Suspension feeding in Copepoda (Crustacea) – a numerical model of setae acting in concert

• Alexander E. Filippov,
• Wencke Krings and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 603–615, doi:10.3762/bjnano.14.50

• these tips are also rather soft and flexible, similar to attachment hairs in insects showing high adhesion at the tips [58]; for in-depth reviews, see [59][60][61]. In contrast, the tips of the long setae did not emit blue signals. The simulation presented here takes into account the actual physical

Straight roads into nowhere – obvious and not-so-obvious biological models for ferrophobic surfaces

• Wilfried Konrad,
• Christoph Neinhuis and
• Anita Roth-Nebelsick

Beilstein J. Nanotechnol. 2022, 13, 1345–1360, doi:10.3762/bjnano.13.111

• “staying dry under water” for a much longer time [4][5]. Such surfaces usually feature functional structures that are larger than the wax crystals on the Lotus leaf (or other superhydrophobic leaf surfaces showing specially structured wax covers). Many of these surfaces possess hairs, such as those of the

• ) and the skin structure of springtails (Collembola, see Figure 3) [3][21][22], both of which are known to accommodate gas layers. Kariba weed (Salvinia molesta) In the case of Salvinia molesta, stable water/air interfaces form at the tips of leaf hairs, which are topped by eggbeater-like structures

• air layer between ship hull and water reduces the drag considerably. The physical basis of the capability of the Salvinia hairs to hold persistent air layers was the topic of various studies [5][26], which also included their elastic properties [27][28]. Main factors for the persistence and resilience

Roll-to-roll fabrication of superhydrophobic pads covered with nanofur for the efficient clean-up of oil spills

• Patrick Weiser,
• Robin Kietz,
• Marc Schneider,
• Matthias Worgull and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2022, 13, 1228–1239, doi:10.3762/bjnano.13.102

• slightly thinner (a few tens of micrometers) than the nominal material thickness. In this way, the laminated films experience only minimal embossing forces during their pass through the calender and the rough sandblasted surface of the heated roller pulls tiny polymer hairs out of the melted surface of the

• contact angle measurements, especially on hydrophobic surfaces, can further distort the measured values [30]. The quality of the nanofur in terms of its hydrophobicity and oil absorption quantity depends on several processing factors including length of the hairs, their density, and their overall

• the nominal thickness to compensate thickness variations in the processed film and to structure the film more uniformly. If the gap size is set just at or slightly above the nominal thickness, only the thickest parts of the film are structured. If the gap is too small, no hairs are pulled out of the

Interaction between honeybee mandibles and propolis

• Leonie Saccardi,
• Franz Brümmer,
• Jonas Schiebl,
• Oliver Schwarz,
• Alexander Kovalev and
• Stanislav Gorb

Beilstein J. Nanotechnol. 2022, 13, 958–974, doi:10.3762/bjnano.13.84

• end (Figure 2B). The medial surface of this tip was examined more extensively because it is used by bees to process and form propolis (Figure 4A). The spoon-shaped tip tapers towards the distal apex. On one side it exhibits an edge densely covered by smooth, long, and flexible hairs (hairy edge

• ), reaching over half of the mandible medial surface (Figure 4A,G), while the edge on the opposite site is sharp and hairless (sharp edge). Though, short, thin hairs grow on the mandible outside close to the sharp edge. A ridge runs along the centre of the medial surface of the mandible tip (central ridge

• the same height as the bristles and hairs. The outside of the mandible is covered with hairs evenly. Surface structures on bee mandibles SEM micrographs also revealed that bee mandibles are covered with anisotropic scale-like micropatterns (Figure 4). Most of the scales on the medial surface of the

Fabrication and testing of polymer microneedles for transdermal drug delivery

• Vahid Ebrahiminejad,
• Zahra Faraji Rad,
• Philip D. Prewett and
• Graham J. Davies

Beilstein J. Nanotechnol. 2022, 13, 629–640, doi:10.3762/bjnano.13.55

• , using experimental procedures approved by the University of Southern Queensland (USQ) and the University of Queensland (UQ) animal ethics and biosafety committees. The skins were shaved to remove the excess hairs and kept frozen at −20 °C on a flat aluminum surface, then sectioned using a surgical knife

Design and characterization of polymeric microneedles containing extracts of Brazilian green propolis

• Camila Felix Vecchi,
• Rafaela Said dos Santos,
• Jéssica Bassi da Silva and
• Marcos Luciano Bruschi

