A nanometric cushion for enhancing scratch and wear resistance of hard films

• Katya Gotlib-Vainshtein,
• Olga Girshevitz,
• Chaim N. Sukenik,
• David Barlam and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2014, 5, 1005–1015, doi:10.3762/bjnano.5.114

• until the working load is reached, then the lateral force is ramped up. In general, a stick–slip behavior is observed whereby initially there is only insipient sliding until eventually the static friction is exceeded and larger movement occurs. Both substrate and layer are assumed to be 3D isotropic

Scale effects of nanomechanical properties and deformation behavior of Au nanoparticle and thin film using depth sensing nanoindentation

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2014, 5, 822–836, doi:10.3762/bjnano.5.94

• from geometrically necessary dislocations (GNDs) generated to accommodate strain gradient in nanoindentation at low penetration depths. Movement of dislocations by slip allows for plastic deformation to occur [27]. After an initial slip, as more dislocations are generated there is an increase in yield

• materials, in which grain sizes can vary from 10–300 µm [35]. In the pile-up mechanism illustrated in Figure 3a, for a given applied stress τ, on the grains illustrated by the vertical arrows, dislocations are generated along slip lines, as depicted by the dashed lines, and eventually pile up against the

• τp. For a slip to occur across the grain boundary, τp must be greater than the critical stress, τcritical. A higher initial τ is therefore required on grain C before the critical stress is reached to allow slip to occur and plastic deformation to continue, which results in a higher yield stress

In vitro toxicity and bioimaging studies of gold nanorods formulations coated with biofunctional thiol-PEG molecules and Pluronic block copolymers

• Tianxun Gong,
• Douglas Goh,
• Malini Olivo and
• Ken-Tye Yong

Beilstein J. Nanotechnol. 2014, 5, 546–553, doi:10.3762/bjnano.5.64

• (Pen Strep) were purchased from Gibco®. The clean-mount solution for fixing a glass cover slip over 8-chamber slides was purchased from electron microscopy sciences. AuNRs synthesis and characterization: Synthesis of AuNRs was adapted from Nikhoobakt et al. [6]. As described in [27], 5 mL of 0.5 mM

• for four hours at room temperature and pressure in the dark. The media and synthesized substances were removed and rinsed with PBS again, and the cells were fixed with 4% paraformaldehyde for 10 min. Thereafter, 4% paraformaldehyde was removed and rinsed with PBS. The well was removed and a cover slip

The softening of human bladder cancer cells happens at an early stage of the malignancy process

• Jorge R. Ramos,
• Joanna Pabijan,
• Ricardo Garcia and
• Malgorzata Lekka

Beilstein J. Nanotechnol. 2014, 5, 447–457, doi:10.3762/bjnano.5.52

• ) cover slip; (8) optical microscope lens. (B) Optical image of the cantilever positioned on top of the cell treated with cytochalasin D. After being treated with cytochalasin D, the cells shrink to a circular form. Force and fluorescence microscopy images of bladder cells. (A–D) Non-malignant cells

Single-asperity contact mechanics with positive and negative work of adhesion: Influence of finite-range interactions and a continuum description for the squeeze-out of wetting fluids

• Martin H. Müser

Beilstein J. Nanotechnol. 2014, 5, 419–437, doi:10.3762/bjnano.5.50

Friction behavior of a microstructured polymer surface inspired by snake skin

• Martina J. Baum,
• Lars Heepe and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 83–97, doi:10.3762/bjnano.5.8

• other peaks resulting from periodic stick-slip behavior. The data showed that the specific ventral surface ornamentation of snakes does not only reduce the frictional coefficient and generate anisotropic frictional properties, but also reduces stick-slip vibrations during sliding, which might be an

• adaptation to reduce wear. Based on this extensive comparative study of different microstructured polymer samples, it was experimentally demonstrated that the friction-induced stick-slip behavior does not solely depend on the frictional coefficient of the contact pair. Keywords: fast Fourier transformation

• ; friction; polymer; snake inspired; stick-slip; Introduction The absence of extremities in snakes has strong tribological consequences for the material of their skin. The ventral body side of the snake is in continuous contact with the substrate. Therefore ventral scales must have optimized frictional

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

• 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

• a perfectly rigid sample. McGuiggan and Yarusso calibrated the instrumental phase shift on a hard surface. They pointed out that this method ignores slip that may occur at the surface [101]. They furthermore note that most models do not include adhesion hysteresis, an unknown tip shape, and other

k-space imaging of the eigenmodes of sharp gold tapers for scanning near-field optical microscopy

• Martin Esmann,
• Simon F. Becker,
• Bernard B. da Cunha,
• Jens H. Brauer,
• Ralf Vogelgesang,
• Petra Groß and
• Christoph Lienau

Beilstein J. Nanotechnol. 2013, 4, 603–610, doi:10.3762/bjnano.4.67

• a cover slip. The main reason for using a Au-coated sample was to enhance the evanescent light contributions to the k-space images. The gold film has three major effects on those images. (i) It substantially suppresses the transmission of propagating waves ( < k0, allowed light), which have to

