Scientists Have Improved The Image Accuracy Of Scanning Microscopes
Researchers from Tomsk Polytechnic University (TPU) and Tver state technical University (TSTU) have found a way to increase the accuracy of microscopes with nanometer resolution up to ten times by offering a method to compensate for fluctuations in the microscope needle that had a negative impact on image quality. The results are published in the journal Applied Surface Science Volume.
According to the TPU staff, the method of scanning probe microscopy with nanometer resolution is based on obtaining the response of the probe to the interaction of the needle with the surface. There are many reasons for the lack of accuracy of the method, one of them is caused by the instability of the cantilever, at the end of which there is a needle.
Usually, according to scientists, researchers only consider the vibrations of the cantilever. However, the needle vibrates with the cantilever, and it also has its own vibrations, the frequency of which is different from the frequency of the cantilever. The authors of the study considered exactly the fluctuations of the SWCNT needle.
Scientists from TPU and TSU analyzed the displacement of the SWCNT needle tip from the equilibrium position, using a mathematical pendulum model, created a model of the needle oscillation equation, and established an analytical relationship between the needle parameters and the characteristics of its instability.
"On the basis of the ratios between the oscillation of the needle, its topography, and structural properties, we analyzed the movement of the needle in the "needle atoms — atoms at surfaces" and found that the oscillations of the needle increase the size of a fragment of the studied surface to the size of the trajectory oscillations of the needle," said associate Professor of Department of oil and gas business, TPU Faith Deeva.
The authors of the study proposed to compensate for needle vibrations by identifying deviations of the center of the needle tip and the center of the surface segment under the needle in the XY plane and then excluding them from the optical sensor signal using signal modulation.