Investigation of water's effect on nanomechanical characteristics of beetle cuticle

The special structural and mechanical characteristics of beetle elytral cuticle will be instructive in bionic for designing composites materials. Because the microscale or nanoscale thickness of the beetle cuticle, it was difficult to determine the cuticle's mechanical characteristics until nanoindentation techniques were developed. The nanomechanical characteristics (reduced modulus Er and hardness H) of dung beetle Copris ochus Motschulsky cuticle were investigated by nanoindenter. To understand water's effect, samples were tested immediately or after different amounts of time. The nanoindentation results showed that the mechanical characteristics were strongly influenced by sample aging and that Er and H increased with a decrease in water content. The results were discussed in following about relationship of the mechanical characteristics of the cuticle and its behaviors.