Meeting Abstract

27.1  Friday, Jan. 4  The Effect of Water on the Gecko Adhesive System STARK, A.Y.*; NIEWIAROWSKI, P.H.; DHINOJWALA, A.; BADGE, I.; Integrated Bioscience Program, The University of Akron, OH; Integrated Bioscience Program, The University of Akron, OH; Department of Polymer Science, The University of Akron, OH; Department of Polymer Science, The University of Akron, OH ays3@zips.uakron.edu

Although we now have thousands of studies focused on the nano, micro and recently whole animal mechanics of gecko adhesion on clean, dry substrates, we know very little about the effects of water on gecko adhesion. For many species of gecko however, rainfall frequently wets the natural surfaces they navigate. We investigated performance of the gecko adhesive system on surfaces fully submerged in water as well as those that were misted with water droplets (as might occur after rain). Although we found distinct limitations of the gecko adhesive system related to surface water and wetting of the adhesive toe pads, we also found that in certain conditions gecko adhesion is not significantly affected by water. While this result is not surprising based on the native environments many geckos inhabit, such as the tropics, anecdotal observations of geckos slipping on wet laboratory surfaces has been noted for years. The loss of adhesion on wet surfaces can be affected by a number of variables including interspecific variation, orientation of the surface, surface chemistry and surface utilization (e.g., clinging vs. running). To test these variables we compared locomotor performance on wet and dry surfaces at different orientations and with multiple species endemic to different environments. We also considered the effect of substrate surface chemistry, noting that geckos often perch and move on plant surfaces such as leaves. While loss of adhesive capability could be detrimental, it is possible that limitations on wet glass surfaces are not necessarily predictive of adhesive system performance on surfaces that are more similar to those in their native environment.