Molecular machines operating on the nanoscale: from classical to quantum

• Igor Goychuk

Beilstein J. Nanotechnol. 2016, 7, 328–350, doi:10.3762/bjnano.7.31

• machines, are reviewed. Special attention is paid to the dual, constructive role of dissipation and thermal fluctuations, the fluctuation–dissipation theorem, heat losses and free energy transduction, thermodynamic efficiency, and thermodynamic efficiency at maximum power. Several basic models are

• the fluctuation–dissipation theorem (FDT) on the nano- and microscale. It is generally wrong. It is valid only for some particular dynamics, as clarified below by giving three counter-examples. The presence of strong thermal fluctuations at ambient temperature, playing a constructive and useful role

• . Review Fluctuation–dissipation theorem, the role of thermal fluctuations Motion in any dissipative environment is necessarily related to the dissipation of energy. Particles experience a frictional force, which in the simplest case of Stokes friction is linearly proportional to the particle velocity with

High-bandwidth multimode self-sensing in bimodal atomic force microscopy

• Michael G. Ruppert and
• S. O. Reza Moheimani

Beilstein J. Nanotechnol. 2016, 7, 284–295, doi:10.3762/bjnano.7.26

• strain dependent voltage source Vp in series with a capacitor Cp as shown in Figure 2c. While the capacitor sufficiently represents the dielectric properties of the piezoelectric material, this simplified model does not take into account dielectric losses or heat dissipation which can be modeled by

Controlled graphene oxide assembly on silver nanocube monolayers for SERS detection: dependence on nanocube packing procedure

• Martina Banchelli,
• Bruno Tiribilli,
• Roberto Pini,
• Luigi Dei,
• Paolo Matteini and
• Gabriella Caminati

Beilstein J. Nanotechnol. 2016, 7, 9–21, doi:10.3762/bjnano.7.2

• has received much less attention [30][31][32] due to the lack of direct monitoring of the assembly process in situ. In this work, we followed the formation of an adlayer of AgNCs on silicon oxide surfaces by means of a quartz crystal microbalance with dissipation monitoring as a function of time and

• surfaces was monitored in situ by means of a quartz crystal microbalance as the nanocubes approach the substrate and adsorb on the surface. In this experiment, the change in frequency, ΔF, related to the adsorbed mass, and the change of the dissipation factor, ΔD, related to the viscoelastic properties of

• . This procedure was repeated until no further changes were recorded, indicating that surface saturation was reached. Typical results for the change in normalized frequency and dissipation factor for the third harmonic obtained for a single addition are reported in Figure 2. The plot shows how both Δf3/3

Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains

• Carlos Sabater,
• Carlos Untiedt and
• Jan M. van Ruitenbeek

Beilstein J. Nanotechnol. 2015, 6, 2338–2344, doi:10.3762/bjnano.6.241

• ensemble of breaking events can be described by thermal activation over a distribution of barrier heights. Dissipation raises the effective temperature above the bath temperature T according to [19], with being TV determined by the applied bias voltage as [20], where γ = 60 K·V−1/2·nm−1/2 and L is the

A simple and efficient quasi 3-dimensional viscoelastic model and software for simulation of tapping-mode atomic force microscopy

• Santiago D. Solares

Beilstein J. Nanotechnol. 2015, 6, 2233–2241, doi:10.3762/bjnano.6.229

• quantification of tip–sample dissipation in atomic force microscopy (AFM) has been an ongoing subject of interest since the early days of the technique [1][2]. A significant percentage of the surfaces characterized with AFM exhibit rate-dependent deformation processes that result in dissipative tip–sample

• ], providing a modulus of elasticity and ‘dissipation’ parameters, which can be practical and efficient in a variety of situations. Nevertheless, further developments still remain in terms of model improvements that consider the most fundamental behaviors of viscoelastic bodies. Specifically, the above

Electrospray deposition of organic molecules on bulk insulator surfaces

• Antoine Hinaut,
• Rémy Pawlak,
• Ernst Meyer and
• Thilo Glatzel

Beilstein J. Nanotechnol. 2015, 6, 1927–1934, doi:10.3762/bjnano.6.195

• differences. A more detailed topography image of such an island is presented in Figure 5a with the corresponding dissipation image (Figure 5b). Using the dissipation image, the identification of the areas with and without molecules is facilitated due to two different contrasts (bright or dark). This

