Evaluation of Accuracy and Repeatability of Scanning Probe Microscope Positioning System

Scanning probe microscope (SPM) positioning system quality depends on the design of the positioning system, environmental factors, frictional forces, and load. The aim of our research is to determine the accuracy and repeatability of a homemade micropositioning system for sample positioning in the experimental SPM setup. For the design of the micropositioning system, micrometric resolution ball-screw drives with stepper motors were used. Axes parameters, such as positioning errors, repeatability, and accuracy, were evaluated using the ISO 230–2 standard methodology. The results from experimental research show positioning accuracy of X-axis $\mathbf{113.67}\ \mu\mathbf{m}$ , and repeatability $\mathbf{13.68}\ \mu\mathbf{m}$ . Although the accuracy value mainly contains a systematic positioning error $\mathbf{103.5}\ \mu\mathbf{m}$ , therefore, this can be compensated using features available in LinuxCNC control software. The positioning accuracy of the Y-axis was $\mathbf{6.86}\ \mu\mathbf{m}$ , and repeatability $\mathbf{6.72}\ \mu\mathbf{m}$ . Improvements in the mechanical components that make up the axis and additional research can improve the value of the repeatability of the X-axis of the system and the adaptability of the positioning system for SPM design.