Bending and punching characteristics of aluminum sheets using the quasi-continuum method

• Man-Ping Chang,
• Shang-Jui Lin and
• Te-Hua Fang

Beilstein J. Nanotechnol. 2022, 13, 1303–1315, doi:10.3762/bjnano.13.108

• and the substrates. This phenomenon is caused by the greater friction between the thicker workpiece and the punch. Besides, the 20 Å workpiece also suffers great shear stress during the punching process (d = 50 Å), because the thicker the workpiece, the greater the friction force between the interface

Relationship between corrosion and nanoscale friction on a metallic glass

• Haoran Ma and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2022, 13, 236–244, doi:10.3762/bjnano.13.18

• friction force microscopy. Here, we apply the same method to investigate differences in corrosion of ZrNiTi MGs after different periods of immersion time between two different solutions. On the one hand, the influence of corrosion on nanoscale friction on MGs is evaluated. On the other hand

• development of friction force with the number of scan cycles after immersion in NaCl solution for 72 h is shown in Figure 2 for experiments at different applied loads. Please note that all friction experiments are performed in the immersion solution without applying a potential. The friction force initially

• (Figure 1b), there are no pits on the sample surface even after immersion in NaCl solution for 72 h. This weak corrosion during immersion without applied potential will be discussed in more detail below. Figure 3a shows the topography of the scan field and corresponding friction force images after 16 scan

Nanoscale friction and wear of a polymer coated with graphene

• Robin Vacher and
• Astrid S. de Wijn

Beilstein J. Nanotechnol. 2022, 13, 63–73, doi:10.3762/bjnano.13.4

• 100 Å, we found that the tip moves deeply inside the substrate and the average friction force is above 90 nN, almost an order of magnitude higher than with graphene. This clearly shows that the addition of the graphene layer drastically reduces the friction. To further investigate the mechanisms and

• would be able to probe this here. Conclusion We investigate the effect on friction and wear of a graphene coating on a polymer by simulating friction force microscopy experiments with molecular dynamics. A rigid counter-body simulating the tip of the AFM is rubbed against a substrate made of a

• displacements of 50 and 100 Å as function of the load applied for tip radii of 50 and 100 Å on the flat graphene specimen. For comparison, in a simulation with no graphene, a normal load of 51 nN, and a tip radius of 100 Å, we find an average friction force above 90 nN. Frictional force versus the position of

Topographic signatures and manipulations of Fe atoms, CO molecules and NaCl islands on superconducting Pb(111)

• Carl Drechsel,
• Philipp D’Astolfo,
• Jung-Ching Liu,
• Thilo Glatzel,
• Rémy Pawlak and
• Ernst Meyer

Beilstein J. Nanotechnol. 2022, 13, 1–9, doi:10.3762/bjnano.13.1

• features resemble typical patterns observed in friction force microscopy (FFM) [28][38] or scanning tunneling hydrogen microscopy (SThM) [70][71], since the trapped Fe atom senses the surface potential in analogy to the probing tip of FFM. For clarity, we overlay the Pb(111) surface lattice on top of the

Two dynamic modes to streamline challenging atomic force microscopy measurements

• Alexei G. Temiryazev,
• Andrey V. Krayev and
• Marina P. Temiryazeva

Beilstein J. Nanotechnol. 2021, 12, 1226–1236, doi:10.3762/bjnano.12.90

• classical contact mode, the friction force can be measured; when using off-resonance dynamic modes, stiffness and adhesion in the samples can be determined. Obviously, in determining the mechanical properties, the force of tip–surface interaction should be somewhat greater than that required if the task is

The effect of heat treatment on the morphology and mobility of Au nanoparticles

• Sven Oras,
• Sergei Vlassov,
• Simon Vigonski,
• Boris Polyakov,
• Mikk Antsov,
• Vahur Zadin,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2020, 11, 61–67, doi:10.3762/bjnano.11.6

• should decrease the contact area compared to faceted particles, and hence reduce the friction forces in accordance with the known relation τ = F/A [6], where τ is the contact strength, F is the friction force and A is the contact area. For a round particle, the contact area is determined by contact

