Length-extension resonator as a force sensor for high-resolution frequency-modulation atomic force microscopy in air

• Hannes Beyer,
• Tino Wagner and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2016, 7, 432–438, doi:10.3762/bjnano.7.38

• avoid stability issues such as “jump-to-contact” while working with small amplitudes, sensors with a high stiffness, e.g., short cantilevers, quartz tuning forks, or length-extension resonators are required [3]. In UHV tuning forks have outperformed conventional cantilevers because the high stiffness (k

• resonance frequency of about 1 MHz, a Q-factor of approximately 15,000 in air and an effective stiffness of keff = 1.08 MN/m. The effective stiffness amounts to twice the stiffness of a single beam (k = 540 kN/m) because the LER consists of two oscillating beams fixed at the center [9]. The very high

• stiffness allows for operation at very small amplitudes down to tens of picometres and atomic resolution has already been achieved in UHV [10][11][12][13]. The sensor is also suited for simultaneous measurements of the frequency shift and tunnelling current [12][13][14]. Only a few applications of the LER

Efficiency improvement in the cantilever photothermal excitation method using a photothermal conversion layer

• Natsumi Inada,
• Hitoshi Asakawa,
• Taiki Kobayashi and
• Takeshi Fukuma

Beilstein J. Nanotechnol. 2016, 7, 409–417, doi:10.3762/bjnano.7.36

• 0.58 and 0.12 N/m and a visible laser beam were used. However, since the excitation efficiency decreases with increasing cantilever stiffness (or with increasing the excitation laser beam wavelength), it is important to experimentally confirm the applicability of such a coating method with a relatively

Functional fusion of living systems with synthetic electrode interfaces

• Oskar Staufer,
• Sebastian Weber,
• C. Peter Bengtson,
• Hilmar Bading,
• Joachim P. Spatz and
• Amin Rustom

Beilstein J. Nanotechnol. 2016, 7, 296–301, doi:10.3762/bjnano.7.27

• . Indeed, several cell/NW-related papers based on experimental and theoretical considerations including mathematical and mechanical models predict a narrow window for the aspect ratio and density of electrodes as well as for factors such as cell stiffness, cell spreading, substrate adhesion or cell

Determination of Young’s modulus of Sb₂S₃ nanowires by in situ resonance and bending methods

• Liga Jasulaneca,
• Raimonds Meija,
• Alexander I. Livshits,
• Juris Prikulis,
• Subhajit Biswas,
• Justin D. Holmes and
• Donats Erts

Beilstein J. Nanotechnol. 2016, 7, 278–283, doi:10.3762/bjnano.7.25

• NWs over the examined cross sectional area range, with the apparent stiffness increasing for NWs with smaller cross sectional area. A linear fit added to the data points marks the tendency with a negative slope of ΔE/ΔA ≈ 230 GPa/μm². This can be explained by a nanoscale surface effect that arises

Single-molecule mechanics of protein-labelled DNA handles

• Vivek S. Jadhav,
• Dorothea Brüggemann,
• Florian Wruck and
• Martin Hegner

Beilstein J. Nanotechnol. 2016, 7, 138–148, doi:10.3762/bjnano.7.16

• lengths, one can choose a certain trap separation during experiments that minimizes contributions due to crosstalk. DH lengths of 1000, 3034 and 4056 bp were chosen for the PDHs in this study. Short handles with greater stiffness could be produced quite easily and increase the signal-to-noise ratio (SNR

• increasing the distance between the two optically trapped beads. For nanomechanical experiments short molecular handles are preferred due to their increased mechanical stiffness, resulting in a favourable signal-to-noise ratio [14]. In order to achieve optimal positional and force resolution a balance had to

• be found between minimising the parasitic optical crosstalk signal in the dual-trap instrument and maximising the stiffness of the tethers. Double handle experiments with DNA handles of 1000 bp (contour lengths of more than 340 nm each), were the shortest possible constructs that still featured the

Dependence of lattice strain relaxation, absorbance, and sheet resistance on thickness in textured ZnO@B transparent conductive oxide for thin-film solar cell applications

• Kuang-Yang Kou,
• Yu-En Huang,
• Chien-Hsun Chen and
• Shih-Wei Feng

Beilstein J. Nanotechnol. 2016, 7, 75–80, doi:10.3762/bjnano.7.9

• , εxx, and in the y-direction, εyy, of ZnO films can be determined by the frequency shift, Δω = ω−ω0 [21], as: where a = −774 cm−1 and b = −375 cm−1 are the deformation potential constants of the A1(TO) mode [22]. The elastic stiffness constants, C33 and C13, are 216 and 104 GPa, respectively [1]. The

