Challenges in realizing ultraflat materials surfaces

• Takashi Yatsui,
• Wataru Nomura,
• Fabrice Stehlin,
• Olivier Soppera,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2013, 4, 875–885, doi:10.3762/bjnano.4.99

• technique, it does require a polishing pad to heat the substrate through friction between the polishing pad and substrate. Thus, the light must be introduced through the substrate, which should therefore be thin. Furthermore, mechanical polishing causes surface damage (scratches or pits) when the polishing

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• importance of surface effects such as friction and surface energy, dropping to the sub-optical regime made optical determination of the contact geometry impossible. This led to the need to determine the contact region size from force–displacement curves. Fundamental equations and their limitations The

• , which is in turn used to express the dynamic elastic moduli as defined above. This shift is frequency-dependent, as the various modes of internal friction of the polymer are excited at distinct characteristic times. In order to probe the viscoelasticity at the nanoscale analogous techniques are applied

• measures the energy dissipated during an oscillation cycle. The phase lag, referred to as loss tangent (tan δ), arises from any of a number of molecular-level lossy processes such as entanglement, slip or friction between the monomer units. Although the phase lag is not amenable to a direct theoretical

Energy-related nanomaterials

• Paul Ziemann and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 678–679, doi:10.3762/bjnano.4.76

• enter both experimental and theoretical simulation routes towards materials optimization. Another materials property worth of being optimized is friction, which, when trying to walk or drive on icy streets is highly welcome, but in many cases is a source of dissipated energy. The friction of an object

• moving on or through a supporting or surrounding medium, respectively, appears to be closely related to surface or interface roughness, so that, again, the micro- and nanoscales are of major importance. For instance, a reduction of the friction of cargo vessels by only a few percent leads to considerable

• energy savings and a significant decrease of the worldwide CO2 emission [1]. It is noteworthy that the nanopatterning of surfaces and interfaces to reduce friction by tailoring their wettability and anti-fouling behavior is often guided by mimicking nature [2][3]. Contributions of advanced materials

Optimal geometry for a quartz multipurpose SPM sensor

• Julian Stirling

Beilstein J. Nanotechnol. 2013, 4, 370–376, doi:10.3762/bjnano.4.43

• -asperity friction [12], where the relationship between normal and lateral force is of interest. In this paper, we suggest the optimum geometry of a quartz sensor to produce a combined AFM/LFM/STM from a quartz crystal resonator with many theoretical benefits over other sensors. Combining NC-AFM and DLFM

Functionalization of vertically aligned carbon nanotubes

• Eloise Van Hooijdonk,
• Carla Bittencourt,
• Rony Snyders and
• Jean-François Colomer

Beilstein J. Nanotechnol. 2013, 4, 129–152, doi:10.3762/bjnano.4.14

• , Dickrell et al. showed that the friction coefficient of oriented MWCNTs films depends on the temperature of the sample and the chemical groups at the surface [77]. In 2007, this problematic stirred the curiosity of Ler et al. [78]. Their work revealed the dependence of the friction coefficient on other

• as the tip moves through the film laterally is measured [79]. Under this condition, it is clear that the CNT sidewall plays a key role in determining the coefficient of friction. Moreover, the CNTs being hydrophobic [80], the water meniscus between the AFM tip and the CNT sidewall can be a hindrance

• to the tip displacement through the CNT forest and can disturb the measurement. To clarify these points, they accomplished a comparison between friction coefficient measurements for VA-CNTs modified by CF4- or O2-plasma treatment, under normal room humidity or reduced ambient humidity. The data

Low-dose patterning of platinum nanoclusters on carbon nanotubes by focused-electron-beam-induced deposition as studied by TEM

• Xiaoxing Ke,
• Carla Bittencourt,
• Sara Bals and
• Gustaaf Van Tendeloo

Beilstein J. Nanotechnol. 2013, 4, 77–86, doi:10.3762/bjnano.4.9

• value during deposition can lead to a varying pitch in the stripe pattering along the long axis of the nanotube. The ability to pattern the nanostructure with switchable high/low density of nanoclusters provides new potential applications in tunable wetting, adhesion, catalysis and friction properties

Effect of normal load and roughness on the nanoscale friction coefficient in the elastic and plastic contact regime

• Aditya Kumar,
• Thorsten Staedler and
• Xin Jiang

Beilstein J. Nanotechnol. 2013, 4, 66–71, doi:10.3762/bjnano.4.7

• during nanoindentation-based scratching has been experimentally investigated by using different surfaces (fused silica and diamond-like carbon) featuring various degrees of roughness. At a sufficiently low applied normal load, wherein the contact is elastic, the friction coefficient is constant. However

