Robust nanobubble and nanodroplet segmentation in atomic force microscope images using the spherical Hough transform

• Yuliang Wang,
• Tongda Lu,
• Xiaolai Li,
• Shuai Ren and
• Shusheng Bi

Beilstein J. Nanotechnol. 2017, 8, 2572–2582, doi:10.3762/bjnano.8.257

• ameliorate oxygen mass transfer to living microorganisms [7], reduce drag force at solid–liquid interfaces in micro/nanofluidics [2][8][9], and enhance ultrasonic tumor imaging contrast [10]. Regarding NDs, they can be applied to fabricate nanolenses on solid surfaces to modify them for antireflection and

Interface conditions of roughness-induced superoleophilic and superoleophobic surfaces immersed in hexadecane and ethylene glycol

• Yifan Li,
• Yunlu Pan and
• Xuezeng Zhao

Beilstein J. Nanotechnol. 2017, 8, 2504–2514, doi:10.3762/bjnano.8.250

• that can affect the drag of fluid flow. For surfaces with different oleophobicity, the boundary slip at the solid–oil interface is mostly larger than that at the solid–water interface. Roughness is a key factor for the wettability of superoleophilic/superoleophobic surfaces, and it has been found to

• significantly inhibit the degree of boundary slip on both superoleophilic surfaces in Wenzel state and superoleophobic surfaces in Cassie state immersed in oil. The oleic systems were likely to enhance boundary slip and resulted in a corresponding reduction in drag with decreasing roughness on the solid–oil

• interfaces. Keywords: boundary slip; roughness; superoleophilic; superoleophobic; Introduction In micro/nanofluidic systems, the increasing surface to volume ratio leads to unignorable fluid drag at the solid–liquid interface. The reduction of fluid drag is an important issue to improve the efficiency of

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

• damage induced by constant tip drag. Additionally, these methods are prone to significant tip wear and contamination which could make quantitative characterization unreliable due to constant changes in tip geometry. Dynamic methods have been designed to overcome the above issues, whereby tapping-mode AFM

A comparative study of the nanoscale and macroscale tribological attributes of alumina and stainless steel surfaces immersed in aqueous suspensions of positively or negatively charged nanodiamonds

• Colin K. Curtis,
• Antonin Marek,
• Alex I. Smirnov and
• Jacqueline Krim

Beilstein J. Nanotechnol. 2017, 8, 2045–2059, doi:10.3762/bjnano.8.205

• of films in both in vacuum and liquid environments [23][24][25]. When immersed in liquid, it can be used to probe frictional drag forces and interfacial effects at complex solid–liquid interfaces [19][27] including those of a biological origin [18][22]. Given that the transverse shear speed of the

• mass and frictional energy losses of materials deposited onto its surface electrodes and/or drag forces and interfacial slippage of fluids that it is immersed in. For a QCM with one side immersed in a fluid with bulk density ρ3 and viscosity η3, the shifts in δf and δ(Q−1) associated with the presence

• = −714 Hz drop in the resonant frequency and an increase of δ(Q−1) = 2.85 × 10−4 in the dissipation. For a QCM with quality factor Q = 50,000 in air this corresponds to a drop to Q = 3,280 after an immersion in water. The viscous drag forces on the QCM electrode are mechanical in nature; a decrease in Q

Collembola cuticles and the three-phase line tension

• Håkon Gundersen,
• Hans Petter Leinaas and
• Christian Thaulow

Beilstein J. Nanotechnol. 2017, 8, 1714–1722, doi:10.3762/bjnano.8.172

• in functional surfaces with effects like self-cleaning, drag reduction and air retention [10][11][12]. The field of superhydrophobic surfaces has made extensive use of biomimetic methods, where the imitation of natural surfaces provides the basis for artificial surfaces [9][13][14]. The exact nature

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

• fields of drag reduction, antifouling, anticorrosion and under water sensing. Current knowledge regarding the shape of the air–water interface is insufficient, although it plays a crucial role with regards to stability in terms of diffusion and dynamic conditions. Optical methods for imaging the

• years, the Salvinia effect – the long term stabilization of an air layer on a submerged surface – has gained increasing interest. There is great potential for various technical applications utilizing this effect, for example, drag reduction, antifouling or anticorrosion applications, and underwater

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

• ], in self-cleaning – because liquid-repellency is correlated with a low adhesion force –, drag reduction [14], fog harvesting [15], and to understand adhesive interactions between imaging materials, which are crucial in print-engine design, and print-process development in the printing industry [16

