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

• presented. Characterization of the protein coating on PDMS masks To characterize the surface roughness and the protein coating, glass and PDMS surfaces were imaged using AFM. Several protein-coated surfaces of both PDMS and glass were imaged. Surfaces of protein-coated glass were smooth with height

• proteins as described for non-labeled proteins. The cantilever coating was performed as previously described [30]. In short, the cantilevers were plasma-cleaned and incubated overnight in 2 mg/mL ConA (Sigma) containing PBS at 4 °C. Characterization of protein coatings To characterize surface roughness and

SERS and DFT study of copper surfaces coated with corrosion inhibitor

• Maurizio Muniz-Miranda,
• Francesco Muniz-Miranda and
• Stefano Caporali

Beilstein J. Nanotechnol. 2014, 5, 2489–2497, doi:10.3762/bjnano.5.258

• substrate must exhibit a surface roughness at the nanometer level. In these nanoscale structures, the excitation of electrons from the metal surface by laser irradiation can be confined, resulting in plasmon resonance [16]. The existence of this resonance is a necessary condition to observe a SERS signal by

• adsorbed species on the metal surface. In order to obtain a suitable surface roughness from a smooth copper substrate, etching in nitric acid was performed (as previously demonstrated [17]), followed by immersion in ammonia solution. The reducing environment limits the oxidation of the copper surface

• ) of the etched sample surface reveals a fine surface arrangement, showing the formation of submicrometer dendritic structures, typical of rapid growth crystals. The existence of these nanostructures is additionally proved by measuring the surface roughness. A line profile was obtained on the etched

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

• faced by tires on roads of varying roughness and wetness has driven the development of theories that may be applicable to biological systems [50][51]. These theories are difficult to assess in a biological context, but an examination of the parameters, surface roughness, substrate compliance, friction

Characterization of 10,12-pentacosadiynoic acid Langmuir–Blodgett monolayers and their use in metal–insulator–metal tunnel devices

• Saumya Sharma,
• Mohamad Khawaja,
• Manoj K. Ram,
• D. Yogi Goswami and
• Elias Stefanakos

Beilstein J. Nanotechnol. 2014, 5, 2240–2247, doi:10.3762/bjnano.5.233

• PDA. However, this AFM characterization could only provide information about the surface morphology and not the film thickness. The surface roughness of the underlying nickel film was recorded as 18 ± 1 Å [24]. Discussion of the MIM structure: Initially, due to the extreme thinness of the PDA

• 0.01 M HCl electrolyte. AFM micrograph of 30 monolayer of PDA deposited using the Langmuir–Blodgett technique showing a surface roughness of 34.2 Å. The roughness of the underlying Ni-coated silicon substrate was 18 Å. A schematic representation of the challenges in MIM device fabrication using LB

Modification of a single-molecule AFM probe with highly defined surface functionality

• Fei Long,
• Bin Cao,
• Ashok Khanal,
• Shiyue Fang and
• Reza Shahbazian-Yassar

Beilstein J. Nanotechnol. 2014, 5, 2122–2128, doi:10.3762/bjnano.5.221

• spectroscopy experiment Single-molecule probe modification: The alkyne-modified probe was engaged to the Cu substrate in contact mode with 1 nN force in 0.05 M azide solution. The average surface roughness Ra of the Cu surface was 1.33 ± 0.24 nm determined through AFM topography (shown in Figure S8, Supporting

Numerical investigation of the effect of substrate surface roughness on the performance of zigzag graphene nanoribbon field effect transistors symmetrically doped with BN

• Majid Sanaeepur,
• Arash Yazdanpanah Goharrizi and
• Mohammad Javad Sharifi

Beilstein J. Nanotechnol. 2014, 5, 1569–1574, doi:10.3762/bjnano.5.168

• impurities, here, we only consider the effect of the substrate material. Any substrate material has some surface roughness (SR). Substrate surface roughness induces a conformal surface roughness on the GNR placed on top of it [27]. It has been shown that SR decreases the mobility of both armchair and zigzag

• data, a two-dimensional Gaussian auto-correlation function is used as a generator of surface roughness [27][30][31]: where h(r) is the variation of the surface height at point r. The values δSR and represent the root mean square and correlation length of the height fluctuations, respectively. The pz

