A post-doctoral position is available in the Dept. of Chemical Engineering at the
University of Pittsburgh to conduct experimental research on developing
"morphing surfaces" that change topology by developing features such
as bumps, folds, spikes, etc. The post-doctoral fellow will develop (1)
surfaces that undergo a change in topology in response to applied stimuli, (2)
methods to control the shape and location of the morphing features on the
surface, and (3) quantitative or heuristic models to guide the design of
texture-changing surfaces.

This paper has been accepted for publication in Soft Matter. DOI: 10.1039/c0sm00335b.

A previous work suggested a critical condition to form surface creases in elastomers and gels. For elastomers, the critical condition seems to have closed a gap between experimental observations (e.g., by bending a rubber block) and the classical instability analysis by Biot. For gels, however, experiments have observed a wide range of critical swelling ratios, from around 2 to 3.7. Here we present a linear perturbation analysis for swollen hydrogels confined on a rigid substrate, which predicts critical swelling ratios in a similar range.

Inspired by recent works by Wei Hong , Xuanhe Zhao, Zhigang Suo, and their coworkers, we started a project on hydrogels, with particular interest in various instability patterns observed in experiments. The attachment is our first manuscript on this subject. Through this work we hope to achieve the following: