A self-correction algorithm for positioning error in sequential point bending tests of a microbeam for Young’s modulus based on atomic force microscopy

The single-point bending method, based on atomic force microscopy (AFM), has been extensively validated for characterizing the structural mechanical properties of micro- and nanobeams. Nevertheless, the influence of AFM probe loading and positioning has yet to be subjected to comprehensive investigation. This paper proposes a novel bending-test method based on sequential loading points, in which a series of evenly distributed loads are applied along the length of the central axis on the upper surface of the cantilever. The preliminary measured values of Young’s modulus for an unknown alloy material were 193, 178, and 176 GPa, exhibiting a considerable degree of dispersion. An algorithm for self-correction of the positioning error was developed, and this resulted in a positioning error of 53 nm and a final converged Young’s modulus of 161 GPa.