Carbon nanotube-cellulose ink for rapid solvent identification

• Tiago Amarante,
• Thiago H. R. Cunha,
• Claudio Laudares,
• Ana P. M. Barboza,
• Ana Carolina dos Santos,
• Cíntia L. Pereira,
• Vinicius Ornelas,
• Bernardo R. A. Neves,
• André S. Ferlauto and
• Rodrigo G. Lacerda

Beilstein J. Nanotechnol. 2023, 14, 535–543, doi:10.3762/bjnano.14.44

• length of 5 μm were produced at CTNano/UFMG [59][60][61]. Morphological analysis was carried out by scanning electron microscopy (SEM) in a Quanta 200 FEG, using secondary electrons between 2 and 10 kV. Atomic force microscopy (AFM) was carried out on a Bruker MultiMode8 SPM using the intermittent

• contact mode. AC160TS silicon cantilevers from Olympus with a typical spring constant of k ≈ 46 N/m, a nominal radius of curvature of r ≈ 7 nm, and a resonant frequency of ω0 ≈ 300 kHz were employed. Heat flow and weight changes of selected solvents were determined by thermogravimetric analysis (TGA

Liquid phase exfoliation of talc: effect of the medium on flake size and shape

• Samuel M. Sousa,
• Helane L. O. Morais,
• Joyce C. C. Santos,
• Ana Paula M. Barboza,
• Bernardo R. A. Neves,
• Elisângela S. Pinto and
• Mariana C. Prado

Beilstein J. Nanotechnol. 2023, 14, 68–78, doi:10.3762/bjnano.14.8

• be in contact with it for 30 to 60 s to ensure optimal coverage. Then the sample is rinsed again in DI water to remove loose flakes and residual surfactant. An in-depth discussion of this procedure can be found in [24]. AFM measurements were performed on a Park XE-70 microscope, in intermittent

• contact mode using commercial silicon probes (MikroMasch, HQ:NSC35/AlBs or HQ:NSC36/AlBs). For each sample, nine different 5 μm × 5 μm fields were chosen at random and scanned at 0.5 Hz with 500 pixels/line (lateral resolution of 10 nm/pixel). Image processing (line and plane corrections) and flake

Measurement of polarization effects in dual-phase ceria-based oxygen permeation membranes using Kelvin probe force microscopy

• Kerstin Neuhaus,
• Christina Schmidt,
• Liudmila Fischer,
• Wilhelm Albert Meulenberg,
• Ke Ran,
• Joachim Mayer and
• Stefan Baumann

Beilstein J. Nanotechnol. 2021, 12, 1380–1391, doi:10.3762/bjnano.12.102

• were performed in a single-pass experiment. For this kind of measurements, the surface potential and the sample topography are mapped in a single pass in intermittent contact mode with the cantilever vibrating at its resonance frequency (i.e., the cantilever is not in lift mode during this experiment

Open-loop amplitude-modulation Kelvin probe force microscopy operated in single-pass PeakForce tapping mode

• Gheorghe Stan and
• Pradeep Namboodiri

Beilstein J. Nanotechnol. 2021, 12, 1115–1126, doi:10.3762/bjnano.12.83

• with the CPD extraction. In this work, a new OL AM-KPFM method was used to acquire the full response of an AFM probe during a single-pass intermittent contact mode. The bias modulation was synchronized with the oscillations of the PeakForce Tapping (PFT) mode [56] and selectively applied only during

A new method for obtaining model-free viscoelastic material properties from atomic force microscopy experiments using discrete integral transform techniques

• Berkin Uluutku,
• Enrique A. López-Guerra and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2021, 12, 1063–1077, doi:10.3762/bjnano.12.79

• force–distance curve, where the cantilever position above the sample follows a ramp function. In the case of intermittent-contact methods (e.g., tapping-mode AFM), the cantilever tip oscillates nearly sinusoidally, but since tip–sample contact is intermittent, the sample does not experience purely

Application of contact-resonance AFM methods to polymer samples

• Sebastian Friedrich and
• Brunero Cappella

Beilstein J. Nanotechnol. 2020, 11, 1714–1727, doi:10.3762/bjnano.11.154

• curves in well-defined spatial intervals, can take several hours to complete. In order to overcome these drawbacks, dynamic scanning methods are a promising alternative to force–distance curves. For example, intermittent-contact (or tapping) mode AFM shows sensitivity to mechanical properties in the

On the frequency dependence of viscoelastic material characterization with intermittent-contact dynamic atomic force microscopy: avoiding mischaracterization across large frequency ranges

