Researchers of the Tomsk Polytechnic University (TPU) and Tver state technical University (TSTU) has found a way to increase up to ten times the accuracy of the microscopes with nanometer resolution proposing a method of compensation of fluctuations of the needle of the microscope, which had a negative impact on image quality. The results were published in the journal Applied Surface Science Volume.
As reported by the staff of the TPU, the method of scanning probe microscopy with nanometer resolution based on the receipt of 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 due to the instability of the cantilever, at the end of which is a needle.
Usually, according to the scientists, researchers consider only oscillations of the cantilever. However, the needle vibrates together with the cantilever, and it also has its own oscillations whose frequency differs from frequency of the cantilever. The authors of the study considered it swings the needle SWCNT.
Scientists of TPU and TSTU analyzed the displacement of the tip of SWCNT from the equilibrium position using the mathematical model of the pendulum, created the model equation of vibrations of a needle and have established analytical relationships between the parameters of the needle with 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 fragment of 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 fluctuations of the needle, highlighting the deviation of the center of the tip of the needle and the center segment of the surface under the needle in the XY plane, and their subsequent expulsion from the optical sensor signal using the modulation signal.
The proposed method of compensation of fluctuations of the needle, according to scientists, prevents the negative influence of the vibrations on image quality of a scanning microscope, reducing the blurring of the signal. This provides a higher degree of accuracy of fragment of studied surface, from two to ten times depending on its topography and its proportionality unevenness in the size of the needle.
In the future, experts plan to explore the possibility of an eagle SWCNT with specified parameters of oscillations by placing in the correct sequence of atoms selected materials, given the impact of the loss or absence of atoms in the SWCN sheet. This can be useful for many nanotesla, for example in medicine when exposed to the inside on the inner walls of blood vessels.