Seminar
Title: |
Converting Light into Motion: Photoresponsive Azobenzene Liquid Crystal Polymer Networks |
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Speaker: |
Dr. Timothy White |
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Affiliation: |
Air Force Research Laboratory; Materials and Manufacturing Directorate |
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When: |
Thursday, March 10, 2011 at 11:00:00 AM |
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Where: |
Love Building, Room 183 |
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Host: |
Alexander Alexeev | |
Abstract Soft materials that efficiently transduce light into motion have shown cable of generating rapid, large magnitude deformations potentially useful in a range of applications including in aerospace and medicine. These large scale rapidly reconfigurable responses leverage the remote (wireless), spatial, and temporal control afforded by light as an input stimulus. We have synthesized a number of glassy, photoresponsive, liquid crystal polymers containing azobenzene in seeking improved light-to-work energy transduction. This talk will focus on two recent areas of examination. First, I will discuss flexural/torsional deformations (both static and oscillatory) that arise when the nematic director of the polymer is offset from the principal axes of a cantilever. The flexural/torsional response of these materials arises from a photoinduced shear gradient. Recently, we have developed new polymers that exploit the self-organizing properties of liquid crystals to generate larger magnitude bending and twisting. Secondly, I will present new results on the realization of light-activated shape memory in these materials. In preliminary findings, promising photo-fixity and all-optical shape fixing/shape restoration are realized. |
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Biography Timothy J. White received his B.A. in Chemistry in 2002 from Central College and a Ph.D. in Chemical and Biochemical Engineering in 2006 from the University of Iowa. He currently is a research engineer for the U.S. Air Force at the Air Force Reasearch Laboratory in the Materials and Manufacturing Directorated. His research currently focuses on photoresponsive materials, including cholesteric liquid crystals and liquid crystal polymers. |
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Notes |
Meet the speaker |
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