Scanning surface images

The ability to control the position of a fine tip in order to scan surfaces with subatomic resolution has brought scanning probe microscopies to the forefront in surface imaging techniques. We discuss the two primary techniques, scanning tunneling microscopy (STM) and atomic force microscopy (AFM) the interested reader is referred to comprehensive reviews [9, 17, 18]. 

Flammiche A, Flourston D J, Pollock FI M, Reading M and Song M 1996 Scanning thermal microscopy sub-surface imaging, thermal mapping of polymer blends, localised calorimetry J. Vac. Sol. Technol. B 14 1486... 

Fig. 9 Surface modification of cells with ssDNA-PEG-lipid. (a) Real-time monitoring of PEG-lipid incorporation into a supported lipid membrane by SPR. (r) A suspension of small unilamellar vesicles (SUV) of egg yolk lecithin (70 pg/mL) was applied to a CH3-SAM surface. A PEG-lipid solution (100 pg/mL) was then applied, (ii) Three types of PEG-lipids were compared PEG-DMPE (C14), PEG-DPPE (C16), and PEG-DSPE (C18) with acyl chains of 14, 16, and 18 carbons, respectively, (b) Confocal laser scanning microscopic image of an CCRF-CEM cell displays immobilized FITC-oligo(dA)2o hybridized to membrane-incorporated oligo(dT)20-PEG-lipid. (c) SPR sensorigrams of interaction between oligo(dA)2o-urokinase and the oligo (dT)2o-PEG-lipid incorporated into the cell surface, (i) BSA solution was applied to block nonspecific sites on the oligo(dT)20-incorporated substrate, (ii) Oligo(dA)20-urokinase (solid line) or oligo(dT)20-urokinase (dotted line) was applied...

Scanning Tunneling Microscopy (STM) Photoemission Electron Microscopy (PEEM) Ellipsometry Microscopy for Surface Imaging (EMSI)... 

Scanning probe images represent a combination between the morphology of the sample surface and the shape of the tip. Features on the samples that are sharper than the tip yield an image of the tip. In such cases so-called supertips improve the image greatly. Note, however, that blunt tips are perfectly suitable for imaging flat surfaces in atomic detail. 

See also SEM/EDS detectors used in, 24 78 development of, 16 487-488 electron sources used in, 24 77-78 in surface imaging, 24 75-76 silica, 22 371-372 for trace evidence, 12 100 Scanning probe microscopies, in surface and interface analysis, 24 80-84 Scanning probe microscopy (SPM), 16 466, 495-503... 

Fig. 14.10. Deconvolution of the tunneling spectra, (a) and (b) The tunneling spectra from the Si surface image in Fig. 14.9. The observed tunneling spectra changed dramatically from the upper half to the lower half of the image, (c) and (d) Results of deconvolution. It indicates that during the scan, the tip picked up a Si cluster, and the tip DOS resembles that of a Si surface. (Reproduced from Chen, 1992b, with permission.)...

The CISs are rapidly becoming more popular and reliable as their field of application broadens. This is mainly due to the production of surface images by multipoint scanning and mapping. Hyperspectral imaging has proven its potential for qualitative analysis of pharmaceutical products and can be used when spatial information becomes relevant for an analytical application. Even if online applications and regulatory method validation require further development, the power of CIS in quality control and PAT needs no further demonstration, whatever the wavelength domain or method of spectra collection. 

Figure 8.17 Left Schematic of a scanning tunneling microscope (STM). Right STM image (2.7 x 2.7 nm) of the atomic structure of a copper (111) surface imaged in an aqueous medium after electrochemical cleaning [357]. The image was kindly provided by P. Broekmann and K. Wandelt.

Fig. 6. Patterning of polythiophene growth on silicon (a) scanning Auger image (with representative line scan) of sulphur on a patterned thienyl terminated surface made via the photooxidation patterning approach discussed in the text, (b) schematic of photoelec-trochemical polymerization on patterned surface and (c) optical micrograph of surface after polymerization to grow 50 nm polythiophene film. Adapted from [52],...

Fig. 18 Scanning electrochemical microscope (SECM) surface images of bare gold electrode top) and AcMn5b modified gold electrode bottom) containing 5 mM ferrocyanide as redox mediator in phosphate buffer. Reproduced with permission from [76]...

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