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

• cedex 9, France Leiden University, LION, Niels Bohrweg 2, 2333CA, Leiden, The Netherlands 10.3762/bjnano.1.20 Abstract We have replaced the periodic Prandtl–Tomlinson model with an atomic-scale friction model with a random roughness term describing the surface roughness of micro-electromechanical

• systems (MEMS) devices with sliding surfaces. This new model is shown to exhibit the same features as previously reported experimental MEMS friction loop data. The correlation function of the surface roughness is shown to play a critical role in the modelling. It is experimentally obtained by probing the

• sidewall surfaces of a MEMS device flipped upright in on-chip hinges with an AFM (atomic force microscope). The addition of a modulation term to the model allows us to also simulate the effect of vibration-induced friction reduction (normal-force modulation), as a function of both vibration amplitude and

A collisional model for AFM manipulation of rigid nanoparticles

• Enrico Gnecco

Beilstein J. Nanotechnol. 2010, 1, 158–162, doi:10.3762/bjnano.1.19

• and r' is the first derivative of r(φ) with respect to φ (Figure 1b). In contact mode the tip hits the particle along the x direction and the force F can be oriented as in tapping mode only if the static friction force f between tip and particle is high enough to prevent sliding along the island profile

• (Figure 1c). Assuming that friction between island and substrate is also high enough to prevent any slippage of the island after a collision with the tip, Equation 1 and Equation 2 can be averaged over the short collision time Δt (in the order of 1/ f , with f ~ 105 Hz being the oscillation frequency of

• , where a ‘mean free path’ d of the nanoparticles was introduced. If the friction force between particle and substrate decreases, and consequently the distance d increases, then the pathway of the nanoparticle fluctuates more and more, but the form of the function θ(b) remains essentially unchanged [8

Review and outlook: from single nanoparticles to self-assembled monolayers and granular GMR sensors

• Alexander Weddemann,
• Inga Ennen,
• Anna Regtmeier,
• Camelia Albon,
• Annalena Wolff,
• Katrin Eckstädt,
• Nadine Mill,
• Michael K.-H. Peter,
• Jochen Mattay,
• Carolin Plattner,
• Norbert Sewald and
• Andreas Hütten

Beilstein J. Nanotechnol. 2010, 1, 75–93, doi:10.3762/bjnano.1.10

• order [49]. Additionally, friction and shear forces can arise between the particles on the one hand and between particles and substrate on the other hand [57][58]. In the latter case, the forces strongly depend on the surface properties such as structure and roughness. Thus, the choice of substrate is