Structural biological composites: An overview

Biological materials are complex composites that are hierarchically structured and multifunctional. Their mechanical properties are often outstanding, considering the weak constituents from which they are assembled. They are for the most part composed of brittle (often, mineral) and ductile(organic)components. These complex structures, which have risen from. millions of years of evolution, are inspiring materials scientists in the design of novel materials. This paper discusses the overall design principles in biological structural composites and illustrates them for five examples: sea spicules, the abalone shell, the conch shell, the toucan and hornbill beaks. and the sheep crab exoskeleton.