Force mapping

Martin, Y., Williams, C. C., and Wickramasinghe, H. K. (1987). Atomic force microscope-force mapping and profiling on a sub 100-A scale. /. Appl. Phys. 61,4723-4729. 

Bright field Conventional microscopy Atomic force Mapping of surfaces to an atomic scale... 

Similarly challenging, but nevertheless important in the context of constant experimental conditions (e.g., imaging at the same force) or force mapping, is the calibration of spring constants in CM AFM. The nominal spring constants stated by the suppliers are mere indications and cannot be trusted. This is primarily due to the impact of the cantilever thickness on N. 

Fig. 4.4 F-d curves recorded with a silicon nitride tip in ambient on (a) CH3 and (b) COOH terminated areas of a patterned SAM model surface, (c) Pull-off force histogram calculated from 4096 individual f-d curves, (d) Corresponding quantitative pull-off force map [22]...

It is noted that S is symmetric and energetically conjugate with the Green-Lagrange strain E. From Equation (4.44), it is seen that S is produced by mapping the stress in the deformed body to the undeformed body. In other words, S represents the force mapped to the undefonned body on the undeformed area. 

Piola-Kirchoff stress T Force mapped to undeformed body on deformed area... 

Kluge D, Abraham F, Schmidt S, Schmidt FI-W, Feiy A. Nanomechanical Properties of Supramolecular Self-Assembled Whiskers Determined by AFM Force Mapping. Langmuir. 2010 26(5) 3020-3. 

Fujihira and coworkers extended PFM-AFM to adhesive force mapping on a patterned SAM [356-358]. In this mode of PFM-AFM, difference in the adhesive force between the —CH3 and —COOH terminated regions on the (xCP patterned SAM was mapped simultaneously with its topographic image. To achieve the quantitative analyses of the adhesive forces for chemical differentiation on the patterned surface by PFM-AFM, accurate information about the tip and substrate geometries [359, 360] and chemical modification of the tip surfaces [361] as well as the precise environmental control, such as electrolyte concentrations [292, 362, 363], and humidity [364] are indispensable. Recently, Bohn and coworkers used PFM-AFM to map the adhesion force between an AFM tip and samples of -substituted alkanethiol monolayer terminated with —CH3 and —COOH prepared by gCP... 

All measurements of AFM, FFM, and the adhesive force mapping with PFM-AFM were performed with a commercial AFM (a Seiko Instruments SPA 300 AFM unit with an SPI-3700 AFM controller) and a PFM box [40, 41]. The cantilever bending forces [49] for FFM and PFM-AFM were ca 10 and 3 nN, respectively. The frequency and the amplitude for PFM-AFM were 0.5-1 kHz and 30-70 nm, respectively. Relative humidity of measuring air atmospheres was 50-60%. The adhesive force mappings in water were performed in a 0.1 mM NaHCOs aqueous solution at room temperature. This slightly basic... 

In Fig. 2 are shown 5x5 pm (256 x 128) images of (a) a topography and (b) a friction force map of an oxidized Si wafer partially covered with polymerized OTS monolayer domains prepared hy the LB method described above [36, 48-50]. These two images were taken simultaneously by contact-mode AFM, using a CH3 tip. The height of the HC domains in Fig. 2(a) was determined to be ca 2.2 nm by AFM. The AFM result indicated that the HC layer was a polymerized OTS mono-layer and the lower surface was the bare oxidized Si surface. In Fig. 2(b), the much higher friction was observed on the bare oxidized Si surface than on the HC domains. As discussed previously [49], the contrast... 

Fig. 2 5x5 gm (256 X 128) images of (a) a topography and (b) a friction force mapping, simultaneously obtained by contact-mode AFM using a CH3 tip in air for a patterned sample prepared with the LB method. 

Fig. 3 A 5 X 5 rm (256 x 128) image of (a) an adhesive force map obtained by PFM-AFM and (b) a histogram of the adhesive forces measured in Fig. 3 (a), using the same CH3 tip on the same patterned surface that was observed in Fig. 2.

Friction Force Map in Phase-separated HC-FC Mixed LB Films with Ca Counterions... 

To develop a new method by which we can study the mixing of two components in each domain in the patterned surfaces, we studied CFM of patterned surfaces prepared by fi-CP methods. Figure 5 shows a comparison between the patterned samples prepared by two different fi-CP methods, that is, the wet-inking and the contact-inking methods [57]. All adhesive force maps in Fig. 5 were observed in a 0.1 mM NaFICOs aqueous solution using a CH3 tip on three samples. The z-piezo was modulated sinusoidally at a frequency of 0.5 kHz with amplitudes of... 

Fig. 6 The loss of contrast in adhesive force mapping by the vapor phase transfer.

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