报告题目：Bio-inspired Design of Stimuli Responsive Materials Based on a Bilayer Structure
报告人：Prof. Luyi Sun, Department of Chemical & Biomolecular Engineering, Institute of Materials Science, University of Connecticut
Dr. Luyi Sun is an Associate Professor and Castleman Professor in Engineering Innovation in the Department of Chemical and Biomolecular Engineering and Institute of Materials Science at the University of Connecticut. Dr. Sun’s current research focuses on the design and synthesis of nano-structured multifunctional materials for various applications, with a focus on energy and environmental engineering. Dr. Sun has published more than one hundred twenty (120) peer-reviewed journal articles. He is the inventor/co-inventor of forty (40) International and US patents/patent applications. Many of his patents have been licensed or commercialized. The scientific results by Dr. Sun’s group have been reported by major media including Chemical & Engineering News of the American Chemical Society, Plastics Engineering magazine of the Society of Plastics Engineers (SPE), Materials 360 of the Materials Research Society (MRS), Smithsonian Magazine, ScienceDaily, MSN, Yahoo, etc. Dr. Sun is a Fellow of the Royal Society of Chemistry as well as a Fellow of the Society of Plastics Engineers (SPE).
A bilayer structure composed of polyvinyl alcohol (PVA) or PVA composite thin film atop thick polydimethylsiloxane (PDMS) substrate was prepared. The bilayer structure shows dynamic strain-responsive optical properties. The transition between a transparent state to an opaque state can be easily achieved by uni-axially stretching and releasing the device. Also, a series of derivative mechanochromisms with capabilities of switching “on/off” fluorescence, changing fluorescent color, revealing/hiding information upon mechanical stimuli were prepared. Mechanical and/or moisture responsive wrinkling surface can also be achieved in a similar manner. By altering the chemical structure of the PVA top layer, three different moisture responsive dynamic wrinkling surfaces can be prepared. Selectively inducing chemical modification on the PVA surface can create moisture responsive patterned wrinkles, which can lead to applications in encryption, anti-counterfeit tab, and water indicator for circuits.