The limiting layer of fish scales: Structure and properties

Abstract

The natural armor of fish, turtles and other animals, has become a topic of substantial scientific interest. The majority of investigations have focused on the more highly organic layer known as the elasmodine. The present study addresses the highly mineralized external portion known as the Limiting Layer (LL). Specifically, the structure, composition and mechanical behavior of the LL were explored for three different fish, including the arapaima (Arapaima gigas), the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio). Results show that there are significant differences in the surface morphology of the LL from posterior and anterior regions in the scales, and between the three species. In addition, the composition of the LL is also unique among the three fish. Results from nanoindentation showed that the LL of tarpon scales is the hardest, followed by the carp and the arapaima and the differences in hardness are related to the apatite structure, possibly induced by the growth rate and environment of each fish. In addition, a new feature was indentified in the LL, which has not been discussed before. As such, we feel this work is unique and makes a significant contribution to the field.

Materials research & measurement needs for ceramics additive manufacturing

“…Natural biological composites, which commonly incorporate simple base materials in complex hierarchical structures, exhibit mechanical properties superior to those of individual components. 25,26 Ceramics AM offers potential for implementing bioinspired multiscale designs to generate armor materials with an optimal combination of properties (density, microstructure, mechanical strength, and fracture toughness). However, the ability to realize this potential remains to be demonstrated, for which more research, together with the development of more extensive modeling capabilities will be required.…”

“…Therefore, new processing technologies are sought. Natural biological composites, which commonly incorporate simple base materials in complex hierarchical structures, exhibit mechanical properties superior to those of individual components 25,26 . Ceramics AM offers potential for implementing bioinspired multiscale designs to generate armor materials with an optimal combination of properties (density, microstructure, mechanical strength, and fracture toughness).…”

A novel lamellar structural biomaterial and its effect on bone regeneration

“…Fish scales are mainly composed of calcium phosphorus compounds and collagen, which have attracted attention owing to their highly ordered multilayer structure. 13,14 Generally, hydroxyapatite, collagen, and derivatives are extracted from sh scales. The collagen and derivatives prepared in this way destroy the original collagen hierarchical structure in sh scales.…”

Caracterização De Escamas De Pirarucu E Compósitos Reforçados Com Escamas De Pirarucu Por Drx, Eds E Mev

“…Torres et al [8] analisaram a influência da presença de diferentes conteúdos de água na transição térmica das escamas através de análises de calorimetria diferencial. Arola et al [9] estudaram a estrutura, a composição e o comportamento mecânico da camada limite das escamas para três peixes diferentes, a saber o pirarucu (Arapaima gigas), o tarpão (Megalopsatlanticus) e a carpa (Cyprinuscarpio).…”