Abstract
To explore the basic principles of hierarchical materials designed from nanoscale and up, we have been studying the mechanics of robust and releasable adhesion nanostructures of gecko [1]. On the question of robust adhesion, we have introduced a fractal-like hierarchical hair model to show that structural hierarchy allows the work of adhesion to be exponentially enhanced as the level of structural hierarchy is increased. We show that the nanometer length scale plays an essential role in the bottom-up design and, baring fracture of hairs themselves, a hierarchical hair system can be designed from nanoscale and up to achieve flaw tolerant adhesion at any length scales. For releasable adhesion, we show that elastic anisotropy leads to orientation-dependent adhesion strength. Finite element calculations revealed that a strongly anisotropic attachment pad in contact with a rigid substrate exhibits essentially two levels of adhesion strength depending on the direction of pulling.
Original language | English |
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Pages (from-to) | 141-150 |
Number of pages | 10 |
Journal | Bulletin of the Polish Academy of Sciences: Technical Sciences |
Volume | 55 |
Issue number | 2 |
Publication status | Published - 1 Jun 2007 |
Externally published | Yes |
Keywords
- Adhesion
- Anisotropic materials
- Bio-inspired mechanics
- Biological material
- Bottom-up design
- Contact mechanics
- Hierarchical materials
- Nanoengineering
- Nanotechnology
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Information Systems
- General Engineering
- Computer Networks and Communications
- Artificial Intelligence