• is obtained by the dissipation image where single molecular rows are visible. A columnar organization of the rows with a length of 20–50 nm, and spaced by roughly 3 nm, compose the islands. This is in good agreement with the molecular size of 2.8 nm (Figure 5d,e) in a tilted position. Inside one

• molecular island and also for different islands, several line orientations can be observed (not shown here). Despite different tries and the intra islands resolution in the dissipation image, we were not able to achieve similar resolution in the topography images to know the exact commensurability between

Improved atomic force microscopy cantilever performance by partial reflective coating

• Zeno Schumacher,
• Yoichi Miyahara,
• Laure Aeschimann and
• Peter Grütter

Beilstein J. Nanotechnol. 2015, 6, 1450–1456, doi:10.3762/bjnano.6.150

• the cantilever thickness. The logarithmic decrement is δ = π/Q. The c stands for the composite system, f for the film and s for the substrate. This assumes no clamping losses and a substrate operating at the fundamental thermoelastic limit of dissipation [8]. We calculate the Q-factor dependence on

Optimization of phase contrast in bimodal amplitude modulation AFM

• Mehrnoosh Damircheli,
• Amir F. Payam and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 1072–1081, doi:10.3762/bjnano.6.108

• map compositional variations under the influence of conservative forces is a main advantage with respect to AFM phase imaging (tapping mode AFM), where the phase contrast is related to variations in energy dissipation [33]. In AM-AFM there are two interacting regimes, attractive and repulsive [2]. The

• function of the amplitude ratio, the amplitude values of the second mode and the kinetic energy ratios of the excited modes. We also study the phase contrast between different materials by including energy dissipation in the tip–sample interaction, by inverting the roles of the excited modes (indirect

• ., tapping mode AFM. For this simulation the best contrast is yielded for an amplitude ratio of 250. This value is significantly larger than the values previously recommended (10–50) which were based on experiments [43][44][45]. Phase contrast in the attractive regime (dissipation): A01 > A02 To study the

Fabrication of high-resolution nanostructures of complex geometry by the single-spot nanolithography method

• Alexander Samardak,
• Margarita Anisimova,
• Aleksei Samardak and
• Alexey Ognev

Beilstein J. Nanotechnol. 2015, 6, 976–986, doi:10.3762/bjnano.6.101

• surrounding resist. It exhibits the characteristic centered peak, indicating the place where the incident electron beam interacted with resist. One explanation for this reduced height effect is the gradual dissipation of primary electrons that penetrate the resist. The single spot with Gaussian shape matching

Stiffness of sphere–plate contacts at MHz frequencies: dependence on normal load, oscillation amplitude, and ambient medium

• Jana Vlachová,
• Rebekka König and
• Diethelm Johannsmann

Beilstein J. Nanotechnol. 2015, 6, 845–856, doi:10.3762/bjnano.6.87

• level on the other. The CM model ignores viscous dissipation. In consequence, the energy dissipated in reciprocating sliding scales as the cube of the oscillation amplitude in the low-amplitude limit. Following from this scaling law, the damping of a resonator, which experiences particle slip in one way

• related to the dissipation factor, D, by D = Γ/(2f). fF is the fundamental frequency, which is often 5 MHz. Zq = 8.8 × 106 kg∙m−2s−1 is the shear wave impedance of AT-cut quartz. is the area-averaged complex amplitude of the tangential stress at the resonator surface, and u0 is the amplitude of

• acounts for viscous dissipation, where ξ is the drag coefficient. ξ quantifies linear processes in the sense that the stress is proportional to the rate of displacement. No statement is made on the mechanism(s) leading to dissipation. The drag coefficient may be linked to the viscoelastic nature of the

Stick–slip behaviour on Au(111) with adsorption of copper and sulfate

• Nikolay Podgaynyy,
• Sabine Wezisla,
• Christoph Molls,
• Shahid Iqbal and
• Helmut Baltruschat

