Meeting Abstract
S12-2 Monday, Jan. 7 08:00 - 08:30 Stick or Slip: Adhesive Performance of Geckos and Gecko-inspired Synthetics in Wet Environments STARK, Alyssa Y.; Villanova University alyssa.stark@villanova.edu http://www.alyssaystark.com
The gecko adhesive system has inspired hundreds of synthetic mimics principally focused on replicating the strong, yet reversible properties of the natural system. Indeed, geckos can attach and detach with relative ease while scaling vertical and even inverted surfaces. Perhaps even more remarkable, they can do this amidst spatially and temporally dynamic environmental conditions, including variation in substrate surface quality, temperature, and humidity. For geckos native to the tropics, substrates they utilize wet from high humidity and frequent rain. Paradoxically, van der Waals forces, the principal mechanism for gecko adhesion, reduce to zero when substrates separate even slightly by entrapped water layers. A series of laboratory studies show that geckos maintain their adhesive performance in many wet conditions, despite the negative repercussions of water in their environment. The mechanism for this is not fully clarified, and likely ranges in scale from the chemical and material properties of the gecko's contact structures (setae), to their locomotor biomechanics and decision making behavior when encountering water on a substrate they move across. Current work has focused on applying our results from the natural system to synthetic gecko-inspired adhesive systems, and improving their performance in wet conditions. Gecko-inspired synthetic adhesives have also provided a unique opportunity to test standing hypotheses about the natural system in non-pristine, semi-natural conditions replicated in the laboratory.