• importantly, it allows us to probe the near-field coupling between the tip dipole, i.e., the near fields at the tip apex, and its image dipole induced in the metal (see [21][22]). The light transmitted through the gold-coated cover slip is collected using an oil immersion objective with high numerical

• = 150 mm and f2 = 100 mm, respectively, image the back focal plane onto a CCD camera (Thorlabs DCC1545M-GL) in a 4f-configuration. In the intermediate real image plane, the filtering of scattered light from the grating coupler is realized with an iris aperture. The distance between probe and cover slip

Deformation-induced grain growth and twinning in nanocrystalline palladium thin films

• Aaron Kobler,
• Jochen Lohmiller,
• Jonathan Schäfer,
• Michael Kerber,
• Anna Castrup,
• Ankush Kashiwar,
• Patric A. Gruber,
• Karsten Albe,
• Horst Hahn and
• Christian Kübel

Beilstein J. Nanotechnol. 2013, 4, 554–566, doi:10.3762/bjnano.4.64

• et al. estimated the dislocations required for purely dislocation based plasticity by with d the grain size, εgrain the strain in the grain (here considered to be 4%) and b the burgers vector, here considered for the slip system {111} and <110>, resulting in an average of 6.1 dislocations per grain

• for the remaining strain that does not come from dislocation/twin activity. Lohmiller et al. has already reported other mechanisms, such as GB shear and slip, as well as GB migration resulting in grain growth [28][45]. Conclusion NcPd thin films with a grain size of about 35 nm (plane view) were

Plasticity of nanocrystalline alloys with chemical order: on the strength and ductility of nanocrystalline Ni–Fe

• Jonathan Schäfer and
• Karsten Albe

Beilstein J. Nanotechnol. 2013, 4, 542–553, doi:10.3762/bjnano.4.63

• composition were tested. Here, dislocation processes can be excluded, since the nucleation of superdislocations cannot be expected for the presented strain rates and no fcc-like slip planes are available in the L12 structure. The structures with an ordered grain interior as obtained by equilibration via the

• the GB and therefore the necessary increase in GB free volume controls the yield strength of the material. This is consistent with observations made for miscible systems [18] and observations on materials where dislocation slip is completely inactive (ultrananocrystalline diamond), where it was

Plasticity of Cu nanoparticles: Dislocation-dendrite-induced strain hardening and a limit for displacive plasticity

• Antti Tolvanen and
• Karsten Albe

Beilstein J. Nanotechnol. 2013, 4, 173–179, doi:10.3762/bjnano.4.17

• immediately meets the sessile partials in the dendrite about the orifice, resulting in a slip and a residual stair rod. When the orifice size is reduced the maximum stress at the onset of plasticity is increased (see Figure 9) but the qualitative behaviour of the system remains the same down to an orifice

• orifice) interacts with the partials in the dendrite pinned to the surface, resulting in a slip. Dislocation interacting to break the dendrite. (a–b) The locking multijunction (see Figure 6) is broken as the <112> partial is disassociated from the junction. (c–d) Partial nucleated at the particle surface

• (here lower right about the orifice) interacts with the partials in the dendrite pinned to the surface, resulting in a slip. Hydrostatic pressure and von Mises stress at the onset of plasticity versus extrusion orifice radius. Lines are guides for the eye. Extrusion from a 11 Å orifice. Hydrostatic

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

• normal load of the instrument, i.e., 10 mN, or the first segment that featured a maximum lateral-load difference larger than its segment size. The latter case usually can be attributed to some stick–slip event, which will contain a strong influence of the properties of the transducers spring setup

Characterization and properties of micro- and nanowires of controlled size, composition, and geometry fabricated by electrodeposition and ion-track technology

• Maria Eugenia Toimil-Molares

Beilstein J. Nanotechnol. 2012, 3, 860–883, doi:10.3762/bjnano.3.97

Reduced electron recombination of dye-sensitized solar cells based on TiO₂ spheres consisting of ultrathin nanosheets with [001] facet exposed

• Hongxia Wang,
• Meinan Liu,
• Cheng Yan and
• John Bell

Beilstein J. Nanotechnol. 2012, 3, 378–387, doi:10.3762/bjnano.3.44

• were then sealed by using a Surlyn film covered with a microscope slip. Characterization The morphology and the crystal structure of the as-prepared TiO2 powder were investigated by scanning electron microscope (SEM, FEI Quanta 200) and powder X-ray diffraction (XRD, PANanalytical Xpert Pro

Analysis of fluid flow around a beating artificial cilium

• Mojca Vilfan,
• Gašper Kokot,
• Andrej Vilfan,
• Natan Osterman,
• Blaž Kavčič,
• Igor Poberaj and
• Dušan Babič

Beilstein J. Nanotechnol. 2012, 3, 163–171, doi:10.3762/bjnano.3.16

• arranged in a square lattice with 28 μm between nearest neighbours. The glass slide with nickel dots was coated with BSA, 20 mg/mL, 5 h incubation, to prevent adhesion of the spheres onto the surface. A cell was made by gluing a cover slip onto the prepared slide with 200 μm spacers to ensure uniform