Beilstein J. Nanotechnol. 2022, 13, 503–516, doi:10.3762/bjnano.13.42

• temperature to be used in further tests. The porcine skin samples were obtained by dissection of skins from the ears of pigs (albinos and youngsters), which were recently slaughtered. The skin patches were washed, the hairs cut and, later, the patches were dissected in order to extract the epidermis and

Physical constraints lead to parallel evolution of micro- and nanostructures of animal adhesive pads: a review

• Thies H. Büscher and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2021, 12, 725–743, doi:10.3762/bjnano.12.57

• secondarily reduced in Zoraptera [59], several other groups include hairy structures. Adhesive hairs not only independently evolved in Dermaptera [96], Plecoptera [179], Phasmatodea [108][109], Dictyoptera [154], and Mantophasmatodea [2][59], but also reveal different stages of reversals or repetitive origins

• under compression but strong under tension, (4) anisotropy in fibre orientation, and (5) presence of fluid in the contact area. Adaptation to fractal substrate surfaces due to hierarchical organization Hairs with high aspect ratios in the hairy systems and internal fibres/filaments of smooth systems

• , reduced due to the reduced ability to form a close contact with rough substrata. Surface pattern and contact splitting The function of hairs/setae in hairy pads is partially discussed in the previous paragraphs. Comparative studies on different animal groups comprising hairy attachment pads reveal

A comparison of tarsal morphology and traction force in the two burying beetles Nicrophorus nepalensis and Nicrophorus vespilloides (Coleoptera, Silphidae)

• Liesa Schnee,
• Benjamin Sampalla,
• Josef K. Müller and
• Oliver Betz

Beilstein J. Nanotechnol. 2019, 10, 47–61, doi:10.3762/bjnano.10.5

• , Hauptstr.1, 79104 Freiburg, Germany 10.3762/bjnano.10.5 Abstract Our aim was to compare friction and traction forces between two burying beetle species of the genus Nicrophorus exhibiting different attachment abilities during climbing. Specifically, the interaction of adhesive hairs and claws during

• traction force measurements of entire animals, whereas the performance of single fore tarsi has been measured with a nanotribometer. Both the number and the special morphology of the tarsal tenent hairs of the fore, middle and hind tarsi have been investigated by scanning electron microscopy (SEM). The

• hairs. The precise way in which the viscosity of the adhesion-mediating tarsal secretion of insects influences friction performance remains the subject of debate. Nevertheless, subtle differences in the hydrocarbon profiles of the tarsal secretion, probably leading to a decreased fluidity in N

Bidirectional biomimetic flow sensing with antiparallel and curved artificial hair sensors

• Claudio Abels,
• Antonio Qualtieri,
• Toni Lober,
• Alessandro Mariotti,
• Lily D. Chambers,
• Massimo De Vittorio,
• William M. Megill and
• Francesco Rizzi

Beilstein J. Nanotechnol. 2019, 10, 32–46, doi:10.3762/bjnano.10.4

• sensory hairs found on crickets. To distinguish between rotation and translation normal to the substrate, two electrodes on a membrane were attached to the base of the pillar. The capacitive read-out indicates the movement of the pillar. High-density arrays were designed to increase the total capacitance

A new bioinspired method for pressure and flow sensing based on the underwater air-retaining surface of the backswimmer Notonecta

• Matthias Mail,
• Adrian Klein,
• Horst Bleckmann,
• Anke Schmitz,
• Torsten Scherer,
• Peter T. Rühr,
• Goran Lovric,
• Robin Fröhlingsdorf,
• Stanislav N. Gorb and
• Wilhelm Barthlott

Beilstein J. Nanotechnol. 2018, 9, 3039–3047, doi:10.3762/bjnano.9.282

• backswimmers (Notonecta sp.) are well known for their ability to retain air layers on the surface of their forewings (hemelytra). While analyzing the hemelytra of Notonecta, we found that the air layer on the hemelytra, in combination with various types of mechanosensitive hairs (clubs and pins), most likely

The effect of flexible joint-like elements on the adhesive performance of nature-inspired bent mushroom-like fibers

• Elliot Geikowsky,
• Serdar Gorumlu and
• Burak Aksak

Beilstein J. Nanotechnol. 2018, 9, 2893–2905, doi:10.3762/bjnano.9.268

• microscopy (CLSM) of a lateral view of discoidal (mushroom-shaped) adhesive hairs in a male ladybird beetle. Differences in the autofluorescence indicate the presence and distribution of different materials. Blue regions (transitions from the hair shaft to the tip structure) indicate portions of the soft

• , rubber-like protein resilin. Light blue regions (hair shaft and discoidal tip structure) mainly consist of stiffer chitinous material. Adapted from [32]. b) Scanning electron microscope (SEM) images of synthetic, polymeric, bent fibers inspired by the adhesive hairs of the beetle, showing joints between

