Kelvin probe force microscopy in liquid using electrochemical force microscopy

• Liam Collins,
• Stephen Jesse,
• Jason I. Kilpatrick,
• Alexander Tselev,
• M. Baris Okatan,
• Sergei V. Kalinin and
• Brian J. Rodriguez

Beilstein J. Nanotechnol. 2015, 6, 201–214, doi:10.3762/bjnano.6.19

• electrode. In OLBS measurements, when using bias sweeps larger than 2 V, large changes in the AFM cantilever deflection signal occurred (not shown), often followed by visible bubble nucleation in the probe–sample gap (e.g., Figure 1f). Attempts at implementing KPFM in ionically-active liquids will often

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

• force (≈95 nN) during contact-mode AFM imaging, that is, by scratching the coating with the AFM cantilever. An area was scratched several times before the scanning angle was rotated 90° and the same area was scratched several more times. After scratching, a 20 × 20 µm2 area surrounding the scratched

• homogeneous protein coatings on glass surfaces and indicate that the PDMS surfaces were similarly coated. Accessibility of the coated area with cantilever-bound cells The accessible area at the bottom of a SCFS well is limited by the geometry of the mask and the AFM cantilever. If these come into contact with

• each other, the recorded force–distance curves will be corrupted or, worse, the AFM cantilever may be displaced and the cantilever can be damaged. Both the height of the coating mask and the 10° angle of the cantilever determine the accessible area. Unfortunately, PDMS masks thinner than 150 µm are

The capillary adhesion technique: a versatile method for determining the liquid adhesion force and sample stiffness

• Daniel Gandyra,
• Stefan Walheim,
• Stanislav Gorb,
• Wilhelm Barthlott and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2015, 6, 11–18, doi:10.3762/bjnano.6.2

• cantilevers, reproducing the spring constants calibrated using other methods. Keywords: adhesion; AFM cantilever; air layer; capillary forces; hairs; measurement; micromechanical systems; microstructures; Salvinia effect; Salvinia molesta; sensors; stiffness; superhydrophobic surfaces; Introduction Surface

• . Validating the capillary adhesion technique using calibrated AFM cantilevers A proof of the validity of the CAT method is given by examining a calibrated atomic force microscopy (AFM) cantilever. The cantilever was studied under the same conditions as the human head hairs (i.e., the chip on which the

Mechanical properties of sol–gel derived SiO₂ nanotubes

• Boris Polyakov,
• Mikk Antsov,
• Sergei Vlassov,
• Leonid M Dorogin,
• Mikk Vahtrus,
• Roberts Zabels,
• Sven Lange and
• Rünno Lõhmus

Beilstein J. Nanotechnol. 2014, 5, 1808–1814, doi:10.3762/bjnano.5.191

• in place during the bending. Cantilever beam bending technique [23][24] was applied to half-suspended NTs inside a TESCAN Vega-II SBU SEM equipped with a x,y,z-nanomanipulator (SLC-1720-S, SmarAct) and a force sensor. The force sensor was made by gluing an AFM cantilever with a sharp tip (ATEC-CONT

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

• viscoelastic surfaces. Methods The numerical simulations of the cantilever dynamics were carried out including three eigenmodes of the AFM cantilever as in previous studies [24][42]. Active eigenmodes, as indicated throughout the paper, were driven at their natural frequency. The surface was modeled in most

Multi-frequency tapping-mode atomic force microscopy beyond three eigenmodes in ambient air

• Santiago D. Solares,
• Sangmin An and
• Christian J. Long

Beilstein J. Nanotechnol. 2014, 5, 1637–1648, doi:10.3762/bjnano.5.175

• simulations five eigenmodes of the AFM cantilever were modeled by using individual equations of motion for each, coupled through the tip–sample interaction forces as in previous studies [8][20]. Driven eigenmodes were excited through a sinusoidal tip force of constant amplitude, and frequency equal to the

Hydrophobic interaction governs unspecific adhesion of staphylococci: a single cell force spectroscopy study

