A robust AFM-based method for locally measuring the elasticity of samples

• Alexandre Bubendorf,
• Stefan Walheim,
• Thomas Schimmel and
• Ernst Meyer

Beilstein J. Nanotechnol. 2018, 9, 1–10, doi:10.3762/bjnano.9.1

• dividing the cantilever spring constant by the cantilever optical sensitivity Sz. The optical sensitivity of value 229 nm·V−1 was determined by measuring a vertical deflection–distance curve on an n-type silicon(111) sample of electrical resistivity = 10 Ω·m and by taking the inverse of the slope. The two

• . Analysis of the force–displacement curve evidences the same relations with, however, a linear relation in the nonlinear domain of the frequency shift–displacement curves. This is explained by the low spring constant of the cantilever in comparison to the normal sample stiffness, beginning at a certain Z

• -displacement value. A good model of the cantilever in contact with the sample surface is two springs in series, k1 and ksample,norm, representing the spring constant of the cantilever and the normal sample stiffness (of constant value in the elastic phase), respectively (Figure 4a). As shown in Figure 4b, the

Material discrimination and mixture ratio estimation in nanocomposites via harmonic atomic force microscopy

• Weijie Zhang,
• Yuhang Chen,
• Xicheng Xia and
• Jiaru Chu

Beilstein J. Nanotechnol. 2017, 8, 2771–2780, doi:10.3762/bjnano.8.276

• effect of amplitude set-point in harmonic AFM imaging remains unclear. In experiments, the sample was a PS/LDPE blend with a nominal elastic moduli of EPS ≈ 2 GPa and ELDPE ≈ 100 MPa. The calibrated cantilever free amplitude and spring constant were 167 nm and 0.32 N/m, respectively. The first two free

• error or environmental fluctuation during the resonance spectrum sweeping. For the experiments, ContAl-G cantilevers (BudgetSensors, Innovative Solutions Bulgaria Ltd., Bulgaria) were used. Prior to the measurements, the spring constant of the cantilevers was determined (typically 0.24 N/m) by using the

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

• left on the top of the SiO2 sphere (see the insert in Figure 7 below). For the adhesion measurements a constant ramp rate of 1.5 μm/s was applied (adhesion measurement with ramp rates between 0.2 and 8 μm/s showed similar results). The spring constant of the cantilever was determined to 7.74 N/m with

Patterning of supported gold monolayers via chemical lift-off lithography

• Liane S. Slaughter,
• Kevin M. Cheung,
• Sami Kaappa,
• Huan H. Cao,
• Qing Yang,
• Thomas D. Young,
• Andrew C. Serino,
• Sami Malola,
• Jana M. Olson,
• Stephan Link,
• Hannu Häkkinen,
• Anne M. Andrews and
• Paul S. Weiss

Beilstein J. Nanotechnol. 2017, 8, 2648–2661, doi:10.3762/bjnano.8.265

• –alkanethiolate monolayers. The AFM images of the PDMS stamps (flat and patterned) were measured using the peak force quantitative nanomechanical property mapping mode. ScanAsyst-Air cantilevers (Bruker, spring constant = 0.4 ± 0.1 N/m) were calibrated with a clean piece of silicon before each measurement. A peak

Tailoring the nanoscale morphology of HKUST-1 thin films via codeposition and seeded growth

• Landon J. Brower,
• Lauren K. Gentry,
• Amanda L. Napier and
• Mary E. Anderson

Beilstein J. Nanotechnol. 2017, 8, 2307–2314, doi:10.3762/bjnano.8.230

• × 500 nm and used a Dimension Icon atomic force microscope (Bruker, Santa Barbara, CA, USA), which was operated in peak force tapping mode. Etched silicon tips, SCANASYST-AIR (Bruker, Santa Barbara, CA, USA), with a spring constant range of 0.2–0.8 N/m and a resonant frequency range of 45–95 kHz were

Magnetic properties of optimized cobalt nanospheres grown by focused electron beam induced deposition (FEBID) on cantilever tips

• Soraya Sangiao,
• César Magén,
• Darius Mofakhami,
• Grégoire de Loubens and
• José María De Teresa

Beilstein J. Nanotechnol. 2017, 8, 2106–2115, doi:10.3762/bjnano.8.210

• cylindrical magnetic microwire [11] (see inset of Figure 6a and the Experimental section for details on the setup). Due to the low stiffness (spring constant k = 6 mN/m) and high quality factor (2000 < Q < 4000 under vacuum) of the cantilever, its frequency accurately probes the magnetic force produced by the

• nanosphere [11]. From the maximal relative variation of the cantilever frequency (1.2% in Figure 6a) and knowing the cantilever spring constant and the second spatial derivative of the magnetic field ((1.5 ± 0.3) × 109 T/m2) in which the measurements are operated, one can estimate the magnetic moment of the

