Piranha-proof armor inspires advanced biomaterials engineering designs for body armor, fuel cells and aerospace

Marc Meyers, a professor at the Jacobs School of Engineering at UC San Diego, was inspired by the intricately designed, piranha-proof scales of the Arapaima fish; the scales combine a heavily mineralized outer layer with an internal design that helps resist the pirahna’s razor-like bite. The mix of materials is similar to the hard enamel of a tooth deposited over softer dentin, said Meyers. “You often find this in nature, where you have something hard on the outside, but it rides on something softer that gives it toughness.” It’s a combination that engineers would like to reproduce for applications such as soldiers’ body armor, which needs to be both tough and flexible. Other applications might include fuel cells, insulation and aerospace designs.