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

• Martin H. Muser Jülich Supercomputing Centre, FZ Jülich, 52428 Jülich, Germany 10.3762/bjnano.5.50 Abstract In this work, single-asperity contact mechanics is investigated for positive and negative work of adhesion Δγ. In the latter case, finite-range repulsion acts in addition to hard-wall

• of the finite-range attraction. The results can benefit the interpretation of atomic force microscopy in liquid environments and the modeling of multi-asperity contacts. Keywords: cohesive zone model; contact mechanics; environmental; fluid squeeze-out; nanomechanics; single-asperity contacts

• ; Introduction The continuum description of single-asperity contact mechanics has received much attention in the last few decades. This is in large parts because it describes force-displacement curves rather accurately down to nanometer scales relevant to atomic force microscopy (AFM) [1][2][3]. The

Tensile properties of a boron/nitrogen-doped carbon nanotube–graphene hybrid structure

• Kang Xia,
• Haifei Zhan,
• Ye Wei and
• Yuantong Gu

Beilstein J. Nanotechnol. 2014, 5, 329–336, doi:10.3762/bjnano.5.37

• in the fields of mechanics, photology, electronics and bio-sensing [1][2]. Through the chemical vapor deposition (CVD) method, a graphene–nanotube hybrid structure (GNHS) has been synthesized recently [3][4][5], which evidently demonstrates an improved performance for the application as field

Modeling and optimization of atomic layer deposition processes on vertically aligned carbon nanotubes

• Nuri Yazdani,
• Vipin Chawla,
• Eve Edwards,
• Vanessa Wood,
• Hyung Gyu Park and
• Ivo Utke

Beilstein J. Nanotechnol. 2014, 5, 234–244, doi:10.3762/bjnano.5.25

• Electrical Engineering, ETH Zürich, Zürich CH-8092, Switzerland Laboratory for Mechanics of Materials and Nanostructures, EMPA, Thun CH-3602, Switzerland 10.3762/bjnano.5.25 Abstract Many energy conversion and storage devices exploit structured ceramics with large interfacial surface areas. Vertically

The role of surface corrugation and tip oscillation in single-molecule manipulation with a non-contact atomic force microscope

• Christian Wagner,
• Norman Fournier,
• F. Stefan Tautz and
• Ruslan Temirov

Beilstein J. Nanotechnol. 2014, 5, 202–209, doi:10.3762/bjnano.5.22

• experiment, and facilitates a better understanding of the mechanics of single-molecular junctions. Our simulations reveal that the surface corrugation adds a positive frequency shift to the measurement that generates an apparent repulsive force. Furthermore, we demonstrate that the scatter observed in the

• manipulation by including the three factors mentioned above into the simulation model and by demonstrating that even their qualitative consideration improves the correspondence between simulations and experiment, and therefore facilitates an improved understanding of the mechanics of single-molecular junctions

• the sliding of the molecule across the corrugated surface potential. On the methodological side, the important message of this work is to demonstrate that the force-field modeling of single-molecule manipulation can be successful in explaining precise details of the NC-AFM junction mechanics. However

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• and compared with the experimentally measured force. The effect of NP morphology on the nanoscale friction is discussed. Keywords: contact mechanics; nanomanipulation; nanoparticles; nanotribology; scanning electron microscopy (SEM); Introduction The manipulation of nanoparticles (NPs) is a powerful

• of the contact: where Θ is the contact angle for Ag/SiO2 interface. As described previously [20], for sphere-like NPs contact mechanics (adhesive contact approach) must be applied. The contact area is typically calculated on the basis of continuum elasticity models for deformable spheres such as the

Energy transfer in complexes of water-soluble quantum dots and chlorin e6 molecules in different environments

• Irina V. Martynenko,
• Anna O. Orlova,
• Vladimir G. Maslov,
• Alexander V. Baranov,
• Anatoly V. Fedorov and
• Mikhail Artemyev