Beilstein J. Nanotechnol. 2015, 6, 820–830, doi:10.3762/bjnano.6.85

• of stick–slip behaviour at normal loads of less than 15 nN. In spite of non-stick–slip resolution the contact between tip and surface is preserved and energy dissipation is still observed. A transition to superlubricity would involve disappearing friction [35][36]. Since this is not the case here one

• investigated. Friction is minimal at the potential of zero charge, suggesting again the role of adsorbates for frictional energy dissipation. On the other hand, friction is particularly large when the adlayer is disordered at the potential of a phase transition, as shown here for the formation of the √3 × √3

Capillary and van der Waals interactions on CaF₂ crystals from amplitude modulation AFM force reconstruction profiles under ambient conditions

• Annalisa Calò,
• Oriol Vidal Robles,
• Sergio Santos and
• Albert Verdaguer

Beilstein J. Nanotechnol. 2015, 6, 809–819, doi:10.3762/bjnano.6.84

• contributions to the net energy dissipation by their physical origin and/or distance-dependence [34] has been the object of recent efforts in the direction of performing quantitative measurements with the AFM [35][36]. For example, Gadelrab and coauthors showed that the difference in the phase signal compared

• approach when relative humidity is allowed to spontaneously reach the ambient value of about 40% and homogeneous micrometer-sized water patches stabilize on top of the crystals surface. The dissipation induced by the capillary bridge formation is unambiguously identified in experimental Ediss and ΔΦ curves

• relative to the drive force, and Q is the quality factor due to dissipation with the medium. The experimental APD curves cover the approach and the retract part during one cycle, with a drift smaller than 0.5 nm (see Supporting Information File 1, Figure S1). Only approach curves for which the cantilever

Electroburning of few-layer graphene flakes, epitaxial graphene, and turbostratic graphene discs in air and under vacuum

• Andrea Candini,
• Nils Richter,
• Domenica Convertino,
• Camilla Coletti,
• Franck Balestro,
• Wolfgang Wernsdorfer,
• Mathias Kläui and
• Marco Affronte

Beilstein J. Nanotechnol. 2015, 6, 711–719, doi:10.3762/bjnano.6.72

• the area around the graphene–metal contact gets heavily damaged due to high power dissipation at these spots. b) EB cycle for a patterned TG disc (see text) showing the transition from low-ohmic (≈200 Ω) to high-ohmic (≈20 kΩ) behavior, which indicates the opening of a gap. c) Corresponding SEM image

Entropy effects in the collective dynamic behavior of alkyl monolayers tethered to Si(111)

• Christian Godet

Beilstein J. Nanotechnol. 2015, 6, 583–594, doi:10.3762/bjnano.6.60

• and the applied voltage using rectifying Hg/C12H25/n-type Si junctions. Partial substitution of methyl end groups by polar (carboxylic acid) moieties was used to enhance the chain end relaxation response. Two thermally activated dissipation mechanisms (B1 and B2, with fB1 < fB2) are evidenced for all

• dependence of the B2 dipolar strength. For both dissipation mechanisms, the observed linear correlation between activation energy and logarithm of pre-exponential factor is consistent with a multi-excitation entropy model, in which the molecular reorientation path is strongly coupled with a large number of

• dissipation mechanisms is the behavior of tethered OML under compressive and shear forces, as found in nano-tribology experiments, where external forces can cause conformational changes. Again, a disorder gradient results from the formation of gauche defects which can be reverted when the atomic force

A scanning probe microscope for magnetoresistive cantilevers utilizing a nested scanner design for large-area scans

• Tobias Meier,
• Alexander Förste,
• Ali Tavassolizadeh,
• Karsten Rott,
• Dirk Meyners,
• Roland Gröger,
• Günter Reiss,
• Eckhard Quandt,
• Thomas Schimmel and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2015, 6, 451–461, doi:10.3762/bjnano.6.46

• , atomic step edges of 2.54 Å height are resolved. For dynamic-mode experiments, the phase-shift signal is of high interest as it provides information about energy dissipation between tip and sample [60][61] and visualizes chemical contrasts [62]. To demonstrate this kind of measurement also with our TMR

• topography contrast in ambient conditions is most likely caused by the thin water films present on hydrophilic SiOx under ambient conditions [65]. This effect obscures the height difference between the FDTS and SiOx. However, as shown in Figure 7a, the difference of the energy dissipation between the two

