Biological and biomimetic materials and surfaces

• Stanislav Gorb and
• Thomas Speck

Beilstein J. Nanotechnol. 2017, 8, 403–407, doi:10.3762/bjnano.8.42

• area and thereby diminish the effectiveness of the biological adhesive system. In the paper by Crawford et al. [20], the authors experimentally tested the effect of surface roughness on the adhesive ability of the tree frog Litoria caerulea. They demonstrated that at small scale roughness, frog pad

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

• abrasion of the pad epithelium. Here, we tested the effect of surface roughness on the attachment abilities of the tree frog Litoria caerulea. This was done by testing shear and adhesive forces on artificial surfaces with controlled roughness, both on single toe pads and whole animal scales. It was shown

• experiments where the conformation of the pad to individual asperities was examined microscopically, our calculations indicate that the pad epithelium has a low elastic modulus, making it highly deformable. Keywords: adhesion; friction; Litoria caerulea; roughness; tree frog; Introduction Tree frogs exhibit

• medical field, as Chen et al. already demonstrated their potential for use as surgical graspers [54]. Experimental Experimental animals Tree frogs Litoria caerulea (n = 8), were used in these investigations. Their mass was 16.7 ± 6.5 g (mean ± standard deviation) and snout-vent length 57.6 ± 5.5 mm. The

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

• and tongue adhesion in frogs of the genus Ceratophrys [13][31]. The Litoria caerulea specimen studied herein was previously used for a study on toe-pad anatomy in tree frogs [32]. We examined the surface structures of frog tongues by using scanning electron microscopy (SEM). For SEM we prepared pieces

• from the surfaces of frog tongues. A – Bombina variegata, B – Discoglossus pictus, C – Ceratophrys ornata, D – Litoria caerulea, E – Megophrys nasuta, F – Rana (Lithobates) pipiens, G – Bufo bufo, H – Oophaga histrionica. Except for C. ornata (C) and O. histrionica (H), the fungiform papillae (grey

• data of tongue tissue fragments at the level of the lacunar layer. A – Bombina variegata, B – Discoglossus pictus, C – Ceratophrys ornata, D – Litoria caerulea, E – Megophrys nasuta, F – Rana (Lithobates) pipiens, G – Bufo bufo, H – Oophaga histrionica. In B. variegata (A), D. pictus (B), and L