Beilstein J. Nanotechnol. 2013, 4, 895–902, doi:10.3762/bjnano.4.101

• Irina V. Martynenko Anna O. Orlova Vladimir G. Maslov Alexander V. Baranov Anatoly V. Fedorov Mikhail Artemyev Saint Petersburg National Research University of Information Technologies, Mechanics and Optics, Saint Petersburg, Russia Institute for Physico-Chemical Problems, Belarussian State

Peak forces and lateral resolution in amplitude modulation force microscopy in liquid

• Horacio V. Guzman and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2013, 4, 852–859, doi:10.3762/bjnano.4.96

• tip motion in liquid. The forces are obtained by using two contact mechanics models, Hertz and Tatara. We present a comparison between the numerical simulations and three analytical models for a wide variety of probe and operational parameters. In general, the forces derived from analytical

• expressions are not in good quantitative agreement with the simulations when the Young modulus and the set-point amplitude are varied. The only exception is the parametrized approximation that matches the results given by Hertz contact mechanics for soft materials and small free amplitudes. We also study the

• mechanics and thus their application range is somehow limited. Numerical simulations have supported the development of AM-AFM by predicting several properties of the tip motion [25][26][27]. Those simulations provide the standards against which new experimental or analytical methods should be compared [28

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

• important phenomenon that drives material response at different scales of time and space. Burgeoning interest in nanoscale dynamic material mechanics has driven, and been driven by two key techniques: instrumented nanoindentation and atomic force microscopy. This review provides an overview of fundamental

• controlling mechanics at the nanometer level is the key to a wide range of cutting-edge topics in science and technology, which range from engineered devices to biological organisms and include novel materials. A number of impressive technologies have been employed in such studies that include, but are not

• the overall force behavior at the nanoscale. Several groups considered the effects of adhesion under various contact mechanics models in the 1970s [9][10][11][12][13]. These models analyze the changing contact shapes and stresses that occur when the surface energy and the adhesive forces in the

Size-dependent characteristics of electrostatically actuated fluid-conveying carbon nanotubes based on modified couple stress theory

• Mir Masoud Seyyed Fakhrabadi,
• Abbas Rastgoo and
• Mohammad Taghi Ahmadian

Beilstein J. Nanotechnol. 2013, 4, 771–780, doi:10.3762/bjnano.4.88

• with an initial gap G0 (state 1 in Figure 1). Continuum mechanics are applied in order to analyze the nanosystem. A voltage V is applied between the CNT as the positive electrode and the graphene sheets as the negative electrode (ground plate). This voltage and cooperated with the interatomic forces

Large-scale atomistic and quantum-mechanical simulations of a Nafion membrane: Morphology, proton solvation and charge transport

• Pavel V. Komarov,
• Pavel G. Khalatur and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2013, 4, 567–587, doi:10.3762/bjnano.4.65

• which local density fields are employed as collective variables for simulating the structural evolution of phase-separation morphologies [11][48][49][50][51][52][53]. Several different quantum mechanics approaches have been used in attempts to understand electronic structure and proton conduction in

High-resolution nanomechanical analysis of suspended electrospun silk fibers with the torsional harmonic atomic force microscope

• Mark Cronin-Golomb and
• Ozgur Sahin

Beilstein J. Nanotechnol. 2013, 4, 243–248, doi:10.3762/bjnano.4.25

• reliable method to investigate the mechanics of materials with complex geometries. Keywords: atomic force microscopy; nanomechanical characterization; silk fibers; tissue scaffolds; torsional harmonic cantilevers; Introduction Dynamic atomic force microscopy (AFM) methods provide opportunities for high

• force–distance curves to parameters representing the material properties. Although contact-mechanics models can be used for a wide variety of polymer composites, block-copolymers, and biomaterials [27][28][29][30][31][32][33][34], these models are not applicable to materials with complex geometries. For

• at the nodes of the fiber network (pinned versus clamped), and the presence of mechanical tension within the fibers can influence their mechanical behavior. We have carried out experiments to determine the relative influences of these parameters on the mechanics of electrospun silk fibers. Results

Spring constant of a tuning-fork sensor for dynamic force microscopy

• Dennis van Vörden,
• Manfred Lange,
• Merlin Schmuck,
• Nico Schmidt and
• Rolf Möller

