Ultrablack color in velvet ant cuticle

• Vinicius Marques Lopez,
• Wencke Krings,
• Juliana Reis Machado,
• Stanislav Gorb and
• Rhainer Guillermo-Ferreira

Beilstein J. Nanotechnol. 2024, 15, 1554–1565, doi:10.3762/bjnano.15.122

• ]. Distinguished by its black integument adorned with contrasting patterns of black and white setae along its body (Figure 2), this species exhibits behavior akin to other females of the family. Frequently observed walking on exposed sandy soil, often in aggregations of bees (personal observation), T. bifurca also

• spines and setae (Figure 4). The setae display nanostructures in the form of grooves and are hollow (Figure 4D). No morphological distinction was observed between white and black setae (Figure 4A). The cuticle is composed of overlapping lamellae with connective pillars and underlying layers (Figure 5

• ). The SEM and TEM images of the T. bifurca cuticle reveal that the cuticle sculpturing and setae together with the black pigment may facilitate structural light absorption (Figure 5). The setae in Figure 4, with their grooved nanostructures and hollow interiors, and the stacked lamellae (see L in Figure

Hymenoptera and biomimetic surfaces: insights and innovations

• Vinicius Marques Lopez,
• Carlo Polidori and
• Rhainer Guillermo Ferreira

Beilstein J. Nanotechnol. 2024, 15, 1333–1352, doi:10.3762/bjnano.15.107

• surface of insects is equipped with hairs (sensu lato) with different morphologies. These structures may first be categorized into two main types, that is, setae, which have a socket (which originates from an adjacent cell) and microtrichia (not socked and thus originating from one cell) [39][40]. Such

• made up of setae and a notched inner surface. This structure was observed to be morphologically highly variable even within hymenopteran families [140], which may suggest that different habitat features (e.g., forests vs open grasslands or sandy soils vs clay soils) may require highly adapted cleaning

• hairs, antennal sensilla, and contaminating particles. Microscopic combs and brushes act as filters for particles of different sizes, with larger particles being scraped off by the bristles and comb, while smaller particles are picked up by the brush’s flexible setae. In the honeybee, hairs on the legs

Functional morphology of cleaning devices in the damselfly Ischnura elegans (Odonata, Coenagrionidae)

• Silvana Piersanti,
• Gianandrea Salerno,
• Wencke Krings,
• Stanislav Gorb and
• Manuela Rebora

Beilstein J. Nanotechnol. 2024, 15, 1260–1272, doi:10.3762/bjnano.15.102

• particle removal efficiency in intact insects and in insects with ablated grooming devices. The grooming devices are constituted of long setae from which a concave cuticular lamina develops towards the medial side of the leg. Each seta shows a material gradient of resilin from its basal to the distal

• devices In the distal portion of the fore tibia of both sexes of Ischnura elegans, modified setae in the form of flag-shaped structures were visible (Figure 1a,c,d). They are located on the medial side of the tibia, and their number ranged from 7.08 ± 0.27 in males to 6.27 ± 0.24 in females. They measure

• also sweep across the eyes. Antennal grooming organs have independently evolved in several insect orders, differing in the morphology and surface complexity of the involved structures [51][52]. These cleaning organs typically consist of modified setae and other cuticular projections that scrape and

The effect of age on the attachment ability of stick insects (Phasmatodea)

• Marie Grote,
• Stanislav N. Gorb and
• Thies H. Büscher

Beilstein J. Nanotechnol. 2024, 15, 867–883, doi:10.3762/bjnano.15.72

• different attachment mechanisms evolved in insects, namely, hairy pads consisting of flexible setae, which adapt to the surface topography, and smooth pads possessing a soft and deformable cuticle to comply with the substrate profile [9]. Both pad types, hairy and smooth, aim to maximize contact area with

• claws (Figure 7C) and on the mechanoreceptors of euplantulae (Figure 7I). While the contact sensilla on the euplantulae are usually found in pairs within groves without micro-ornamentation and are well recognizable (Figure 7H), the setae of the mechanoreceptors were often worn off in older animals

• system to statically hold the insect’s weight on the ceiling. Apart from insects, roughness plays a role in adhesion of non-arthropods as well. Roughnesses of 100–300 nm had the largest attachment-reducing effect for both single setae and whole geckos in experiments with the species Gekko gecko (Linnaeus