Tuning adhesion forces between functionalized gold colloidal nanoparticles and silicon AFM tips: role of ligands and capillary forces

• Sven Oras,
• Sergei Vlassov,
• Marta Berholts,
• Rünno Lõhmus and
• Karine Mougin

Beilstein J. Nanotechnol. 2018, 9, 660–670, doi:10.3762/bjnano.9.61

• violin bow hairs observed at nanoscale by AFM, may cause strong consequences at mascoscopic scale during the stick–slip phenomenon of the rubbing hairs surfaces and in fine such different acoustic outputs. Therefore, control of the nanoscale interactions between two surfaces through chemistry and contact

Dry adhesives from carbon nanofibers grown in an open ethanol flame

• Christian Lutz,
• Julia Syurik,
• C. N. Shyam Kumar,
• Christian Kübel,
• Michael Bruns and
• Hendrik Hölscher

Beilstein J. Nanotechnol. 2017, 8, 2719–2728, doi:10.3762/bjnano.8.271

• properties [10][11][12][13][14][15][16][17][18]. This utilization is inspired by geckos, which have very impressive adhesion properties, originating from thousands of hierarchically arranged hairs covering their toes. The smallest hairs with a tip diameter of about 200 nm efficiently get in contact with

• GPa [30]. CNTs act similarly to the hairs of a Gecko, due to their diameters in the nanometer-range, they can bend quite easily when getting in contact with a rough surface. This effect enables effective contact splitting [31], which leads to an increased contact area, resulting in a high adhesion

Surfactant-induced enhancement of droplet adhesion in superhydrophobic soybean (Glycine max L.) leaves

• Oliver Hagedorn,
• Ingo Fleute-Schlachter,
• Hans Georg Mainx,
• Viktoria Zeisler-Diehl and
• Kerstin Koch

Beilstein J. Nanotechnol. 2017, 8, 2345–2356, doi:10.3762/bjnano.8.234

• hairs on the leaves. Agnique® SBO10 and the nonionic surfactant XP ED 75 increased the droplet adhesion and caused an increase of the TA from 20.9° to 85° and 90°, respectively. Scanning electron microscopy showed that surfactants with a hydrophilic–lipophilic balance value below 10 caused a size

• solubilization of the waxes and gas chromatography (GC–FID) and mass spectroscopy (GC–MS). Results Micromorphology of the leaf surface The micromorphology of leaf surfaces was investigated by scanning electron microscopy (SEM) and 3D light microscopy. Trichomes, commonly termed hairs, are slightly tilted, up to

• 2 mm in length, and are evenly distributed over the upper (adaxial) (Figure 1A,B) as well as the lower (abaxial) leaf sides. In contrast to the epidermal cells, the hairs were not covered with wax crystals. The epidermis cells are polygonal with undulated anticlinal cell boundaries (Figure 1C). The

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

• Notonecta (Figure 1c,d) with its double structure of longer hairs and a dense “carpet” of so-called microvilli. Based on the analysis of hundreds of aquatic and semiaquatic species, four criteria for the maintenance of persistent air layers underwater have been identified [3]. The structures on these

• the total internal reflection of light at the air–water interface. d) The backswimmers double structure of longer hairs (grey and yellow) and a dense “carpet” of smaller hairs (microvilli, green) is responsible for the long-term air-retention capability. Representation of the measurement of the air

Studying friction while playing the violin: exploring the stick–slip phenomenon

• Santiago Casado

Beilstein J. Nanotechnol. 2017, 8, 159–166, doi:10.3762/bjnano.8.16

• the stick–slip effect at the mesoscale. Two violin bow hairs were studied, a natural horse tail used in a professional philharmonic orchestra, and a synthetic one used with a violin for beginners. Atomic force microscopy characterization revealed clear differences when comparing the surfaces of both

• bow hairs, suggesting that a structure having peaks and a roughness similar to that of the string to which both bow hairs rubbed permits a better control of the stick–slip phenomenon. Keywords: atomic force microscopy; bow hair; friction; stick–slip; tribology; violin; Introduction Friction is

• dependence), bow position, tilt, inclination, and bow force [9][10][11] (see Figure 1). Therefore, if these parameters are fixed, we can use the resulting sound of a bow-stringed musical instrument as a signal to measure characteristics of the mesoscale friction between the bow hairs and the strings. However

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

• particle size is big enough for the tip of the hair (often a spatula) to make full contact, adhesion and friction forces are similar to those on smooth surfaces. Only when the spatula size is larger than the particle size do the forces decline. For instance, the setal hairs of geckos are built so that they

