Mechanical design of the echinoid test and its biomimetic potentialities

Echinoids, known as sea urchins, are invertebrates populating the seas since the late Ordovician. During their evolution, they underwent a relevant adaptive radiation leading to a variety of specialized forms and lifestyles. Most of the evolutionary success of echinoids is certainly due to the strategic employment of their endoskeleton, with particular reference to the coherent shell-structure of the test adapted to resist both biotic and abiotic stresses related to marine environments. This optimized structure, which minimizes both energy and materials employed, could also represent an ideal model for transferring functional bio-inspired solutions to building constructions and different industrial sectors. The present contribution intends to provide a short overview on the echinoid strategic morpho-functional adaptation of the test and its potential in the biomimetic field.