Radular teeth as models for the improvement of industrial cutting devices

Limpets (Gastropoda) and chitons (Polyplacophora) feed on epi- and endolith ic organisms by means of the radula, a specialized feeding apparatus locate d in the mouth cavity. The radula owes most of its abrasive capability to t he presence of numerous mineralized teeth. Here we report on the shape, int ernal structure, wearing pattern, feeding position, and distribution of har dness and elastic properties of these teeth in an attempt to generate ideas for the innovation of industrial cutting devices. The teeth remain sharp d uring their entire working-life mainly due to the fact that wearing prefere ntially occurs along surfaces formed by the internal structure of the tooth . It is shown that shape, internal structure, positioning and material char acteristics concertedly function in minimizing the rate at which the teeth wear down and in maintaining optimal cutting behaviour. Implementation of t hese self-sharpening characteristics into industrial cutting devices is dis cussed. (C) 2000 Elsevier Science S.A. All rights reserved.