try to increase the strength of an object by adding more material, nature designs for strength by crafting a more complicated structure.
Don’t expect nature to take out any patents just yet, though. “There’s a long lag between taking some building block nature has perfected and using it in a different way to make something new,” says Case. And some scientists, led by MRS president Rustum Roy of Pennsylvania State University, have blasted what they see as the exaggerated claims of biomimetics: Roy says natural materials take so long to synthesize that anything modeled on them-just won’t be practical on an industrial scale. Still, nature at least has what other inventors don’t: a multimillion-year winning track record.
