Meeting Abstract
For nearly two decades the gecko adhesive system has inspired the fabrication of synthetic, gecko-inspired adhesive products. Although derived from the study of the natural system, these synthetics can illuminate details about the mechanisms of the biological system by creating a bidirectional pathway of knowledge. For example, geckos take advantage of small, hair-like structures on their toes called setae. The keratin-based setae soften in high humidity and become more adhesive. Consequently, shear adhesion of live geckos shows that whole animal adhesive performance is significantly impacted by humidity, but this is temperature-dependent. Specifically, whole animal adhesion increases as humidity increases, but only at low temperatures. Interestingly, the same is true for a gecko-inspired synthetic, except when ambient humidity was raised to 80% and temperature remains low. One hypothesis for this discrepancy is that the synthetic lacks the ability to change modulus at high humidity, and that this change is the key to improved adhesive performance in the natural system. To test this hypothesis, we measured adhesive performance by exposing polydimethylsiloxane (PDMS) gecko-inspired synthetic tape samples, each with its own modified modulus of elasticity, to the same set of conditions as previous studies (both the live gecko and synthetic). The results of our work elicit potential improvements for the synthetic and shed light on the adhesion mechanism of the natural system. The striking similarities between synthetic and natural adhesive systems offer the opportunity to conduct research that improves understanding of both systems concurrently.
