Tattoo ink nanoparticles in skin tissue and fibroblasts

• Colin A. Grant,
• Peter C. Twigg,
• Richard Baker and
• Desmond J. Tobin

Beilstein J. Nanotechnol. 2015, 6, 1183–1191, doi:10.3762/bjnano.6.120

• ) and imaged in air in intermittent contact mode using Olympus AC160 silicon probes (k ≈ 40N/m, tip radius ≈ 10 nm) and AC240 probes (k ≈ 2N/m, tip radius ≈ 10nm). The AFM optics (10×) were used to identify an appropriate region of interest before scanning. Diluted tattoo ink (1:10,000) from the

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

• × 1024 pixels. Imaging was done in the intermittent contact mode of the AFM with a setpoint of 89% of the free amplitude of the cantilever. Due to the large step heights of up to 2 μm on the surface of the chip, and the corresponding high demands on the z-feedback loop the scan speed was set to 30 μm/s

Increasing throughput of AFM-based single cell adhesion measurements through multisubstrate surfaces

• Miao Yu,
• Nico Strohmeyer,
• Jinghe Wang,
• Daniel J. Müller and
• Jonne Helenius

Beilstein J. Nanotechnol. 2015, 6, 157–166, doi:10.3762/bjnano.6.15

• protein coatings of PDMS and glass-surfaced wells, a NanoWizzard II AFM (JPK Instruments) mounted on an inverted microscope (Axio Observer.Zi, Zeiss) was used. AFM imaging was performed in intermittent contact mode with a v-shaped cantilever (SNL, Brucker) having a nominal spring constant of 0.58 N/m

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

• utilization of that information to derive material properties is not trivial in tapping mode AFM. The nature of the technique with its intermittent contact, during which the probe interacts with nonlinear tip–sample forces ranging from attractive to repulsive, hinders the derivation of simple relationships

• (a common term used in the characterization of viscoelastic samples) [16] although it has been reported that this approach can be inaccurate for intermittent-contact applications [17]. Notably, one of the key factors preventing the extraction of reliable material information has been the absence of

• Linear Maxwell sample has yielded sufficiently to allow the tip to oscillate at its free oscillation amplitude, without any tip–sample interaction). Since we are interested in the response of the Linear Maxwell sample with an intermittent contact probe, we have used a prescribed tip trajectory for the

Probing viscoelastic surfaces with bimodal tapping-mode atomic force microscopy: Underlying physics and observables for a standard linear solid model

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1649–1663, doi:10.3762/bjnano.5.176

• properties and the AFM observables. The physics of the tip–sample interactions and its effect on the observables are illustrated and discussed, and a brief research outlook on viscoelasticity measurement with intermittent-contact AFM is provided. Keywords: amplitude-modulation; bimodal; dissipation

• by using contact resonance techniques [4][5][6][7][8], whereby classical properties are approximated by using contact models under small-amplitude oscillatory deformations. Such characterization is much more challenging to carry out by using intermittent-contact techniques due to the non-linear

• qualitative behavior for creep compliance and stress relaxation, its study can highlight the range of open issues that remain in the development of surface viscoelasticity measurement methods based on intermittent-contact AFM. This paper begins with a background section providing a very brief description of

Dry friction of microstructured polymer surfaces inspired by snake skin

• Martina J. Baum,
• Lars Heepe,
• Elena Fadeeva and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 1091–1103, doi:10.3762/bjnano.5.122

• [44], the detailed characterization of the surface topography was performed by a NanoWizard® atomic force microscope (JPK Instruments), mounted on an inverted light microscope (Zeiss Axiovert 135, Carl Zeiss MicroImaging GmbH). The SIMPS were imaged by using the intermittent contact mode of the AFM

• . Scans were carried out at a 1 Hz scan rate and a resolution of 1024 × 1024 pixels with an intermittent contact mode cantilever (c = 50 N·m−1, NST-NCHF, Nascatec GmbH, Stuttgart, Germany), at ambient conditions (room temperature 24° C, relative humidity 41%). NanoWizard® SPM software 3.3.23 (JPK

Insect attachment on crystalline bioinspired wax surfaces formed by alkanes of varying chain lengths

• Elena Gorb,
• Sandro Böhm,
• Nadine Jacky,
• Louis-Philippe Maier,
• Kirstin Dening,
• Sasha Pechook,
• Boaz Pokroy and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2014, 5, 1031–1041, doi:10.3762/bjnano.5.116

• samples were measured from digital images using the image analysis software SigmaScan Pro 5.0.0 (SPSS Inc., Chicago, IL, USA). The topography of wax surfaces was examined using the AFM (Typ NanoWizard, JPK Instruments AG, Berlin, Germany). On each sample, areas of 5 μm × 5 μm were scanned in intermittent

• contact mode with a supersharp silicon non-contact cantilever (SSS-NCH, Nanoworld, Neuchâtel, Switzerland). The scanned area was comparable with the size of setal tips in adhesive pads of the beetle C. septempunctata [52]. The images obtained were processed with the scanning probe image processing

