Draping Materials: Enabling Advanced Adhesives and Multifunctional Technologies

Alfred J. Crosby
University of Massachusetts Amherst
Thursday, February 6, 2014
Duke University Schiciano B | 4:30pm

Many materials in Nature demonstrate a unique ability to gently conform to complex topology while maintaining extreme robustness in mechanical strength. In a similar fashion, one of the oldest forms of synthetic materials, fabric, displays the same balance of properties that are virtually unmatched in any other mass-produced continuous material. Key to the presentation of such properties is the creation of materials with structural hierarchy, discretized combinations of lengths and angles, and interactions between flexible, yet stiff, components that permit rotational freedom. Although the use of fabric and fibers in technological solutions is not new, recent demands for new material functionality combined with lessons learned from inspirational biological examples have led to new questions and opportunities for furthering our understanding and guided-development of fabric-like materials. In this presentation, we describe the development of a gecko-inspired adhesive material, called Geckskin™, which can sustain large forces, permit easy release, and be reused without loss in performance. Building upon a scaling design principle, we demonstrate how the same balance of materials properties and geometry that controls draping leads to a unique set of interfacial properties. Furthermore, this link provides new understanding of how adhesion-based locomotion has developed in organisms ranging from insects to large lizards. We finish by highlighting recent efforts to assemble tailored nanoparticles into materials structures that possess fabric-inspired attributes on both sub-10nm as well as multi-centimeter length scales. These structures represent a new materials paradigm, possessing the functionality of inorganic cores with unique nanoscale properties combined with macroscale properties similar to fabric. Overall, these stories will provide insight into how we think as a group and learn from Nature, without losing focus on the importance of fundamental materials principles and engineering design.