Nature‐Inspired Protecto‐Flexible Impact‐Tolerant Materials

Abstract

The search for impact‐tolerant, light‐weight flexible materials has challenged materials scientists and engineers for decades. In this quest, many researchers have focused on studying natural armor as a guide to propose bioinspired materials with enhanced properties. The energy dissipation and flexibility mechanisms activated at different hierarchical structural levels of natural systems are used here as a guide to improve the energy and flexibility of synthetic materials. In particular, fish scales and osteoderms are selected as proper biological models to develop a novel family of cost‐effective bioinspired protecto‐flexible (Pf) materials. Furthermore, a bullet‐proof protecto‐flexible prototype is manufactured and tested. The ballistic tests suggest that under real stringent conditions, the system is capable of absorbing high levels of energy while remaining flexible enough to allow movement to the user. Remarkably, the material system developed allows its implementation into realistic high volumes of production with low added costs. Consequently, the proposed strategy for developing bioinspired Pf materials will enable the development of the next generation of high‐performance impact‐resistant materials.

Anomalous inapplicability of nacre-like architectures as impact-resistant templates in a wide range of impact velocities

“…shown that the impressive toughness enhancement originates from the tablet sliding mechanism 10,[34][35][36] , where millions of tablets slide on one another over large volumes under tensile forces or low-velocity impact loads. Due to the energy-dissipation capacities of different structures depending on their specific failure modes, studies have reported that, upon static loads or a specific low-speed impact, the structures with energy-dissipation abilities from low to high are monolithic structures, laminated structures and nacre-like structures, respectively 10,11,26,27,[37][38][39][40][41][42] . We have collected experimental data on energy dissipations versus loading velocity for nacre-like structures, traditional laminated structures and stiff monolithic structures as shown in the map of Fig.…”

Tuning protecto‐flexibility in nature: Case of the fish scale

“…In this paper, the suture region of the LL in elasmoid fish scales was evaluated for the first time, and its contribution to the structural behavior of elasmoid scales was characterized. Overall, this feature appears to play a key role in the structural behavior of the scales and is an important element of the topological design in achieving biomimetic materials with so‐called protecto‐flexibility, viz., the multifunctionality consisting of flexibility and toughness 29,48 …”

“…Overall, this feature appears to play a key role in the structural behavior of the scales and is an important element of the topological design in achieving biomimetic materials with so-called protecto-flexibility, viz., the multifunctionality consisting of flexibility and toughness. 29,48 An ideal material for "wearable" armor applications would possess low bending stiffness and high toughness. Although important, an increase in strength is not necessarily of direct value to function.…”

Fish scale inspired structures—a review of materials, manufacturing and models

“…The sample design was inspired by fish scale hierarchical structure (from one to six hierarchical levels), with ultra-high molecular weight polyethylene (UHMWPE) being used as the base material. It has been discovered that these materials can absorb a high level of energy, making them useful as high impact resistant materials [90]. Quasi-static and impact loading conditions were applied to panels of biomimetic ceramic building blocks having different interlocking angles where they were placed on an aluminum frame.…”