Functional fibrillar interfaces: Biological hair as inspiration across scales

• Guillermo J. Amador,
• Brett Klaassen van Oorschot,
• Caiying Liao,
• Jianing Wu and
• Da Wei

Beilstein J. Nanotechnol. 2024, 15, 664–677, doi:10.3762/bjnano.15.55

• length scales. Keywords: adhesion; fibers; fluid–structure interactions; mastigonemes; mechanosensing; setae; wettability; Introduction Given the bottom-up approach that biology uses to create materials, fibrous structures formed by molecular chains are found everywhere. For example, internally in the

• review include the hair and fur of mammals, the feathers of birds, the trichomes of plants, the setae of arthropods, and the ultrastructures of single-celled organisms. Figure 1A shows how the total hair mass mh scales with body mass mb. For mh, a material density of 1 g·cm−3 was assumed. A relationship

• ]. At the scale of insects, setae may also contribute to thermoregulation. Bumblebees, which inhabit globally northern regions, possess dense arrays of setae on their thorax, while other species of bees inhabiting the tropics and hot deserts have very sparse arrays of setae [36]. Such a stark difference

Comparative analysis of the ultrastructure and adhesive secretion pathways of different smooth attachment pads of the stick insect Medauroidea extradentata (Phasmatodea)

• Julian Thomas,
• Stanislav N. Gorb and
• Thies H. Büscher

Beilstein J. Nanotechnol. 2024, 15, 612–630, doi:10.3762/bjnano.15.52

• ) at their distal ends. The pretarsus features the arolium (ar) situated between a pair of claws (cl). The euplantulae, the cuticle between them, and the arolium bear a rather smooth surface structure. The remaining surface of the tarsomeres, where no attachment pads are situated, is covered with setae

• morphologically differ from the smooth ones examined herein. The differences between them manifest primarily in the morphology of the procuticle region. Hairy attachment organs are characterized by cuticle outgrowths (e.g., setae or acanthae [5][68][69][70][71]), whereas smooth attachment organs consist of

• , consequently, enhancing attachment [1][2][72][73]. Differences between smooth and hairy attachment pads The primary difference between hairy and smooth attachment organs manifests in the cuticular morphology. Hairy attachment organs consist of cuticle outgrows (e.g., setae or acanthae [5][68][69][70]), the

Insect attachment on waxy plant surfaces: the effect of pad contamination by different waxes

• Elena V. Gorb and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2024, 15, 385–395, doi:10.3762/bjnano.15.35

• experimentally supports the contamination hypothesis. Keywords: adhesion; Chrysolina fastuosa; Chrysomelidae; Coleoptera; epicuticular wax projections; tenent setae; traction force; Introduction It has been shown in numerous experimental studies that insects possessing hairy adhesive pads (i.e., specialized

• and the tips of tenent setae covering insect adhesive pads, which are responsible for establishing an intimate contact with the surface [14]. The fluid absorption hypothesis assumes that because of the high capillarity of the 3D wax coverage, the adhesive fluid may be absorbed from the insect pad

• [1][38]). Tenent setae of these pads have different shapes of the tip: (1) a flat discoidal terminal element in mushroom-like setae situated in the central part of the basal and distal tarsomeres (only in males, present in all legs); (2) a flat and widened end plate called spatula in setae located

Biomimetics on the micro- and nanoscale – The 25th anniversary of the lotus effect

• Matthias Mail,
• Kerstin Koch,
• Thomas Speck,
• William M. Megill and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2023, 14, 850–856, doi:10.3762/bjnano.14.69

• and the geometry of the setae with age and size of the animals. The authors find that the diameter of the fibres and their density in the toepad do not change with size in this species. The toepads scale isometrically with body size, and the setae get relatively shorter with body size. The scaling is

• , and therefore the surface is multifunctional. In the paper “Suspension feeding in Copepoda (Crustacea) – a numerical model of setae acting in concert”, Filippov et al. [20] present a numerical modelling approach to understand the influence of different parameters on the feeding efficiency of

