An energy-based model to predict wear in nanocrystalline diamond atomic force microscopy tips

Atomic force microscopy (AFM) is one of the most powerful techniques to probe surfaces and material properties at the nanoscale, and pattern organic and inorganic molecules. In all cases, knowledge of the tip geometry and its evolution with continued use is essential. In this work, a broadly applicable energy model for the evolution of scanning probe tip radii during use is presented based on quantitative wear experiments. Experiments were conducted using AFM probes made of both undoped and nitrogen-doped diamond. Undoped diamond probes were found to be nearly ten times more wear resistant than commercially available silicon nitride probes. For a constant applied force, a linear relationship between wear volume and total dissipation energy is identified. The change in tip radius was also found to be proportional to the square root of scan distance, x^0.5.