3. Tribology of biological materials
(a) Sea Shells
In the present study, the scratch and indentation properties of the outer and inner (nacre) layers of green mussel shells under dry and water-soaked conditions are investigated.
Fig. 2(a) and (b): Pictures of the inner nacreous layer and outer calcitic layer respectively. (c) and (d): SEM images of the top view of the nacreous and calcitic layer respectively. (e): SEM image of an etched cross section of the nacreous layer shows that the aragonite platelets are relatively flat. (f): FESEM image of an etched cross section of the outer layer shows that calcite platelets have a distinct curvature, in contrast to the aragonite platelets.
H. M. Leung and S. K. Sinha, Scratch and indentation tests on seashells. Tribology International (In press).