• in spiders yielded a similar result, with their adhesive hairs performing poorly when asperity sizes were between 300 nm and 1 µm [37]. The attachment of smooth adhesive pads is more complex. From our data, there is evidence of enhanced adhesion and friction when the wavelength of the surface is

From iron coordination compounds to metal oxide nanoparticles

• Mihail Iacob,
• Carmen Racles,
• Codrin Tugui,
• George Stiubianu,
• Adrian Bele,
• Liviu Sacarescu,
• Daniel Timpu and
• Maria Cazacu

Beilstein J. Nanotechnol. 2016, 7, 2074–2087, doi:10.3762/bjnano.7.198

• structures protruding from the surface at various angles, but generally in a radial direction from the sphere center. The diameter of the spheres is 80 ± 60 nm, and the hairs are of 20 ± 5 nm length and 2 ± 0.5 nm width. The analysis of the samples by IR spectroscopy (Supporting Information File 1, Figure S6

Functional diversity of resilin in Arthropoda

• Jan Michels,
• Esther Appel and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1241–1259, doi:10.3762/bjnano.7.115

• of hairs (setae) and applied shear force lead to the formation of a maximal real contact area without slippage within the contact [104]. This indicates that material flexibility is very important for the contact formation of adhesive pads. With a minimal normal load, flexible materials can create a

• composed of large proportions of resilin [10][127][129]. On the dorsal side of the pretarsus of the drone fly (Eristalis tenax), for example, hair plate sensilla with rather long and relatively thick hairs are present (Figure 9A–E). The base of each hair is surrounded

Frog tongue surface microstructures: functional and evolutionary patterns

• Thomas Kleinteich and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 893–903, doi:10.3762/bjnano.7.81

• smaller taxonomic scale. Further, the tongues of Megophrys nasuta, Rana (Lithobates) pipiens, Litoria spp., and Ceratophrys ornata all have unique characters, such as the hair-like protrusions on the flat tips of the filiform papillae in M. nasuta, the patches of hairs on the filiform papillae in R

Comparative kinematical analyses of Venus flytrap (Dionaea muscipula) snap traps

• Simon Poppinga,
• Tim Kampowski,
• Amélie Metzger,
• Olga Speck and
• Thomas Speck

Beilstein J. Nanotechnol. 2016, 7, 664–674, doi:10.3762/bjnano.7.59

• understood. After reception of mechanical stimuli by prey on trigger hairs, the two trap lobes begin to move towards each other. This initial motion is mainly driven by active hydraulic actuation (i.e., turgor-induced cell deformation) [4][5], but a relaxation of mechanically pre-stressed mesophyll cells

• Freiburg. General cinematographic analyses For filming fast closure motions, traps were stimulated with a nylon thread on the trigger hairs of one lobe and recorded with a high-speed camera (Motion Scope Y4, Redlake, USA, recording speed 100 fps) in combination with a macro objective lens (Zeiss Makro

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

• ) determination of the water adhesion force and the elasticity of individual hairs (trichomes) of the floating fern Salvinia molesta. (2) The investigation of human head hairs both with and without functional surface coatings (a topic of high relevance in the field of hair cosmetics) was performed. The method

• also resulted in the measurement of an elastic modulus (Young’s modulus) for individual hairs of 3.0 × 105 N/cm2, which is within the typical range known for human hair. (3) Finally, the accuracy and validity of the capillary adhesion technique was proven by examining calibrated atomic force microscopy

• 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

Equilibrium states and stability of pre-tensioned adhesive tapes

• Carmine Putignano,
• Luciano Afferrante,
• Luigi Mangialardi and
• Giuseppe Carbone

Beilstein J. Nanotechnol. 2014, 5, 1725–1731, doi:10.3762/bjnano.5.182

• reproducing such properties in artificial bio-mimetic adhesives [1][2][3]. In nature, many adhesive systems consist of arrays of hierarchical hairs or setae, enabling large contact areas and hence high adhesion owing to the van der Waals interaction forces [4]. This morphology enables many insects, spiders

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

• has fascinated scientists and the underlying mechanisms have been debated since the early days of light microscopy. From “gluten-filled sponges”, the interlocking of fine hairs, suction cups and adhesive secretions, many hypotheses about insect adhesion have been proposed over the last two centuries

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

• multiple contacts that contribute to an enhancement of overall length of the total peeling line [7]. We have recently shown that thin tape-like contact tips of hairs (setae) in combination with applied shear force lead to the formation of maximal real contact area without slippage within the contact [8