• Nicolas Thewes,
• Peter Loskill,
• Philipp Jung,
• Henrik Peisker,
• Markus Bischoff,
• Mathias Herrmann and
• Karin Jacobs

Beilstein J. Nanotechnol. 2014, 5, 1501–1512, doi:10.3762/bjnano.5.163

• adhesion force, dashed lines: range of the standard deviation. B–D: Dotted lines: linear fit to the data. Sketch of approach (A) and retraction (B) of a single bacterial probe and respective force/distance curves. For clarity, neither the AFM cantilever nor the macromolecules that are not involved in

Trade-offs in sensitivity and sampling depth in bimodal atomic force microscopy and comparison to the trimodal case

• Babak Eslami,
• Daniel Ebeling and
• Santiago D. Solares

Beilstein J. Nanotechnol. 2014, 5, 1144–1151, doi:10.3762/bjnano.5.125

• container. During the experiments reported in this paper, the air in the AFM chamber was monitored to be at 23 °C and 17% relative humidity. Computational For the numerical simulations the first three eigenmodes of the AFM cantilever were modeled by using individual equations of motion for each, coupled

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

• , meaning there were no anisotropic frictional properties. The reduction in friction is in accordance to our findings, but it is necessary to mention, that the contact geometry in Marchetto et al. [52] is different to our experimental setup, because they used a cut-off AFM cantilever tip. One can assume

The study of surface wetting, nanobubbles and boundary slip with an applied voltage: A review

• Yunlu Pan,
• Bharat Bhushan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2014, 5, 1042–1065, doi:10.3762/bjnano.5.117

• was prepared as described in the last section. The nanobubbles were imaged and recorded with a Dimension 3000 atomic force microscope (AFM) (Bruker Instruments, Santa Barbara, CA) in tapping mode. In order to image in liquid, the AFM cantilever was held by a polychlorotrifluoroethylene (PCTFE) fluid

Control theory for scanning probe microscopy revisited

• Julian Stirling

Beilstein J. Nanotechnol. 2014, 5, 337–345, doi:10.3762/bjnano.5.38

• input voltage by replacing the numerator with the relevant piezoelectric coefficient. This is not done as it has no effect for a model in arbitrary units, and also as in this form Equation 22 can equally be used as the response of an AFM cantilever. It is, however, important to note that for some

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

• different purposes [1][12][13][14][15][16][17][18]. Previous researchers have shown that the dynamics of the AFM cantilever become extremely complex for low-Q environments, such as liquids [19][20][21][22][23][24][25][26][27][28] (see Figure 1), and have identified phenomena such as the momentary excitation

• questions that require further attention within multifrequency AFM. Methods For the numerical simulations three eigenmodes of the AFM cantilever were modeled using individual equations of motion for each, coupled through the tip–sample interaction forces as in previous studies [9][38]. Driven eigenmodes

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

• in which the driving amplitude is constant and the frequency is adjusted continuously to maintain a constant phase difference between drive and response, φPLL. In the case of an AFM cantilever brought into contact from air, the PLL reference phase would be the phase of the free oscillation of the

Manipulation of nanoparticles of different shapes inside a scanning electron microscope

• Boris Polyakov,
• Sergei Vlassov,
• Leonid M. Dorogin,
• Jelena Butikova,
• Mikk Antsov,
• Sven Oras,
• Rünno Lõhmus and
• Ilmar Kink

Beilstein J. Nanotechnol. 2014, 5, 133–140, doi:10.3762/bjnano.5.13

• ) equipped with a custom-made force sensor. The force sensor was made by gluing an electrochemically sharpened tungsten wire or commercial AFM cantilever with a sharp tip (Nanosensor ATEC-CONT cantilevers C = 0.2 N/m) to one prong of a commercially available quartz tuning fork (QTF). The tip of ATEC-CONT

• voltage were 20–50 mV and the corresponding tip oscillation amplitude was in order of 100 nm. The tip oscillated parallel to the sample surface, i.e., in the shear mode [20]. The QTF force sensors were calibrated on a reference contact mode AFM cantilever (NT-MDT, CSG11), which was previously calibrated

