Lateral force microscopy

Lateral force microscopy (LFM) has provided a new tool for the investigation of tribological (friction and wear) phenomena on a nanometre scale [110]. Alternatively known as friction force microscopy (FFM), this variant of AFM focuses on the lateral forces experienced by the tip as it traverses the sample surface, which... 

Adechanical stahility. ChemisoriDtion to tire surface, intennolecular interactions and crosslinking between adjacent compounds—if possible—all contribute to tire resulting stability of tire monolayer film. Lateral force microscopy investigations revealed tliat tire mechanical stability towards lateral forces on tire nanometre scale is likely to be detennined by tire defect density and tire domain size on a nano- to micrometre scale [163, 1731. 

Mate [6] first obtained the friction force signal as well as the normal load signal by modifying an AFM in 1987. The modified AFM was called FFM or LFM (lateral force microscopy). The friction force signal was obtained by detecting the tor-... 

Resch, R. Friedbacher, G Grasserbauer, M. Kanniainen, T. Lindroos, S. Leskela, M. Niinisto, L. 1997. Lateral force microscopy and force modulation microscopy on SILAR-grown lead sulfide samples. Appl. Surf. Sci. 120 51-57. 

Tanaka et al. have studied the surface molecular motions of PS films coated on a solid substrate by lateral force microscopy and revealed that the Tg at the surface was much lower than the corresponding bulk one [148]. Possible reasons for this included an excess free volume induced by localized chain ends, a reduced cooperativity for of-relaxation process, a reduced entanglement, and a unique chain conformation at the surface. For comparison, they examined surface relaxation behavior of high-density PMMA brushes. 

In 1987 Mate et al. [468] used, for the first time, an atomic force microscope (AFM) to measure friction forces on the nanometer scale (review Ref. [469]). This technique became known as friction force microscopy (FFM) or lateral force microscopy (LFM). To measure friction forces with the AFM, the fast scan direction of the sample is chosen perpendicular to the direction of the cantilever. Friction between the tip and the sample causes the flexible cantilever to twist (Fig. 11.7). This torsion of the cantilever is measured by using a reflected beam of light and a position-sensitive detector in the form of a quadrant arrangement of photodiodes. This new method made it possible for the first time to study friction and lubrication on the nanometer scale. 

For example, chemical contrast images were obtained by lateral force microscopy (LFM) from a topologically flat surface of a self assembled monolayer consisting of chemically different domains. In order to make the chemical adhesion the dominant contribution to the friction signal, the tip was modified by a monolayer with appropriate terminal groups [149-155]. However, since LFM operates in contact mode, the surface deformation is inevitable. 

To further miniaturize the sensors, nanotechniques such as surface probe microscopy and lithography, lateral force microscopy, atomic force microscopy (AFM), and AFM lithography can be utilized.46 Nanoimprint lithography is a low-cost technique that has been shown to produce patterns on the nanometer scale.98 99... 

Fig. 13 Comparative study of symmetric and asymmetric electroactive nanoarrays for the study of cell adhesion and polarization (a) DPN was used to pattern a SAM nanospot of hydroquinone-terminated alkanethiolates for subsequent RGD immobilization and cell adhesion, (b) Lateral force microscopy image of a symmetric nanoarmy (left) and fluorescent cell having a diffusive nucleus-centrosome-Golgi vector that indicates no preferential migratory direction (right), (c) Cell polarity vectors orient toward the direction of higher RDG density on asymmetric nanoarrays, (d) Higher magnification of the cell polarization vector (above) and its schematic (below). Reproduced from [37, 38] with permission. Copyright The American Chemical Society, 2008...

QUANTITATIVE APPLICATION OF LATERAL FORCE MICROSCOPY FOR CARBON NANOTUBES INVESTI GATION... 

Abstract. Quantitative measurements of lateral force required for displacement of SWNTs bundle on the surface of highly oriented pyrolytic graphite with the help of atomic force microscope (AFM) were performed in real time . New method of quantitative calibration of lateral forces was used for interpretation results of lateral force microscopy (LFM). It allows us to receive numerical values of adhesion force of bundle to substrate easy and without specific equipment. 

Keywords Carbon nanotubes, Lateral force microscopy, Atomic force microscopy. 

Atomic force microscopy [6, 7] is one of the most suitable methods for research carbon nanotubes. AFM allows to receive not only a relief of the studied sample, but also distribution of mechanical characteristics, electric, magnetic and other properties on its surface. With the help of AFM, controllable manipulation of individual CNTs and CNTs bundles became possible. In this paper we report our approach to manipulating SWCNTs bundles with lateral force microscopy. LFM gives possibility to study lateral forces that probe acts upon bundles. In spite of good visualization of LFM, its lack is absence of reliable techniques of quantitative interpretation of results. The new way of calibration developed ourselves has allowed to pass from qualitative estimations to quantitative investigations [8], The given calibration technique is much more exact, than others known till now [9, 10], and does not assume simplification. With the help of new technique we may study adhesion of bundles to substrate and adhesion of CNTs in bundle qualitatively in real time more easy way. This result will provide new possibilities for nanotube application. 

Lateral force microscopy (LFM), where the longitudinal vibrations of the cantilever are monitored. 

FFM = LFM friction force (lateral force) microscopy/microscope 3.7d... 

The core concept that the water meniscus at the tip-substrate contact can indeed be controlled and can be used as the molecular transport medium came from basic investigations of water meniscus on lateral force microscopy (LFM) [83]. It was... 

The quality of the gradient was observed by contact angle measurements, infrared spectroscopy, XPS, ellipsometry, and lateral force microscopy. 

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