Challenges and complexities of multifrequency atomic force microscopy in liquid environments

• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 298–307, doi:10.3762/bjnano.5.33

• extended to intermittent contact characterization using open loop and frequency modulation [3][4], imaging in liquid and vacuum environments [5][6][7][8], and to trimodal operation [9][10][11]. There also exist a number of other multifrequency and multiharmonic AFM techniques which have been developed for

Frequency, amplitude, and phase measurements in contact resonance atomic force microscopies

• Gheorghe Stan and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 278–288, doi:10.3762/bjnano.5.30

• phase and amplitude response at two frequencies around the resonance frequency during a real-time scan [12]. Intermittent-contact methods have also been used to characterize conservative and dissipative tip–sample interactions simultaneously with topographical acquisition. This was originally performed

• ), respectively [15][16][17][18][19][20]. In the last ten years, intermittent-contact measurements have been enhanced through multifrequency excitation methods [21][22][23][24][25][26][27]. In multifrequency AFM, the fundamental cantilever eigenmode is typically controlled in conventional AM- or FM-AFM mode for

• sensitivity. However, with the exception of small-amplitude FM-AFM [28][29] in which the tip–sample force gradient can be measured directly, the mapping of Vts and Pts in intermittent-contact imaging generally only provides a qualitative map of surface viscoelasticity. In this work the focus is on the CR-AFM

Constant-distance mode SECM as a tool to visualize local electrocatalytic activity of oxygen reduction catalysts

• Michaela Nebel,
• Thomas Erichsen and
• Wolfgang Schuhmann

Beilstein J. Nanotechnol. 2014, 5, 141–151, doi:10.3762/bjnano.5.14

• control mechanism. The concept of 4D CD-SECM was recently extended to intermittent contact-SECM [16]. Here, we describe the adaptation of the 4D SF/CD-SECM to the investigation of the activity of powdery oxygen reduction catalysts. In order to understand the properties of catalyst powders on a local scale

Friction behavior of a microstructured polymer surface inspired by snake skin

• Martina J. Baum,
• Lars Heepe and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 83–97, doi:10.3762/bjnano.5.8

• NanoWizard® atomic force microscope (JPK Instruments), mounted on an inverted light microscope (Zeiss Axiovert 135, Carl Zeiss MicroImaging GmbH). The SIMPS were imaged by using the intermittent contact mode of the AFM. The error channel (also known as the amplitude channel) visualizes the change in damping

• intermittent contact mode cantilever (c = 50 Nm−1, NST-NCHF, Nascatec GmbH, Stuttgart, Germany), at ambient conditions (room temperature 24 °C, relative humidity 41%). NanoWizard® SPM software 3.3.23 (JPK Instruments) was used to obtain AFM images and NanoWizard® image processing software 3.3.25 was applied to

Site-selective growth of surface-anchored metal-organic frameworks on self-assembled monolayer patterns prepared by AFM nanografting

• Tatjana Ladnorg,
• Alexander Welle,
• Stefan Heißler,
• Christof Wöll and
• Hartmut Gliemann

Beilstein J. Nanotechnol. 2013, 4, 638–648, doi:10.3762/bjnano.4.71

• grafting solutions. The nanografting in the case of MPA/DT was performed in contact mode with a loading force of 345 nN, while for MHDA/ODT a loading force of 303 nN was used to remove thiols out of the existing matrix SAM. All AFM surface analysis experiments were carried out in the intermittent contact

Photoresponse from single upright-standing ZnO nanorods explored by photoconductive AFM

• Igor Beinik,
• Markus Kratzer,
• Astrid Wachauer,
• Lin Wang,
• Yuri P. Piryatinski,
• Gerhard Brauer,
• Xin Yi Chen,
• Yuk Fan Hsu,
• Aleksandra B. Djurišić and
• Christian Teichert

Beilstein J. Nanotechnol. 2013, 4, 208–217, doi:10.3762/bjnano.4.21

• evaporation of Zn in dry argon flow following a procedure described in more detail elsewhere [41]. The morphology of the resulting arrays of upright standing ZnO NRs was precharacterized by means of scanning electron microscopy (SEM) and intermittent contact mode AFM using PPP-NCHR™ probes from Nanosensors

• -standing ZnO NRs, the following procedure was employed. ZnO NRs were located in intermittent contact mode, and then the system was switched to contact mode AFM for the investigation of the transient photocurrent behavior of ZnO NRs. The loading force during the transient PC-AFM characterization was on the

• side and biased. Use of ATEC-CONTPt™ probes helps to avoid shadowing by the cantilever. (a) 5 μm × 5 μm intermittent contact mode AFM image and SEM micrograph (inset) of ZnO nanorods grown by thermal evaporation, (b) time-resolved (blue curve) and integral (red curve) PL spectra from the array of

Bimodal atomic force microscopy driving the higher eigenmode in frequency-modulation mode: Implementation, advantages, disadvantages and comparison to the open-loop case

• Daniel Ebeling and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 198–207, doi:10.3762/bjnano.4.20