• on- and off-state, respectively [45]. Results and Discussion A typical sample of s-BN-ZGNR with a width of five hexagons of atoms (5h) is shown in Figure 1 with (right) and without (left) surface roughness. As depicted, the one hexagonal chain of atoms at each edge along the transport direction is

Formation of Cu_xAu_1−x phases by cold homogenization of Au/Cu nanocrystalline thin films

• Alona Tynkova,
• Gabor L. Katona,
• Gabor A. Langer,
• Sergey I. Sidorenko,
• Svetlana M. Voloshko and
• Dezso L. Beke

Beilstein J. Nanotechnol. 2014, 5, 1491–1500, doi:10.3762/bjnano.5.162

• shown in Figure 1. The presence of the smeared interface in the as-deposited sample can be explained by some initial surface roughness, diffusion during the sample preparation or instrumental effects of the sputter depth profiling [27][28]. It can be clearly seen that, during heat treatments the Cu

Restructuring of an Ir(210) electrode surface by potential cycling

• Khaled A. Soliman,
• Dieter M. Kolb,
• Ludwig A. Kibler and
• Timo Jacob

Beilstein J. Nanotechnol. 2014, 5, 1349–1356, doi:10.3762/bjnano.5.148

• electrocatalytic activity is probably related to a lower CO binding energy, a higher surface roughness and a larger amount of defect sites on the faceted Ir(210) surface. The results verify the theoretical prediction that faceting of Ir(210) is possible under electrochemical conditions. Cyclic voltammograms of Ir

Surface topography and contact mechanics of dry and wet human skin

• Alexander E. Kovalev,
• Kirstin Dening,
• Bo N. J. Persson and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 1341–1348, doi:10.3762/bjnano.5.147

• topography of the human wrist skin is studied by using optical and atomic force microscopy (AFM) methods. By using these techniques the surface roughness power spectrum is obtained. The Persson contact mechanics theory is used to calculate the contact area for different magnifications, for the dry and wet

• and AFM data we have obtained the surface roughness power spectrum over all relevant length scales. This enabled us to perform a more accurate theoretical contact mechanics study of the frictional properties of skin, which we will report on in this paper. Experimental The topography of human wrist

• skin and (121.4 ± 1.6)° (n = 9) on wet skin. The larger contact angle on wet skin could reflect either a change in the skin surface chemistry, or more likely may be due to the increase in the surface roughness of wet skin. The receding contact angle was not measured but it would be smaller than the

Observation and analysis of structural changes in fused silica by continuous irradiation with femtosecond laser light having an energy density below the laser-induced damage threshold

• Wataru Nomura,
• Tadashi Kawazoe,
• Takashi Yatsui,
• Makoto Naruse and
• Motoichi Ohtsu

Beilstein J. Nanotechnol. 2014, 5, 1334–1340, doi:10.3762/bjnano.5.146

• decreased as the surface roughness increased. In addition, we found that the reflected light spectrum changed as degradation proceeded. We analyzed the details of the degradation by measuring instantaneous reflectance changes with a pump–probe method; we observed an increase in the generation probability of

• relation between laser-induced degradation and surface roughness is revealed, it may contribute to the development of a surface polishing technology for optical components with higher resistance against not only laser-induced damage but also degradation. Moreover, the clarification of the mechanism and

• relaxation lifetime, we found that compositional changes in the molecular structure occurred as laser-induced degradation proceeded. Results and Discussion 1 Evaluation of laser-induced degradation of fused silica 1.1 Surface roughness dependence of threshold fluence in laser-induced degradation First, to

Review of nanostructured devices for thermoelectric applications

• Giovanni Pennelli

Beilstein J. Nanotechnol. 2014, 5, 1268–1284, doi:10.3762/bjnano.5.141

• surface is assumed. On the basis of these intriguing experimental results, several works [62][63][64][65][66][67] developed theoretical models for phonon boundary scattering, taking into account coherent effects. For an appropriate scale of surface roughness, these coherent effects can be important for

• limited by impurity scattering and the electron mean free path is very small with respect to the nanowire diameter. Thus, in nanowires wider than 20–40 nm, phonon thermal conduction kph can be strongly reduced by increasing the surface roughness, meanwhile the electrical conductivity remains comparable

Physical principles of fluid-mediated insect attachment - Shouldn’t insects slip?

