Mechanical Properties of the Lobster Cuticle

摘要

We present experiments on the mechanical and structural gradients through the cuticle of homarus americanus (lobster). The exocuticle (outer layer) is characterized by a very fine woven structure of the chitin-protein matrix (Bouligand structure) and by a high stiffness (8.5-9.5 GPa). The hardness increases within the exocuticle between the surface region (130 MPa) and the region close to the interface to the endocuticle (270 MPa). In the endocuticle which is characterized by a much coarser twisted plywood (Bouligand) structure both, the stiffness (3-4.5 GPa) and hardness (30-55 MPa) are much smaller than in the exocuticle. The transition in mechanical properties and structure between the exo- and endocuticle is abrupt.