Horacio Espinosa¹, Alireza Zaheri¹, Hoang Nguyen¹, David Restrepo², Michael Frank³, Joanna McKittrick³; ¹Northwestern University, ²University of Texas, San Antonio, ³University of California, San Diego

Animals’ teeth have evolved, based on their natural habitat, to provide food procurement, mastication, and protection against predation. These functions require superior hardness and abrasion-resistance. Such resistance typically emerges from damage tolerance and sharpness preservation during the organism life span. In this presentation the use of nanomechanics and in-situ SEM experiments will be demonstrated to identify conditions for tooth deformation and wear. For the case of the sea urchin tooth, movies of wear leading to a previously hypothesized self-sharpening mechanism will be shown and discussed. Nonlinear finite element modeling of the wear process will be presented to provide insights as to the synergy between constituent material properties and tooth microstructural elements on the self-sharpening mechanism. The reported findings should inspire design of novel tools used in machining operations, e.g., cutting and grinding, as well as in mining and tunnel boring.