• Jan-Henning Dirks

Beilstein J. Nanotechnol. 2014, 5, 1160–1166, doi:10.3762/bjnano.5.127

• and smooth surfaces by maximizing the contact area and achieving close contact [27][28]. In contrast to the hairy adhesives, smooth pads of insects increase the contact area by adapting as a whole to the surface roughness (Figure 1F, [29][30][31][32]). Smooth adhesive organs can be found in many

• adhesive fluid increased adhesion, as the additional fluid compensated the surface roughness and thus increased the effective contact area [16][46]. In addition, the presence of adhesive fluid has been shown to improve the self-cleaning of the adhesive pads in comparison to dry adhesive pads [47][48

Organic and inorganic–organic thin film structures by molecular layer deposition: A review

• Pia Sundberg and
• Maarit Karppinen

Beilstein J. Nanotechnol. 2014, 5, 1104–1136, doi:10.3762/bjnano.5.123

• control of the electrical properties is required for storage capacitors, non-volatile memories as well as for transparent thin-film transistors [18][19]. Moreover, the tunability of the surface roughness is advantageous when fabricating gas sensors [20]. Over the years a number of excellent reviews

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

• . californiae and the influence of the stiffness of the underlying skin layers and the surface roughness of the substrate on the frictional coefficient [10]. In the present study, we used a similar experimental setup to characterise frictional properties of the SIMPS. Additionally, frictional properties of a

• geometries of the other microstructured surfaces due to the comparison of surface roughness of the investigated surfaces (Table 5). Referring to the threshold of detectable microstructure dimensions and the corresponding roughness value, it can be concluded that the interaction between the investigated

• PGMS in perpendicular direction to the microstructure at a dimension of 25 µm. Sondhauß et al. [38] and Baum et al. [44] concluded that the frictional response is dominated by the geometry of the tribo-pair. Based on these assumptions they stated that moderate modification of surface roughness can

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

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

• surface roughness. The crystal size (length and thickness) decreased with an increase of the chain length of the alkanes that formed these surfaces, whereas the density of the wax coverage, as well as the surface roughness, showed an opposite relationship. Traction tests demonstrated a significant, up to

• (Figure 2, Table 1). Values of the surface roughness parameters dropped by factors of 7–9, when C36 was compared with C50. Both middle-chain alkanes created surfaces with relatively similar mid-range roughness. All four wax samples showed superhydrophobic properties: apparent contact angles of water

• differences in the wax coverage micromorphology caused distinctions in the surface roughness. Samples bearing looser coverage were composed of larger (longer and thicker) crystals and were rougher than samples with smaller (shorter and thinner) crystals covering the surface more densely. Since the surface

A nanometric cushion for enhancing scratch and wear resistance of hard films

• Katya Gotlib-Vainshtein,
• Olga Girshevitz,
• Chaim N. Sukenik,
• David Barlam and
• Sidney R. Cohen

Beilstein J. Nanotechnol. 2014, 5, 1005–1015, doi:10.3762/bjnano.5.114

• related to changes in surface roughness [42], as we have previously shown that roughness does not vary with thickness for these films [37]. Nonetheless, local roughness can significantly affect the absolute values of friction coefficient measured in single and multiple asperity friction experiments [43

Direct observation of microcavitation in underwater adhesion of mushroom-shaped adhesive microstructure

• Lars Heepe,
• Alexander E. Kovalev and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2014, 5, 903–909, doi:10.3762/bjnano.5.103

• velocities (400 µm/s and 800 µm/s) a suction effect of about 10% contributed to the overall pull-off force [17]. This was explained by air being able to percolate through the contact interface (due to, e.g., surface roughness resulting in partial contact) and instantaneously balancing the pressure in the

Fibrillar adhesion with no clusterisation: Functional significance of material gradient along adhesive setae of insects

• Stanislav N. Gorb and
• Alexander E. Filippov

Beilstein J. Nanotechnol. 2014, 5, 837–845, doi:10.3762/bjnano.5.95

• spectral density. Here A is amplitude of surface roughness, i is imaginary unit, qx are Fourier components along x direction, and ζ is a random phase. Details of the generation procedure for the profile Y(x) have been described in a number of previous papers [19][20]. In the current literature [21] it is

• different from gradients reported in hairy pads of ladybird beetles [12]. Smooth adhesive pads consist of a softer core covered by a stiffer layer, whereas hairy pads have opposite arrangement: stiffer bases combined with softer distal part. Both types of gradients combine conformability to the surface

