Fish Skin: A Natural Inspiration for Innovation

Natural materials and the structures they form, developed and perfected through millions of years of evolution, have long inspired researchers for innovations in science and engineering. One example, fish scales are notable for their strength, toughness, flexibility, and lightweight. These properties are the result of collagen fibrils and hydroxyapatite crystals that have been arranged into three-layer structures through mechanical locking and chemical bonds, via a process that is still poorly understood. This review aims to compile the established knowledge on the composition, structure, and surface/interfacial features offish scales. Using mainly Arapaima gigas as a focus, published information and supplementary data acquired through imaging, analytical techniques, and tensiometry are combined. This is done to take a closer look at the surfaces and interfaces offish scales to identify their unique features and begin to overcome some of the limited understanding of surface functionalities that are created by nature.