Beilstein J. Nanotechnol. 2012, 3, 809–816, doi:10.3762/bjnano.3.90

• thickness of the glue, keeping all the others exactly the same. The simulations were performed with the commercial FEM-software COMSOL Multiphysics 3.5 (COMSOL Multiphysics GmbH, Berlin, Germany) and the additional module “Structural Mechanics”. The model introduced below is simulated by the 3-D model

• “Solid, Stress-Strain” and statically analyzed by the module “Structural Mechanics”. A grid model is built for the TF (see Figure 5a) including the glue that is used to attach it to the rigid support. To simulate the experimental configuration as well as possible, it is assumed that the prong of the TF

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

• properties of self-assembled monolayers and end-tethered protein thin films in aqueous media. Furthermore, we describe a simple analysis of the contact mechanics that enables the selection of FMM imaging parameters and thus yields a reliable interpretation of the FMM image contrast. Keywords: acoustic

• mechanics when the static contact force is much greater than the adhesion force [41][42][43]. Furthermore, the Hertzian contact model has been successfully extended to characterize the stiffness of thin, layered materials [3][44]. If necessary, tip–sample adhesion can easily be included in the contact

• analysis by selecting an appropriate contact mechanics model, such as the Johnson–Kendall–Roberts (JKR) or the Derjaguin–Muller–Toporov (DMT) model [41][45]. Although contact deformation and force have a nonlinear relationship in the Hertzian contact model, this model can be linearized for a small force

Theoretical study of the frequency shift in bimodal FM-AFM by fractional calculus

• Elena T. Herruzo and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2012, 3, 198–206, doi:10.3762/bjnano.3.22

• of the interaction force. The approximations are also valid for two different types of forces, namely Lennard-Jones interactions and DMT contact-mechanics forces. We conclude that the fractional-calculus approach is well suited to describe bimodal frequency modulation AFM experiments, which are

Direct monitoring of opto-mechanical switching of self-assembled monolayer films containing the azobenzene group

• Einat Tirosh,
• Enrico Benassi,
• Silvio Pipolo,
• Marcel Mayor,
• Michal Valášek,
• Veronica Frydman,
• Stefano Corni and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2011, 2, 834–844, doi:10.3762/bjnano.2.93

• bonds and from intermolecular interactions in the film. These results demonstrate the power and insights gained from cutting-edge AFM technologies, and advanced computational methods. Keywords: AFM; azobenzene; elastic modulus; molecular dynamics; nanomechanics; photoswitch; quantum mechanics

• in their ability to resolve the pattern of switching. For instance molecularly resolved images identified concerted switching in a small monolayer domain. And whereas concerted switching in such small domains may provide a path to overcome steric constraints, the fine mechanics of the cis↔trans

Mechanical characterization of carbon nanomembranes from self-assembled monolayers

• Xianghui Zhang,
• André Beyer and
• Armin Gölzhäuser

Beilstein J. Nanotechnol. 2011, 2, 826–833, doi:10.3762/bjnano.2.92

• the center of the membrane and measuring the corresponding deflection (the central-point method). These techniques can be used to determine Young’s modulus and the prestress. They also allow us to investigate the viscoelastic behavior and thus generate insights into the mechanics of CNMs. Results and

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

• particle is proportional to (the curl of) the local momentum flux of the flow, [p(r)j(r)], with a constant of proportionality σtr. At this stage, quantum mechanics has all but disappeared from the problem: We have a classical interaction between a, generally, spatially nonuniform steady gas flow and an

Self-organizing bioinspired oligothiophene–oligopeptide hybrids

• Alexey K. Shaytan,
• Eva-Kathrin Schillinger,
• Elena Mena-Osteritz,
• Sylvia Schmid,
• Pavel G. Khalatur,
• Peter Bäuerle and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2011, 2, 525–544, doi:10.3762/bjnano.2.57

• –peptide conjugates and to gain more insight into the structure and dynamical behavior of the aggregates at finite temperatures, a theoretical methodology based on classical mechanical force fields and molecular dynamics simulations was developed [23]. Although molecular models based on classical mechanics