• suspension feeding in common Crustacea. The results show that a system combining long and short setae with different mechanical properties has the best performance. The numerical simulation can in future be easily adapted to other systems and therefore be used for biomimetic developments (e.g., in the field

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

• -Luther-King-Platz 3, 20146 Hamburg, Germany Department of Cariology, Endodontology and Periodontology, Universität Leipzig, Liebigstraße 12, 04103 Leipzig, Germany 10.3762/bjnano.14.50 Abstract Suspension feeding via setae collecting particles is common within Crustacea. Even though the mechanisms

• behind it and the structures themselves have been studied for decades, the interplay between the different setae types and the parameters contributing to their particle collecting capacities remain partly enigmatic. Here, we provide a numerical modeling approach to understand the relationship among the

• mechanical property gradients, the mechanical behavior and the adhesion of setae, and the feeding efficiency of the system. In this context, we set-up a simple dynamic numerical model that takes all of these parameters into account and describes the interaction with food particles and their delivery into the

Growing up in a rough world: scaling of frictional adhesion and morphology of the Tokay gecko (Gekko gecko)

• Anthony J. Cobos and
• Timothy E. Higham

Beilstein J. Nanotechnol. 2022, 13, 1292–1302, doi:10.3762/bjnano.13.107

• adhesive pads is the contact area between the setae and the surface. With increasingly rough surfaces, the area for contact decreases, leading to decreased adhesive performance. In a modeling framework, the force of adhesion can be related to surface energy of the substrate, the area of the adhering pad

• body size, 2) do more compliant setae translate to higher adhesive force, and 3) do larger geckos exhibit greater adhesive force, relative to body mass? Additionally, to better understand how gecko adhesive structures interact with surface asperities on the setal level, we tested the impact of surface

• , and the average force per seta, are reliant upon the assumption that every single seta makes contact. Our results suggest that, even on incredibly smooth surfaces such as acrylic glass, quite a few setae are not in contact with the surface. However, there are other reasons for this mismatch. The manus

Laser-processed antiadhesive bionic combs for handling nanofibers inspired by nanostructures on the legs of cribellate spiders

• Sebastian Lifka,
• Kristóf Harsányi,
• Erich Baumgartner,
• Lukas Pichler,
• Dariya Baiko,
• Karsten Wasmuth,
• Johannes Heitz,
• Marco Meyer,
• Anna-Christin Joel,
• Jörn Bonse and
• Werner Baumgartner

Beilstein J. Nanotechnol. 2022, 13, 1268–1283, doi:10.3762/bjnano.13.105

• that are actually able to efficiently produce, process, and handle nanofibers, namely cribellate spiders. For that, the spiders use the calamistrum, a comb-like structure of modified setae on the metatarsus of the hindmost (fourth) legs, to which the 10–30 nm thick silk nanofibers do not stick due to a

• nm. In the spinning process, the spiders extract this silk from the cribellum (spinning plate) and process it by “combing” the fibers to form a puffy structure surrounding the axial fibers [10]. To process the fibers, the spiders use the calamistrum, a comb-like structure of modified setae on the

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

• substrates: hairy (setose) pads and smooth pads. Next, we will focus on the attachment systems used for terrestrial locomotion. Hairy pads are covered with setae, acanthae and microtrichia [33], fine cuticular surface outgrowths which, due to their small size and flexibility, can maximise the extent of

• extremely diverse, the design of attachment devices within insects can be subdivided into the two fundamental types of hairy and smooth attachment pads [1][3], as abovementioned, similarly at the level of the animal kingdom. In insects, the hairy structures consist of deformable adhesive setae, typically

• [133]. In many polyneopteran species the attachment pads have been described to be smooth; however, they are covered with cuticular patterns or protuberances [133]. These outgrowths have been differentiated from setae/acantae according to their low aspect ratio (height-to-width ratio). In contrast to

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

• species, males and females can show different attachment performances attributable to sex-specific adhesive hair morphologies [10]. In rosemary beetles (Chrysolina americana, Chrysomelidae), only males exhibit setae with discoid terminal ends and are thus able to generate higher attachment forces on

• . vespilloides beetles, we found tiny pores on the ventral cuticle between the adhesive setae (Figure 1, inset: white arrows). Such pores could not be detected in N. nepalensis. A pair of flexibly hinged claws was seen to insert at the distal end of the fifth tarsus. The ventral side of the T1-T4 mainly bore two