• sample system, dissipative tip–sample forces are dominant. Therefore, a high phase-signal contrast can be observed and reveals the different materials of the sample due to different energy dissipation between tip and sample while the amplitude-signal feedback reveals no topographic features. b) On such

Influence of spurious resonances on the interaction force in dynamic AFM

• Luca Costa and
• Mario S. Rodrigues

Beilstein J. Nanotechnol. 2015, 6, 420–427, doi:10.3762/bjnano.6.42

• and the dissipation are shown in Figure 2e and Figure 2f. In both cases it is possible to observe the same results in terms of force gradient and dissipation, the main difference between the two excitation methods being only the calibration parameters a and , which were in the case of electrostatic

• (Figure 4a), whereas the dissipation remains constant and approximately equal to zero. The force was used to obtain all unknown constants. Interestingly, the values of r and that result from the calibration are those that would be expected if the spurious peaks were not present. Notice in Figure 4d that

• excited (blue) and mechanically excited (red) in liquid; (c and d) normalized excitation and phase, respectively; e) force gradient and f) dissipation measured at the mica/deionized water interface with electrostatic excitation of the tip (blue) and conventional piezoelectric excitation (red). Equation 14

A surface acoustic wave-driven micropump for particle uptake investigation under physiological flow conditions in very small volumes

• Florian G. Strobl,
• Dominik Breyer,
• Phillip Link,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Matthias F. Schneider and
• Achim Wixforth

Beilstein J. Nanotechnol. 2015, 6, 414–419, doi:10.3762/bjnano.6.41

• generator is no solution to that problem since dissipation would heat the sample. However, as we will show, the application of focusing interdigital transducers (FIDTs) in an L-shape configuration allows for shear rates of up to 4000 s−1 without significant sample heating. Results and Discussion

• significant heating due to dissipation at the applied input power of PSAW ≈ 19 dBm. Characterization of the flow pattern The characterization of the SAW-induced velocity field is done by particle image velocimetry (PIV). For improving the resolution while being able to capture the whole chamber the method is

Dynamic force microscopy simulator (dForce): A tool for planning and understanding tapping and bimodal AFM experiments

• Horacio V. Guzman,
• Pablo D. Garcia and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2015, 6, 369–379, doi:10.3762/bjnano.6.36

• ]. They explained the origin of the phase contrast observed on heterogeneous samples by tapping mode AFM in air [3] and liquid [4][5]. In the process, simulations validated the theory of AFM phase imaging in air [6][7], its use to identify energy dissipation processes [7] or to measure the energy

Mechanical properties of MDCK II cells exposed to gold nanorods

• Anna Pietuch,
• Bastian Rouven Brückner,
• David Schneider,
• Marco Tarantola,
• Christina Rosman,
• Carsten Sönnichsen and
• Andreas Janshoff

Beilstein J. Nanotechnol. 2015, 6, 223–231, doi:10.3762/bjnano.6.21

• about cellular properties like the cytoskeleton or the plasma membrane [21]. Alternatively, mechanical properties of cells in response to nanoparticle exposure can be monitored time resolved by the quartz crystal microbalance with dissipation monitoring (D-QCM) [14][22][23]. The QCM-method records

• of cells with GDA results in a shift to lower resonance frequency by a few hundred Hertz, while dissipation grows [14]. The same is observed for CTAB-coated gold nanorods and nanospheres (Figure 6). In good accordance, elasticity measurements of MDCK II cells after GDA fixation with an AFM provides a

• that both mass load (change in resonant frequency) and dissipation (representing energy loss) increase upon administration of CTAB coated gold nanorods. The response time of the cells to administration of particles is fairly fast (few hours) and depends heavily on particle concentration. We carried out

High-frequency multimodal atomic force microscopy

• Adrian P. Nievergelt,
• Jonathan D. Adams,
• Pascal D. Odermatt and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2014, 5, 2459–2467, doi:10.3762/bjnano.5.255

• our system for noise performance will decrease the baseline noise value further [35]. Dissipation imaging Bimodal imaging The capability for clean, high-frequency cantilever excitation, and low-noise, high-frequency deflection readout provide a powerful platform for extending multifrequency techniques

