Harnessing Patterning in Polymeric Materials: From Creating Defect-free Devices to Sorting Damaged Cells

Condensed Matter lunchtime seminar

Harnessing Patterning in Polymeric Materials: From Creating Defect-free Devices to Sorting Damaged Cells

  • Event time: 1:00pm
  • Event date: 14th January 2008
  • Speaker: Anna Balazs (University of Pittsburgh)
  • Location: Room 2511,

Event details

Using theory and simulation, we examine two scenarios where chemical reactions induce novel pattern formation in polymeric materials. In particular, we investigate how photo-induced chemical reactions in polymeric mixtures can be exploited to create long-range order in materials whose features range from the sub-micron to the nanoscale. The findings point to a facile, non-intrusive process for manufacturing high quality polymeric devices in a low-cost, efficient manner. In the second study, we develop an efficient model for responsive gels that captures large-scale, two-dimensional deformations and chemical reactions within a swollen polymer network. Focusing on gels undergoing the oscillatory Belousov-Zhabotinsky reaction, we observe traveling waves of local swelling that form a rich variety of dynamic patterns, and give rise to distinctive oscillations in the gel's shape. The approach provides a useful computational tool for probing the dynamics of chemo-mechanical processes and uncovering morphological transformations in responsive gels. The results also facilitate the design of novel micro-pumps, micro-actuators, and micro-scale components that could be use to propel small robots. Finally, we consider a scenario involving patterned polymer films; by developing a three-dimensional computational model of fluid-filled, elastic spheres rolling on substrates patterned with diagonal stripes, we demonstrate a useful method for separating cells or microcapules by their compliance. Since mechanically and chemically patterned surfaces can be readily fabricated through soft lithography and can easily be incorporated into microfluidic devices, our results point to a facile method for carrying out continuous ''on the fly'' separation processes.

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

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