Switching adhesion forces by crossing the metal–insulator transition in Magnéli-type vanadium oxide crystals

• Bert Stegemann,
• Matthias Klemm,
• Siegfried Horn and
• Mathias Woydt

Beilstein J. Nanotechnol. 2011, 2, 59–65, doi:10.3762/bjnano.2.8

• the MIT temperature are shown in Figure 3. The plot shows the force interaction during approach and retraction of the spherical AFM tip from the sample surface. During retraction the tip adheres to the sample until the spring constant of the cantilever overcomes the adhesion force and the cantilever

• to the sample acceptance stage. The actual temperature of the sample plates is taken from a calibration curve with an accuracy of ±20 K as provided by the manufacturer. The spring constant of the cantilevers with attached microsphere (typically 3.0 ± 0.2 N/m) was determined by means of the reference

• cantilever technique, where the cantilever under test was deflected in situ against a cantilever with a precisely known spring constant [40][41]. The spring constant of the reference cantilever (Park Scientific Instruments) was determined by a calculation based on geometrical dimensions and resonance

Oriented growth of porphyrin-based molecular wires on ionic crystals analysed by nc-AFM

• Thilo Glatzel,
• Lars Zimmerli,
• Shigeki Kawai,
• Ernst Meyer,
• Leslie-Anne Fendt and
• Francois Diederich

Beilstein J. Nanotechnol. 2011, 2, 34–39, doi:10.3762/bjnano.2.4

• maintaining a constant shift of the first flexural resonance frequency f1st with respect to the resonance far from the surface. Highly doped silicon cantilevers with integrated tips (Nanosensors, NCL), a typical resonance frequency f1st ≈ 160 kHz and a spring constant k ≈ 30 N/m were employed as a force

The description of friction of silicon MEMS with surface roughness: virtues and limitations of a stochastic Prandtl–Tomlinson model and the simulation of vibration-induced friction reduction

• W. Merlijn van Spengen,
• Viviane Turq and
• Joost W. M. Frenken

Beilstein J. Nanotechnol. 2010, 1, 163–171, doi:10.3762/bjnano.1.20

• the spring constant of the device. This calibration has been implemented by designing two MEMS tribometers on the same chip, which have identical springs, but a known difference in mass. From the difference in resonance frequency we extract the spring constant, being 2.0 ± 0.2 N/m for the device used

Sensing surface PEGylation with microcantilevers

• Natalija Backmann,
• Natascha Kappeler,
• Thomas Braun,
• François Huber,
• Hans-Peter Lang,
• Christoph Gerber and
• Roderick Y. H. Lim

Beilstein J. Nanotechnol. 2010, 1, 3–13, doi:10.3762/bjnano.1.2

• . Rectangular-shaped Si3N4 AFM-cantilevers (Biolever, Olympus/OBL, Veeco) with V-shaped tips were used in all measurements. Spring constant calibrations typically fell within a 20% margin of error from the nominal spring constant of 0.005 N/m. The radius of curvature of each AFM-cantilever tip (Rtip) was

• the AFM-cantilever spring constant kAFM. For the force curves the F vs Z data were converted to F vs tip - sample approach distance (D) by further subtraction of the AFM-cantilever deflection from Z [32]. The AFM contact mode images were obtained at a scan rate of ~1.5 µm/s. (A) Scanning electron