Pull-off and friction forces of micropatterned elastomers on soft substrates: the effects of pattern length scale and stiffness

• Peter van Assenbergh,
• Marike Fokker,
• Julian Langowski,
• Jan van Esch,
• Marleen Kamperman and
• Dimitra Dodou

Beilstein J. Nanotechnol. 2019, 10, 79–94, doi:10.3762/bjnano.10.8

• Effect of geometry and stiffness on friction forces on soft substrates On soft substrates, force–time plots of friction force (Figure 4) show that the static friction force (phase V in Figure 4) is comparable to the dynamic friction. A minor increase in friction force during sliding was typically

• of geometry on friction forces on glass On the glass substrate, force–time plots of friction force (Figure 6) show that static friction (peak at phase V in Figure 6) is dominant over dynamic friction. Some sort of zigzag was typically visible in the dynamic friction regime, indicating stick-slip-like

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae)

• Liesa Schnee,
• Benjamin Sampalla,
• Josef K. Müller and
• Oliver Betz

Beilstein J. Nanotechnol. 2019, 10, 47–61, doi:10.3762/bjnano.10.5

• push) direction. This behaviour is related to the arrangement angle of the tenent hairs on the tarsal surface. The traction force of entire animals and the friction force of single tarsi were tested on smooth, micro-rough and rough surfaces. All the used polymer surfaces were tested in duplicate, i.e

• fraction has been investigated so far, polar components such as proteins/peptides and carbohydrates might contribute to its amphiphilic property. Directionality of friction force Our nanotribometer experiments (performed on the fore tarsi) clearly revealed a direction-dependent (anisotropic) friction

Contact splitting in dry adhesion and friction: reducing the influence of roughness

• Jae-Kang Kim and
• Michael Varenberg

Beilstein J. Nanotechnol. 2019, 10, 1–8, doi:10.3762/bjnano.10.1

• that splitting the adhesive microstructure in parallel to the peeling force may improve the attachment ability not only due to better adaptation to surface topography, but also due to the effective decrease of the peeling angle. The friction force measured at the point of sliding inception on all

• the second case that its growth due to the contact splitting is comparable to the measurement error. Interestingly, a paired t-test, according to which the mean friction force measured with the split microstructure exceeds that measured with the original microstructure by an amount that is greater

• counterface sample was withdrawn from the contact at the speed of 100 µm/s at the pulling angle of 90° until it detached from the structured sample, and the detachment (pull-off) force was measured. The maximum friction force was measured at the instance of sliding inception while the counterface sample was

Characterization of the microscopic tribological properties of sandfish (Scincus scincus) scales by atomic force microscopy

• Weibin Wu,
• Christian Lutz,
• Simon Mersch,
• Richard Thelen,
• Christian Greiner,
• Guillaume Gomard and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2018, 9, 2618–2627, doi:10.3762/bjnano.9.243

• diameter of 1 mm provided by Saphirwerk AG (Bruegg, Switzerland). The normal load for all experiments was 0.1 N and the sliding speed was 0.5 mm/s. The number of reciprocating cycles was ten. Friction force was measured with a strain gauge-based system and recorded with a custom-programmed LabView

Evidence of friction reduction in laterally graded materials

• Roberto Guarino,
• Gianluca Costagliola,
• Federico Bosia and
• Nicola Maria Pugno

Beilstein J. Nanotechnol. 2018, 9, 2443–2456, doi:10.3762/bjnano.9.229

• there is normal force Fn(i) = pl2. Hence, the total normal force is Fn = pL2. The interaction between blocks and substrate is modelled through the classic Amontons–Coulomb friction force: each block has a static µs(i) and dynamic µk(i) friction coefficient, randomly assigned at the beginning of the

• simulation from a Gaussian statistical distribution (to account for surface roughness) with mean values denoted with µs(m) and µk(m), respectively. The standard deviation on the local coefficients of friction are denoted with σµs and σµk, respectively. If the block i is at rest, the static friction force Ffr

