Mechanical and thermodynamic properties of Aβ₄₂, Aβ₄₀, and α-synuclein fibrils: a coarse-grained method to complement experimental studies

• Adolfo B. Poma,
• Horacio V. Guzman,
• Mai Suan Li and
• Panagiotis E. Theodorakis

Beilstein J. Nanotechnol. 2019, 10, 500–513, doi:10.3762/bjnano.10.51

• considered. The former refers to the way that the indentation load is measured by the deflection of the AFM cantilever. The latter is an assumption of the semi-infinite half-space approximation. Once the AFM data is obtained, it requires interpretation by using a contact mechanics theory. There is no

In situ characterization of nanoscale contaminations adsorbed in air using atomic force microscopy

• Jesús S. Lacasa,
• Lisa Almonte and
• Jaime Colchero

Beilstein J. Nanotechnol. 2018, 9, 2925–2935, doi:10.3762/bjnano.9.271

• experimentally very challenging, due to very large tip–sample interaction. In spite of these problems, we have been able to image an AFM cantilever and its tip. Figure 1 shows the flat cantilever part (Figure 1a), an optical image of the whole cantilever (Figure 1b) and the tip (Figure 1c). In the optical image

• silicon surfaces this second step forms a thin passivating layer. Finally, the surface of the samples is dried by blowing with N2 for about 1 min. AFM images (a, c) and optical image (b) of the tip side of an Olympus OMCL-HA-100 AFM cantilever. Image sizes: 4 × 4 μm2 and 80 nm height scale for the AFM

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

• contact angle of a single sandfish scale is about 100° (droplet volume 1 µL). SEM images of some probes used in this study. (a) Sharp tip of a conventional AFM cantilever made from silicon. (b) Sand particle glued to the end of a tipless cantilever (“sand probe”). The inset is a side view. (c) Glass

Nanoscale characterization of the temporary adhesive of the sea urchin Paracentrotus lividus

• Ana S. Viana and
• Romana Santos

Beilstein J. Nanotechnol. 2018, 9, 2277–2286, doi:10.3762/bjnano.9.212

• . lividus could be easily collected on mica (Figure 1a,b) and subsequently located using an optical microscope to be precisely positioned beneath the AFM cantilever (Figure 1c). The diameter of the adhesive footprints roughly corresponded to the size of the tube feet discs (±1 mm). The thickness of the

• ×) illustrating the positioning of the moist adhesive footprint (indicated by the arrow) beneath the triangular-shaped AFM cantilever. Peak force tapping AFM (PFT-AFM) image (a) and height profile (b) of Paracentrotus lividus moist footprints at the edge of the adhesive material. Image obtained with a ScanAsyst

Multimodal noncontact atomic force microscopy and Kelvin probe force microscopy investigations of organolead tribromide perovskite single crystals

• Yann Almadori,
• David Moerman,
• Jaume Llacer Martinez,
• Philippe Leclère and
• Benjamin Grévin

Beilstein J. Nanotechnol. 2018, 9, 1695–1704, doi:10.3762/bjnano.9.161

• by AFM under illumination originate mainly from the intrinsic material deformation [16]. More precisely, thanks to a rigorous experimental protocol, they demonstrated that it is possible to discriminate between the intrinsic material deformation and the extrinsic effects related to the AFM cantilever

Automated image segmentation-assisted flattening of atomic force microscopy images

• Yuliang Wang,
• Tongda Lu,
• Xiaolai Li and
• Huimin Wang

Beilstein J. Nanotechnol. 2018, 9, 975–985, doi:10.3762/bjnano.9.91

• while the z-scanner adjusts the vertical position of the AFM cantilever substrate to maintain constant interaction between the cantilever tip and sample surface. Together, the two stages provide a three-dimensional (3D) topographical reconstruction of the sample surface. However, the obtained images are

Scanning speed phenomenon in contact-resonance atomic force microscopy

• Christopher C. Glover,
• Jason P. Killgore and
• Ryan C. Tung

Beilstein J. Nanotechnol. 2018, 9, 945–952, doi:10.3762/bjnano.9.87

• dependence has also been observed in contact-resonance spectroscopy experiments. Killgore et al. [3] reported a scan-speed dependence of the measured CR frequencies of an AFM cantilever. Above a critical speed, CR frequency and quality factor decreased with increasing scan speed. However, in that work, the

