Earlier this month I wrote about the difficult task of imitating materials found in nature. The article noted that though many natural objects contain properties that engineers would love to recreate in synthetic products, the design process can be slow, and regulatory approval of, say, a new composite material for airframes can be decades in the making.
On other fronts, the imitation game is going much faster. Examples of promising “bioinspired” products include climbing devices that mimic the gecko’s remarkable gripping ability and, in the case of the Ortiz Lab at the Massachusetts Institute of Technology, better body armor that owes a debt to the tough qualities of fish scales.
Materials scientist Christine Ortiz, who runs the lab, explains that when conventional armor gets hit by a bullet, it shatters. This renders it ineffective if a second bullet comes along soon afterward. “Armored fish have multi-hit capability,” Ortiz says. “Basically, when it gets hit, it just cracks locally in a circle.”
Ortiz’s lab, which receives funding from the Department of Defense, is looking at other ways to integrate naturally occurring defense techniques into human warfare. One is transparent armor. “Think of a ballistic windshield,” Ortiz says. “[It’s] smashed all over the place from one hit, then you can’t see anywhere.” Another involves using natural designs to create armor that has the ballistic protection of ceramic plates — a material commonly used in body armor for the way it dissipates force — but remains flexible and easy to wear. Ortiz refers to this combination as “mechanical invisibility.” “You don’t feel that you’re constrained with a rigid ceramic,” she says. “It feels like a soft polymer.”
Whether this technology ever ends up on the battlefield remains to be seen. In the meantime, we can be grateful that we don’t have to go up against armies of heavily armored three-spined sticklebacks: Some of their innovations are way ahead of ours.