• cobalt particle is: where k is the cantilever spring constant, Bz the vertical component of the magnetic field from the cylinder, and z0 is the equilibrium position of the particle in the field gradient. STEM-EELS chemical mapping and quantification was carried out at an acceleration voltage of 300 kV in

Application of visible-light photosensitization to form alkyl-radical-derived thin films on gold

• Rashanique D. Quarels,
• Xianglin Zhai,
• Neepa Kuruppu,
• Jenny K. Hedlund,
• Ashley A. Ellsworth,
• Amy V. Walker,
• Jayne C. Garno and
• Justin R. Ragains

Beilstein J. Nanotechnol. 2017, 8, 1863–1877, doi:10.3762/bjnano.8.187

• spring constant of 40 N/m (Budget Sensors, Innovative Solutions Bulgaria Ltd.) were used to acquire topography and corresponding phase images with tapping mode. Nanoshaving experiments were conducted using a liquid cell containing ethanolic solution. Contact mode in liquid was used for nanoshaving using

• tips with an average spring constant of 0.6 N/m (Bruker Instruments, Camarillo, CA, USA). Digital images were processed with Gwyddion (v 2.30) software [53]. Grazing angle infrared reflectance absorbance spectroscopy (IRRAS): IRRAS spectra were recorded using a Bruker Tensor 27 instrument equipped with

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

• a nominal resonance frequency of 325 kHz. Submerged samples were measured using a commercial liquid cell (Bruker) filled with demineralized water. Images were taken in contact mode with Pt-coated CSC 37 cantilevers (MikroMasch) with force constants between 0.3 N/m and 0.8 N/m. The spring constant of

High-speed dynamic-mode atomic force microscopy imaging of polymers: an adaptive multiloop-mode approach

• Juan Ren and
• Qingze Zou

Beilstein J. Nanotechnol. 2017, 8, 1563–1570, doi:10.3762/bjnano.8.158

• tapping amplitude is close to the free vibration amplitude). Finally, the mean tip–sample interaction force (per tapping period T), , can be quantified as [1][10][11], where kc and m are the spring constant and the mass of the cantilever, respectively, Q is the quality factor of the cantilever, dtot(t

• , and a Celgard sample) were imaged using the AMLM approach on an AFM system (Dimension Icon, Bruker Nano Inc.) along with a tapping-mode cantilever (MPP-21120-10, Bruker Inc., nominal spring constant: 3 N/m, resonant frequency: 75 kHz). Both the conventional TM imaging and AMLM imaging were designed

Scaling law to determine peak forces in tapping-mode AFM experiments on finite elastic soft matter systems

• Horacio V. Guzman

Beilstein J. Nanotechnol. 2017, 8, 968–974, doi:10.3762/bjnano.8.98

• mass of the fluid [39], and ω0, Q, k and Fts are the angular resonant frequency, quality factor, spring constant and tip–sample interaction forces, respectively. The latter has been modelled according to the Tatara contact mechanics [35][36][37] which is given by with the constitutive material

• numerical simulations for Tatara’s contact mechanics model. The comparisons cover Young’s moduli in the range of 30 to 300 MPa, and two fixed set-point amplitudes, namely 0.9A0 and 0.7A0. In addition, the spring constant is fixed to k = 0.1 N/m and the free oscillation amplitudes are 1 nm (Figure 1b) and 4

• surface [28][29], in particular when the quantitative imaging process involves only elastic mechanical modeling. The dependence of the peak forces with the microcantilever spring constant follows a power-law dependence that monotonically increases by increasing the value of k as shown in previous

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

• , 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

Measuring adhesion on rough surfaces using atomic force microscopy with a liquid probe

• Juan V. Escobar,
• Cristina Garza and
• Rolando Castillo

Beilstein J. Nanotechnol. 2017, 8, 813–825, doi:10.3762/bjnano.8.84

• cantilever is obtained by multiplying its deflection by the spring constant of the cantilever. In the standard AFM technique, the tip apex typically has a radius of 5–50 nm, whereas the radii of colloidal probes are in the range of 1–100 μm, resulting in much higher adhesion forces. Mercury: Double distilled

• modeled as an ideal spring with a spring constant kc. The thermal noise of the mean square displacement, , allows us to determine the constant using [31][32]. With a spectral analyzer (Stanford Research Systems, 760 FFT, USA), we identify the peak corresponding to the first fundamental resonant mode of

• contact part of the force curve; the inverse slope is the deflection calibration factor, s. We obtain a raw spring constant kraw using the calibration factor s. This kraw has to be corrected, because when the optical beam deflection technique is used, the inclination at the end of the cantilever is

