Fabrication and measurement of nanostructures on the micro ball surface using a modified atomic force microscope

In order to machine and measure nanostructures on the micro ball surface, a modified atomic force microscope (AFM) combining a commercial AFM system with a home built precision air bearing spindle is established. Based on this system, motions of both the AFM scanner and the air bearing spindle are controlled to machine nanostructures on the micro ball based on the AFM tip-based nano mechanical machining approach. The eccentric error between the axis of the micro ball and the axis of the spindle is reduced to 3-4 μm by the provided fine adjusting method. A 1000 nano lines array, 36 square pits structure, 10 square pits structure, and a zig-zag structure on the circumference of the micro ball with the diameter of 1.5 mm are machined successfully. The measurement results achieved by the same system reveal that the profiles and mode-power spectra curves of the micro ball are influenced by the artificially machined nanostructures significantly according to their distributions. This work is an useful attempt for modifying the micro ball profile and manufacture of the spherical modulation targets to study the experimental performance of the micro ball in implosion.