• different types of seta. The first type were setae with distinctly broadened tips (Figure 2, aI–aIV). The second type were bristle-like hairs with pointed tips (Figure 2 bI–bII). In both species, the number of hairs with broadened tips decreased from the fore to the hind tarsus, whereby the number of

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

• Notonecta use to maintain this air layer while submerged, Ditsche-Kuru et al. [12] investigated the micro- and nanostructure of the hemelytra of Notonecta glauca. They found that the upper side of the hemelytra is hierarchically structured by two types of setae and many microtrichia. One type of setae is

• tapered and bent and the tip points in an anterior-distal direction (Figure 1b). The other type is clubbed, the tip of this type points in a posterior direction (Figure 1b) [12]. In the present study, we investigated the micromorphology and innervation pattern of the two types of setae of Notonecta glauca

• and Notonecta maculata. In addition, we studied the mechanical interaction between the air-covered hemelytra, the setae and the surrounding water, especially in the case of pressure changes. This part of our study suggests that Notonecta can use its setae to detect pressure changes, e.g., those caused

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

• particular, for male ladybird beetles, research has shown that the adhesive setae feature a material gradient such that the elastic modulus of the material at the junction between the stalk and the divergent distal end is close to minimum. This soft material acts like a flexible joint, improving the bending

• micrometer-scale setae, to the nanometer-scale spatulae at the contact level, fibers are made from beta keratin [8] which has an elastic modulus of 1–4 GPa [9]. To enhance performance, given the high elastic modulus, all of the hierarchical levels forming the adhesive patch of the gecko are tilted rather

• than vertically aligned [10]. This tilt, in addition to enhanced performance [11], equips the gecko with directional adhesion properties as shown by Autumn et al. [12]. When they tested setae using a load–drag–pull (LDP) experiment, they found that setae exhibit very high interfacial shear and tension

Evidence of friction reduction in laterally graded materials

• Roberto Guarino,
• Gianluca Costagliola,
• Federico Bosia and
• Nicola Maria Pugno

Beilstein J. Nanotechnol. 2018, 9, 2443–2456, doi:10.3762/bjnano.9.229

• , display setae with a graded stiffness that optimises the adhesive performance on rough surfaces [1]. Hardness and stiffness gradients are of fundamental importance in the biomechanics of contacts, since they allow increased resistance against wear, impact, penetration and crack propagation [2][3][4][5][6

Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations

• Jaison Jeevanandam,
• Ahmed Barhoum,
• Yen S. Chan,
• Alain Dufresne and
• Michael K. Danquah

Beilstein J. Nanotechnol. 2018, 9, 1050–1074, doi:10.3762/bjnano.9.98

• insect cuticles was developed and mentioned in a review by Byun et al. [223]. The review focused on describing the structures using SEM images and highlights distinct insect wing morphologies. Generally, the characteristics of wax crystals that exist on the wing surfaces are described by the terms “Setae

• ”, “denticles” and “fractal”. The setae are needle or hair-like structures with a high aspect ratio; a denticle is structured with morphology ranging from smaller hemispherical to taller fractal; pillars are fine irregular nanoscale projections [223]. SEM images and photographs of various insect species and

• orders are provided. It is observed that wood termite (Schedorhinotermes sp.) and cicada (Meimuna microdon) wings are concealed by a denticle layer, while hornet (Vespa sp.) wings are covered by multiple setae. The water contact angles (WCA) are observed to be less than 150° for both the structures [224

Effect of microtrichia on the interlocking mechanism in the Asian ladybeetle, Harmonia axyridis (Coleoptera: Coccinellidae)

• Jiyu Sun,
• Chao Liu,
• Bharat Bhushan,
• Wei Wu and
• Jin Tong

Beilstein J. Nanotechnol. 2018, 9, 812–823, doi:10.3762/bjnano.9.75

• (HW1) and with the abdomen. The left and right sides of the internal face of the elytra were symmetrical. The 1st level, on the external surface of the epipleuron, is shown to have a patch of long setae in Figure 3f. It is bent sideways, but the exact direction is inconsistent. The 2nd level (Figure 3b