• (i) opposes the total driving force, so that Ffr(i) = −Fmot(i) , up to the threshold value Ffr(i) = µs(i) Fn(i). When this threshold is exceeded, a constant dynamic friction force with modulus Ffr(i) = µk(i) Fn(i) opposes the motion. Thus, Newton’s equation of motion for the block i can be written as

Nanotribology

• Enrico Gnecco,
• Susan Perkin,
• Andrea Vanossi and
• Ernst Meyer

Beilstein J. Nanotechnol. 2018, 9, 2330–2331, doi:10.3762/bjnano.9.217

• , has triggered a true revolution in our understanding of friction at the atomic scale. This is exemplified by the lattice resolved friction force images on oxidized silicon surfaces in the tribochemistry study presented by the Bennewitz group [9]. On a larger scale, alternative surface scan methods

Recent highlights in nanoscale and mesoscale friction

• Andrea Vanossi,
• Dirk Dietzel,
• Andre Schirmeisen,
• Ernst Meyer,
• Rémy Pawlak,
• Thilo Glatzel,
• Marcin Kisiel,
• Shigeki Kawai and
• Nicola Manini

Beilstein J. Nanotechnol. 2018, 9, 1995–2014, doi:10.3762/bjnano.9.190

• . But studies of atomically flat surfaces in vacuum demonstrate that the actual origin of friction is at the atomic scale. The friction force results from the sum of atomic-scale forces, including all kinds of interactions including Coulombic forces, covalent bonding and van der Waals forces. As a

• of the field foreseeable in the near future. Review Controlled nanomovements Friction force microscopy (FFM) is a well-defined AFM operation mode in which tiny lateral forces acting on the tip, as it scans across the surface, are recorded [9]. Atomic forces involving few-atom contacts can provide

• particle size increases, ultimately leading to a sublinear relation between friction and contact area described by , with F the friction force, A the contact area, and γ < 1 the scaling exponent [66][67][68]. A first experimental verification of this effect has been provided by UHV nanomanipulation

Friction force microscopy of tribochemistry and interfacial ageing for the SiO_x/Si/Au system

• Christiane Petzold,
• Marcus Koch and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2018, 9, 1647–1658, doi:10.3762/bjnano.9.157

• Christiane Petzold Marcus Koch Roland Bennewitz INM – Leibniz Institute for New Materials, Campus D2 2, 66123 Saarbrücken, Germany 10.3762/bjnano.9.157 Abstract Friction force microscopy was performed with oxidized or gold-coated silicon tips sliding on Au(111) or oxidized Si(100) surfaces in

• wear. Friction, wear, and the re-passivation by oxides are discussed based on results for the temporal development of friction forces, on images of the scanned area after friction force microscopy experiments, and on electron microscopy of the tips. Keywords: contact ageing; friction; nanotribology

• structure [10], for which friction maxima have been predicted [11]. Friction force microscopy (FFM) is a key method to investigate the microscopic mechanisms underlying friction, wear, and lubrication as it allows for measurements of static and kinetic friction of single nanometer-scale contacts. In FFM, an

Atomistic modeling of tribological properties of Pd and Al nanoparticles on a graphene surface

• Alexei Khomenko,
• Miroslav Zakharov,
• Denis Boyko and
• Bo N. J. Persson

Beilstein J. Nanotechnol. 2018, 9, 1239–1246, doi:10.3762/bjnano.9.115

• temperature, the velocity and position of the center of mass, the dimensions of the nanoparticle, and the friction and substrate forces acting on the particle. We also study how the friction force depends on the nanoparticle–graphene contact area and the temperature. Conclusion: The tribological properties of

• nanoparticles strongly depend on the materials. The particles move in an irregular (saw-like) manner. The averaged friction force depends nearly linearly on the contact area and non-monotonously on temperature. We observe ordered crystalline domains of atoms at the bottom surface of the metal particles, but the

• peaks of radial distribution function are blurred indicating that the nanoparticles are amorphous or polycrystalline. Keywords: aluminum; friction force; graphene; nanoparticle; nanotribology; palladium; Introduction The study of surface or interface phenomena at the atomic level has attracted