When the going gets rough – studying the effect of surface roughness on the adhesive abilities of tree frogs

• Niall Crawford,
• Thomas Endlein,
• Jonathan T. Pham,
• Mathis Riehle and
• W. Jon P. Barnes

Beilstein J. Nanotechnol. 2016, 7, 2116–2131, doi:10.3762/bjnano.7.201

• twigs [50]. We are thus building up a good understanding of both the underlying mechanisms and the ecology of tree frog adhesive mechanisms. But this study goes further: comparable to the drag reduction mechanisms of snake skin [51], the superhydrophobicity and self-cleaning mechanisms of lotus leaves

• friction forces. Simple LabView programs (similar to those used in Crawford et al. [33]) were used to move the pad over the force plate so that maximum frictional and adhesive forces could be measured. This involved a proximal lateral drag (5 mm drag at 1 mm s−1), followed by a vertical pull off. Above the

Dynamic of cold-atom tips in anharmonic potentials

• Tobias Menold,
• Peter Federsel,
• Carola Rogulj,
• Hendrik Hölscher,
• József Fortágh and
• Andreas Günther

Beilstein J. Nanotechnol. 2016, 7, 1543–1555, doi:10.3762/bjnano.7.148

• (i). As time goes by, the higher energetic particles will drag more and more behind, leading to a relative dephasing between particle oscillations (ii–iv). This results in a spread of the phase-space distribution and a center-of-mass shift towards the equilibrium position. For the density

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

• experienced by the cantilever is due to plan-view-dependent drag as opposed to viscous shear, and the former is not significantly influenced by the presence of the tip. The reason for the observed hysteresis in the speed-dependent deflection (Figure 5) is not entirely clear. Some cantilevers showed no

Single-molecule mechanics of protein-labelled DNA handles

• Vivek S. Jadhav,
• Dorothea Brüggemann,
• Florian Wruck and
• Martin Hegner

Beilstein J. Nanotechnol. 2016, 7, 138–148, doi:10.3762/bjnano.7.16

• fluid-flow dependent DNA extension, corresponding to the hydrodynamic drag experienced by the DNA molecule. The flow force induced stretching as presented here is consistent with the original experimental findings by Perkins et al. [15] and follows the theoretical description of Stigter et al. [16

• cell. Variations in the fluid flow speed change the hydrodynamic drag experienced by the long dsDNA molecule, altering its extension. Interaction rate of streptavidin- and neutravidin-DNA coupled to anti-DIG beads with the ratio 40:1 in various buffers. Acknowledgements This work was supported by

Electroviscous effect on fluid drag in a microchannel with large zeta potential

• Dalei Jing and
• Bharat Bhushan

Beilstein J. Nanotechnol. 2015, 6, 2207–2216, doi:10.3762/bjnano.6.226

• /bjnano.6.226 Abstract The electroviscous effect has been widely studied to investigate the effect of surface charge-induced electric double layers (EDL) on the pressure-driven flow in a micro/nano channel. EDL has been reported to reduce the velocity of fluid flow and increase the fluid drag

• potential on the pressure-driven flow in a microchannel with no-slip and charge-dependent slip conditions. The results show that the EDL leads to an increase in the fluid drag, but that slip can reduce the fluid drag. When the zeta potential is large enough, the electroviscous effect disappears for flow in

• the microchannel under a no-slip condition. However, the retardation of EDL on the flow and the enhancement of slip on the flow counteract each other under a slip condition. The underlying mechanisms of the effect of EDL with large zeta potential on fluid drag are the high net ionic concentration near

Stiffness of sphere–plate contacts at MHz frequencies: dependence on normal load, oscillation amplitude, and ambient medium

• Jana Vlachová,
• Rebekka König and
• Diethelm Johannsmann

Beilstein J. Nanotechnol. 2015, 6, 845–856, doi:10.3762/bjnano.6.87

• displacement is evaluated in the undeformed regions far outside the contact zone. The ratio of force and displacement is the contact stiffness. As we show in the modeling section, the spring constant and the dashpot’s drag coefficient can be easily determined from the shifts of frequency and bandwidth. The

• acounts for viscous dissipation, where ξ is the drag coefficient. ξ quantifies linear processes in the sense that the stress is proportional to the rate of displacement. No statement is made on the mechanism(s) leading to dissipation. The drag coefficient may be linked to the viscoelastic nature of the