• , at increased normal loads the contact involves plastic deformation and the friction coefficient increases with increasing normal load. The critical load range for a transition from predominantly elastic to plastic contact, between the indenter and sample surface, increases with increasing size of

• plasticity index and contact load. Their recent work [10] showed that the static friction coefficient (ratio of friction force and normal load) depends on the external force and nominal contact area. Recently, FEM based work by Flores et al. [11] showed that the apparent friction coefficient at a low level

Growth behaviour and mechanical properties of PLL/HA multilayer films studied by AFM

• Cagri Üzüm,
• Johannes Hellwig,
• Narayanan Madaboosi,
• Dmitry Volodkin and
• Regine von Klitzing

Beilstein J. Nanotechnol. 2012, 3, 778–788, doi:10.3762/bjnano.3.87

• . Both relaxation times decrease with increasing initial indentation velocity, suggesting a non-Newtonian, shear-thinning fluid character. Frequency-dependent AFM force [41] and quartz crystal microbalance measurements are planned for a better understanding of shear and friction effects on the mechanical

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2012, 3, 759–772, doi:10.3762/bjnano.3.85

• applications in liquids requiring controlled manipulation and targeting. On the macroscale, nanoparticles in solids and liquids have been shown to reduce friction and wear. On the nanoscale, atomic force microscopy (AFM) studies have been performed in single- and multiple-nanoparticle contact, in dry

• environments, to characterize friction forces and wear. However, limited studies in submerged liquid environments have been performed and further studies are needed. In this paper, spherical Au nanoparticles were studied for their effect on friction and wear under dry conditions and submerged in water. In

• single-nanoparticle contact, individual nanoparticles, deposited on silicon, were manipulated with a sharp tip and the friction force was determined. Multiple-nanoparticle contact sliding experiments were performed on nanoparticle-coated silicon with a glass sphere. Wear tests were performed on the

Friction and durability of virgin and damaged skin with and without skin cream treatment using atomic force microscopy

• Bharat Bhushan,
• Si Chen and
• Shirong Ge

Beilstein J. Nanotechnol. 2012, 3, 731–746, doi:10.3762/bjnano.3.83

• friction and durability of damaged skin were measured and compared with those of virgin (intact/undamaged) skin. The effect of skin cream on friction and durability of damaged and virgin skin samples is discussed. The effects of velocity, normal load, relative humidity and number of cycles were studied

• . The nanoscale studies were performed by using atomic force microscope (AFM), and macroscale studies were performed by using a pin-on-disk (POD) reciprocating tribometer. It was found that damaged skin has different mechanical properties, surface roughness, contact angle, friction and durability

• compared to that of virgin skin. But similar changes occur after skin cream treatment. Rat and pig skin show similar trends in friction and durability. Keywords: atomic force microscopy; damaged skin; pig skin; rat skin; skin cream; Introduction Skin is the largest outer organ. The skin structure of

Polymer blend lithography: A versatile method to fabricate nanopatterned self-assembled monolayers

• Cheng Huang,
• Markus Moosmann,
• Jiehong Jin,
• Tobias Heiler,
• Stefan Walheim and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2012, 3, 620–628, doi:10.3762/bjnano.3.71

• SAM template. The cross section shown here is the average of the trace and the retrace images. (d) Schematic drawing of the AFM friction imaging. The first SAM that was deposited is APTES. Its height is half the height of the FDTS-SAM, which was complemented after the PMMA mask had been removed

Nanotribology at high temperatures

• Saurav Goel,
• Alexander Stukowski,
• Gaurav Goel,
• Xichun Luo and
• Robert L. Reuben

Beilstein J. Nanotechnol. 2012, 3, 586–588, doi:10.3762/bjnano.3.68

• , Livermore, California, USA School of Engineering and Technology, Sharda University, Greater Noida, 201306, India 10.3762/bjnano.3.68 Abstract Recent molecular dynamics simulation results have increased conceptual understanding of the grazing and the ploughing friction at elevated temperatures, particularly

• friction and nearly zero wear [1]. Recent research, however, has shown a steep rise in the grazing friction during wearless sliding, primarily attributed to the adhesion between the interacting surfaces [2]. A major assumption in the atomistic simulation associated with this finding was the consideration

• of the diamond tip as a wearless rigid body for ease of computation. Accordingly, it has been suggested [2] that the steep rise in grazing friction and the gradual drop in ploughing friction at high temperatures may affect all materials and should be pursued experimentally [3]. However, diamond is

Mapping mechanical properties of organic thin films by force-modulation microscopy in aqueous media

