Meeting Abstract
Recently, phospholipids have been discovered on the setal surfaces of the gecko adhesive system. These surface lipids have been hypothesized to affect a number of properties of gecko adhesive setae, including underwater adhesion/superhydrophobicity, ease of release, wear prevention, fibril condensation, and self-cleaning. Presently, surface lipids do not affect the adhesion of gecko toe pads underwater or their anti-wetting properties. Interestingly, however, removal of surface lipids directly results in increased adhesion on dry, hydrophilic surfaces, suggesting that removal of surface lipids corresponds to subsequent increases in setal surface energy. A potential increase in setal surface energy could have detrimental effects on many of the above-mentioned properties. Indeed, the surface energy of setae is critical in the self-cleaning property of gecko toe pads, as the adhesion energy between setae and dirt particles is generally lower than the adhesion energy between dirt particles and the substrate. Here we present data demonstrating the effect of surface lipids in the self-cleaning ability of gecko subdigital adhesive pads. We chemically removed surface lipids and measured resultant changes in the efficacy of gecko self-cleaning. The results of this study highlight the multifunctional capacities of the gecko adhesive system, which are not only important ecologically, but also important to the design and fabrication of multifunctional gecko-inspired synthetic adhesives.