• roughness of the substrate and resistance to the environment. The opposite directionality of gradients can be well explained by difference in pad architecture. Smooth pads consist of branching rods or cellular foams, which in combination with fluid-filled spaces between solid structures hold the shape of

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

• the rough surface respectively, f1 + f2 = 1. (L/l)D−2 is the surface roughness fractor. L and l are the extremal dimensions of the upper and lower limits of the fractal surface respectively. D is the fractal cone. For the heart valves, L and l correspond to the diameter of the cobblestones and the

• dimension of the nano-cilia respectively. In the Koch curve, D is about 2.2618 in three-dimensional space and (L/l) is 3n, where the size of n is determined by the specific fractal structure, and the surface roughness factor will increase with the increasing of n. Therefore, if the upper limit L is constant

Biocalcite, a multifunctional inorganic polymer: Building block for calcareous sponge spicules and bioseed for the synthesis of calcium phosphate-based bone

• Xiaohong Wang,
• Heinz C. Schröder and
• Werner E. G. Müller

Beilstein J. Nanotechnol. 2014, 5, 610–621, doi:10.3762/bjnano.5.72

• cells retain their capacity to synthesize HA crystallites. Furthermore, the mechanical properties, including surface roughness and hardness, of the hydrogel were determined. If silica is included in the hydrogel matrix, the encapsulated SaOS-2 cells were found to increasingly express the gene encoding

Towards precise defect control in layered oxide structures by using oxide molecular beam epitaxy

• Federico Baiutti,
• Georg Christiani and
• Gennady Logvenov

Beilstein J. Nanotechnol. 2014, 5, 596–602, doi:10.3762/bjnano.5.70

• the mixed termination of the substrate can act in the direction of smearing these terraces given the fact that the surface roughness of each of the terraces is comparable to half of the La2CuO4 molecular layer size of about 0.65 nm. The XRD θ–2θ scan for a La2NiO4–La2CuO4 bi-layer is shown in Figure 5

DNA origami deposition on native and passivated molybdenum disulfide substrates

• Xiaoning Zhang,
• Masudur Rahman,
• David Neff and
• Michael L. Norton

Beilstein J. Nanotechnol. 2014, 5, 501–506, doi:10.3762/bjnano.5.58

• of the cross-like DNA origami structure on a mica surface are shown in Figure 1b and Figure 1c. The surface morphology and surface roughness of the MoS2 mineral sample were investigated by using AFM. As anticipated, the newly cleaved pristine MoS2 surface was very smooth, featureless, and homogenous

• constructs. While the surface roughness increased significantly to 5.3 Å after surface modification (Figure 3a), we found that DNA nanostructures remained intact in the presence of the 1-pyrenemethylamine adhesion layer (Figure 3b–d), in contrast to the DNA nanostructures deposited on the bare MoS2 surface

Effect of contaminations and surface preparation on the work function of single layer MoS₂

• Oliver Ochedowski,
• Kolyo Marinov,
• Nils Scheuschner,
• Artur Poloczek,
• Benedict Kleine Bussmann,
• Janina Maultzsch and
• Marika Schleberger

Beilstein J. Nanotechnol. 2014, 5, 291–297, doi:10.3762/bjnano.5.32

• table power. The chamber pressure was adjusted to 8·10−3 mbar during this procedure. Reactive ion etching was employed to locally alter the surface roughness and introduce defects in the SiO2 substrate [30][31]. The resulting structures on the SiO2 surface consist of etched holes with a depth of about

• values in the range from 4.74 eV to 5.54 eV have been reported as well [50][51]. Surface roughness, homogeneity and humidity can have an effect on the measured work function of metal surfaces as Guo et al. recently demonstrated [52]. The presented data is measured in situ after annealing and we are

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

• ; Figure 2f,h; Figure 3f,h). Stick-slip behavior of randomly-rough surfaces (RRS) with different grain size The frictional measurements on RRS showed a strong influence of the surface roughness on the frictional coefficient. A minimum in friction was measured on a surface with grain size of 9 µm (Table 3

• partners like microstructured surfaces, meaning external vibrations lead to a "virtual" surface roughness and are thereby able to influence frictional properties in a comparable way. Reducing friction-induced instabilities by active dampening is advantageous due to simple controllability and adaptability

• microstructure. Additionally, by sliding along or across the microstructure, it was possible to investigate the influence of an anisotropic geometry of microstructures on frictional properties. The RRS samples with different grain sizes were used to investigate the influence of the surface roughness, the contact