• . To the best of our knowledge, we were the first to apply the rational principles of structure prediction by means of conformation space search based on molecular mechanics, and subsequent MD simulations to study the peptide-directed, noncovalent assembly of thiophene-peptide hybrids [23][31][32][33

Towards a scalable and accurate quantum approach for describing vibrations of molecule–metal interfaces

• David M. Benoit,
• Bruno Madebene,
• Inga Ulusoy,
• Luis Mancera,
• Yohann Scribano and
• Sergey Chulkov

Beilstein J. Nanotechnol. 2011, 2, 427–447, doi:10.3762/bjnano.2.48

• systems and, as such, are able to account for resonance phenomena, combination bands and vibrational overtones in a hierarchical and consistent manner. While temperature effects can be included using a statistical mechanics framework, these are usually neglected, and thus the approach is better suited to

Functional morphology, biomechanics and biomimetic potential of stem–branch connections in Dracaena reflexa and Freycinetia insignis

• Tom Masselter,
• Sandra Eckert and
• Thomas Speck

Beilstein J. Nanotechnol. 2011, 2, 173–185, doi:10.3762/bjnano.2.21

• conspicuous crowns by anomalous secondary growth, F. insignis remains relatively small and is only capable of primary growth. Biomechanical investigations were performed by applying vertical loads up to rupture to lateral branches of both species. This allows the analysis of the fracture mechanics and the

• morphology and mechanics of branch–stem-junctions have yet not been analysed quantitatively. For our studies we chose two branched arborescent monocotyledons, Dracaena reflexa and Freycinetia insignis, in order to answer the following questions: How are the fibrous bundles in the main stem connected to those

Review of "Contact Mechanics and Friction: Physical Principles and Applications" by Valentin L. Popov

• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2011, 2, 57–58, doi:10.3762/bjnano.2.7

• Stanislav N. Gorb Department of Functional Morphology and Biomechanics, Zoological Institute at the University of Kiel, Am Botanischen Garten 1–9, D-24098 Kiel, Germany 10.3762/bjnano.2.7 Keywords: adhesion; capillarity; contact mechanics; continuum mechanics; friction; lubrication; materials

• science; structural mechanics; system dynamics; tribology; Popov, V. L. Contact Mechanics and Friction: Physical Principles and Applications, 1st ed. Springer-Verlag: Berlin, Heidelberg, 2010. XV, 362 pages, ISBN 978-3-642-10802-0 (Print), 978-3-642-10803-7 (Online). doi:10.1007/978-3-642-10803-7 The

• book “Contact Mechanics and Friction: Physical Principles and Applications” is written by a theoretical physicist but from the point of view of an engineer. It covers an amazingly broad spectrum of topics ranging from atomic scale friction, continuum and structural mechanics, materials science

Defects in oxide surfaces studied by atomic force and scanning tunneling microscopy

• Thomas König,
• Georg H. Simon,
• Lars Heinke,
• Leonid Lichtenstein and
• Markus Heyde

Beilstein J. Nanotechnol. 2011, 2, 1–14, doi:10.3762/bjnano.2.1

• quantum mechanics [10][11]. Furthermore magnetic forces, friction forces, capillary forces etc. can in principle occur in NC-AFM. These forces are not relevant in this paper, since, e.g., a magnetic tip is necessary to detect magnetic forces, or non conservative forces have to be measured to determine

Tip-sample interactions on graphite studied using the wavelet transform

• Giovanna Malegori and
• Gabriele Ferrini

Beilstein J. Nanotechnol. 2010, 1, 172–181, doi:10.3762/bjnano.1.21

• GS corresponds to more oscillations under the envelope. The "Heisenberg box" shows the relationship between the time and frequency resolution, like the uncertainty principle in quantum mechanics (adapted from [15]). b) A graphical representation of the delay and dilation transformations used in the

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

• ] using a dedicated contact mechanics model. This paper first reviews typical MEMS friction measurements with our fully MEMS-based tribometer, showing the irregular, but repeatable, stick-slip motion of MEMS surfaces in contact. Then we extend the common Prandtl–Tomlinson model with a stochastic component