Novel Engineered Composite Materials for Protection Inspired by Natural Dermal Armors

Abstract

To achieve protection from potential environmental and physical threats, fish, mammals and reptiles have developed flexible dermal armors. Engineers and scientists have been inspired by the design of these biological materials and their potential for guiding the development of new structural composites for protection. In this study, we examine the scales from carp fish and find aspects of the microstructure that can serve as a valuable model for the design of a new generation of lightweight, bioinspired armors. Elasmoid fish scales possess a unique balance of stiffness, strength and light weight to provide protection against predators while not interfering with locomotion. When compared to a puncture resistant rubber the scales provide up to 4X improvement in load required for puncture. In evaluation of the scale microstructure, the outer mineralized layer plays a major role in puncture resistance and the external elasmodine and internal elasmodine layer has a hierarchical structure which join the hard, mineralized layer with collagen fibers. The unique structure of elasmoid fish scales provides flexibility without sacrificing strength and toughness. Expanding on these results, novel synthetic soft and hard composite armors were designed and tested. The biomimetic composite material surpasses other synthetic materials in many aspects such as high specific strength and low specific flexural stiffness. Further work is underway to improve on these designs for specific applications that require puncture and penetration resistance.