Participants: A.Crosby and J.Rothstein (coordinators) with K.Carter, B.Davidovitch, J.Davis, R.Hayward,
T.McCarthy, N.Menon, T.Russell, M.Santore, P.Wadworth, 9 Graduate Students and 1 Postdoctoral
Fellow

A material’s surface dictates most of its interactions with the environment, affecting properties ranging
from optical reflectivity to cell adhesion. Efforts to control surface structure across multiple length scales
thus lie at the heart of national initiatives for nano- and bio-technology. In Nature, elastic instabilities are
ubiquitous as ways to define the shape, structure, and function of surfaces. Examples include ridges on
plant leaves, wrinkles on human skin, and blebs (protrusions) in cell membranes. In synthetic
materials, elastic instabilities have been studied predominantly in the context of materials failure, with the
focus on how to avoid instabilities. However, over the past decade, elastic instabilities have begun to be
explored as mechanisms to rationally control polymer surface morphology.  Developing elastic
instabilities to their full potential will require a fundamental understanding of how the surface and bulk
materials properties define kinetically trapped and equilibrium surface structures. This IRG will develop a
new materials design paradigm that invokes elastic instabilities on polymer surfaces not only to arrange
surface structures into complex, long-range hierarchies, but also to define surface responsiveness,
thereby providing scaleable strategies for tuning response rate, sensitivity, selectivity, and magnitude of
materials properties.