Surface characterization of nanoparticles using near-field light scattering

• Eunsoo Yoo,
• Yizhong Liu,
• Chukwuazam A. Nwasike,
• Sebastian R. Freeman,
• Brian C. DiPaolo,
• Bernardo Cordovez and
• Amber L. Doiron

Beilstein J. Nanotechnol. 2018, 9, 1228–1238, doi:10.3762/bjnano.9.114

• and waveguide surface is represented by a friction force, Ffric, which is a complex function of numerous dynamic properties. We use a simple approach, assuming Ffric is inversely proportional to height and increases linearly with velocity (Ffric = Av/z, where A is a constant and v is the velocity). By

Effect of microtrichia on the interlocking mechanism in the Asian ladybeetle, Harmonia axyridis (Coleoptera: Coccinellidae)

• Jiyu Sun,
• Chao Liu,
• Bharat Bhushan,
• Wei Wu and
• Jin Tong

Beilstein J. Nanotechnol. 2018, 9, 812–823, doi:10.3762/bjnano.9.75

• friction force of the DS–DS and VS–VS interactions is greater than that of the interaction between the VS and the abdomen. An additional explanation is that the vein is like a spring-loaded tape measure (that is, a carpenter’s tape) that can stabilize in the unfolded shape and confer sufficient stiffness

Exploring wear at the nanoscale with circular mode atomic force microscopy

• Olivier Noel,
• Aleksandar Vencl and
• Pierre-Emmanuel Mazeran

Beilstein J. Nanotechnol. 2017, 8, 2662–2668, doi:10.3762/bjnano.8.266

• lateral force microscopy (LFM) signal proportional to the friction force) of the cantilever stemming from the circular displacement of the contact features a sinusoidal signal with the same frequency as the relative circular displacement of the contact. Then a lock-in amplifier is used to register the

• real-time amplitude of the LFM signal of the cantilever (or friction force) during the wear experiment in order to determine prospective variations of the friction properties during the experiment. For example, this option may be advantageously implemented for investigating the correlation between

Numerical investigation of the tribological performance of micro-dimple textured surfaces under hydrodynamic lubrication

• Kangmei Li,
• Dalei Jing,
• Jun Hu,
• Xiaohong Ding and
• Zhenqiang Yao

Beilstein J. Nanotechnol. 2017, 8, 2324–2338, doi:10.3762/bjnano.8.232

• technique. The effects of micro-dimple size and the Reynolds number on film pressure, friction force as well as the friction coefficient were investigated and the optimum range for the micro-dimple depth was recommended. Published papers regarding hydrodynamic lubrication of micro-dimple textured surfaces

Velocity dependence of sliding friction on a crystalline surface

• Christian Apostoli,
• Giovanni Giusti,
• Jacopo Ciccoianni,
• Gabriele Riva,
• Rosario Capozza,
• Rosalie Laure Woulaché,
• Andrea Vanossi,
• Emanuele Panizon and
• Nicola Manini

Beilstein J. Nanotechnol. 2017, 8, 2186–2199, doi:10.3762/bjnano.8.218

• , representing a crystalline substrate. This interaction converts a part of the kinetic energy of the slider into phonon waves in the substrate. As a result, the slider experiences a friction force. As a function of the slider speed, we observe dissipation peaks at specific values of the slider speed, whose

• of the atomic force microscope (AFM) and its friction force microscope (FFM) variant [6][7][8], as well as the extensive usage of atomistic molecular dynamics (MD) simulations and modeling made possible by the vastly increased computing power availability [9][10][11][12][13][14][15][16]. Despite this

• viscous damping, and to study the intrinsic dissipation properties of a sliding interface, as a function of several physical quantities, the most interesting of which is the sliding speed. Earlier work also investigated the speed dependence of the kinetic friction force in several models [1][25][43][44

Stick–slip boundary friction mode as a second-order phase transition with an inhomogeneous distribution of elastic stress in the contact area