• are the known non-dimensional wavenumbers for a freely vibrating cantilevered beam ( = 1.8751, = 4.6941, = 7.8548), are the measured free frequencies of the AFM cantilever, and are the measured in-contact frequencies of the AFM cantilever. The tip parameter is calculated using the lowest-speed

• surface moves at a uniform speed U = VS. The measured in-contact resonance frequency of the second mode of an AFM cantilever as a function of the dynamic scan speed on a mica surface at 100 nN force set-point, 41% relative humidity, and a scan angle of 90°. The measured in-contact frequency is clearly

Dry adhesives from carbon nanofibers grown in an open ethanol flame

• Christian Lutz,
• Julia Syurik,
• C. N. Shyam Kumar,
• Christian Kübel,
• Michael Bruns and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2017, 8, 2719–2728, doi:10.3762/bjnano.8.271

• the AFM cantilever completely from the surface. This quantity is indicated as the lowest (negative) force in the diagrams. The adhesion energy is defined as the area between retrace and zero line. It corresponds to the energy necessary to free the sphere from the surface. The force–distance diagrams

• the preload force. The symbols correspond to the oriented CNFs (blue squares), the randomly oriented CNFs (red triangles) and the flat reference (green circles). The dashed lines represent linear fits. The insert in panel (b) shows a SEM image of the AFM cantilever with the glued SiO2 sphere to

Material property analytical relations for the case of an AFM probe tapping a viscoelastic surface containing multiple characteristic times

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

Beilstein J. Nanotechnol. 2017, 8, 2230–2244, doi:10.3762/bjnano.8.223

• tip trajectory for an AFM cantilever interacting with a viscoelastic surface in tapping-mode AFM (simulation details are provided in the figure caption). The instantaneous tip–sample distance, taking as reference the undeformed sample surface, is approximately given by: where Zeq refers to the average

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

• infinitely rigid AFM cantilever, wait until a steady-sliding regime is established, and discard the initial part affected by transients. For the remaining part of the simulation, we record the total force experienced by the slider as a function of time. This force has fluctuations as a result of collisions

• . Recently published research also identified relations between dissipation peaks and the properties of a dispersion relation in a different model [63]. The present model can also be investigated in a spring-pulling scheme analogous to the Prandtl–Tomlinson model, to simulate the finite stiffness of an AFM

• cantilever. In that scheme a stick-slip to smooth-sliding transition can also be investigated, especially at low speed (see Appendix “The static friction force”), allowing one to study in detail the nonlinear phenomena and mechanisms of phonon excitations that arise at slip times. The stick-slip regime and

Air–water interface of submerged superhydrophobic surfaces imaged by atomic force microscopy

• Markus Moosmann,
• Thomas Schimmel,
• Wilhelm Barthlott and
• Matthias Mail

Beilstein J. Nanotechnol. 2017, 8, 1671–1679, doi:10.3762/bjnano.8.167

• force–distance curve in the negative height regime is the cumulative force constant k of the cantilever and the air–water interface according to Hooke’s law: F = k × height. As we calibrated the AFM cantilever in advance, we were able to determine the force constant of the interface in this case to be

Functional dependence of resonant harmonics on nanomechanical parameters in dynamic mode atomic force microscopy

• Federico Gramazio,
• Matteo Lorenzoni,
• Francesc Pérez-Murano,
• Enrique Rull Trinidad,
• Urs Staufer and
• Jordi Fraxedas

Beilstein J. Nanotechnol. 2017, 8, 883–891, doi:10.3762/bjnano.8.90

• below 20 GPa). Keywords: atomic force microscopy; metrology; multifrequency; nanomechanics; Introduction When an AFM cantilever oscillating freely and harmonically at a given frequency f and amplitude A1 approaches a solid surface, the oscillation becomes anharmonic due to the non-linear interaction

• topographic, phase and amplitude images. (a) Amplitude of the fundamental mode, (b) phase of the fundamental mode and (c) amplitude of the 6th harmonic. Experiments have been performed with a nominally kc ≈ 44 N/m rectangular AFM cantilever with f0 = 293 kHz on silicon surfaces and A1 = 34 nm. (color online

• ) Evolution of the mean value of the amplitude of the 6th harmonic extracted from the amplitude image simultaneously acquired with the topography and phase images. Experiments have been performed with a nominally 44 N/m rectangular AFM cantilever with resonance frequency 350 kHz on silicon surfaces under

