Manufacturing method of nanofiber probe tip for measuring surface topography of sample

Abstract

The invention relates to a method for preparing a nanofiber probe tip. The method comprises the following specific steps of preparing a substrate, covering a surface of a conductive flat plate with adielectric layer; probe surface treatment, covering a surface of a probe with a conductive layer; preparing solution, namely preparing turbid liquid from nanofibers and the distilled water according to a certain proportion; bonding fibers, controlling the probe to slowly approach the liquid drops till the probe is in contact with the liquid drops. The method is advantaged in that the surface tension of liquid is adjusted by utilizing an electric field, the shape and the height of a liquid bridge between the probe and a substrate are controlled, so fibers are absorbed on the surface of the probe. The prepared nanofiber probe tip can improve sensitivity of an atomic force microscope to surface topography characteristics of a material and measurement precision of mechanical properties, the method has the capability of controlling the fiber orientation at the same time, so the nanofiber prepared by the method can be applied to special tests, and the preparation method is simple to operate,relatively low in cost and high in robustness.

Description

technical field [0001] The invention belongs to the technical fields of micro-nano measurement, nanometer material, surface topography measurement and mechanical performance test, and in particular relates to a method for manufacturing a nanofiber probe tip used for sample surface topography measurement. Background technique [0002] In 1986, G. Binning invented the atomic force microscope (AFM) on the basis of the scanning tunneling microscope, thereby realizing the observation of the atomic level of non-conductive samples (LiJ, XieJ, XueW, etc., Microsystemtechnologies (2013) 19: 285-290) . The performance of the atomic force microscope is closely related to the probe used. Due to the limitation of the probe preparation process, the minimum size of the probe tip on the market is about 10 nanometers, which is difficult to meet the stringent requirements for the accuracy of nanostructure scanning. The current general practice It is to bond nanostructures (for example: carbo...

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Problems solved by technology

The performance of the atomic force microscope is closely related to the probe used. Due to the limitation of the probe preparation process, the minimum size of the probe tip on the market is about 10 nanometers, which is difficult to meet the stringent requirements for the accuracy of nanostructure scanning. The current general practice It is to bond nanostructures (such as carbon nanotubes) to the tip of the probe (Chinese patent application number: CN107436366A)

At present, there are three mainstream preparation methods. The first method is to modify the tip of an ordinary probe, bond a catalyst, and then put the nanotube into it for reaction, so that the carbon nanotube grows at the tip (CN1232813C). It is cumbersome, has high requirements for instruments, and is only suitable for bonding carbon nanotubes at the tip of the needle; the second method is to suspend the nanostructure to be adsorbed on the surface of the liquid, and then let the tip of the needle touch the water surface, so that the nanostructure suspended on the water surface The structure is adsorbed at the tip of the needle (LeeJH, KangWS, ChoiBS, etc., Ultramicroscopy, (2008) 108: 1163-1167.). This method has strict requirements on the density of the liquid and the density of the nanostructure on the water surface. Therefore, the density of the material during the preparation process The consumption is large, the utilization rate is low, and the bonding position and direction of the nanostructure cannot be controlled; the third method uses the polarity of the fiber to adsorb the probe to the tip of the probe through the tip electric field (TangJ, YangG, ZhangQ, etc. , Nanoletters (2005) 5: 11-14; StevensRM, Materialstoday, (2009) 12: 42-45), but this method is only applicable to polar materials, such as carbon nanotubes, so the scope of application is limited

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