A prescan method improving the reproducibility of force-distance curves obtained with a piezoelectric tube scanner

Abstract

We present a method based on pre- and postscanning a piezoelectric tube scanner used in a force probe that improves the reproducibility of the scan lengths. Instead of prescanning in the same direction as when acquiring data (the z direction), which could destroy a sensitive surface, we perform lateral (x/y direction) prescans. As lateral motions of the tube scanner involve out of phase elongations and compressions of the tube in the z direction, these kinds of prescans will have a stabilizing effect on the z motion as well. By adding an additional postscan in the ±z directions, we reduce the piezoelectric creep following the data acquisition scan. When comparing the lengths of z scans with and without the pre/postscan procedure, preceded by a z voltage step 60 s before data acquisition, the deviation between four consecutive scans improved from 12% to 1.4%.