Relationships between chemical structure, mechanical properties and materials processing in nanopatterned organosilicate fins

• Gheorghe Stan,
• Richard S. Gates,
• Qichi Hu,
• Kevin Kjoller,
• Craig Prater,
• Kanwal Jit Singh,
• Ebony Mays and
• Sean W. King

Beilstein J. Nanotechnol. 2017, 8, 863–871, doi:10.3762/bjnano.8.88

• probe tip in contact with the sample. The repetition rate of the IR laser is tuned to a contact resonance of the AFM cantilever to maximize the oscillation amplitude of the cantilever. By sweeping the IR laser over the wavelengths of interest and monitoring changes in the amplitude of the AFM probe tip

• angle of 60° from the front of the AFM probe, and swept continuously over the wavenumber range of interest [39]. The AFM-IR spectra were collected by tuning the repetition rate of the QCL to match a contact resonance of the AFM cantilever, typically the second flexural mode of the cantilever at ca. 180

• , respectively. The spring constant of the cantilever was determined to be 7.35 ± 0.05 N/m by a laser Doppler vibrometer. A lock-in amplifier with an internal signal generator (Signal Recovery AMETEK, Oak Ridge, TN) was used to vibrate the AFM cantilever and to detect the AFM photodiode signal (MultiMode 8

Multimodal cantilevers with novel piezoelectric layer topology for sensitivity enhancement

• Steven Ian Moore,
• Michael G. Ruppert and
• Yuen Kuan Yong

Beilstein J. Nanotechnol. 2017, 8, 358–371, doi:10.3762/bjnano.8.38

• AFM cantilever instrumentation requires a piezoelectric stack actuator at the base of the cantilever for excitation [3] inevitably adding additional resonances as is visible from the so called forest of peaks [22]. These additional frequency components make cantilever resonance tuning almost

• topology of the piezoelectric layer on an AFM cantilever to maximize the actuator gain and sensor sensitivity with respect to the cantilever’s higher order modes. Compared to previous work on modal sensor/actuators [42][43][44][45][46], the design specification of the presented work is to enhance the

• fashion for the optimized output voltages Vo1–Vo4. In comparison to using a single piezoelectric transducer with a sum of sinusoids excitation, the multi-electrode design provides increased amplitudes at the expense of more complex instrumentation. Conclusion An AFM cantilever with a piezoelectric layer

Coupled molecular and cantilever dynamics model for frequency-modulated atomic force microscopy

• Michael Klocke and
• Dietrich E. Wolf

Beilstein J. Nanotechnol. 2016, 7, 708–720, doi:10.3762/bjnano.7.63

• include the full extent of an AFM cantilever nor that of a substrate within an atomistic simulation. As in previous studies [1][6][20][21][22] the simulation must be restricted to a small volume around the crucial region of interaction between the tip and the substrate. This is sketched in Figure 1. The

• Michael Klocke Dietrich E. Wolf Department of Physics, University of Duisburg-Essen and CeNIDE, D-47048 Duisburg, Germany 10.3762/bjnano.7.63 Abstract A molecular dynamics model is presented, which adds harmonic potentials to the atomic interactions to mimic the elastic properties of an AFM

• cantilever. It gives new insight into the correlation between the experimentally monitored frequency shift and cantilever damping due to the interaction between tip atoms and scanned surface. Applying the model to ionic crystals with rock salt structure two damping mechanisms are investigated, which occur

Cantilever bending based on humidity-actuated mesoporous silica/silicon bilayers

• Christian Ganser,
• Gerhard Fritz-Popovski,
• Roland Morak,
• Parvin Sharifi,
• Benedetta Marmiroli,
• Barbara Sartori,
• Heinz Amenitsch,
• Thomas Griesser,
• Christian Teichert and
• Oskar Paris

Beilstein J. Nanotechnol. 2016, 7, 637–644, doi:10.3762/bjnano.7.56

• layer is related to the cantilever deflection using simple bilayer bending theory. We also develop a simple quantitative model for cantilever deflection which only requires cantilever geometry and nanostructural parameters of the porous layer as input parameters. Keywords: AFM cantilever; bilayer

• -controlled actuation of a microcantilever based on a mesoporous silica/nonporous silicon bilayer using a commercial AFM cantilever as a substrate. The simplicity and versatility of the approach is promising for applications in several fields where similar systems based on swellable polymers are not