Graphene quantum interference photodetector

• Mahbub Alam and
• Paul L. Voss

Beilstein J. Nanotechnol. 2015, 6, 726–735, doi:10.3762/bjnano.6.74

• generation mechanisms in graphene photodetectors include the photovoltaic effect, photothermoelectric effect, bolometric effect and phonon drag effect [3]. In the photovoltaic effect, the built-in electric field generated in the junction of p- and n-type graphene is utilized for separation of photogenerated

A surface acoustic wave-driven micropump for particle uptake investigation under physiological flow conditions in very small volumes

• Florian G. Strobl,
• Dominik Breyer,
• Phillip Link,
• Adriano A. Torrano,
• Christoph Bräuchle,
• Matthias F. Schneider and
• Achim Wixforth

Beilstein J. Nanotechnol. 2015, 6, 414–419, doi:10.3762/bjnano.6.41

• Cloc > Cm. Ignoring these effects can in fact lead to misinterpretation of experimental data, especially to an overestimation of the impact of big particles or agglomerates. Furthermore, particles on a cell surface under shear are subject to drag and torsion forces [3]. For spherical particles in the

• nano-regime it can be easily derived from the Stokes equation that these drag forces are typically of the order of a few piconewtons or below, i.e, one or more orders of magnitude weaker than typical receptor–ligand binding strengths [4]. Nevertheless, in the case of weak unspecific particle adhesion

• 2000 s−1, its rolling velocity will be of the order of 100 μm/s. Relevant disruption forces for specific bindings can be achieved for large particle agglomerates, since the drag force scales with r2. An agglomerate with an hydrodynamic radius of r = 500 nm at a shear rate of 2000 s−1, for instance

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

• [4][5] because of the significant drag reduction [6][7][8][9][10][11][12]. However, an essential requirement for the functionality of these surfaces is the persistence of the air layer [13][14][15]. As all of the highly engineered surfaces developed to date have failed in this respect [9][10][11][12

• molesta attracts considerable attention due to its ability to maintain a persistent layer of air on its leaves under water. This feature could be of high technological relevance, opening perspectives for completely new concepts for drag reduction of ships, for example, lubricating a ship hull with a

High-frequency multimodal atomic force microscopy

• Adrian P. Nievergelt,
• Jonathan D. Adams,
• Pascal D. Odermatt and
• Georg E. Fantner

Beilstein J. Nanotechnol. 2014, 5, 2459–2467, doi:10.3762/bjnano.5.255

• spring constants [10][11][12]. Increasing the cantilever resonance frequency enables faster imaging and force spectroscopy [12][13][14][15][16][17], and small, high-frequency AFM cantilevers have less viscous drag, lowering force noise [18]. Many of the techniques for extracting mechanical information

Aquatic versus terrestrial attachment: Water makes a difference

• Petra Ditsche and
• Adam P. Summers

Beilstein J. Nanotechnol. 2014, 5, 2424–2439, doi:10.3762/bjnano.5.252

• acting to detach animals and forces of attachment. While in a terrestrial environment gravity is commonly understood as the most important detachment force, under submerged conditions gravity is nearly balanced out by buoyancy and therefore matters little. In contrast, flow forces such as drag and lift

• the same in terrestrial systems compared with aquatic ones in either scale or type (Table 1). While in terrestrial systems gravitation is the most relevant, in aquatic systems gravity is mostly cancelled by buoyancy. In contrast, in aquatic systems flow forces such as drag and lift are very important

• while they are seldom substantial in terrestrial systems. The magnitude of these forces varies by environment and so does the direction: while gravity always acts only in the direction of the earth, drag pushes the animal across the surface, and lift can pull it off regardless of orientation (Figure 1

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

• The drag of fluid flow at the solid–liquid interface in the micro/nanoscale is an important issue in micro/nanofluidic systems. Drag depends on the surface wetting, nanobubbles, surface charge and boundary slip. Some researchers have focused on the relationship between these interface properties. In

• force on the probe were measured on an octadecyltrichlorosilane (OTS) surface with applied voltage. The influence of the surface charge on the boundary slip and drag of fluid flow has been discussed. Finally, the influence of the applied voltage on the surface wetting, nanobubbles, surface charge

• , boundary slip and the drag of liquid flow are summarized. With a smaller surface charge density which could be achieved by applying a voltage on the surface, larger and fewer nanobubbles, a larger slip length and a smaller drag of liquid flow could be found. Keywords: atomic force microscopy; boundary

Measuring air layer volumes retained by submerged floating-ferns Salvinia and biomimetic superhydrophobic surfaces

• Matthias J. Mayser,
• Holger F. Bohn,
• Meike Reker and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2014, 5, 812–821, doi:10.3762/bjnano.5.93