• amplification is kept constant with the PLL, the amount of drive signal needed to keep the amplitude constant is proportional to the power dissipated in the tip–sample interaction. The power dissipation (Pdiss) is calculated from the applied excitation signal (Vex·sin (2πf)) and the intrinsic power dissipation

• of the cantilever (P0) as where V0 is the excitation voltage, f0 the excitation frequency, k the spring constant, A the amplitude and Q the quality factor far from the surface [39]. The acquired dissipation is, to a first approximation, only dependent on the materials properties and the additional

Modeling viscoelasticity through spring–dashpot models in intermittent-contact atomic force microscopy

• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 2149–2163, doi:10.3762/bjnano.5.224

• quantitative information about the dissipative and conservative tip–sample interactions by converting them to energy-based quantities, namely the dissipated power (Pts) and virial (Vts) [9][11]. Although several authors have achieved quantification of energy dissipation processes [12][13][14][15], the further

• force–distance curve and dissipation behavior of these models, focusing on single-eigenmode tip–sample impacts. Throughout the paper, the advantages and disadvantages of the various models are discussed, along with possible enhancements that can lead to more accurate simulation of viscoelastic material

• to its original position. Despite the limitations of the Linear Maxwell model, it is able to model dissipation which is evidenced by the presence of a hysteresis loop in the force–distance (FD) curve (see Figure 1c). This dissipation loop arises from the gap between the energy input (energy given by

Effect of channel length on the electrical response of carbon nanotube field-effect transistors to deoxyribonucleic acid hybridization

• Hari Krishna Salila Vijayalal Mohan,
• Jianing An,
• Yani Zhang,
• Chee How Wong and
• Lianxi Zheng

Beilstein J. Nanotechnol. 2014, 5, 2081–2091, doi:10.3762/bjnano.5.217

• charge traps are in the filled state [35][37]. On the contrary, in the near-threshold regime, the lack of dissipation of injected charges on account of hysteresis causes the potential induced by the trapped charges to exceed the potential of the back gate voltage [37], which emphasized the need to

Dissipation signals due to lateral tip oscillations in FM-AFM

• Michael Klocke and
• Dietrich E. Wolf

Beilstein J. Nanotechnol. 2014, 5, 2048–2057, doi:10.3762/bjnano.5.213

• usually uncontrolled mechanical damping of the lateral excitation. For certain cantilevers, this dissipation mechanism can lead to dissipation rates larger than 0.01 eV per period. The mechanism produces an atomic contrast for ionic crystals with two maxima per unit cell in a line scan. Keywords: atomic

• force microscopy (AFM); frequency-modulated atomic force microscopy (FM-AFM); energy dissipation; Introduction The usage of scanning probe microscopes requires an understanding of the physical processes during the scan, otherwise images can be misinterpreted. Due to the importance of frequency

• -modulated atomic force microscopy (FM-AFM), the physical processes involved have been studied intensively in the past [1]. This includes the relation between tip–surface interaction and frequency-shift [2], as well as features such as the energy dissipation during the scan [3], which is an interesting side

Dynamic calibration of higher eigenmode parameters of a cantilever in atomic force microscopy by using tip–surface interactions

• Stanislav S. Borysov,
• Daniel Forchheimer and
• David B. Haviland

Beilstein J. Nanotechnol. 2014, 5, 1899–1904, doi:10.3762/bjnano.5.200

• damage since the dissipation is almost zero in this regime. Finally, the linear method is dependent on the unknown higher eigenmode free amplitude, , which must be small for the linear approximation to be valid. Since is not known a priori, one can use the following formula to try to make a rough guess

Real-time monitoring of calcium carbonate and cationic peptide deposition on carboxylate-SAM using a microfluidic SAW biosensor

• Anna Pohl and
• Ingrid M. Weiss

Beilstein J. Nanotechnol. 2014, 5, 1823–1835, doi:10.3762/bjnano.5.193

• microbalances with dissipation QCM-D [35]. Mass and viscosity changes can be continuously and simultaneously monitored in standardized systems, as long as the amplitude signal is strongly correlated with the viscosity of the fluid [36]. Recently, multichannel experiments became possible, enhancing the