LiU Electronic Press
Download:
File size:
6880 kb
Format:
application/pdf
Author:
Karlsson, Nils (Linköping University, Department of Management and Engineering, Mechanics) (Linköping University, The Institute of Technology)
Title:
Multiscale mechanics and physics of nature’s dry adhesion systems
Department:
Linköping University, Department of Management and Engineering, Mechanics
Linköping University, The Institute of Technology
Publication type:
Student thesis
Language:
English
Level:
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE credits
Undergraduate subject:
Engineering Mechanics
Uppsok:
Technology
Pages:
47
Year of publ.:
2012
URI:
urn:nbn:se:liu:diva-89846
Permanent link:
http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-89846
ISRN:
LIU-IEI-TEK-A--12/01543--SE
Subject category:
Engineering and Technology
Keywords(en) :
dry adhesion, detachment, thermal fluctuations, interaction potential, FEM
Abstract(en) :

Dry adhesion systems adhere via physical bonds without any significant contribution from a liquid medium. In nature, these systems are found among the footpads of spiders, lizards and many other small animals, with high adhesion force, low detachment force and elfcleaning properties. These features are highly interesting for biomimetic man-made adhesives.

Heavy animals have an adhesion force much higher than its muscle force, and to enable detachment, they have evolved a functional surface with hair-like structures called setae. Each seta branches into numerous microcontact elements that interact with the contacting area.

This thesis continue on previous work, analyzing the functional surface in terms of contact geometries and stress distribution, and considers, for the first time, the effect of thermal fluctuations. Numerical and analytical results show how the muscle force is concentrated to a small fraction of the adhesion area, where each microcontact element is trapped in a potential well.

The rate of detachment depends on the maximal concentration of stress across the crocontacts. When a seta is axially loaded, the concentration of stress is minimized, whereas radial loading amplifies the concentration of stress by a factor of maximum 68 and enable detachment with the animal’s limited muscle force.

The results give theoretical insight in the adhesion and detachment of a functional surface. This knowledge is valuable and can be considered when constructing man-made adhesives with inspiration from nature’s dry adhesion solutions.

Supervisor:
Lindström, Stefan (Linköping University, Department of Management and Engineering, Mechanics) (Linköping University, The Institute of Technology)
Examiner:
Johansson, Lars (Linköping University, Department of Management and Engineering, Mechanics) (Linköping University, The Institute of Technology)
Available from:
2013-03-08
Created:
2013-03-08
Last updated:
2013-03-08
Statistics:
79 hits
FILE INFORMATION
File size:
6880 kb
Mimetype:
application/pdf
Type:
fulltext
Statistics:
113 hits