Optimizing qPlus sensor assemblies for simultaneous scanning tunneling and noncontact atomic force microscopy operation based on finite element method analysis

• Omur E. Dagdeviren and
• Udo D. Schwarz

Beilstein J. Nanotechnol. 2017, 8, 657–666, doi:10.3762/bjnano.8.70

• enable the simultaneous collection of local forces and tunneling currents, the exact realization of this wire connection has a major effect on sensor properties such as spring constant, quality factor, resonance frequency, and its deviation from an ideal vertical oscillation. Keywords: force sensor

• considerable experience. As a result, personal skills have often a major impact on the sensing characteristics of the completed device. To help minimizing the related problems, this work investigates the influence of different tip mounting options on the spring constant, Q-factor, resonance frequency, and

• , we find that spring constant, Q-factor, and eigenfrequency are attenuated for tip-holder setups that feature an increasing degree of asymmetry. This effect is, however, modest if compared to the effect of an asymmetric wire connection, as they are frequently added to collect a tunneling current for

Analysis and modification of defective surface aggregates on PCDTBT:PCBM solar cell blends using combined Kelvin probe, conductive and bimodal atomic force microscopy

• Hanaul Noh,
• Alfredo J. Diaz and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2017, 8, 579–589, doi:10.3762/bjnano.8.62

• the spring constant of the third eigenmode is ca. 308 times the spring constant of the first mode [18], the indentation depth and peak force of the bimodal treatment are mainly controlled by the higher eigenmode [36]. The small free amplitude of the third eigenmode (ca. 3 nm, Figure S7, Supporting

• correlating the potential and currents in Figure 4 (PPP-CONTSCPt, NanoSensors) has a smaller spring constant (k = 0.5–1.0 N/m) and thus also a weaker torsional stiffness. In general, it is not possible to sustain a repulsive tapping-mode imaging process for the softer cantilever on polymer samples. On the

Advances in the fabrication of graphene transistors on flexible substrates

• Gabriele Fisichella,
• Stella Lo Verso,
• Silvestra Di Marco,
• Vincenzo Vinciguerra,
• Emanuela Schilirò,
• Salvatore Di Franco,
• Raffaella Lo Nigro,
• Fabrizio Roccaforte,
• Amaia Zurutuza,
• Alba Centeno,
• Sebastiano Ravesi and
• Filippo Giannazzo

Beilstein J. Nanotechnol. 2017, 8, 467–474, doi:10.3762/bjnano.8.50

• , from consumer devices [3] to biomedical in vivo applications [4][5]. Among all the two-dimensional materials, graphene is one of the most appealing to be used as a flexible, conductive membrane, given its Young’s modulus on the order of TPa and large spring constant (1–5 N/m) [6]. Besides its high

Impact of surface wettability on S-layer recrystallization: a real-time characterization by QCM-D

• Jagoba Iturri,
• Ana C. Vianna,
• Alberto Moreno-Cencerrado,
• Dietmar Pum,
• Uwe B. Sleytr and
• José Luis Toca-Herrera

Beilstein J. Nanotechnol. 2017, 8, 91–98, doi:10.3762/bjnano.8.10

• (AFM): Recrystallized proteins were visualized using a multimode-AFM (Bruker AXS, Santa Barbara, USA) controlled by a Nanoscope V equipped with a J-scanner. Silicon-nitride probes (DNP-S, Bruker, USA) with a spring constant of about 0.3 N/m were used in the experiments, which were calibrated on SiO2

Surface roughness rather than surface chemistry essentially affects insect adhesion

• Matt W. England,
• Tomoya Sato,
• Makoto Yagihashi,
• Atsushi Hozumi,
• Stanislav N. Gorb and
• Elena V. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1471–1479, doi:10.3762/bjnano.7.139

• (AFM, XE-100, Park Systems), with a Si probe (910M-NCHR; spring constant of 42 N/m and response frequency of 330 kHz, Park Systems). The surface roughness (root-mean square roughness, Rrms) were estimated using two separate techniques due to the huge disparity in the size of surface textures on smooth

Customized MFM probes with high lateral resolution

• Óscar Iglesias-Freire,
• Miriam Jaafar,
• Eider Berganza and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2016, 7, 1068–1074, doi:10.3762/bjnano.7.100

• ); AFM probes; high-resolution microscopy; magnetic force microscopy (MFM); magnetic materials; Introduction Conventional MFM probes consist of pyramidal Si or SiN tips with a ferromagnetic thin film coating (generally a CoCr alloy) mounted on a cantilever with resonance frequency and spring constant of

• also select the cantilever properties for each experiment, such as the spring constant, resonance frequency or the position of the tip on the lever. We have found neither in the literature nor in the market any MFM probe with cantilever characteristics far from the range of the aforementioned. Making

