Donetsk Institute for Physics and Engineering, National Academy of Science, Ukraine.
J Theor Biol. 2011 May 7;276(1):126-31. doi: 10.1016/j.jtbi.2011.01.049. Epub 2011 Feb 3.
Most biological hairy adhesive systems of insects, arachnids, and reptiles, involved in locomotion, rely not on flat punches on their tips, but rather on spatulate structures. Several hypotheses have been previously proposed to explain the functional importance of this particular contact geometry: (1) enhancement of adaptability to the rough substrate; (2) contact formation by shear force rather than by normal load; (3) increase in total peeling line due to the use of an array of multiple spatulae; (4) contact breakage by peeling off. In the present paper, we used numerical approach to study dynamics of spatulate tips during contact formation on rough substrates. The model clearly demonstrates that the contact area increases under applied shear force, especially when spatulae are misaligned prior to the contact formation. Applied shear force has an optimum describing the situation when maximal contact is formed but no slip occurs. At such equilibrium, maximal adhesion can be generated. This principle manifests the crucial role of spatulate terminal elements in biological fibrillar adhesion.
大多数昆虫、蛛形纲动物和爬行动物的生物毛发粘性系统，参与运动，不依赖于其尖端的平面冲压件，而是依赖于匙形结构。先前已经提出了几种假设来解释这种特殊接触几何形状的功能重要性：（1）增强对粗糙基底的适应性；（2）通过剪切力而不是法向载荷形成接触；（3）由于使用数组多个匙形物，总剥离线增加；（4）通过剥离接触破坏。在本文中，我们使用数值方法研究了在粗糙基底上接触形成过程中匙形尖端的动力学。该模型清楚地表明，在施加剪切力时接触面积会增加，特别是当在接触形成之前匙形物未对准时。施加的剪切力具有最佳描述情况，此时形成最大接触但不会发生滑动。在这种平衡状态下，可以产生最大的附着力。这一原理体现了匙形末端元件在生物纤维状附着中的关键作用。