• , respectively; (c, h) the third-level microtrichia and sutural binding patches on the elytra; (d, e) the fourth-level microtrichia and patches of small spicules; and (f) the first-level microtrichia with a patch of long setae. (a) SEM photograph of the abdominal terga of H. axyridis; (b, c, d) the pattern of

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

• . Setae, rings in the cuticle around the base of setae, primary and secondary granules were imaged in fluorescent lighting on unstained samples (not all features were equally autofluorescent on all studied species). This autofluorescence effect can easily be distinguished by its weaker luminescence. On

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

• can adapt (acting like a soft material) and conform to rough surfaces of different length scales [36]. Their setae work least effectively on surfaces where the contact area of individual spatulae is split between several asperities (100 to 300 nm root mean squared roughness) [36]. Traction experiments

• [52], and the adhesive setae of geckos [53] the toe pads of tree frogs exhibit significant biomimetic potential to advance the technology of surface engineering. This is because they combine high friction under wet conditions [3] with self-cleaning [33]. Their main applications will likely be in the

Surface roughness rather than surface chemistry essentially affects insect adhesion

• Matt W. England,
• Tomoya Sato,
• Makoto Yagihashi,
• Atsushi Hozumi,
• Stanislav N. Gorb and
• Elena V. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1471–1479, doi:10.3762/bjnano.7.139

• to identify the most important parameters influencing insect attachment. Many insects, including beetles, can attach to inverted surfaces using specific hairy adhesive pads, covered with tenent setae, which secrete an adhesive fluid which typically consists of a mixture of alcohols, fatty acids, and

• adhesive setae, these beetles are able to walk on flooded substrates, including those under water. Their attachment to hydrophilic surfaces was reduced when under water, compared to their attachment in air; whereas the attachment to hydrophobic surfaces under water was considerably stronger, and comparable

• numerical predictions. Attachment of male C. septempunctata was significantly stronger on the smooth hydrophilic surfaces. This effect was less pronounced or even vanished on our textured surfaces, which has been previously explained by the differences in the contact shape of the tenent setae [23][38]. In

Influence of ambient humidity on the attachment ability of ladybird beetles (Coccinella septempunctata)

• Lars Heepe,
• Jonas O. Wolff and
• Stanislav N. Gorb

Beilstein J. Nanotechnol. 2016, 7, 1322–1329, doi:10.3762/bjnano.7.123

• tarsal soles of tenent setae, supplemented with an adhesive fluid. We studied the attachment ability of the seven-spotted ladybird beetle (Coccinella septempunctata) at different humidities by horizontal traction experiments. We found that both low (15%) and high (99%) relative humidities lead to a

• decrease of attachment ability. The significantly highest attachment forces were revealed at 60% humidity. This relationship was found both in female and male beetles, despite of a deviating structure of adhesive setae and a significant difference in forces between sexes. These findings demonstrate that

• not only dry adhesive setae are affected by ambient humidity, but also setae that stick due to the capillarity of an oily secretion. Keywords: adhesion; beetle; biomechanics; force measurement; friction; insect; locomotion; surface; Introduction Substrate attachment plays an important role in the

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

• reflected by gradients of the mechanical properties of the respective resilin-containing composites. The material composition of adhesive tarsal setae of beetles (Figure 2B) represents a good example for such gradients. Recently, the Young’s modulus of such setae was measured along the longitudinal axis of

• the setae (Figure 2C). The measurements revealed that the Young’s modulus of the material in the most distal section of each seta is relatively low (1.2 ± 0.3 MPa), whereas it is considerably higher at the setal base (6.8 ± 1.2 GPa). The differences in the Young’s modulus between different regions

• correlate with the resilin proportion observed in the seta material [48]. When the setae are dehydrated, the Young’s modulus of the setal tip material strongly increases from 1.2 to 7.2 GPa, and it exhibits no statistically significant differences along the complete setae [48], which is in accordance with

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

• ) ventral view, (B) claw of the foreleg, (C) setae of the pads on the ventral side of the gill lamellae, (D) areas with spiky acanthae on the lateral parts of the abdominal sternits. Reproduced with permission from [26]; (E) Structure on the distal edge of the ventral side of the beetle larva Elmis sp

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