Abstract:

Cholesteric liquid crystals (Ch LCs) Bragg reflect visible light because of their periodic helical structure. They also exhibit two stable states at zero field: the reflecting planar texture and non-reflecting focal conic texture. Because of the bistability, Ch LCs can be used to make multiplexed displays on passive matrices. Because of the reflection, they do not need power-hungry backlights, and therefore are energy-saving. Also because of the bistability, they do not need to be addressed constantly to display static images, saving even more energy. Ch LCs can also be encapsulated to make flexible displays with plastic substrates, making the displays rugged and light-weight. Furthermore, they can be fabricated in roll-to-roll process. The merits of energy-saving, flexibility, lightweight，and ruggedness are highly desirable for E-books and E-signage. In this talk, I will address the optical properties of Ch liquid crystal, bistability and transitions between the textures as well as the encapsulation for flexible displays.

Biography:

Prof. Deng-Ke Yang received his Ph.D. (1989) in Physics from University of Hawaii. He is a member of the Chemical Physics graduate faculty within Liquid Crystal Institute. His specialties 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. He published 2 books on liquid crystal displays, 2 book chapters, and over 100 journal publications. He is an SID Fellow.