Apertureless scanning near-field optical microscopy of sparsely labeled tobacco mosaic viruses and the intermediate filament desmin

• Alexander Harder,
• Mareike Dieding,
• Volker Walhorn,
• Sven Degenhard,
• Andreas Brodehl,
• Christina Wege,
• Hendrik Milting and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2013, 4, 510–516, doi:10.3762/bjnano.4.60

• illuminated AFM cantilever tip apex exposes strongly confined non-propagating electromagnetic fields that can serve as a coupling agent for single dye molecules. Thus, combining both techniques by means of apertureless scanning near-field optical microscopy (aSNOM) enables concurrent high resolution

• stage. The sample holder is attached on a 3D piezo stage (P-733.3, Physik Instrumente, Karlsruhe, Germany) for lateral sample scanning and vertical fine alignment. The AFM head holds a separate piezo actuator (PSt 150/2x3/5, Piezomechanik, München, Germany) for vibrational excitation of the AFM

• cantilever and surface distance control. The system is controlled by a commercially available scanning probe microscopy control system (Nanonis OC4, Specs, Zürich, Switzerland). The sample is evanescently illuminated by a laser diode (RLT6830MG, λ = 685 nm, 30mW, Roithner Lasertechnik, Vienna, Austria

Multiple regimes of operation in bimodal AFM: understanding the energy of cantilever eigenmodes

• Daniel Kiracofe,
• Arvind Raman and
• Dalia Yablon

Beilstein J. Nanotechnol. 2013, 4, 385–393, doi:10.3762/bjnano.4.45

• . Bimodal AFM traditionally uses the first two eigenmodes of the AFM cantilever. In this work, the authors explore the use of higher eigenmodes in bimodal AFM (e.g., exciting the first and fourth eigenmodes). It is found that such operation leads to interesting contrast reversals compared to traditional

• . Keywords: atomic force microscopy; bimodal AFM; cantilever eigenmodes; polymer characterization; Introduction Atomic force microscopy (AFM) has arisen as one of the key tools for characterization of morphology and surface properties of materials (e.g., polymer blends and composites) at the micro

• images. An extension of AM-AFM called bimodal AFM [2], a capability that has been applied to a variety of materials over the past five years, can overcome some of these limitations. Bimodal AFM oscillates the AFM cantilever at two frequencies simultaneously. This adds two additional channels of

High-resolution nanomechanical analysis of suspended electrospun silk fibers with the torsional harmonic atomic force microscope

• Mark Cronin-Golomb and
• Ozgur Sahin

Beilstein J. Nanotechnol. 2013, 4, 243–248, doi:10.3762/bjnano.4.25

• µm, we obtain the resonance frequency ƒ = 129.4 MHz, which is far above the torsional resonance frequency of the AFM cantilever. Therefore, we neglect the effects of the inertia of the fibers in our experiments. While gradual changes in stiffness of the suspended fiber are not surprising, the precise

Determining cantilever stiffness from thermal noise

• Jannis Lübbe,
• Matthias Temmen,
• Philipp Rahe,
• Angelika Kühnle and
• Michael Reichling

Beilstein J. Nanotechnol. 2013, 4, 227–233, doi:10.3762/bjnano.4.23

• demonstrate that the latter method is in particular useful for noncontact atomic force microscopy (NC-AFM) where the required simple instrumentation for spectral analysis is available in most experimental systems. Keywords: AFM; cantilever; noncontact atomic force microscopy (NC-AFM); Q-factor; thermal

Interpreting motion and force for narrow-band intermodulation atomic force microscopy

• Daniel Platz,
• Daniel Forchheimer,
• Erik A. Tholén and
• David B. Haviland

Beilstein J. Nanotechnol. 2013, 4, 45–56, doi:10.3762/bjnano.4.5

• the AFM cantilever oscillates close to the sample surface, as depicted in Figure 1. In order to achieve stable oscillatory motion, an external drive force is applied to the cantilever, which is usually purely sinusoidal in time with a frequency that is close to the resonance frequency of the first

