Biological Blueprints Towards Next Generation Multiscale Composites*

There is an increasing need for the development of multifunctional lightweight materials that are strong, tough, and reconfigurable. Natural systems have evolved efficient strategies, exemplified in the biological tissues of numerous animal and plant species, to synthesize and construct composites from a limited selection of available starting materials that often exhibit exceptional mechanical properties that are similar, and frequently superior to, mechanical properties exhibited by many engineering materials. These biological systems have accomplished this feat by establishing controlled synthesis and hierarchical assembly of nano- to micro-scaled building blocks that are integrated into macroscale structures. However, Nature goes one step further, often producing materials with that display multi-functionality in order to provide organisms with a unique ecological advantage to ensure survival.
In this work, we investigate a variety of organisms that have taken advantage of hundreds of millions of years of evolutionary changes to derive structures, which are not only strong and tough, but also demonstrate the ability to articulate as well as display multifunctional features including damage sensing and self-cooling. We discuss the mechanical properties and functionality stemming from these hierarchical features as well as how they are formed. From the investigation of synthesis-structure-property relationships in these unique organisms, we are now developing and fabricating cost-effective and environmentally friendly multifunctional engineering composites.