主题：Cholesteric Liquid Crystals, Color Tuning and Their Applications
Abstract：Cholesteric liquid crystals (Ch liquid crystals) are self-assembled systems consisting of elongated chiral organic molecules. They process a helical structure where the local average direction of the molecules twists spatially around an orthogonal helical axis. They selectively reflect light. A variety of stimuli, such as voltage, light, heat and mechanical press, can be used to change the color and reflectance of cholesteric liquid crystals. They also exhibit two stable states in the absence of applied voltage. They can be used to make reflective displays which cost no energy. I will discuss the physics of reflection and phase transition in cholesteric liquid crystals. I will also their applications, such as reflective display, writing tablet, tunable color filter and temperature sensor.
Biography：Yang received his Ph.D. (1989) in Physics from University of Hawaii. He is a member of the Chemical Physics graduate faculty within LCI. His specialities include cholesteric liquid crystals, liquid crystal/polymer composites and electro-optic devices. He is co-inventor of bistable cholesteric display (BCD) technology, currently the world's most promising technology for electronic paper.