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

• the material composition of attachment pads and the distribution process of the adhesive secretion can potentially aid in the development of more effective artificial attachment systems. Keywords: adhesion; arolium; biomechanics; euplantulae; friction; functional morphology; tarsal secretion

• -walled attachment pads [29] and assists in chemical communication [30]. The tarsal secretion can facilitate these functions due to its chemical composition and the resulting physical properties. Chemical analyses of the tarsal fluid revealed that its composition differs between different insect groups

• but mostly contains water-soluble and lipid-soluble substances [31][32][33][34][35] creating lipid droplets in an aqueous fluid [27][36] or hydrophilic nanodroplets embedded in an oily continuous phase [23][37]. Additionally, the tarsal secretion could be a mixture of multiple substances that are

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

• the genus Nicrophorus have recently awakened the interest of scientists in the field of bioadhesion with regard to their tarsal secretion [2][3]. So far, the measurement of the physical strength and the description of the morphological traits of the attachment devices of various insects in the context

• 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

• demand to keep it fluid under the lower environmental temperatures than those experienced by its tropical congeneric N. nepalensis. The higher tropical temperatures might have exerted selective pressures that have kept the cuticular lipid layer (from which the tarsal secretion is derived) more viscous to

Structural and tribometric characterization of biomimetically inspired synthetic "insect adhesives"

• Matthias W. Speidel,
• Malte Kleemeier,
• Andreas Hartwig,
• Klaus Rischka,
• Angelika Ellermann,
• Rolf Daniels and
• Oliver Betz

Beilstein J. Nanotechnol. 2017, 8, 45–63, doi:10.3762/bjnano.8.6

• strength and viscosity of the tarsal secretion should be rather low, thereby decreasing viscous dissipation during tarsal retraction [48]. From this perspective, our four second generation emulsions SA2, OA2, SW2 and OW2 (all combining the hydrocarbons squalane or octacosane with the protein albumin or

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

• affect the attachment ability in this case, since the contact is mediated by the tarsal secretion and not by a solid–solid contact. Coming back to the abovementioned mechanisms of capillary forces and/or changes in the effective short-range van der Waals interaction, which might influence the humidity

• ]. Due to the high content of lipids in the tarsal secretions of the beetles, a direct effect of water capillary bridges can be neglected. Though, it cannot totally be excluded that the composition and properties of the tarsal secretion are altered by ambient humidity. Thus, for example, different

• contributions from viscous forces could be expected [31][53]. For C. septempunctata, viscosity of the tarsal secretion was found to be of order 20 mPa·s [31] and droplets of volumes around 1 fL of the tarsal secretion made contact angles smaller than 10° with freshly cleaved mica surfaces (calculation based on