The effect of surface anisotropy in the slippery zone of Nepenthes alata pitchers on beetle attachment

• Elena V. Gorb and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2011, 2, 302–310, doi:10.3762/bjnano.2.35

• given in Figure 2. These cells are responsible for the anisotropic surface relief of up to 10 μm in height, whereas crystalline wax coverage creates an additional roughness in the range of about 1 µm. De-waxed pitcher samples and their polymer replicas displayed a very similar surface structure with a

Sorting of droplets by migration on structured surfaces

• Wilfried Konrad and
• Anita Roth-Nebelsick

Beilstein J. Nanotechnol. 2011, 2, 215–221, doi:10.3762/bjnano.2.25

• . In our approach, it is essentially the surface structure which is varied, not the contact angle. It may be speculated that suitably patterned surfaces are also utilised in biological surfaces where a large variety of ornamentations and surface structuring are often observed. Keywords: microdroplets

• droplet diameter. In our approach, it is essentially the surface structure which is varied, not the contact angle. The actual movement of the droplet on the continuously varying solid surface pattern depends both on the surface pattern and on the contact angle between droplet and solid. Therefore, it is

Moisture harvesting and water transport through specialized micro-structures on the integument of lizards

• Philipp Comanns,
• Christian Effertz,
• Florian Hischen,
• Konrad Staudt,
• Wolfgang Böhme and
• Werner Baumgartner

Beilstein J. Nanotechnol. 2011, 2, 204–214, doi:10.3762/bjnano.2.24

• , these replicas have a good resemblance to the surface structure (see Supporting Information File 4). As expected, the replicas did not exhibit an improved wetting behaviour if they were dried before the experiment. Under these conditions the contact angle is almost identical to the contact angle of the

• were recorded with a frame rate of 18 frames per second. Even in the first frame after contact, thus at about 50 ms after the droplet contacts the surface, the droplet is mostly spread and within 2 s the water is completely spread on the surface structure. Scale of Phrynosoma cornutum dipped into

Superhydrophobicity in perfection: the outstanding properties of the lotus leaf

• Hans J. Ensikat,
• Petra Ditsche-Kuru,
• Christoph Neinhuis and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 152–161, doi:10.3762/bjnano.2.19

• structure consisting of papillae with a dense coating of agglomerated wax tubules, which is the basis for the famous superhydrophobicity (Figure 1). However, a hierarchical surface structure which induces strong water repellency and contact angles above 150° is not a special feature of lotus leaves. It has

• regenerate damaged or lost waxes. Conclusion It is true that lotus exhibits outstanding water repellency on the upper side of its leaves. The basis of this behaviour is the hierarchical surface structure. In comparison to other species with a hierarchical surface structure composed of papillae and wax

• (SEM) image of the upper leaf side prepared by ‘glycerol substitution’ shows the hierarchical surface structure consisting of papillae, wax clusters and wax tubules. (c) Wax tubules on the upper leaf side. (d) Upper leaf side after critical-point (CP) drying. The wax tubules are dissolved, thus the

Capillary origami: superhydrophobic ribbon surfaces and liquid marbles

• Glen McHale,
• Michael I. Newton,
• Neil J. Shirtcliffe and
• Nicasio R. Geraldi

Beilstein J. Nanotechnol. 2011, 2, 145–151, doi:10.3762/bjnano.2.18

• origami or droplet wrapping. In this work, we consider how the conditions for the spontaneous, capillary induced, folding of a thin ribbon substrate might be altered by a rigid surface structure that, for a rigid substrate, would be expected to create Cassie–Baxter and Wenzel effects. For smooth thin

• consideration to ribbon-type substrates and disconnected solid grains with a rigid surface structure. We review the case for surface roughness that has low aspect ratio so that the liquid can penetrate into the structure – the Wenzel case [14][15]. We then consider whether droplet wrapping can occur without

• penetration into the surface structure – the Cassie–Baxter case [16][17]. We show that droplet wrapping should occur with both types of configuration and we derive a condition for the transition between these two cases; this condition is the same as for the Wenzel to Cassie–Baxter transition on a

Superhydrophobic surfaces of the water bug Notonecta glauca: a model for friction reduction and air retention

• Petra Ditsche-Kuru,
• Erik S. Schneider,
• Jan-Erik Melskotte,
• Martin Brede,
• Alfred Leder and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2011, 2, 137–144, doi:10.3762/bjnano.2.17