• two streams, the relative humidity can be continuously controlled. The AFM cantilever was mounted inside a closed commercial fluid cell with a volume of about 10 mL. In addition, a Sensirion SHT21 sensor, which records the relative humidity as well as the temperature, is mounted in the fluid cell

Contact-free experimental determination of the static flexural spring constant of cantilever sensors using a microfluidic force tool

• John D. Parkin and
• Georg Hähner

Beilstein J. Nanotechnol. 2016, 7, 492–500, doi:10.3762/bjnano.7.43

• and demonstrate that this, in combination with a thermal noise spectrum, can provide the static flexural spring constant for cantilever sensors of different geometric shapes over a wide range of spring constant values (≈0.8–160 N/m). Keywords: AFM; cantilever sensors; microfluidic force tool; spring

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

• at the respective mode. System identification The AFM cantilever used in this work is a piezoelectric self-actuated silicon microcantilever described in section Modeling. Compared to a standard base excited cantilever whose frequency response is shown in Figure 6a, the piezoelectric cantilever has

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

• under the surface. Instead, it consists of ‘small’ SLS models distributed evenly in the x- and y-directions of the surface, each of which can relax independently in the z-direction upon interaction with the tip, which is modeled here as a hard sphere attached to the AFM cantilever. As depicted in Figure

• tip geometries. These limitations can be partially mitigated by adding additional viscous and elastic elements between adjacent surface locations, although these would come with an added computational cost. Experimental Cantilever dynamics modeling The dynamics of the AFM cantilever were modeled as in

Kelvin probe force microscopy for local characterisation of active nanoelectronic devices

• Tino Wagner,
• Hannes Beyer,
• Patrick Reissner,
• Philipp Mensch,
• Heike Riel,
• Bernd Gotsmann and
• Andreas Stemmer

Beilstein J. Nanotechnol. 2015, 6, 2193–2206, doi:10.3762/bjnano.6.225

• the following. Figure 1 shows a model calculation using typical cantilever and interaction parameters, summarising how much tip apex, cone, and beam of an AFM cantilever probe contribute to the measured KFM signal in AM and FM operation. Shown are the percentages of the contributions and corresponding

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

• be tackled [5][6][7][8]. Nanoindentation experiments requiring very low force values and high resolution usually use a standard AFM system. With this setup, an AFM cantilever probe is used for indenting the material and the probe displacement is monitored by laser beam bounce technology also known as

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

• nanometer-scale plastic deformation of Pt(111) and the Pt57.5Cu14.7Ni5.3P22.5 metallic glass was investigated in ultra-high vacuum by AFM indentation and subsequent nc-AFM imaging using a VT-AFM manufactured by Omicron Nanotechnology GmbH, Germany. In non-contact AFM an AFM cantilever is driven to oscillate

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

• of the cantilever arrays for micromechanical sensing. Keywords: anodic aluminium oxide; atomic force microscopy (AFM); cantilever arrays; humidity; mechanical sensor; porous alumina; Introduction The last two decades have seen a surge in resonant micro- and nanomechanical engineering raised by the

Probing fibronectin–antibody interactions using AFM force spectroscopy and lateral force microscopy

• Andrzej J. Kulik,
• Małgorzata Lekka,
• Kyumin Lee,
• Grazyna Pyka-Fościak and
• Wieslaw Nowak

Beilstein J. Nanotechnol. 2015, 6, 1164–1175, doi:10.3762/bjnano.6.118

• between the two left and two right quadrants. For an AFM working in force spectroscopy mode (referred to here as AFM-FS), the interactions forces are determined from the analysis of force curves. A force curve represents the dependence between the deflection of the AFM cantilever in the direction

• , recently, Dendzik et al. proposed that the stretching of a reference single molecule (e.g., dextran) could be used to determine the normal and lateral AFM cantilever calibration [15]. Although this new method presents a clear improvement over previous attempts to obtain a reliable calibration for lateral

• similarity in the unbinding process, independent of how the rupture force was applied by the AFM cantilever movement: either normal (AFM-FS) or lateral (LFM). The relation between the measured unbinding force and the loading rate applied overlapped for the AFM-FS and LFM methods. These findings demonstrate

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

• resulting resonance frequencies of the cantilevers vary from 170 kHz to 270 kHz and their spring constants from 40 N/m to 440 N/m. Measurements with TMR sensors As shown in Figure 5 the detection principle of a magnetostrictive TMR sensor can be easily applied to measure the bending of an AFM cantilever. In