Mechanical properties of terrestrial isopods

Terrestrial isopods have developed a lightweight exoskeleton to the demands of different predation possibilities, for example fast escaping behavior (runner) to rolling into a ball to withstand external forces. However, detailed mechanical investigations onto them are not available yet. Therefore, the aim of this study is the characterization of the mechanical properties of different terrestrial isopods to create new biomimetic impact materials. Pill bugs and woodlice show a gradual change of the mechanical properties from the outer to the innermost part of the cuticle, which was measured by nanoindentation. These tests showed a young’s modulus of 10–30 GPa and a hardness from 0·1 GPa to more than 2·0 GPa in Porcellio scaber and a higher hardness in Armadillidium vulgare. These results will serve as basis for further biomimetic investigations.