• Jianming Zhang,
• Zehra Parlak,
• Carleen M. Bowers,
• Terrence Oas and
• Stefan Zauscher

Beilstein J. Nanotechnol. 2012, 3, 464–474, doi:10.3762/bjnano.3.53

• atomic force microscopy; biomolecules; elastic modulus mapping; nanomechanical characterization; self-assembled monolayers; Introduction Mapping the mechanical properties, such as elastic modulus, friction, and adhesion of surfaces and thin films in aqueous (or liquid) environments with nanoscale

• , which suggests that the thiol molecules are not close-packed, and have some disorder in their arrangement on the surface. The contrast in the lateral-force image shows a friction difference between the gold surface and the EG3 patterns that can be attributed to the surface-energy difference between the

• stripping off of the photoresist, and backfilling in 0.5 mM EG3-thiol for 1 h. Both height and friction images do not show any pattern-related contrast, which suggests that the molecules have a similar height and the same surface chemical properties. Importantly, however, the original patterns become

Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

• Miriam Jaafar,
• David Martínez-Martín,
• Mariano Cuenca,
• John Melcher,
• Arvind Raman and
• Julio Gómez-Herrero

Beilstein J. Nanotechnol. 2012, 3, 336–344, doi:10.3762/bjnano.3.38

• dissipation setpoints of 1.2 pW and 4.5 pW, respectively, with the PLL enabled, as calculated following the expression [23][24] where P0 is the power dissipation caused by internal friction in the freely oscillating cantilever given by Stable imaging in DAM does not require tip safe or any other kind of

• regime, in which it is contaminated by the polymer. DAM-AFM in liquids Low quality factors are common when imaging in liquids due to the viscous hydrodynamic loading between the cantilever and the environment. This friction in some cases induces an overdamped dynamic of the cantilever, making it very

Wavelet cross-correlation and phase analysis of a free cantilever subjected to band excitation

• Francesco Banfi and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2012, 3, 294–300, doi:10.3762/bjnano.3.33

• ; Introduction Atomic force microscopy (AFM) has made important progresses towards the characterization of material properties at the nanoscale (elastic constants, force interactions, friction, molecular interactions, to name only a few) by means of dynamic techniques that extended the microscope capabilities

Modeling noncontact atomic force microscopy resolution on corrugated surfaces

• Kristen M. Burson,
• Mahito Yamamoto and
• William G. Cullen

Beilstein J. Nanotechnol. 2012, 3, 230–237, doi:10.3762/bjnano.3.26

• neither crystalline nor atomically flat and this presents a challenge for the assessment of measurement resolution and the ultimate determination of the structures of interest. Problems of friction and adhesion serve as examples in which roughness is a determining factor, and a full understanding of the

Quantitative multichannel NC-AFM data analysis of graphene growth on SiC(0001)

• Christian Held,
• Thomas Seyller and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2012, 3, 179–185, doi:10.3762/bjnano.3.19

• around 100 kHz. This choice of cantilever gives the opportunity to perform complementary contact-mode friction and noncontact KPFM experiments on the same surface areas [20]. Graphene grown in UHV The substrate material for the study is the Si face of 6H-SiC(0001). The unit cell of 6H-SiC is composed of

• surface areas such as the one in Figure 4b by KPFM allows subsequent experiments to be aimed at a direct comparison between single and double layer graphene, for example, in friction experiments. While this visualization method allows for a quick identification of the surface structure, we will now

Current-induced forces in mesoscopic systems: A scattering-matrix approach

• Niels Bode,
• Silvia Viola Kusminskiy,
• Reinhold Egger and
• Felix von Oppen

Beilstein J. Nanotechnol. 2012, 3, 144–162, doi:10.3762/bjnano.3.15

• the scattering matrix and its parametric derivatives. These are given by Equation 39 for the mean force Fν(X), Equation 42 for the correlator Dνν′(X) of the stochastic force ξν, and Equation 47, and Equation 50 for the two kinds of forces (dissipative-friction force and effective “Lorentz” force, as

• given by Equation 44. (For an alternative derivation confirming the positive sign of the friction coefficient in a resonant-level system, see [52]). After some manipulation, we obtain and hence the damping coefficient becomes We can evaluate the remaining integrals analytically in the zero-temperature

• Information File 1, Section D) combines with the elastic force to give rise to the effective potential depicted, for zero temperature, in Figure 3. As in the case studied in the previous section, the system can exhibit various levels of multistability with changes in the bias. The results for the friction

Self-assembly of octadecyltrichlorosilane: Surface structures formed using different protocols of particle lithography

