Physics (Internal)

Wrinkling, Crumpling, and Snapping Polymer Surfaces

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract:
Upon the development of a critical stress, many materials and geometries experience a mechanical instability, which produces significant changes in geometry with small changes in stress. In nature, mechanical instabilities are ubiquitous with the definition of shape, morphology, and function. Examples range from fingerprints to the snapping of Venus Flytrap. Inspired by these examples, we use elastic instabilities to control the morphology and function of soft polymer surfaces. We present our control of kinetically-trapped and equilibrium wrinkle and crumple morphologies and our success in using these structures to biomimetically control properties ranging from adhesion to optics. Additionally, new efforts to use these instabilities in the characterization of early tissue formation will be presented.

BIOGRAPHY: Al is an Associate Professor in the Polymer Science & Engineering Department at the University of Massachusetts Amherst, which he joined in 2002. He received his BS degree in Civil Engineering and Applied Mechanics at the University of Virginia and his Ph.D. in Materials Science and Engineering at Northwestern University. He was awarded a National Research Council Research Fellowship for his postdoctoral research in the Polymers Division at the National Institute of Standards and Technology. At UMass, he has received many awards including the 3M Non-tenured Faculty Award (2003), the NSF CAREER Award (2004), the Army Research Office Young Investigator Award (2005), the Adhesion Society’s Young Scientist Award (2008), and the Rohm and Haas New Faculty Award (2008). His research interests include mechanics of hierarchical structures; polymer adhesion; biomimetic materials design; responsive surfaces and materials; elastic instabilities; deformation and fracture of thin films; polymer patterning; and nanocomposites.