• present a comparison of the MFM images obtained with four different sorts of probes: three kinds of commercial tips [26][27] and the custom-made probes described here, all of them using cantilevers of similar properties (namely resonance frequency and spring constant of around 75 kHz and 3 N/m

Signal enhancement in cantilever magnetometry based on a co-resonantly coupled sensor

• Julia Körner,
• Christopher F. Reiche,
• Thomas Gemming,
• Bernd Büchner,
• Gerald Gerlach and
• Thomas Mühl

Beilstein J. Nanotechnol. 2016, 7, 1033–1043, doi:10.3762/bjnano.7.96

• usually achieved through geometric changes, making the cantilever itself very small and thin. An oscillating cantilever beam can be represented by a harmonic oscillator model for each flexural eigenmode of the beam [5]. Considering an external force gradient as an additional spring constant Δk, the

• eigenfrequency of the cantilever as a harmonic oscillator is given by: with the spring constant k and effective mass meff of the cantilever. Please note that the eigenfrequency f0 and the resonance frequency of a harmonic oscillator should in principle be distinguished. They are connected by the relation

• frequency of the cantilever. The magnetic interaction between sample and external magnetic field acts as the additional spring constant Δk, altering the resonance frequency of the cantilever. The frequency shift Δf induced by these interactions can be derived from Equation 1 as: In the case of cantilever

Understanding interferometry for micro-cantilever displacement detection

• Alexander von Schmidsfeld,
• Tobias Nörenberg,
• Matthias Temmen and
• Michael Reichling

Beilstein J. Nanotechnol. 2016, 7, 841–851, doi:10.3762/bjnano.7.76

• deflection. To further optimize the signal, we introduce a method for positioning the fiber precisely in the optimal lateral position and examine the importance of this positioning. Finally, we investigate the impact of the interferometric signal on the effective modal spring constant and the modal Q-factor

• parameters are compiled in Table 1. The fringe-dependent effective cantilever stiffness k± is determined by a method relating the intrinsic stiffness to the optical spring constant as described in detail in [8]. In a series of measurements, we determine the noise floor by measuring the displacement noise

In situ observation of deformation processes in nanocrystalline face-centered cubic metals

• Aaron Kobler,
• Christian Brandl,
• Horst Hahn and
• Christian Kübel

Beilstein J. Nanotechnol. 2016, 7, 572–580, doi:10.3762/bjnano.7.50

• were acquired as reference for determining the strain (all strain values in this paper are giving relative to the initial dog bone length) and the spring constant of the PTP device was measured with the film ruptured to subtract the PTP device related forces from the measured stress–strain curve

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

• sensing elements. They enable nanomechanical measurements, are essential for the characterization of nanomaterials, and form an integral part of many nanoscale devices. Despite the fact that numerous methods described in the literature can be applied to determine the static flexural spring constant of

• 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

• employed as freestanding sensors [8][9][10][11][12][13]. In many applications where a cantilever-type sensor is involved, the calibration of the sensor stiffness (spring constant, k) is a prerequisite for obtaining quantitative data. Several methods describing how the static flexural spring constant can be

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

• improving the photothermal excitation efficiency by coating cantilever backside surface near its fixed end with colloidal graphite as a photothermal conversion (PTC) layer. The excitation efficiency for a standard cantilever of PPP-NCHAuD with a spring constant of ≈40 N/m and a relatively stiff cantilever

• of AC55 with a spring constant of ≈140 N/m were improved by 6.1 times and 2.5 times, respectively, by coating with a PTC layer. We experimentally demonstrate high stability of the PTC layer in liquid by AFM imaging of a mica surface with atomic resolution in phosphate buffer saline solution for more

• low excitation efficiency, the cantilever oscillation with a desired vibrational amplitude is often difficult to achieve with a moderate laser power (on the order of milliwatts). In particular, a cantilever with a large spring constant requires a large laser power modulation. To overcome this

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

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

• , mechanical oscillation of the NW can be easily monitored directly in SEM images. For static bending experiments, soft silicon nitride AFM cantilevers with spring constants of 0.002–0.02 N/m (Olympus BL-RC-150VB) were used. The spring constant of the cantilever was calibrated in AFM (Asylum Research MFP-3D

• cantilever displacement, ∆x, and the cantilever spring constant, k, as F = k·Δx. For static bending the load was applied at different vertical positions along the vertical axis of the NW. The measurements showed that the examined NWs exhibited uniform elastic properties along their length. The inset in

• solving Eresonance(L) = Ebending(L) for L, the calculated value was compared with experimentally obtained results, giving a mean relative error of 31%. Measurement errors due to cantilever spring constant calibration were taken into account. Figure 3 suggests that a size effect exists for the investigated