• ChaMarra K. Saner,
• Kathie L. Lusker,
• Zorabel M. LeJeune,
• Wilson K. Serem and
• Jayne C. Garno

Beilstein J. Nanotechnol. 2012, 3, 114–122, doi:10.3762/bjnano.3.12

• images indicate differences in tip–surface interactions, but were not normalized for the comparison of friction changes between different tips or experiments. The tips were silicon nitride probes. Tips used with tapping-mode AFM were rectangular shaped ultrasharp silicon tips that have an aluminium

Electron-beam patterned self-assembled monolayers as templates for Cu electrodeposition and lift-off

• Zhe She,
• Andrea DiFalco,
• Georg Hähner and
• Manfred Buck

Beilstein J. Nanotechnol. 2012, 3, 101–113, doi:10.3762/bjnano.3.11

• the same. The depth between the Cu surface and the copper-free area was 30 nm after lift-off, revealing an incomplete filling of the trench by the glue, which is again likely due to trapping of air. On comparison of the friction images of the Cu structure as deposited and after lift-off (Figures 9b

• and 9d), a very different friction contrast is seen between deposition and Cu free areas according to the mechanical properties of the materials. While in both cases the friction inside the trench is higher than on the Cu deposit, the difference between the two areas is more than 30 times larger

• quality of passivation of the cross-linked MBP0-SAM. Topography (a,c) and friction (b,d) images of the Cu structure as deposited (a,b) and after transfer to epoxy glue (c,d); (e) height and (f) friction profile along the line for Cu as deposited; (g,h) corresponding profile for the lifted-off structure

Impact of cell shape in hierarchically structured plant surfaces on the attachment of male Colorado potato beetles (Leptinotarsa decemlineata)

• Bettina Prüm,
• Robin Seidel,
• Holger Florian Bohn and
• Thomas Speck

Beilstein J. Nanotechnol. 2012, 3, 57–64, doi:10.3762/bjnano.3.7

• forces are due to an improved grip of the beetles’ claws caused by the elevated cell shape. Furthermore, friction might be increased with the setae possibly getting caught behind the elevated epidermal cells. In plant surfaces possessing epicuticular wax crystals or cuticular folds the influence of cell

• . To understand fully the underlying mechanism of force reduction including the proportion of friction and adhesion on insect attachment, further investigations are needed. Taking into account the multifunctionality of the plant surfaces [1], our results indicate that the main function of convex and

Self-assembled monolayers and titanium dioxide: From surface patterning to potential applications

• Yaron Paz

Beilstein J. Nanotechnol. 2011, 2, 845–861, doi:10.3762/bjnano.2.94

Self-assembly at solid surfaces

• Sidney R. Cohen and
• Jacob Sagiv

Beilstein J. Nanotechnol. 2011, 2, 824–825, doi:10.3762/bjnano.2.91

• examination, prevention of spreading of liquids, friction and wear reduction, and surface passivation and protection. Whereas the early study of such monolayers indeed attracted considerable attention over the years, perhaps their greatest impact was yet to come, in new directions of research that could not

Current-induced dynamics in carbon atomic contacts

• Jing-Tao Lü,
• Tue Gunst,
• Per Hedegård and
• Mads Brandbyge

Beilstein J. Nanotechnol. 2011, 2, 814–823, doi:10.3762/bjnano.2.90

• properties when exchanging modes(n ↔ m) and electrodes(α ↔ β), and which are helpful when examining the terms in Equation 11, which are summarized in the following: Friction – The first term in Equation 11 is imaginary and symmetric in mode index m,n. It describes the friction force due to the generation of

• electron–hole pairs in the electronic environment by the ionic motion. This process exists even in equilibrium [31]. For slowly varying AL/R with energy as compared to the vibrational energies (wide-band limit) we obtain the simple time-local electron friction force, , with NC (wind) force – The second

• term in Equation 11 is real and antisymmetric, which means that the general curl of this force is not zero. It describes the NC force, discussed very recently by Dundas and co-workers [5]. This force is finite, even in the limit of zero frequency, where the friction and Joule heating effect is not

Nonconservative current-induced forces: A physical interpretation

• Tchavdar N. Todorov,
• Daniel Dundas,
• Anthony T. Paxton and
• Andrew P. Horsfield

Beilstein J. Nanotechnol. 2011, 2, 727–733, doi:10.3762/bjnano.2.79

• (first term) is due to the ordinary electronic friction experienced by the two independent modes X and Y (each of which carries half of the energy of mode (+)). This friction is due to phonon absorption by electrons, and is present even at zero current. The driving term (the second term) comes solely