Seminar 12/14/2011 - Ryan C. Hayward, University of Massachusetts-Amherst: Swelling-Induced Shaping of Constrained and Patterned Hydrogel Sheets
Abstract: The stresses developed when soft solids are swelled in the presence of constraints can lead to a variety of different elastic shape instabilities, depending on the constraining geometry. In one example, we study the surface âcreasingâ instability of thin layers confined in two-dimensions by attachment to a rigid substrate. We have verified that the conditions for instability are quite insensitive to both material properties and layer thickness, in agreement with simple predictions. Using temperature-responsive gels, we seek to elucidate the mechanisms of crease formation and growth, and take advantage of this instability as a way to create dynamic polymer surfaces with reconfigurable chemical patterns. In a second example, we consider the behavior of gel sheets internally constrained in their swelling through lateral variations in crosslinking. A newly developed method for patterning these materials provides access to opportunities for studying the controlled folding and buckling of gel micro-objects.
Bio: Ryan C. Hayward received his degrees in Chemical Engineering from Princeton University (B.S.E, 1999) and the University of California, Santa Barbara (Ph.D., 2004). Following a post-doctoral fellowship at Harvard University, he joined the faculty of the Department of Polymer Science and Engineering at the University of Massachusetts Amherst in 2006. His group works on a variety of topics in soft materials, including swelling-induced deformation of constrained and micro-patterned stimuli-responsive gels, and solution state self-assembly of polymer and particle-based nanostructures. He has received an NSF CAREER Award, a DOE Early Career Award, the ACS Division of Colloid and Surface Chemistry Unilever Award, the 3M Nontenured Faculty Award, and the Presidential Early Career Award for Scientists and Engineers.
All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.
Location: Bowen Hall Atrium
Date/Time: 12/14/11 at 12:00 pm - 12/14/11 at 1:00 pm
Category: PRISM/PCCM Seminar Series