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

• . Possibility to obtain these structures relies on the ratio between the in-plane stiffness and out-of-plane bending stiffness: large values of this parameter translate in membrane-like material that more easily bend and crumple. Optical microscopy in reflection mode images (Figure 4) of the two systems

Nanoscale rippling on polymer surfaces induced by AFM manipulation

• Mario D’Acunto,
• Franco Dinelli and
• Pasqualantonio Pingue

Beilstein J. Nanotechnol. 2015, 6, 2278–2289, doi:10.3762/bjnano.6.234

• cantilever longitudinal and lateral stiffness, the scan direction and velocity, the spacing between successive lines (named ‘feeding’). Depending on these parameters, the nanoripple patterns form in either one or several scan frames. The most significant physical observables of the process are the lateral

• upon penetration of the tip. If one knows the time dependence N(t) and the indenter width, the process is found to be governed only by the scan velocity v and the lateral stiffness k. Specifically, the amplitude A and ripple periodicity increase when N exceeds a critical value Nc or, vice versa, when k

• or v fall below the critical values of vc and kc, respectively (Figure 7). A transition from stick–slip to gliding can be also predicted for an indentation rate below a critical value or, alternatively, for large values of the sliding velocity, the lateral stiffness or the tip width. It is suggested

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

• analyze the depth dependence of the contact stiffness by performing a fit to appropriate models of elastic, viscous and adhesive forces, as is demonstrated in [13] for polymer blends. This approach is associated with small tip oscillations and is sensitive to the speed at which the base of the cantilever

Fabrication of hybrid nanocomposite scaffolds by incorporating ligand-free hydroxyapatite nanoparticles into biodegradable polymer scaffolds and release studies

• Balazs Farkas,
• Marina Rodio,
• Ilaria Romano,
• Alberto Diaspro,
• Romuald Intartaglia and
• Szabolcs Beke

Beilstein J. Nanotechnol. 2015, 6, 2217–2223, doi:10.3762/bjnano.6.227

• concentration. The MPExSL process yielded PPF thin films with a stable and homogenous dispersion of the embedded HA nanoparticles. Here, it was not possible to tune the stiffness and hardness of the scaffolds by varying the laser parameters, although this was observed for regular PPF scaffolds. Finally, the

• also proved that these scaffolds did not cause immune rejection [21]. A constant release of HA NPs during scaffold degradation may vastly improve the healing process. Also, certain tuning capabilities emerge with PPF:DEF resins when fabrication parameters are changed [22][23]: The stiffness/Young

• nanoindentation (Figure 2b) measurements show that the stiffness of the fabricated samples can be considered identical, independent of the concentration of the nanoparticles, as well as the laser parameters. Also, the samples (samples 1–6) fabricated with three different HA concentrations (50, 100 and 300 ppm

Development of a novel nanoindentation technique by utilizing a dual-probe AFM system

• Eyup Cinar,
• Ferat Sahin and
• Dalia Yablon

Beilstein J. Nanotechnol. 2015, 6, 2015–2027, doi:10.3762/bjnano.6.205

• . Therefore, stiffness can be approximated with the slope of unloading curve as shown in Figure 1a. If the unloading curve is fit to a power law such as F = α(h − hf)m where α and m are power-law fitting constants then the unloading stiffness S can be approximated as in Equation 1 by the slope of the fitting

• force curve such as that in Figure 1a is obtained, one can calculate elastic unloading stiffness through Equation 2 defined as the slope of the upper part on the unloading curve as shown in Figure 1a: where Eeff is effective elastic modulus including both the elastic modulus of the indenter (E1) and of

• calculate the stiffness parameter S from the slope of the unloading part and use Equation 2 and Equation 3 to extract the unknown elastic modulus of the sample (E2). In the next section we introduce an overview of the proposed system and its components in detail. We also present the calibration data and the

A simple method for the determination of qPlus sensor spring constants

• John Melcher,
• Julian Stirling and
• Gordon A. Shaw

Beilstein J. Nanotechnol. 2015, 6, 1733–1742, doi:10.3762/bjnano.6.177

• System of Units (SI) [19][21][37], measures a force vs displacement curve by pressing a sharp indenter tip into the qPlus sensor surface at a known axial distance from the distal edge of the tine. From the indentation curve, a stiffness kI is inferred, taking care to remove the machine compliance and

• were acquired along the axis of the tine and additionally at the base of the sensor in order to remove the contact stiffness and machine compliance from the spring constant prediction. To avoid interference with the indenter tip, tips were not attached to the tine. Figure 7 shows the indentation

• (less than 3%) in stiffness by testing at a lateral offset from the beam axis. Finally, we note that for sufficiently long tips, the compliance of the tip contributes to the parasitic tip motion [32][33]. This, in turn, influences the spring constant and force spectroscopy results presented here. To

Lower nanometer-scale size limit for the deformation of a metallic glass by shear transformations revealed by quantitative AFM indentation

• Arnaud Caron and
• Roland Bennewitz

Beilstein J. Nanotechnol. 2015, 6, 1721–1732, doi:10.3762/bjnano.6.176

• bending stiffness of the cantilever was calculated according to the beam geometry method [16] and was found to be kn = 46 N/m. The sensitivity of the photo-diode was calibrated in the non-contact mode of AFM, following the method proposed in [17] and considering a conversion factor of for the vibration

Atomic force microscopy as analytical tool to study physico-mechanical properties of intestinal cells

• Christa Schimpel,
• Oliver Werzer,
• Eleonore Fröhlich,
• Gerd Leitinger,
• Markus Absenger-Novak,
• Birgit Teubl,
• Andreas Zimmer and
• Eva Roblegg

Beilstein J. Nanotechnol. 2015, 6, 1457–1466, doi:10.3762/bjnano.6.151

• of the outerleaflets of the membranes of adjacent cells. They are responsible to maintain the integrity of the cell layer, which is likely to be associated with the cell mechanics such as high cell stiffness and reduced cell elasticity at the cell periphery. In contrast, once enterocytes are

Nanomechanical humidity detection through porous alumina cantilevers

• Olga Boytsova,
• Alexey Klimenko,
• Vasiliy Lebedev,
• Alexey Lukashin and
• Andrey Eliseev

Beilstein J. Nanotechnol. 2015, 6, 1332–1337, doi:10.3762/bjnano.6.137

• substances through micromechanical sensing still holds a tremendous potential [4][5][6][7][8]. To improve the shifts of the resonant frequency one needs to enlarge the active surface area of the sensor while preserving its mechanical stiffness. This necessitates the use of the porous systems with “open

• array. Experimentally we established the excitation of mechanical vibrations perpendicular to the cantilever surface as torsion. The thickness of cantilever arrays influences on stiffness and may also cause an increasing in resonance frequency: from 500 kHz for 2 μm thick cantilevers to 670 kHz for 30

Automatic morphological characterization of nanobubbles with a novel image segmentation method and its application in the study of nanobubble coalescence

• Yuliang Wang,
• Huimin Wang,
• Shusheng Bi and
• Bin Guo

Beilstein J. Nanotechnol. 2015, 6, 952–963, doi:10.3762/bjnano.6.98

• (MultiMode III, Digital Instruments) operating in tapping mode was used for imaging the sample. A silicon rotated force-modulated etched silicon probe (RFESP, Bruker Corporation) cantilever with a tip radius of 8 nm and a stiffness of 3 N/m was used. A modified tip holder was used for tapping mode atomic

Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

• Mykola Telychko,
• Jan Berger,
• Zsolt Majzik,
• Pavel Jelínek and
• Martin Švec

Beilstein J. Nanotechnol. 2015, 6, 901–906, doi:10.3762/bjnano.6.93

• custom-built quartz-tuning fork sensor was used for the measurements. It had a main resonance frequency of 51294 Hz, a quality factor above 1000 and an estimated stiffness of ≈3800 N·m−1 [22]. The contact to the tungsten tip was made of a thin golden wire in order to avoid crosstalk with the deflection

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

• Jana Vlachova Rebekka Konig Diethelm Johannsmann Clausthal University of Technology, Institute of Physical Chemistry, Arnold-Sommerfeld-Straße 4, 38678 Clausthal-Zellerfeld, Germany 10.3762/bjnano.6.87 Abstract The stiffness of micron-sized sphere–plate contacts was studied by employing high

• results from experiments undertaken in the dry state and in water are compared. Building on the shifts in the resonance frequency and resonance bandwidth, the instrument determines the real and the imaginary part of the contact stiffness, where the imaginary part quantifies dissipative processes. The

• method is closely analogous to related procedures in AFM-based metrology. The real part of the contact stiffness as a function of normal load can be fitted with the Johnson–Kendall–Roberts (JKR) model. The contact stiffness was found to increase in the presence of liquid water. This finding is

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

• below the figure) characterizes the effective lateral stiffness of the surface–tip contact. In our case it is 10 N/m and therefore much smaller than the lateral stiffness of the cantilever (190 N/m). The somewhat rounded shape might be due to a not completely commensurable tip–substrate contact [32

Mapping of elasticity and damping in an α + β titanium alloy through atomic force acoustic microscopy

• M. Kalyan Phani,
• Anish Kumar,
• T. Jayakumar,
• Walter Arnold and
• Konrad Samwer

Beilstein J. Nanotechnol. 2015, 6, 767–776, doi:10.3762/bjnano.6.79

• . Physikalisches Institut, Georg-August-Universität, Friedrich Hund Platz 1, D-37077 Göttingen, Germany 10.3762/bjnano.6.79 Abstract The distribution of elastic stiffness and damping of individual phases in an α + β titanium alloy (Ti-6Al-4V) measured by using atomic force acoustic microscopy (AFAM) is reported

• in the present study. The real and imaginary parts of the contact stiffness k* are obtained from the contact-resonance spectra and by using these two quantities, the maps of local elastic stiffness and the damping factor are derived. The evaluation of the data is based on the mass distribution of the

• micrometer resolution. An improved UAFM technique was used for mapping the resonance frequency and the quality factor, Q, in carbon reinforced plastics composites [7]. In recent years, AFAM has been extensively used to determine elastic stiffness or damping properties in nano-crystalline nickel [2], PMMA

Manipulation of magnetic vortex parameters in disk-on-disk nanostructures with various geometry

• Maxim E. Stebliy,
• Alexander G. Kolesnikov,
• Alexey V. Ognev,
• Alexander S. Samardak and
• Ludmila A. Chebotkevich

Beilstein J. Nanotechnol. 2015, 6, 697–703, doi:10.3762/bjnano.6.70

• by using OOMMF software [9] with standard parameters for Py: Ms = 860 Gs, exchange stiffness A = 1.38 · 106 erg/cm, damping factor α = 0.05 [11]. The magnetic anisotropy was chosen zero in order not to insert an asymmetry of magnetic properties into the system. Dimension of the simulated disk-on-disk

Mandibular gnathobases of marine planktonic copepods – feeding tools with complex micro- and nanoscale composite architectures

• Jan Michels and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2015, 6, 674–685, doi:10.3762/bjnano.6.68

• silica very likely increases the hardness and stiffness of the gnathobase teeth and therefore has a similar effect as zinc and manganese have in insect mandibles. Mandibular gnathobases, diatom frustules and the evolutionary arms race In addition to the presence of mechanically stable silica-containing

Chains of carbon atoms: A vision or a new nanomaterial?

• Florian Banhart

Beilstein J. Nanotechnol. 2015, 6, 559–569, doi:10.3762/bjnano.6.58

• . Carbon chains could thus be considered as the stiffest known material. This is supported by the specific stiffness, which for carbyne is predicted to be 109 Nm/kg [19], clearly larger than for graphene (4.5 × 108 Nm/kg [56]) or diamond (3.5 × 108 Nm/kg [57]). The ultimate tensile strength corresponds to

• an ultimate strain of the order of 15% (graphene can be strained up to 20%). Liu et al. have also calculated a bending stiffness K= 3.56 eV·Å. This can be related to a persistence length lp = K/kBT = 14 nm (corresponding to a chain of 110 atoms) at T = 300 K which is comparable to many polymers

Raman spectroscopy as a tool to investigate the structure and electronic properties of carbon-atom wires

• Alberto Milani,
• Matteo Tommasini,
• Valeria Russo,
• Andrea Li Bassi,
• Andrea Lucotti,
• Franco Cataldo and
• Carlo S. Casari

Beilstein J. Nanotechnol. 2015, 6, 480–491, doi:10.3762/bjnano.6.49

• to cumulenes, it has to be observed by Liu et al. that finite cumulenes have a well-defined torsional stiffness. Therefore, the relative twisting vibrations of the CH2 end groups should be considered as potential Raman signals useful for the characterization of these systems, given that their

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

• direct drive, approximately 1 m of piezo ceramic per axis would be required. Such large piezo stacks, however, are neither commercially available nor mechanically stable enough for such a large-area scan stage. However, this design has a reduced mechanical stiffness and resonance frequency. The reduced

• x–y piezo stage and a dedicated z-piezo for a short response time. Additionally, the x–y stage must only move in the x–y plane without any cross-talk to the z-axis. This is reached by flexure joints. However, as the stiffness of a lever amplified system is reduced quite significantly, the initial

• stiffness of the flexure stage has to be quite high. A custom-built scanning stage fulfilling those requirements was therefore developed specifically for this application. Because of the stiff flexure joints, each axis of the stage is equipped with two piezos in parallel movement to increase their pushing