题目：Shape Memory Polymers: Physics and Mechanics
Hang (Jerry) Qi (齐航),
Mechanical Engineering，University of Colorado, Boulder
Reconfigurable multifunctional structures, which allow combined changes of shape, functionality and mechanical properties on demand, require new adaptive materials and novel chemistry that permit reversible modulation of mechanical properties in effective manner. Shape memory polymers (SMPs) are
a unique class of smart materials
that can “memorize” their permanent (equilibrium) shape, be temporarily fixed in non-equilibrium shapes, and recover their permanent shape on command when exposed to heat, light, or other external stimuli. Because polymers are intrinsically soft, SMPs allow much larger shape change than other smart materials, such as shape memory alloys and piezoelectric materials. This makes them good candidates for the applications of reconfigurable multifunctional structures. In this presentation, we introduce some recent exciting development in SMPs, such as amorphous polymer based one-way SMP, semi-crystalline polymer based two-way SMP, and SMP based on light activated polymers. We will then focus on the physics and mechanics underlying the actuation of these materials and emphasize on developing physics-based large deformation constitutive models and applying these models to novel design of smart polymers applications. Finally, future works on developing material models for these materials are discussed.
About the speaker
Dr. Qi is an Assistant Professor in the Department of Mechanical Engineering at University of Colorado (CU) at Boulder. He received his bachelor and graduate degrees in Engineering Mechanics from Tsinghua University, Beijing, China, and received his doctor degree in Mechanical Engineering from Massachusetts Institute of Technology (MIT) in 2003. Prior to joining CU-Boulder in 2004, he did a one-year post-doctoral research at the MIT’s Institute of Soldier Nanotechnology (ISN), a research institute sponsored US Army Research. His past and current research includes theoretical and experimental investigation of structure-function relationships of polymers and elastomers, carbon nanotubes, biological composites and nano-structures, soft tissues, and cells, and development of soft materials-based sensors and actuators. He received the Junior Faculty Development Award from University of Colorado at Boulder (2005), the CAREER award from NSF (2007), Woodward Outstanding Mechanical Engineering Faculty (2007), and Mechanical Engineering Outstanding Research Award (2009). He is the Mechanical Engineering Chair Faculty Fellow (2008-2011)