• Iakov A. Lyashenko,
• Vadym N. Borysiuk and
• Valentin L. Popov

Beilstein J. Nanotechnol. 2017, 8, 1889–1896, doi:10.3762/bjnano.8.189

• structure states which may lead to the stick–slip motion with non-monotonic time dependence of the friction force [1][2][4][5]. Stick–slip motion is known to cause fast destruction of the contact parts of microscopic devices, which is why it receives significant attention from the scientists and engineers

• V0. Thus, the equation of motion for the upper friction block with mass m has the following form [4]: where t is the time, and Fx is the friction force between two contacting surfaces. The magnitude of the friction force Fx depends on the properties of the system shown in Figure 1. As the upper stamp

• be defined from the known distribution τ(r) as: From the obtained q(x), the one-dimensional distribution of the displacements can be calculated as: and the distribution can be obtained from the equation: The elastic component of the friction force in the system can be defined in two ways (in one

Nanotribological behavior of deep cryogenically treated martensitic stainless steel

• Germán Prieto,
• Konstantinos D. Bakoglidis,
• Walter R. Tuckart and
• Esteban Broitman

Beilstein J. Nanotechnol. 2017, 8, 1760–1768, doi:10.3762/bjnano.8.177

• friction coefficient, and a load of 3 µN in a stroke of 10 µm for 12 scanning cycles was used to evaluate the surface roughness. The obtained topographic information at the low load is used to calculate the wear rate and roughness evolution, while the force transducers measure the friction force variations

Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

• Hanaul Noh,
• Alfredo J. Diaz and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 579–589, doi:10.3762/bjnano.8.62

• treatment, this is not as practical since the lateral friction force is not controlled, so that the contact-mode treatment sometimes leaves broken leftovers around the area of interest (see Figure S8, Supporting Information File 1) and can damage the sample. On the origin of the surface aggregates The

Structural and tribometric characterization of biomimetically inspired synthetic "insect adhesives"

• Matthias W. Speidel,
• Malte Kleemeier,
• Andreas Hartwig,
• Klaus Rischka,
• Angelika Ellermann,
• Rolf Daniels and
• Oliver Betz

Beilstein J. Nanotechnol. 2017, 8, 45–63, doi:10.3762/bjnano.8.6

• WG20 showed the highest friction force (39 mN), whereas at the higher velocities (200 and 500 µm s−1), emulsion VG50 gave the highest friction performance (39 mN and 32 mN, respectively) (Figure 4a; Supporting Information File 1, Table S2). Whereas the friction force increased with increasing sliding

• increasing speed (Supporting Information File 1, Tables S2 and S12). Similar to squalane, the friction forces of SG2 increased with increasing speed, but initially the friction force dropped, although not significantly, over the course of 50 to 200 µm s−1 (Figure 4b; Supporting Information File 1, Tables S2

• and S12). The friction behaviour of emulsion OG2 was similar to that of the first generation emulsion WG20 (Figure 4a), showing a significant decrease in friction force with increasing sliding speed (Figure 4b; Supporting Information File 1, Tables S2 and S12). Statistical relationships between

When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs

• Niall Crawford,
• Thomas Endlein,
• Jonathan T. Pham,
• Mathis Riehle and
• W. Jon P. Barnes

Beilstein J. Nanotechnol. 2016, 7, 2116–2131, doi:10.3762/bjnano.7.201

• ]. With slip angles, an angle of 90° represents the maximum friction force that this technique can measure. One might therefore predict that, if a frog did not slip by 90° then it should not slip at all, but simply fall from the platform when the angle for maximum adhesion was reached. This occurred in

• friction force was related to the density of asperities, and thus could have been caused by interlocking of the 2 µm diameter asperities with the 1–2 µm channels between the toe pad epithelial cells. An alternative explanation for this increase in friction relates to the fact that the toe pad epithelium

• can be thought of as a viscoelastic material and, as such, will dissipate energy when it is deformed [29]. Such energy would contribute to the friction force on rough surfaces. Indeed, such viscoelastic deformations can also enhance adhesion [30]. For larger roughnesses on the polishing disc surfaces