• interactions (conservative and dissipative) [26] (note that the measured frequency shift is also indirectly affected by dissipation in large-amplitude intermittent-contact experiments, in that dissipative forces can limit penetration of the probe tip into the repulsive region of the tip–sample interaction

• . Finally, FM-AFM also has the potential advantage to enable real-time 3D force spectroscopy in multifrequency operation, in the limit of small response time. As previously simulated [31][32], if a sufficiently high eigenmode were self-excited while performing intermittent contact imaging with the

Towards 4-dimensional atomic force spectroscopy using the spectral inversion method

• Jeffrey C. Williams and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2013, 4, 87–93, doi:10.3762/bjnano.4.10

• undergoes intermittent contact with the surface, which in turn excites the torsional eigenmode (recall that the tip is located on one of the arms of the “T” and not on the center of the cantilever end). Since the torsional eigenmode is not directly driven by the piezo shaker, the only driving force acting

• 4D implementation is relatively straightforward, requiring no new technology. However, important limitations still exist in performing the method upgrade accurately and using it meaningfully, depending on the application. In particular, the study of viscoelastic models in intermittent contact AFM

Pure hydrogen low-temperature plasma exposure of HOPG and graphene: Graphane formation?

• Baran Eren,
• Dorothée Hug,
• Laurent Marot,
• Rémy Pawlak,
• Marcin Kisiel,
• Roland Steiner,
• Dominik M. Zumbühl and
• Ernst Meyer

Beilstein J. Nanotechnol. 2012, 3, 852–859, doi:10.3762/bjnano.3.96

• spectroscopy measurements were prepared by exfoliation of HOPG using a PDMS stamp and transferring them on SiO2 [42]. The number of layers was determined from the 2D peak of the Raman spectra, which was acquired prior to plasma treatment. An intermittent contact-mode AFM experiment was performed by means of a

Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

• Dave Maharaj and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2012, 3, 759–772, doi:10.3762/bjnano.3.85

• nanoparticles (120–400 nm) [29], (50–500 nm) [30], spherical SiO2 nanoparticles (30 nm) [31] and spherical Au nanoparticles (25 nm) [32], (30–50 nm) [31] and (80 nm) [33] have been studied in both contact and intermittent-contact modes in dry environments. In liquid environments, Au nanoparticles (20–30 nm

• ) have also been manipulated in water and ethanol with an AFM operated in intermittent-contact mode [34]. In addition to the contact-area dependence of friction observed in these studies, the relative-humidity (RH) dependence of friction was investigated by Mougin et al. [32] and Palacio and Bhushan [31

Drive-amplitude-modulation atomic force microscopy: From vacuum to liquids

• Miriam Jaafar,
• David Martínez-Martín,
• Mariano Cuenca,
• John Melcher,
• Arvind Raman and
• Julio Gómez-Herrero

Beilstein J. Nanotechnol. 2012, 3, 336–344, doi:10.3762/bjnano.3.38

• associated with the transition between noncontact and intermittent-contact regimes. This feature translates to stable scanning of heterogeneous samples of technological relevance that are cumbersome to scan in vacuum, and which can be different to the standard samples used in UHV fundamental surface-science

Noncontact atomic force microscopy

• Udo D. Schwarz

Beilstein J. Nanotechnol. 2012, 3, 172–173, doi:10.3762/bjnano.3.17

• taps the surface while vibrating, and, whichever mode is used, tips quickly blunt through either permanent or intermittent contact. Maintaining the atomic sharpness of an initially atomically sharp tip requires that the tip never touches the surface. But how can the tip know that the surface is there

Single-pass Kelvin force microscopy and dC/dZ measurements in the intermittent contact: applications to polymer materials

• Sergei Magonov and
• John Alexander

Beilstein J. Nanotechnol. 2011, 2, 15–27, doi:10.3762/bjnano.2.2

• interactions can be performed in the intermittent contact regime in different environments. Such combination provides sensitive detection of the surface potential and capacitance gradient with nanometer-scale spatial resolution as it was verified on self-assemblies of fluoroalkanes and a metal alloy. The KFM

• compositional mapping of organic materials and polymers. In the intermittent contact operation, proximity of the conducting probe to a sample helps in avoiding screening the sample’s electrical response by a water layer when measurements are performed at high humidity. A selective swelling of individual

• amplitude Asp = 0.6–0.8 A0. These imaging conditions correspond to the intermittent contact imaging when Asp is chosen on the steep part of the amplitude-versus-distance curve. Another LIA (LIA-2), which is used for KFM, applies AC and DC voltages to the probe and detects the electrostatic response either

Scanning probe microscopy and related methods

• Ernst Meyer

Beilstein J. Nanotechnol. 2010, 1, 155–157, doi:10.3762/bjnano.1.18

• Microscopy, FMM: Force Modulation Microscopy, ic-AFM: intermittent contact AFM, TMAFM: tapping mode AFM, nc-AFM: non-contact AFM, KPFM: Kelvin probe force microscopy, EFM: Electrostatic force microscopy, MFM: Magnetic force microscopy, MRFM: Magnetic resonance force microscopy, NSOM: Near-field scanning