초록 |
Various living organisms commonly use mechanically strong materials for hunting, defensing, eating and etc. Grasshoppers develop strong teeth (i.e. mandibles) to cutoff rice plants for eating. Hard materials from animals such as human teeth, spider fang, and turtle shell normally include a large amount of inorganic sources. On the other hand, we cannot find any inorganic trace in grasshopper mandibles though their mechanical properties exhibit great performance (hardness: ~ 0.4 Gpa) compare to other hard materials from nature. In general, insects use two type of catecholamine, N-acetyl-dopamine and N-β-alanyl-dopamine, for reinforcing cuticles (i.e. sclerotization). Herein, we proposed a role of a new type of catecholamine, dopamine known as neurotransmitter, in the mechanically strong mandibles formation. We assumed that chemically unprotected dopamine might rapidly cross-linked with chitin and proteins by oxidation at the air-liquid interface. |