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

Beilstein J. Nanotechnol. 2020, 11, 1409–1418, doi:10.3762/bjnano.11.125

• characterization frequency regardless of the materials properties. In this paper we present a linear viscoelastic analysis of intermittent-contact, nearly resonant dynamic AFM characterization of such materials, considering the possibility of multiple characteristic times. We describe some of the intricacies

• material 1 has not yet peaked in the range of frequency shown in the graph – a similar plot over a wider frequency range is discussed in the Results and Discussion section). Although all of the above phenomena occur similarly within intermittent-contact dynamic AFM methods (such as tapping-mode AFM), the

• have a specific recommendation on what this procedure may look like, our results do suggest that the dimensionality and/or richness of the mechanical features we are seeking to characterize is appreciably greater than that of the available observables for traditional intermittent-contact modes

An atomic force microscope integrated with a helium ion microscope for correlative nanoscale characterization

• Santiago H. Andany,
• Gregor Hlawacek,
• Stefan Hummel,
• Charlène Brillard,
• Mustafa Kangül and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2020, 11, 1272–1279, doi:10.3762/bjnano.11.111

• down the sample using the z-piezo of the scanner, causing intermittent contact between the cantilever and the sample [25]. The maximum interaction force is computed and used as feedback by the controller, providing fine force control, reducing shear forces and thus preserving the tip and the sample [26

Current measurements in the intermittent-contact mode of atomic force microscopy using the Fourier method: a feasibility analysis

• Berkin Uluutku and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2020, 11, 453–465, doi:10.3762/bjnano.11.37

• surface properties, such as topography, viscoelasticity, electrical potential and conductivity. Some of these properties are measured using contact methods (static contact or intermittent contact), while others are measured using noncontact methods. Some properties can be measured using different

• discuss a possible approach to develop an intermittent-contact conductive AFM mode based on Fourier analysis, whereby the measured current response consists of higher harmonics of the cantilever oscillation frequency. Such an approach may enable the characterization of soft samples with less damage than

• contact-mode imaging. To explore its feasibility, we derive the analytical form of the tip–sample current that would be obtained for attractive (noncontact) and repulsive (intermittent-contact) dynamic AFM characterization, and compare it with results obtained from numerical simulations. Although

A review of demodulation techniques for multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2020, 11, 76–91, doi:10.3762/bjnano.11.8

• , which establishes the requirement for demodulation in AFM. In intermittent-contact constant-amplitude AFM [5], a constant cantilever oscillation amplitude is maintained by feeding back the demodulated fundamental amplitude of the deflection signal. The imaging of delicate biological samples [6][7][8] is

• particularly suited to intermittent-contact AFM [9] when tip–sample contact is gentle. Environmental damping has a large effect on the quality factor (Q) of the cantilever. Values can range from as low as Q ≈ 1 in liquid [10], up to Q ≈ 10,000 in ultra-high vacuum [11]. This affects the mechanical bandwidth of

Integration of sharp silicon nitride tips into high-speed SU8 cantilevers in a batch fabrication process

• Nahid Hosseini,
• Matthias Neuenschwander,
• Oliver Peric,
• Santiago H. Andany,
• Jonathan D. Adams and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2019, 10, 2357–2363, doi:10.3762/bjnano.10.226

• Abstract Employing polymer cantilevers has shown to outperform using their silicon or silicon nitride analogues concerning the imaging speed of atomic force microscopy (AFM) in tapping mode (intermittent contact mode with amplitude modulation) by up to one order of magnitude. However, tips of the

Growth dynamics and light scattering of gold nanoparticles in situ synthesized at high concentration in thin polymer films

• Corentin Guyot,
• Philippe Vandestrick,
• Ingrid Marenne,
• Olivier Deparis and
• Michel Voué

Beilstein J. Nanotechnol. 2019, 10, 1768–1777, doi:10.3762/bjnano.10.172

• films was studied with a Park XE70 AFM (Park Systems Corp., Korea), operated in air in intermittent-contact mode with commercial ACTA tips (resonance frequency 309 kHz). Areas of 5 μm × 5 μm, 2 μm × 2 μm and 1 μm × 1 μm were imaged for every sample. The resolution of the images was 256 pixels × 256

Development of a new hybrid approach combining AFM and SEM for the nanoparticle dimensional metrology

