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

• does not always point in the ventral direction. In Figure 1, the beetle is attached to a substrate above it and the gravitational vector points almost exactly opposite to the attachment force. Buoyancy The density of water (ρw) is much higher than the density of air and is closer to the typical density

• important difference between adhesion in terrestrial and aquatic systems. Nevertheless, there are exceptions. Some terrestrial animals can step in droplets, e.g., on plant surfaces or even be completely submerged under water for a short time due to heavy rainfall. For example, the beetle Gastrophysa

• viridula can walk under water [43]. This beetle develops higher adhesive forces on hydrophobic surfaces compared to hydrophilic ones. The hydrophobic setose pads of the beetle hold air under water, so if it encounters hydrophobic surfaces the contact interface gets de-wetted, but not on hydrophilic

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

• work, in particular a more accurate in vivo measurement of the height of the mediating fluid and high-resolution single-leg force measurements on smooth substrates with well known physical properties are required to answer these questions [14]. Adhesive pad morphology of a male dock beetle (Gastrophysa

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

• experimental studies. The aim of this study was to examine the effect of different parameters of crystalline wax coverage on insect attachment. We performed traction experiments with the beetle Coccinella septempunctata and pull-off force measurements with artificial adhesive systems (tacky

• apparent contact angle of water, which were very close to those measured on plant surfaces bearing three-dimensional waxes (e.g., [49][50][51]). The tarsal attachment system of the C. septempunctata beetle used in this study has been previously described in detail by Gorb et al. [52]. The tarsus bears two

• the studied substrates were lacking surface structures suitable for claw interlocking (larger than 4 μm according to [1]), we assume that insect attachment relied solely on the performance of adhesive pads. Traction force tests demonstrated a great reduction in beetle attachment on microstructured

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

• fibers with longer soft tips on the stiff bases and fibers with stiff tips on the soft bases. This study not only manifests the crucial role of gradients in material properties along the setae in beetle fibrillar adhesive system, but predicts that similar gradients must have been convergently evolved in

• presented the combined study on the material structure and local mechanical properties in tarsal setae of the beetle Coccinella septempunctata and demonstrated the presence of a material gradient at the level of each single seta [12]. Setal elasticity modulus, probed by atomic force microscope (AFM), ranges

• gradients of material properties in real beetle setae was used in the numerical model presented below. Numerical model In principle, to model mechanics of the setae a classical beam theory can be applied. However, for long array of the beams it needs in extremely time consuming numerical calculation. To

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

• microstructures of the water skipper’s leg, the moth’s eye, shark skin, the darkling beetle, and the cicada’s wing [6][7][8][9][10][11][12][13][14][15]. At the same time, the relationship between superhydrophobicity and surface microstructures attracted strong interest. A large number of surfaces with all kinds

Impact of cell shape in hierarchically structured plant surfaces on the attachment of male Colorado potato beetles (Leptinotarsa decemlineata)

• Bettina Prüm,
• Robin Seidel,
• Holger Florian Bohn and
• Thomas Speck

Beilstein J. Nanotechnol. 2012, 3, 57–64, doi:10.3762/bjnano.3.7

• . Independent of superimposed microstructures we found that convex and papillate epidermal cell shapes slightly enhance the attachment ability of the beetles. Thus, in plant surfaces, cell shape and superimposed microstructuring yield contrary effects on the attachment of the Colorado potato beetle, with convex

• , claws generally improve grip [14][15] depending on the dimensions of the surface asperities and the insect’s claws [15][16]. If the diameter of the claw tip is smaller than the surface roughness, the claws can hook into the surface irregularities and the beetle thereby increases attachment forces. As in

• of the beetle. Similar to the findings of Voigt et al. [13], our results support the principal role of adhesive pads in attachment to both smooth and rough substrates. On petals of Rosa hybrid Floribunda cv. “Sarabande” traction-force measurements showed a distinctively higher variation towards

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

• in two types of experiments, where surface samples of (1) intact pitchers, (2) chemically de-waxed pitchers, and (3) their polymer replicas were placed horizontally. Beetle traction forces were measured when they walked on test surfaces in either an upward (towards the peristome) or downward (towards

• epidermal cells due to the drying process. The tarsus of the C. septempunctata beetle ends distally with two ventrally curved claws having tip diameters of 3.7 ± 0.64 μm (N = 10, Figure 3). Attachment pads belong to the hairy type of locomotory organs in insects. Pads and types of adhesive setae in this

• beetle species have been previously described in detail by [30]. Traction forces of beetles on different surface samples On intact pitcher surfaces bearing both lunate cells and epicuticular crystalline waxes, traction forces of insects were drastically reduced compared to those measured on a glass

Infrared receptors in pyrophilous (“fire loving”) insects as model for new un-cooled infrared sensors

• David Klocke,
• Anke Schmitz,
• Helmut Soltner,
• Herbert Bousack and
• Helmut Schmitz

Beilstein J. Nanotechnol. 2011, 2, 186–197, doi:10.3762/bjnano.2.22

• sensory organs, which can be found on the thorax or on the abdomen. In the pyrophilous beetle Melanophila acuminata infrared receptors and their associated sensory neurons are derived from mechanoreceptors [1]. Unlike other mechanosensory neurons, IR sensitive neurons directly send their information to be

• Buprestidae) can be classified as pyrophilous: About a dozen species of the genus Melanophila, which are distributed nearly all over the world except for Australia, and the ”fire-beetle” Merimna atrata, which is endemic to Australia [3][4]. Despite the fact that Melanophila and Merimna show almost the same

• buprestid genera are equipped with antennal smoke receptors and thoracic or abdominal IR organs [6][7][8][9]. Another pyrophilous beetle can also be found in Australia, i.e., the “little ash beetle” Acanthocnemus nigricans (family Acanthocnemidae). This inconspicuous beetle is only 4 mm long and highly