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

• multiple-nanoparticle contact, a glass sphere attached to an AFM cantilever, as shown in Figure 2b as an example, was used to slide over several nanoparticles. This type of study simulates the contacts experienced by MEMS/NEMS devices when nanoparticles are introduced for the purpose of friction and wear

• reduction. Previous studies have been performed using a colloidal glass sphere attached to an AFM cantilever on bare silicon surfaces [35] and in multiple-nanoparticle contact with both immobile asperities on polymer surfaces [36] and mobile nanoparticles, such as spherical Au and SiO2 nanoparticles on

• nanoparticles with a sharp tip is used to determine the friction force between the nanoparticle and the silicon substrate by AFM. The coefficient of friction is also investigated, with the aid of a glass sphere attached to an AFM cantilever sliding over multiple nanoparticles. Wear tests were performed on the

Mapping mechanical properties of organic thin films by force-modulation microscopy in aqueous media

• Jianming Zhang,
• Zehra Parlak,
• Carleen M. Bowers,
• Terrence Oas and
• Stefan Zauscher

Beilstein J. Nanotechnol. 2012, 3, 464–474, doi:10.3762/bjnano.3.53

• angular frequency of the actuation, kc is the spring constant of the AFM cantilever, and k* is the contact stiffness, The contact stiffness is a function of the reduced Young’s modulus, E*, the tip radius, R, and the applied force, F. Equation 1 explains how the amplitude of the AFM cantilever deflection

Pulse-response measurement of frequency-resolved water dynamics on a hydrophilic surface using a Q-damped atomic force microscopy cantilever

• Masami Kageshima

Beilstein J. Nanotechnol. 2012, 3, 260–266, doi:10.3762/bjnano.3.29

• limited [22][23][24][25]. Using the method of exciting the AFM cantilever with a well-characterized magnetic force [26][27], attempts have been made to measure the frequency-resolved viscoelasticity spectrum of soft-matter systems. The most straightforward approach is a frequency-domain measurement, in

Noncontact atomic force microscopy study of the spinel MgAl₂O₄(111) surface

• Morten K. Rasmussen,
• Kristoffer Meinander,
• Flemming Besenbacher and
• Jeppe V. Lauritsen

Beilstein J. Nanotechnol. 2012, 3, 192–197, doi:10.3762/bjnano.3.21

• Nanoworld with a resonance frequency of 330 kHz and a force constant of 42 N/m were utilized. The constant-detuning mode was used for topographic imaging of the surface by fixing the detuning of the AFM cantilever at a specific setpoint (Δfset) and recording the variation of the tip height (z) while raster

The atomic force microscope as a mechano–electrochemical pen

• Christian Obermair,
• Andreas Wagner and
• Thomas Schimmel

Beilstein J. Nanotechnol. 2011, 2, 659–664, doi:10.3762/bjnano.2.70

• with force constants between 0.03 N/m and 0.1 N/m, were used. Within each experiment, the same AFM cantilever tip was used both for nanolithography and for subsequent AFM imaging. The position of the tip was controlled by a lithography mode of our software, which at the same time allows control of the

Distance dependence of near-field fluorescence enhancement and quenching of single quantum dots

• Volker Walhorn,
• Jan Paskarbeit,
• Heinrich Gotthard Frey,
• Alexander Harder and
• Dario Anselmetti

Beilstein J. Nanotechnol. 2011, 2, 645–652, doi:10.3762/bjnano.2.68

• interface and a gold coated AFM cantilever tip was elucidated by means of a combined TIRFM–AFM approach based on a home-built AFM setup that was mounted on an inverted microscope (Figure 1a). The cantilever position relative to the sample surface can be set and adjusted with subnanometer precision. The

• evanescent field and the AFM cantilever tip (Figure 3a). At small tip distances a strong field enhancement is observed that rapidly decreases with growing gap size. This strong distance dependence is characteristic of dipole–dipole coupling effects. Upon further retraction from the surface Γexc exhibits a