• gaps (underside of elytra) or even vanished completely after a few days (sternites). Moreover, the upper side of the elytra was able to keep an air film up to flow velocities of 5 m/s. Obviously the complex surface structure with tiny dense microtrichia and two types of larger specially shaped setae is

• ? (2) Is there a correlation between surface structure and air film persistence? (3) How is it possible to hold the air film under hydrodynamic conditions? (4) How much is the friction on the elytron surface reduced? Results and Discussion Characteristics of air retaining surfaces Notonecta glauca is

• surfaces in order to exclude an influence of a possibly different surface chemistry. The results show similar air film persistence on untreated and treated surfaces (Table 3). Consequently, the surface structure can be identified as the relevant feature. The air covering the surfaces can be identified by

Schottky junction/ohmic contact behavior of a nanoporous TiO₂ thin film photoanode in contact with redox electrolyte solutions

• Masao Kaneko,
• Hirohito Ueno and
• Junichi Nemoto

Beilstein J. Nanotechnol. 2011, 2, 127–134, doi:10.3762/bjnano.2.15

• surface structure by ligand exchange of the Fe2+/3+ center between CN− and Ti–O−. When both the methanol and the [Fe(CN)6]4− were present in the aqueous phase, the behavior was interesting. In the dark, the CV also showed clear reversible redox waves for the [Fe(CN)6]4−/3− couple (Figure 7) at 0.26 V vs

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

• Bharat Bhushan

Beilstein J. Nanotechnol. 2011, 2, 66–84, doi:10.3762/bjnano.2.9

• 5°, respectively. As shown in Figure 11 and Table 3, it is observed that both surfaces are oleophilic in solid–water–oil interface. To study the surface structure of an aquatic animal, experiments with water and oil droplets on the shark skin replica were performed in a three phase interface [20

Defects in oxide surfaces studied by atomic force and scanning tunneling microscopy

• Thomas König,
• Georg H. Simon,
• Lars Heinke,
• Leonid Lichtenstein and
• Markus Heyde

Beilstein J. Nanotechnol. 2011, 2, 1–14, doi:10.3762/bjnano.2.1

• height that is 10 pm lower than the average height of corresponding terrace sites (see Figure 11b). Knowing the surface structure with highest accuracy, it is still very desirable to determine aspects of electronic structures to gain further insight. In Figure 12, the effective contact potential is

• defect-free MgO. The NC-AFM investigation on aluminum oxide on NiAl(110) unveils the surface structure of the domain and at the APDBs with atomic resolution. Apart from the determined topography, F2+-like centers, which have been predicted by DFT calculations, were experimentally verified for the APDBs

The description of friction of silicon MEMS with surface roughness: virtues and limitations of a stochastic Prandtl–Tomlinson model and the simulation of vibration-induced friction reduction

• W. Merlijn van Spengen,
• Viviane Turq and
• Joost W. M. Frenken

Beilstein J. Nanotechnol. 2010, 1, 163–171, doi:10.3762/bjnano.1.20

• micronscale. This surface structure is formed by the 2-step RIE (Reactive Ion Etching) process used for etching the structures from an initially continuous polycrystalline silicon film. These surface features are consistently there, from die to die, and from run to run, although they are, of course, also

A collisional model for AFM manipulation of rigid nanoparticles

• Enrico Gnecco

Beilstein J. Nanotechnol. 2010, 1, 158–162, doi:10.3762/bjnano.1.19

• which is determined by several factors such as the scan pattern, the surface structure and the geometry of both tip and particle. Predicting the direction of motion of nanoparticles is very important, especially if it is desired to manipulate several particles at the same time. Here, we show that this

Sensing surface PEGylation with microcantilevers

• Natalija Backmann,
• Natascha Kappeler,
• Thomas Braun,
• François Huber,
• Hans-Peter Lang,
• Christoph Gerber and
• Roderick Y. H. Lim

Beilstein J. Nanotechnol. 2010, 1, 3–13, doi:10.3762/bjnano.1.2

• surface structure (Figure 6). In contrast, the Au surface topography does not change regardless of the scanning force used in 20% 2-propanol (poor solvent). This is due to the collapsed conformation of tethered PEG chains that offers minimal resistance against the AFM tip. The influence of solvent quality