title: Sticky gecko feet: the role of temperature and humidity.
abstract: Gecko adhesion is expected to be temperature insensitive over the range of temperatures typically experienced by geckos. Previous work is limited and equivocal on whether this expectation holds. We tested the temperature dependence of adhesion in Tokay and Day geckos and found that clinging ability at 12 degrees C was nearly double the clinging ability at 32 degrees C. However, rather than confirming a simple temperature effect, our data reveal a complex interaction between temperature and humidity that can drive differences in adhesion by as much as two-fold. Our findings have important implications for inferences about the mechanisms underlying the exceptional clinging capabilities of geckos, including whether performance of free-ranging animals is based solely on a dry adhesive model. An understanding of the relative contributions of van der Waals interactions and how humidity and temperature variation affects clinging capacities will be required to test hypotheses about the evolution of gecko toepads and is relevant to the design and manufacture of synthetic mimics.
authors.affiliation: Department of Biology, Program in Integrated Bioscience, University of Akron, Akron, Ohio, United States of America. phn@uakron.edu
authors.forename: Peter H
authors.initials: PH
authors.lastname: Niewiarowski
authors.forename: Stephanie
authors.initials: S
authors.lastname: Lopez
authors.forename: Liehui
authors.initials: L
authors.lastname: Ge
authors.forename: Emily
authors.initials: E
authors.lastname: Hagan
authors.forename: Ali
authors.initials: A
authors.lastname: Dhinojwala
mesh_terms: D000269:Adhesives; D000818:Animals; D006813:Humidity; D008116:Lizards / Q000502:physiology*; D013696:Temperature
chemical_list: D000269:Adhesives