Spinner Marlene, Westhoff Guido, Gorb Stanislav N
1] Functional Morphology and Biomechanics, Zoological Institute, Kiel University, Am Botanischen Garten 9, 24118 Kiel, Germany [2] Institute of Zoology, University of Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany.
1] Institute of Zoology, University of Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany [2] Tierpark Hagenbeck gGmbH, Lokstedter Grenzstraβe 2, 22527 Hamburg, Germany.
Sci Rep. 2014 Jun 27;4:5481. doi: 10.1038/srep05481.
Hairy adhesive systems of microscopic setae with triangular flattened tips have evolved convergently in spiders, insects and arboreal lizards. The ventral sides of the feet and tails in chameleons are also covered with setae. However, chameleon setae feature strongly elongated narrow spatulae or fibrous tips. The friction enhancing function of these microstructures has so far only been demonstrated in contact with glass spheres. In the present study, the frictional properties of subdigital setae of Chamaeleo calyptratus were measured under normal forces in the physical range on plane substrates having different roughness. We showed that chameleon setae maximize friction on a wide range of substrate roughness. The highest friction was measured on asperities of 1 μm. However, our observations of the climbing ability of Ch. calyptratus on rods of different diameters revealed that also claws and grasping feet are additionally responsible for the force generation on various substrates during locomotion.
具有三角形扁平尖端的微观刚毛组成的多毛粘附系统在蜘蛛、昆虫和树栖蜥蜴中趋同进化。变色龙的脚底和尾巴腹面也覆盖着刚毛。然而，变色龙的刚毛具有强烈拉长的窄刮刀状或纤维状尖端。到目前为止，这些微观结构的摩擦增强功能仅在与玻璃球接触时得到证实。在本研究中，在具有不同粗糙度的平面基板上，在物理范围内的法向力下测量了头盔变色龙指下刚毛的摩擦特性。我们发现变色龙刚毛在很宽的基板粗糙度范围内使摩擦力最大化。在1μm的粗糙面上测得的摩擦力最高。然而，我们对头盔变色龙在不同直径杆上攀爬能力的观察表明，爪子和抓握脚在运动过程中对在各种基板上产生力也有额外作用。
