Bioinspired design of flexible armor based on chiton scales

Abstract

Man-made armors often rely on rigid structures for mechanical protection, which typically results in a trade-off with flexibility and maneuverability. Chitons, a group of marine mollusks, evolved scaled armors that address similar challenges. Many chiton species possess hundreds of small, mineralized scales arrayed on the soft girdle that surrounds their overlapping shell plates. Ensuring both flexibility for locomotion and protection of the underlying soft body, the scaled girdle is an excellent model for multifunctional armor design. Here we conduct a systematic study of the material composition, nanomechanical properties, three-dimensional geometry, and interspecific structural diversity of chiton girdle scales. Moreover, inspired by the tessellated organization of chiton scales, we fabricate a synthetic flexible scaled armor analogue using parametric computational modeling and multi-material 3D printing. This approach allows us to conduct a quantitative evaluation of our chiton-inspired armor to assess its orientation-dependent flexibility and protection capabilities.

State of the Art Review about Bio-Inspired Design and Applications: An Aerospace Perspective

“…Turtle Shell [22] Rib [25]. It closely resembled a ball-socket joint structure arranged in a lay-up structure consisting of fibrils.…”

“…These multilayer structures consisted of porous structures which were used in composite damping material. Moreover, the inspiration for composite structures that we see today was drawn from these porous shells [22]. Bone-inspired microstructures include bone regeneration to provide cell attachment and ingrowth.…”

Recent Advancements in Biomimetic 3D Printing Materials With Enhanced Mechanical Properties

“…The 3D printing bioinspired reinforced structures. (A) Mechanical properties of 3D printed thick honeycombs (Hedayati et al, 2016); (B) honeycomb-inspired structures and the in-plane compressive stress-strain curves for different layer thicknesses (Yan et al, 2020); (C) chiton scale-inspired flexible armor using rigid polymers (Connors et al, 2019); (D) the adult Allomyrina dichotoma beetle-inspired structure with the metal lattice structure fabricated by selective laser melting (SLM) (Du et al, 2020).…”

“…Chiton scale-inspired flexible armor was studied to accurately mimic natural structures by using 3D printed polymer materials with a modulus of elasticity of 2 GPa (Connors et al, 2019). The 3D printed structure showed good flexibility, protection, could attach well to the human body, and demonstrated potential applications as a military or sports armor (Figure 2C).…”

Discovery of protein-based natural hydrogel from the girdle of the ‘sea cockroach’ Chiton articulatus (Chitonida: Chitonidae)

“…The girdle is often ornamented with calcareous and chitinous elements including scales, spines, spicules, needles, bristles and hairs that differ in appearance and occurrence among species ( Eernisse & Reynolds, 1994 ). The appearance of armature provided by these small, mineralised scales has inspired the design of flexible, man-made armour ( Connors et al, 2019 ), although their biological function for the animal is uncertain ( Leise & Cloney, 1982 ).…”