Growth dynamics of red abalone shell: a biomimetic model

A model of shell formulation was developed in red abalone in which the nacre forms over the prismatic section. The model was based on roughness variations of the growing edge of the mollusc determined by atomic force microscopy. These variations were spatially distinguished and related to various sections of the shell, i.e., nacreous, prismatic, and the interface in between. With a diffusional growth model, it was estimated that for a relatively rough, zrms=(1.34±0.23) μm, surface, it will take (16.5±2.5) days for this surface to become flat, zrms=1 nm. This is the time it takes what was once a rough prismatic surface eventually smoothening to become a nacreous layer. For this time interval, the shell will have grown radially by approximately 1.2 mm. The smoothening coefficient, which measures the rate at which the nacre forms over the prismatic surface, was found to be εs=(0.042±0.005) μm2/day. The model may have implications both for better understanding of biological hard tissue formation and their biomimetic regeneration.