Engineering Gecko-Inspired Adhesives
The last 20 years have seen considerable interest in bioinspired dry adhesives, based on discoveries regarding the adhesive system of the gecko and some arthropods. Such adhesives typically have the advantage of being reusable, leaving no residue, and allowing control of the adhesion through loading states. However, the number of practical applications of these adhesives remains small. One possible reason is that unlike in mechanical design, where design, simulation, and testing methodologies are all well established, there are significant gaps in all of these phases of engineering as applied to gecko-inspired adhesives. There are a variety of methods and metrics used for evaluating adhesives, often giving differing results, and even in some cases results that do not accurately reflect those observed in practical applications. Even with an accurate evaluation of an adhesive material, refining the design is challenging, as the design and manufacturing methods are typically time-consuming, overly constraining, or both.This dissertation begins with a discussion of testing methodologies and discusses a new force-control test apparatus developed to provide accurate measurements. We then consider how the incorporation of spatial variation as a bioinspired design principle allows for simplification of the design problem for more tailored adhesives. Finally, we discuss how a new manufacturing technique can allow for the fabrication of more complex adhesive geometries, and evaluate the performance of a material having one-way friction.