Actuated adhesion elements with hierarchical structure for applications on technical surfaces

干胶表面提供了广泛的应用潜力，然而，它们的技术实现是复杂的，苛刻的和雄心勃勃的。这里提出的工作打算调查与层次设计的驱动微结构相对于一个重复的附件和脱离技术表面。分层结构使得不同的操作原理（原子相互作用、机械相互作用）的组合能够最大化粘合强度。外部致动使得能够附接和分离，并且此外，允许克服技术表面通常非常明显的形貌。在该项目的第一阶段，通过复制工艺制造这种微结构的分层粘附元件。在拉伸和剪切载荷下粘附元件的受控附接和分离可以通过气动致动来实现。为此开发的测量系统可以确定宏观力/运动，并对接触区域的微观过程进行可视化记录。研究工作的现状允许去到更复杂的各向异性粘附的情况。本项目的后续工作将集中在对各向异性粘附元件的研究上。取决于力的方向的所得粘附将允许系统地控制附接和分离功能。 测量数据将与有限元模拟进行比较，以了解这种分层系统的连接和分离过程的工作原理，并推导出技术实现的设计规则。除了基本的科学见解，计划验证与驱动先进的粘附系统的可持续性有关的制备过程（复杂性和局限性）。这里的决定性标准是通过应用复制技术可以实现的技术表面上的粘合系统的功能。

Dry adhesive surfaces provide a broad potential of application, however, their technical realisation is complex, demanding, and ambitious. The work proposed here intends to investigate actuated microstructures with hierarchical design with respect to a repeated attachment to and detachment from technical surfaces. The hierarchical structure enables the combination of different operating principles (atomic interactions, mechanic interactions) to maximise the adhesion strength. External actuation enables attachment and detachment and, in addition, allows to overcome topography which with technical surfaces typically is very pronounced. In the first phase of the project the fabrication of such micro-structured hierarchical adhesion elements by means of replication processes was shown. A controlled attachment and detachment of the adhesion elements under tensile and shear loading could be realised by pneumatic actuation. The measuring system developed for this purpose enables the determination of macroscopic forces/motions and the visual documentation of microscopic processes in the contact area. The present status of the research work allows to go over to more complex anisotropic adhesion situations. The continuation of the project applied here will focus on the investigation of anisotropic adhesion elements. The resulting adhesion which depends on the direction of force will allow a systematic control of the attachment and detachment function. The measurement data will be compared with FEM simulations in order to gain an understanding of the operating principles governing the attachment and detachment processes of such hierarchical systems as well as to deduce design rules for a technical realisation. Beyond basic scientific insight it is planned to validate the preparation processes (complexity and limitations) with regard to the sustainability of advanced adhesion systems with actuation. The decisive criterion here is the functionality of the adhesion systems on technical surfaces that can be achieved by applying replication techniques.