Laboratory of Bio-inspired, Bionic, Nano, Meta Materials & Mechanics, Department of Civil, Environmental and Mechanical Engineering, University of Trento, Via Mesiano, 77, 38123 Trento, Italy. Center for Micro-BioRobotics, Istituto Italiano di Tecnologia, Viale Rinaldo Piaggio 34, 56025 Pontedera, Italy.
Bioinspir Biomim. 2020 Mar 20;15(3):035006. doi: 10.1088/1748-3190/ab72da.
Organisms like the octopus or the clingfish are a precious source of inspiration for the design of innovative adhesive systems based on suction cups, but a complete mechanical description of their attachment process is still lacking. In this paper, we exploit the recent discovery of the presence of hairs in the acetabulum roof of octopus suction cups to revise the current model for its adhesion to the acetabulum wall. We show how this additional feature, which can be considered an example of a hierarchical structure, can lead to an increase of adhesive strength, based on the analysis of the cases of a simple tape and an axisymmetrical membrane adhering to a substrate. Using peeling theory, we discuss in both cases the influence of hierarchical structure and the resulting variation of geometry on the adhesive energy, highlighting how an increase in number of hierarchical levels contributes to its increment, with a corresponding improvement in functionality for the octopus suckers.
章鱼或吸盘鱼等生物为基于吸盘的创新粘附系统的设计提供了宝贵的灵感来源，但它们的附着过程的完整机械描述仍然缺乏。在本文中，我们利用最近发现的章鱼吸盘髋臼顶存在毛发这一事实，来修正其与髋臼壁粘附的现有模型。我们展示了这种附加特征（可以被认为是分层结构的一个例子）如何基于对简单胶带和轴对称膜粘附到基底的情况分析，导致粘附强度的增加。使用剥脱理论，我们在这两种情况下讨论了分层结构的影响以及由此产生的几何形状变化对粘附能的影响，突出了分层级数的增加如何有助于其增加，从而提高章鱼吸盘的功能。
