STRUCTURE-FUNCTION RELATIONSHIPS FOR THE BIO-INSPIRED DESIGN OF SCALES

The structure of scales, found in organisms ranging from fish to plants, demonstrates a wide range of patterned design. Composed of keratin, collagen, or other biomaterials, scales exhibit a hierarchical organization with diverse patterning strategies. Functionally, scales serve several critical roles in organisms' survival and adaptation. The applications of scale-inspired designs span a diverse array of fields, from improving the hydrodynamic efficiency of aircraft and underwater vehicles, to developing advanced wound dressings and prosthetic materials in the biomedical field. Scale-inspired structures have also been integrated into architecture and building materials. Despite some examples, there has been limited exploration of bio-inspired design of scales, which have received a lot of attention with the progress made in computational design and additive manufacturing. We argue there that this is at least partly on account of the limited design principles formally abstracted for scales, which further, may be attributed to a tenuous connection between structure-function relationships that are well described for families of organisms in biology, and engineering applications. Towards addressing this gap, we first develop a new structural and functional classification for scales that cuts across multiple groups of organisms, using a designer's perspective. We show how such a perspective emphasizes design choices as opposed to phylogenetic relationships, commonly used in biological classification. Structure-function relationships are then mapped to each other, providing a direction from scale structure to potential applications. We end with a discussion of how such a structure-function map may be embedded into a computational design tool for scales, and how it may also deepen our understanding of the evolution of scales in biology by providing a pathway for engineering studies of structure-function relationships.