Atomic force microscopy schematic

Atomic force microscopy (AFM) or, as it is also called, scanning force microscopy (SFM) is based on the minute but detectable forces - of the order of nano Newtons -between a sharp tip and atoms on the surface. The tip is mounted on a flexible arm, called a cantilever, and is positioned at a subnanometre distance from the surface. If the sample is scanned under the tip in the x-y plane, it feels the attractive or repulsive force from the surface atoms and hence it is deflected in the z-direction. The deflection can be measured with a laser and photo detectors as indicated schematically in Fig. 4.29. Atomic force microscopy can be applied in two ways. 

Fig. 3. (A) Schematic of force-measuring atomic force microscopy. A molecule is...

Figure 7 Examples of nanotribology on dry carbon surfaces for atomic force microscopy (AFM) (a) schematic description of the out-of-plane graphene deformation with the sliding AFM (Lee et al., 2010), (b) nanotube without tip (left) and tip-nanotube interaction under 2.5 nN normal force (right) (Lucas et al., 2009), (c) stick-slip rolling model with a step rotation of a C60 molecule (Miura et al., 2003), and (d) ballistic sliding of gold nanocluster on graphite (Schirmeisen, 2010).

FIG. 2 Schematic representation of the constitution of carbon black particles, (a, b) On the basis of the data obtained by scanning tunneling microscopy. (From Refs. 60 and 62.) (c) On the basis of the data obtained by atomic force microscopy. (From Ref. 64.)... 

Figure 6.14 Schematic of a modified atomic force microscopy (AFM) tip used for TERS. Reprinted from Yeo, B.-S., Stadler, )., Schmid, T. et al. (2009) Chemical Physics Letters, 472, 1. Copyright (2009), with permission from Elsevier.

Scheme 3.2 (Top and middle) General schematic for the generation of nanoporous PS film. (Bottom) Atomic force microscopy (AFM) phase images of (a) PS375-tR.il]-PE0225 thin film, and (b) nanoporous PS film from oxidation-induced cleavage of the [Ru] junction.

Figure 3.9 Schematic view of the cell used for in situ ECAFM measurement. (Reprinted with permission from Electrochimica Acta, In situ atomic force microscopy in the study of electrogeneration of polybithiophene on Pt electrode by M. Innocent , F. Logio, L. Pigani et ai, 50, 7-8. Copyright (2005) Elsevier Ltd)...

Fig. 2 Atomic force microscopy (AFM) friction images and schematic illustrations of the patterning processes of a microcontact printed SAMs (mercaptoethanol dots in oc-tadecanethiol matrix, scale bar 10 xm) b patterned molecular printboards fabricated by supramolecular dip-pen nanolithography (DPN) (reprinted with permission from [92] Copyright 2004. WUey VCH) e locally hydrolyzed tert-butyl acrylate-terminated polymer film on oxidized silicon (soft lithography scale bar 3 xm) (Feng CL, Vancso GJ, SchOn-herr H, manuscript submitted to Langmuir) d photopatterned bilayer of diacetylene lipid (scale bar 10 xm). Reprinted in part with permission from [93], copyright (1999), American Chemical Society...

Fig. 5.15 Schematical illustration of photoisomerization of molecular motor, a Molecular structure of chiral motor 21. b Polygonal texture of a LC film doped with 1 wt% chiral motor 21. c Glass rod rotating on the LC during irradiation with ultraviolet light. Frames 1-4 (from l ) were taken at 15 s intervals and show clockwise rotations of 28° (Irame 2), 141° (frame 3) and 226° (Same 4) of the rod relative to the position in fiame 1. Scale bars, 50 pm. d Surface structure of the liquid-crystal film (atomic force microscopy image 15 pm ). Reproduced with permission from [103]. Copyright 2006 Nature Publishing Group...

Atomic force microscopy (AFM) is another technique used to characterize nanocomposites.AFM can provide information about the mechanical properties of a surface at a length scale that is limited only by the dimensions of the AFM tip. AFM tips with 10 nm radius of curvature are readily available from commercial suppliers. When probing mechanical properties, the attractive and repulsive force interactions between the tip and sample are monitored. Schematic depicting the intercalation process between a polymer melt and an organic-modified layered silicate is shown on Figure 6.8. 

Dip-pen nanolithography (DPN) is a atomic force microscopy-based lithographic technique that can be used to generate patterns with dimensions extending from a few nanometers to micrometers. In this technique, a water meniscus, deliberately created by slowly scanning an atomic force cantilever on a substrate, is used to deliver molecules or other material previously coated on the tip to the surface. The cantilever acts as a nib delivering previously coated ink to the substrate. The ink usually binds chemically to the substrate. The process is schematically illustrated in Fig. 6.8 for the case of Au nanocrystals. Different DPN-based methods have been used to generate... 

Figure 10 Representations of the CpA peptide, (a) Molecular model of the CpA peptide showing the position of the hydrophobic face (b) Schematic representation of how the monomeric tectons form staggered fibers (c) Atomic force microscopy (AFM) image of the resulting fibers in ammonium sulfate. (Reproduced with permission from Ref. 54. National Academy of Sciences, 2005.)...

Figure 7 Molecular brushes with block copolymer side chain In selective solvent schematic presentation (a) and pearl-necklace structure In poly(acryllc acld)-Woc/(-poly(/7-butyl acrylate) molecular brushes In toluene (b), dip coated on mica (atomic force microscopy (AFM) phase Image). Adapted from Polotsky, A. V. Charlaganov, M. I. Xu, Y. etal. Macromolecules 200S, 41, 4020. ...

Fig.3. Schematic distribution of siloxane polymer in pores of MCM-41 material 3.2. Atomic force microscopy...

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