The physical properties of the stick insect pad secretion are independent of body size
File(s)
Accepted version
Author(s)
Kaimaki, Domna-Maria
Andrew, Charlotte NS
Attipoe, Andrea EL
Labonte, David
Type
Journal Article
Abstract
Many insects use adhesive organs to climb. The ability to cling to surfaces is advantageous but is increasingly challenged as animals grow, due to the associated reduction in surface-to-volume ratio. Previous work has demonstrated that some climbing animals overcome this scaling problem by systematically altering the maximum force per area that their adhesive pads can sustain; their adhesive organs become more efficient as they grow, an observation which is also of substantial relevance for the design of bioinspired adhesives. What is the origin of this change in efficiency? In insects, adhesive contact is mediated by a thin film of a liquid, thought to increase adhesive performance via capillary and viscous forces. Here, we use interference reflection microscopy and dewetting experiments to measure the contact angle and dewetting speed of the secretion of pre-tarsal adhesive pads of Indian stick insects, varying in mass by over two orders of magnitude. Neither contact angle nor dewetting speed change significantly with body mass, suggesting that the key physical properties of the pad secretion-its surface tension and viscosity-are size-invariant. Thus, the observed change in pad efficiency is unlikely to arise from systematic changes of the physical properties of the pad secretion; the functional role of the secretion remains unclear.
Date Issued
2022-06-01
Date Acceptance
2022-06-01
Citation
Journal of the Royal Society Interface, 2022, 19 (191)
ISSN
1742-5662
Publisher
The Royal Society
Journal / Book Title
Journal of the Royal Society Interface
Volume
19
Issue
191
Copyright Statement
© 2022 The Author(s)
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/35730174
Subjects
Adhesiveness
Adhesives
Animals
Biomechanical Phenomena
Body Size
Extremities
Insecta
Surface Properties
adhesion
biological attachment
climbing
fluid mechanics
pad secretion
Publication Status
Published
Coverage Spatial
England
Article Number
ARTN 20220212
Date Publish Online
2022-06-22