• Loïc Crouzier,
• Alexandra Delvallée,
• Sébastien Ducourtieux,
• Laurent Devoille,
• Guillaume Noircler,
• Christian Ulysse,
• Olivier Taché,
• Elodie Barruet,
• Christophe Tromas and
• Nicolas Feltin

Beilstein J. Nanotechnol. 2019, 10, 1523–1536, doi:10.3762/bjnano.10.150

• . In contact mode, the interaction force is kept constant during the scanning thanks to a feedback loop that controls the tip–sample distance. This mode is not really suitable for NP imaging because the NPs might be displaced by the tip over the sample. To avoid this effect, the intermittent contact

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

• sample surface was polymeric, and thus viscoelastic effects could not be ruled out as a root cause of the observed trend. It may be possible to avoid the in-contact scanning-speed phenomenon altogether through specialized AFM scanning modes, such as intermittent-contact scanning modes. However, this

• option may be unavailable to researchers due to various experimental and theoretical constraints. Additionally, such effects cannot be entirely ruled out for lower-frequency (e.g., sub-resonance) intermittent-contact methods. In this article, we present experimental results on a model non-viscoelastic

Lyapunov estimation for high-speed demodulation in multifrequency atomic force microscopy

• David M. Harcombe,
• Michael G. Ruppert,
• Michael R. P. Ragazzon and
• Andrew J. Fleming

Beilstein J. Nanotechnol. 2018, 9, 490–498, doi:10.3762/bjnano.9.47

• the lateral scan trajectories of the nanopositioner. In static-mode AFM (contact mode), the control loop attempts to maintain a constant contact force [3]. Where as in dynamic modes, for example intermittent-contact constant-amplitude AFM [4], the control loop acts to maintain a constant cantilever

• oscillation amplitude. This is achieved by feeding back the demodulated fundamental frequency present in the deflection signal. In intermittent-contact mode AFM [5], the tapping amplitude is chosen such that only gentle tip–sample interactions occur. This is particularly suitable for studying biological

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

• model developed by Herruzo et al. [7] for the computation of the effective elastic modulus of samples Eeff ranging from 1 MPa to 3 GPa from the measured frequency shifts of the two flexural modes of a cantilever operated in intermittent-contact mode: where R is the effective tip radius and ki, Ai, f0,i

• , pressure or humidity. Since its invention, the atomic force microscope (AFM) [4] has confirmed its value for locally determining nanomechanical properties, such as the Young’s modulus, of the sample surface. Initially, the measures were done qualitatively, with the cantilever operated in intermittent

• -contact mode by showing the phase-shift contrast between regions of different elasticities [5]. This was followed by quantitative measurements using various static and dynamic methods [6][7]. Although the results obtained with these methods are in good agreement with theoretical data and data obtained

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

• patterned only with the Au–alkanethiolate monolayers. We imaged patterns of Au–alkanethiolate monolayers on PDMS substrates using nanoscale characterization tools. The topographies were measured using peak-force atomic force microscopy (PF-AFM), an intermittent-contact mode suitable for interrogating soft

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

• (DMA) and for AFM techniques where tip–sample sinusoidal interaction is permanent. This comparison highlights the substantial complexity added by the intermittent-contact nature of the interaction, which precludes the derivation of straightforward equations as is the case for the well-known harmonic

• excitations. The derivations offered have been thoroughly validated through numerical simulations. Despite the complexities inherent to the intermittent-contact nature of the technique, the analytical findings highlight the potential feasibility of extracting meaningful viscoelastic properties with this

• highlighted the challenges involved in characterizing viscoelastic materials with dynamic intermittent-contact methods [19][20][21][22], but further work remains, both in accurately pinpointing the issues involved and in finding robust solutions for them. Typically, viscoelasticity in AFM has been

High-stress study of bioinspired multifunctional PEDOT:PSS/nanoclay nanocomposites using AFM, SEM and numerical simulation

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

Beilstein J. Nanotechnol. 2017, 8, 2069–2082, doi:10.3762/bjnano.8.207

• intermittent-contact AFM technique in which two eigenmodes of the cantilever are excited simultaneously, resulting in an enhanced material contrast and the ability to modulate indentation depth or applied force during imaging [62]. The strategy followed consisted of mapping the conservative and dissipative

Annealing-induced recovery of indents in thin Au(Fe) bilayer films

• Anna Kosinova,
• Ruth Schwaiger,
• Leonid Klinger and
• Eugen Rabkin

Beilstein J. Nanotechnol. 2016, 7, 2088–2099, doi:10.3762/bjnano.7.199

• by an isothermal annealing for the required time. Quenching was achieved by rapid withdrawal of the boat with the sample from the hot zone. After each treatment, the samples were characterized by atomic force microscopy (AFM; Park Systems XE-70) in intermittent-contact mode, using NSG30 Si probes

