The Novel Mechanical Property of Tongue of a Woodpecker

Biomaterials such as bone, teeth, nacre and silk are known to have superior mechanical properties due to their specific nanocomposite structures. Here we report that the woodpecker's tongue exhibits a novel strength and flexibility due to its special composite micro/nanostructure. The tongue consists of a flexible cartilage-and-bone skeleton covered with a thin layer tissue of high strength and elasticity. At the interface between the cartilage-and-bone skeleton and the tissue layer, there is a hierarchical fiber-typed connection. It is this special design of the tongue that makes the woodpeckers efficient in catching the insects inside trees. The special micro/nanostructures of the woodpecker's tongue show us a potential method to enhance the interfacial connection between soft and hard material layers for bio-inspired composite system designs.