Distance dependence of near-field fluorescence enhancement and quenching of single quantum dots

• Volker Walhorn,
• Jan Paskarbeit,
• Heinrich Gotthard Frey,
• Alexander Harder and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2011, 2, 645–652, doi:10.3762/bjnano.2.68

• the sample surface at an angle of total reflection. The intensity of the evanescent wave projecting beyond the cover slip decreases exponentially. An image-intensified CCD camera detects the fluorescence light. b) Single CCD camera frame of a single quantum dot. Integrated fluorescence intensity of a

Fabrication of multi-parametric platforms based on nanocone arrays for determination of cellular response

• Lindarti Purwaningsih,
• Tobias Schoen,
• Tobias Wolfram,
• Claudia Pacholski and
• Joachim P. Spatz

Beilstein J. Nanotechnol. 2011, 2, 545–551, doi:10.3762/bjnano.2.58

• magnification with a SE2 detector. Percentage of adherent cells compared to cell adhesion on control surfaces (glass cover slip coated with laminin, value equals 100%). The nanocone arrays with gold tips show overall higher cell adhesion in comparison to gold nanoparticles on glass or bare glass. Cell adhesion

Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

• Philipp Comanns,
• Christian Effertz,
• Florian Hischen,
• Konrad Staudt,
• Wolfgang Böhme and
• Werner Baumgartner

Beilstein J. Nanotechnol. 2011, 2, 204–214, doi:10.3762/bjnano.2.24

• pressure, i.e., the atmospheric pressure plus the hydrostatic pressure acting on the liquid. γ is the surface tension, φ is the contact angle of the liquid on the unstructured capillary material, r is the radius of the capillary, η is the viscosity of the liquid, and ε is the coefficient of slip. The

• by tubes assuming the radius to be 30 µm and by introducing the parameters according to the literature and the above measurements (i.e., PO = 0 as the species were almost horizontally, γ = 72.5 mN/m, φ = 60°, η = 1mPa·s) and by least square fitting the unknown coefficient of slip ε to be 0.1, one

Manipulation of gold colloidal nanoparticles with atomic force microscopy in dynamic mode: influence of particle–substrate chemistry and morphology, and of operating conditions

• Samer Darwich,
• Karine Mougin,
• Akshata Rao,
• Enrico Gnecco,
• Shrisudersan Jayaraman and
• Hamidou Haidara

Beilstein J. Nanotechnol. 2011, 2, 85–98, doi:10.3762/bjnano.2.10

• different types of particle motion during manipulation, such as sliding, rolling, stick-slip and spinning, is crucial since the mode of motion of particles determines the energy loss and wear in the contacting surfaces. In this paper, the sensitivity of those critical parameters on the mobility of gold

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

• Bharat Bhushan

Beilstein J. Nanotechnol. 2011, 2, 66–84, doi:10.3762/bjnano.2.9

• inspired by the lotus leaf and shark skin and studied the influence of structure on pressure drop and fluid drag. One of the basic properties of interest in fluid flow is slip. The relative velocity between a solid wall and liquid is believed to be zero at the solid–liquid interface, which is the so called

• no-slip boundary condition (Figure 2, left) [25][26]. However, for hydrophobic surfaces, fluid film exhibits a phenomenon known as slip, which means that the fluid velocity near the solid surface is not equal to the velocity of the solid surface (Figure 2, right) [27][28][29][30][31][32][33]. The

• degree of boundary slip at the solid–liquid interface is characterized by a slip length. The slip length b is defined as the length of the vertical intercept along the axis orthogonal to the interface when a tangent line is drawn along the velocity profile at the interface (Figure 2, right). Recent

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

• with individual atoms or a small part of a crystal lattice on the Ångstrom scale. It was found that regular, repeatable stick-slip behaviour of a contacting highest point (asperity) over the lattice of the other surface forms the very basis of the frictional processes as previously described [2][3]. To

• physically describe the stick-slip behaviour observed, the theories of Prandtl [4] and Tomlinson [5] were used [6][7]. This Prandtl–Tomlinson model has proven to be remarkably effective in describing atomic-scale friction. Further research on atomic-scale friction has resulted in a wealth of information on

• and wear problems [12]. The question is now how to describe friction on the larger scale of actual MEMS devices, which pair micrometer features and nanometer-scale surface roughness with nano- to micro-Newton forces. This friction is characterized by irregular, but repeatable, stick-slip motion. Can

Scanning probe microscopy and related methods

• Ernst Meyer

Beilstein J. Nanotechnol. 2010, 1, 155–157, doi:10.3762/bjnano.1.18

• studied in great detail, where the main mechanism is related to atomic instabilities, which lead to the characteristic stick slip behaviour. The loading and velocitiy dependence were interpreted in terms of a thermally activated Prandtl–Tomlinson-model [5][6]. The transition into the superlubricity regime