1. 제목 : Exploiting mechanical instabilities on soft structured materials

2. 연사 : Shu Yang Ph.D.

            Associate Professor, Department of Materials Science and Engineering,

            University of Pennsylvania

3. 일시 : 2011년 6월 13일 (월) 10:30-11:30

4. 장소 : 301동 1512-2호

5. 내용 :

Mechanical instabilities in soft materials, precipitated by dewetting, swelling, and buckling during the production stage are often viewed as failure mechanisms that can interfere with the performance of devices. Nature, on the other hand, provides many examples of intrinsic, bottom-up effects from the phyllotactic growth of plants, to the pattern of animal stripes, and to fingerprints.  In these systems, instabilities, packing constraints, and simple geometries drive the formation of delicate, detailed, and beautiful patterns.

 

Taking a cue from Nature, we are interested in exploiting mechanical instability on patterned polymer surfaces for engineering complex, multi-functional structures.  Specifically, we study clustering and deformation of polymer pillars, pattern evolution and transformation in 2D and 3D porous membranes upon exposure to mechanical forces, including osmotic pressure, capillary force and shape memory effect. In each system, we compare the experiments with theoretical modeling to elucidate different mechanisms of mechanical instability in different soft materials systems, including elastomeric poly(dimethylsiloxane) (PDMS), responsive poly(2-hydroxy ethyl methacrylate) (PHEMA) based hydrogels, and shape memory polymers (SMPs). Finally, I will demonstrate potential applications in tunable dry adhesion, nanomanufacturing, and tunable optical display.

 

6. 약력 :

Ph.D., Chemistry and Chemical Biology, Cornell University, 1999
M.S., Chemistry and Chemical Biology, Cornell University, 1997

B.S., Materials Science, Fudan University, China, 1992

※ 문의 : 기계항공공학부  서갑양 교수 (880-9103)