Structures and composition of the crab carapace – an archetypal material in biomimetic mechanical design

The structures and composition of crab carapaces are of interest to biomimetic designers and materials scientists as they have been found to be organised, hierarchical crab carapaces are optimised to dissipate fracture energies from the molecular to macroscopic length scales. At each length scale, mechanical energy is absorbed and redirected, circumventing thus, catastrophic fast-fracture through the carapace cross-section on impact. The objective of this section is to elucidate the structural, chemical, and compositional makeup of crab carapaces, to provide links between their architectures and mechanical properties, and to discuss highlight papers where attempts have been made to mimic the structure-property characteristics of crab carapaces in modern engineering composites.