Drag force of polyethyleneglycol in flows of polymer solutions measured by a scanning probe microscope

The drag force of polyethyleneglycol thiol (mPEG-SH) attached to a cantilever probe in the flows of glycerol and polyethyleneglycol (PEG) solutions was measured. The effects of the molecular weights of...

Измерения контактной жесткости в атомно-силовом микроскопе

A method is proposed for increasing the accuracy of nanomechanical measurements in an atomic force microscope. To describe the contact interaction of the cantilever with the sample, an analytical model was used that takes into account the following factors: the cantilever probe sticks to the sample surface or slides along it, the geometric and mechanical characteristics of the sample and cantilever, and their relative position. Under the assumption of sliding, a filter was developed to correct the signals of contact stiffness and deformation measured on a sample with a developed relief. The use of the filter is illustrated in images obtained in an atomic force microscope with an imaging mode based on point-by-point registration of the force quasistatic interaction of the cantilever probe with the sample.

Three-Dimensional Atomic Force Microscopy for Sidewall Imaging Using Torsional Resonance Mode

This article presents an atomic force microscopy (AFM) technique for true three-dimensional (3D) characterization. The cantilever probe with flared tip was used in a home-made 3D-AFM system. The cantilever was driven by two shaking piezoceramics and oscillated around its vertical or torsional resonance frequency. The vertical resonance mode was used for upper surface imaging, and the torsional resonance mode was used for sidewall detecting. The 3D-AFM was applied to measure standard gratings with the height of 100 nm and 200 nm. The experiment results showed that the presented 3D-AFM technique was able to detect the small defect features on the steep sidewall and to reconstruct the 3D topography of the measured structure.