Biological and Biologically Inspired Functional Nanostructures: Insights into Structural, Optical, Thermal, and...

Biological materials developed over millennia consist of simple biogenic materials, yet exhibit exceptional functional properties. Leveraging design features from these structures with engineered nanomaterial components can lead to bio-inspired structures that demonstrate superior performance over traditional engineering materials. We describe nanoscale based architectures in biological systems, their role in enhancement of structural, optical, thermal and sensing properties, and their subsequent translation to bio-inspired structures. In structurally robust biological materials, we highlight nanoscale design features that enhance strength and stiffness, while retaining toughness. In optically active biological materials, we show how periodic nanostructures manipulate electromagnetic waves resulting in structural coloration as well as antireflective and camouflaging properties. Thermally regulating biological materials utilize nanopores and other nanostructural features to statically or dynamically control temperature. In addition, biological materials that are used in sensing utilize various nanostructures that enhance sensitivity by decreasing activation thresholds for signal transduction. We discuss challenges and opportunities including understanding control mechanisms in the formation of biological materials and leveraging advancements in self-assembly with new additive manufacturing techniques. The continued evaluation of organisms, including those that exhibit multifunctionality, provides not only new design features and pathways, but significant prospects for innovation in this ever-emerging field.