High-resolution noncontact AFM and Kelvin probe force microscopy investigations of self-assembled photovoltaic donor–acceptor dyads

• Benjamin Grévin,
• Pierre-Olivier Schwartz,
• Laure Biniek,
• Martin Brinkmann,
• Nicolas Leclerc,
• Elena Zaborova and
• Stéphane Méry

Beilstein J. Nanotechnol. 2016, 7, 799–808, doi:10.3762/bjnano.7.71

• ± 5 nm thick, determined from intermittent-contact AFM measurements, not shown) were deposited from toluene solutions (10 mg/mL) via spin-coating on indium–tin–oxide (ITO) functionalized with PEDOT:PSS (thickness 40 ± 5 nm). In this study, PEDOT:PSS was primarily used to reduce the roughness of the

Correlative infrared nanospectroscopic and nanomechanical imaging of block copolymer microdomains

• Benjamin Pollard and
• Markus B. Raschke

Beilstein J. Nanotechnol. 2016, 7, 605–612, doi:10.3762/bjnano.7.53

• ][13][14]. Here, we combine IR s-SNOM and force–distance spectroscopy for a multimodal study of heterogeneous molecular thin films. Although s-SNOM is commonly already based on intermittent-contact atomic force microscopy (AFM), the enabled compatibility with numerous advanced scanning probe modalities

• case due to the long chain lengths. We measure the nanomechanical properties of the copolymer film using several modes of scanning force microscopy. We use intermittent contact mode under ambient conditions to map the ordering of block copolymer domains [19]. This modality, especially its phase images

• Figure 3b represent PS-rich regions where there is insufficient resonant PMMA signal to perform a computational fit and extract a linewidth value. Standard intermittent contact mode topography (Figure 3d) and tapping phase (Figure 3e) channels were collected concurrently during s-SNOM scans. The images

Nanoscale effects in the characterization of viscoelastic materials with atomic force microscopy: coupling of a quasi-three-dimensional standard linear solid model with in-plane surface interactions

• Santiago D. Solares

Beilstein J. Nanotechnol. 2016, 7, 554–571, doi:10.3762/bjnano.7.49

• -solid viscoelastic elements. The enhanced model introduces in-plane surface elastic forces that can be approximately related to a two-dimensional (2D) Young’s modulus. Relevant cases are discussed for single- and multifrequency intermittent-contact AFM imaging, with focus on the calculated surface

• frequencies well below the cantilever resonance frequency [21]. Novel spectroscopy methods have also been recently developed for intermittent-contact imaging. For example, it is now possible to extract tip–sample force curves using dual-eigenmode frequency-modulation AFM [10] and intermodulation AFM [11][12

• only in methods such as CR-AFM or FMOD-AFM [2][3][4][5][6][21]. Therefore, neither the use of the complex modulus nor of quantities derived from it (e.g., the loss tangent, which is the ratio of the loss modulus to the storage modulus) are appropriate for analysis of intermittent-contact AFM

Chemiresistive/SERS dual sensor based on densely packed gold nanoparticles

• Sanda Boca,
• Cosmin Leordean,
• Simion Astilean and
• Cosmin Farcau

Beilstein J. Nanotechnol. 2015, 6, 2498–2503, doi:10.3762/bjnano.6.259

• alpha300 R) using a 100× objective (NA = 0.9) and 785 nm laser. Topography was studied by intermittent contact mode AFM measurements using the same Witec system. Electrical measurements were performed with a Keithley electrometer; a voltage of 1 V was applied in the chemiresistor experiments. Schematic

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

• the measurement process is not in steady state, it becomes extremely difficult to quantify viscoelastic behaviors in a meaningful way. Nevertheless, other authors [6][7][8] have very successfully implemented experimental intermittent-contact multi-frequency AFM methods that allow the extraction of

• , the surface must remain depressed, with a cavity in it, and gradually relax afterwards. In particular, if the tip–sample interaction is of an intermittent contact nature, it may possible that the surface does not fully return to the original (undisturbed) position before the tip impacts it again. That

• is, during the second impact the tip may find the surface at a lower position than prior to the previous impact. These behaviors are discussed in detail in [10][11]. In an effort to provide a more fundamentally correct viscoelastic description of the surface, in recent intermittent-contact AFM