Radular teeth as models for the improvement of industrial cutting devices

Limpets (Gastropoda) and chitons (Polyplacophora) feed on epi- and endolithic organisms by means of the radula, a specialized feeding apparatus located in the mouth cavity. The radula owes most of its abrasive capability to the presence of numerous mineralized teeth. Here we report on the shape, internal structure, wearing pattern, feeding position, and distribution of hardness and elastic properties of these teeth in an attempt to generate ideas for the innovation of industrial cutting devices. The teeth remain sharp during their entire working-life mainly due to the fact that wearing preferentially occurs along surfaces formed by the internal structure of the tooth. It is shown that shape, internal structure, positioning and material characteristics concertedly function in minimizing the rate at which the teeth wear down and in maintaining optimal cutting behaviour. Implementation of these self-sharpening characteristics into industrial cutting devices is discussed.