• biomimetic applications like drag reduction in ship coatings of up to 30%. Here we present a novel method for measuring air volumes and air loss under water. We recorded the buoyancy force of the air layer on leaf surfaces of four different Salvinia species and on one biomimetic surface using a highly

• also allows to measure decrease or increase of air layers with high accuracy in real-time to understand dynamic processes. Keywords: air layer; biomimetic; drag reduction; functional surfaces; plastron; Salvinia effect; volume measurement; Introduction Since the description of hierarchically

• applications for these trapped air layers in the Cassie wetting regime have been proposed which include drag reducing ship coatings or fluid channels [22][23][24][25][26] with the capability of 30% drag reduction [27] and could provide high economic and ecologic value [28][29]. While superhydrophobic plant

The surface microstructure of cusps and leaflets in rabbit and mouse heart valves

• Xia Ye,
• Bharat Bhushan,
• Ming Zhou and
• Weining Lei

Beilstein J. Nanotechnol. 2014, 5, 622–629, doi:10.3762/bjnano.5.73

• adhesion, and drag reduction. Therefore, studying the surfaces of natural organisms is extremely important and significant. Moreover, results of this study could have a substantial effect on the manufacturing of artificial biological products. During the past decade, the special surface microstructures of

Exploring the retention properties of CaF₂ nanoparticles as possible additives for dental care application with tapping-mode atomic force microscope in liquid

• Matthias Wasem,
• Joachim Köser,
• Sylvia Hess,
• Enrico Gnecco and
• Ernst Meyer

Beilstein J. Nanotechnol. 2014, 5, 36–43, doi:10.3762/bjnano.5.4

• layer (hydrodynamic drag of water layer), but the intrinsic particle–sample interaction energies. The frequency distribution of the calculated power dissipated for each of the particles enables us to examine the chemical affinity between the calcium fluoride nanoparticles adsorbed on mica and on

Dynamic nanoindentation by instrumented nanoindentation and force microscopy: a comparative review

• Sidney R. Cohen and
• Estelle Kalfon-Cohen

Beilstein J. Nanotechnol. 2013, 4, 815–833, doi:10.3762/bjnano.4.93

• its behavior suspended in air [103]. A known reference was used for calibration, allowing them to measure storage and loss modulus with an ultrasonic contact technique utilizing the first three flexural modes. For measurements in any fluid, including air, there will be a drag force on the bulk

• cantilever. In liquid, this drag force is very significant. Mahaffy et al. recorded this force in an aqueous environment as the tip approached the surface, but before it made contact and thus comprised a noncontact measurement of the phase shift [104]. A combination of the two corrections was made in a study

• of viscoelastic behavior of cells [105]. In this work, the hydrodynamic drag of the cantilever was measured at varying heights above the surface, and in addition, the phase response of the AFM piezo was measured in contact with a stiff cantilever probe on a hard surface in air. These few examples

Nanoglasses: a new kind of noncrystalline materials

• Herbert Gleiter

Beilstein J. Nanotechnol. 2013, 4, 517–533, doi:10.3762/bjnano.4.61

• concentration at the interfaces of the FeSc nanoglass. This enhanced concentration may delay the interfacial delocalization. For example, in the case of Y–Fe nanocrystalline materials grain growth was found to cease due to the solute segregation to the interfaces [29][30][31] (“solute drag effect”) [32][33][34

Structural and thermoelectric properties of TMGa₃ (TM = Fe, Co) thin films

• Sebastian Schnurr,
• Ulf Wiedwald,
• Paul Ziemann,
• Valeriy Y. Verchenko and
• Andrei V. Shevelkov

Beilstein J. Nanotechnol. 2013, 4, 461–466, doi:10.3762/bjnano.4.54

• conclusion on the amorphous state of the presently discussed films has immediate implications on their thermoelectric behavior. First of all, the scattering of electrons is dominated by the static disorder rather than by phonons. As a consequence, phonon drag effects, which usually are responsible for strong

• temperature behavior with no indication for phonon drag peaks in the lower temperature range. Also the magnitude of the S(300 K)-values ranging between 4 and 8 μV/K are typical of high-resistance metallic glasses [16]. This clearly confirms the idea of amorphous rather than nanocrystalline structures for the

• (300 K)-values of only some μV/K are likely. However, in crystalline samples a possibly present phonon drag may give rise to more pronounced nonlinearities in the temperature dependence of the Seebeck coefficient. Thus, at this point we conclude that the thermoelectric behavior of our films as