bigsid4          http://ewh.ieee.org/r8/ukri/leos/IEEE%20photonics%20society%20logo.jpg

Field-Effect Liquid Crystal Displays, LC-Materials

& Optical Alignment of LCs

 Dr. Martin Schadt

MS High-Tech Consulting, CH-4411 Seltisberg, Switzerland

Friday, November 14, 2014 / 12:00pm-1:00pm@ HEC  101

Abstract:

Since the invention of the twisted nematic (TN) field-effect in 1970, the nematic liquid crystal display technology which is based on electric field-effects has made remarkable progress. Field-effects are characterized by polarization sensitive macroscopic molecular liquid crystal configurations with electrically tunable optical appearance. The unique electro-optical building block concept of field-effect LCDs enables the integration and individual optimization of anisotropic optical thin-films and silicon electronics in LCDs. The remarkable progress made over the past 45 years, renders today virtually all applications of the communication between man and machine possible. They range from reflective LCDs with “zero power” consumption, such as digital watch LCDs, or remotely controlled electronic price tags in Shopping centers, to iPhones and large size, ultra-high resolution 4k television LCDs. Since the beginnings in 1970 this development has been spurred by interdisciplinary R&D between physics, material sciences, synthetic chemistry, semiconductor electronics, and engineering. It includes TN-LCDs (1970), super-twisted nematic (STN)-LCDs (1980s), thin-film transistor (TFT)-addressed TN-LCDs for computer monitors in the early 1990s and beyond, and multi-domain LCD configurations. The latter became possible in the late 1990s either by electric fringe-field electrode geometries, or by photo-alignment/patterning of LC molecules. Further enhanced contrast, large angles of view and shorter response times were the result. Moreover, spin-offs into potential future types of field-effect LCDs, such as polymer stabilized blue phase LCDs and ferroelectric LCDs became possible. This development is reviewed with examples of the multidisciplinary R&D of the author and collaborators on electro-optical field-effects, liquid crystal materials and polarized optical alignment and alignment patterning of monomeric and polymeric liquid crystal molecules in LCDs and optical thin-films based on liquid crystal polymers.

 

Biography:

Dr. Martin Schadt was born on 16th August 1938 in Liestal, Switzerland. After having gained practical experience as electrician Martin Schadt majored in experimental physics at the University of Basel, Switzerland, where he received his PhD in 1967. He was granted a two year post-doctoral fellowship at the National Research Council, Ottawa, Canada, where he continued his research on the electronic and optical properties of organic semiconductors. In 1969 he and D.F Williams patented the first solid state, organic light emitting display (OLED). Dr. Schadt’s first professional association was with the watch company Omega, where he investigated atomic beam standards. In 1970 he joined the Central Research Laboratories of F. Hoffmann-La Roche Ltd., Basel. Except for two years in biophysics, his research focused on the development of electro-optical field-effects based on liquid crystals and on liquid crystal materials. 1970 Dr. Helfrich and Dr. Schadt invented the twisted nematic (TN)-effect at F. Hoffmann-La Roche. The Roche TN-field-effect patent was granted in 20 countries and was licensed world-wide to the emerging field-effect LCD industry by Roche. The invention initiated a paradigm change towards flat panel field-effect liquid crystal displays (LCDs) enabling today’s LCD industry. The search for correlations between molecular structures, material properties and display performance, which Dr. Schadt started in the early 1970s, enabled the development of new liquid crystals for TN- and subsequent field-effect applications. As a consequence the pharmaceutical company Roche established itself as a major liquid crystal materials supplier for the emerging LCD-industry. Apart from his pioneering work on OLEDs, the TN-effect and liquid crystal materials, Dr. Schadt and collaborators invented the linear photo-polymerization (LPP) technology in 1991 enabling alignment of liquid crystal molecules by light instead of mechanically. This opened up novel LCD configurations and LCD operating modes, as well as numerous anisotropic optical polymer thin-films. Until 1994 Dr. Schadt headed the Liquid Crystal Research Division of Roche. Based on its photo-alignment technology the Division was turned in 1994 into the spin-off company ROLIC Ltd, an interdisciplinary Research and Development Company which Dr. Schadt built-up and headed as CEO and delegate of the Board of Directors until his retirement from the operating business in October 2002. He is now active as a scientific advisor to research organisations and continues research in collaboration with partner companies as an independent inventor. He is inventor or co-inventor of 166 patent families filed in Europe (EP) and holds more than 119 US patents. He has published 191 papers in leading scientific journals, including chapters in 6 books. Dr. Schadt became a Fellow of the Society Information Display (SID) in 1992 and a Fellow of the European Academy of Sciences in 2011. He is inventor or co-inventor of 166 patent families filed in Europe (EP) and holds more than 119 US patents. He has published 193 scientific papers in leading scientific journals, has given more than 150 lectures and contributed to 6 books. He has received the following Awards: the Roche Research and Development Award (1987), a Special Recognition Award and a Best SID Paper Award (1987), the SID Karl Ferdinand Braun Award (1992). Together with W. Helfrich, he received the Aachener und Munchener Preis fur Technik und angewandte Naturwissenschaften (1994) and the Robert-Wichard-Pohl Prize of the German Physical Society (1996). Together with W. Helfrich and James Fergason, he received the IEEE Jun-ichi Nishizawa Medal (2008). In 2009 he received the Eduard Rhein Technoloy Prize. The G.W. Gray Medal of the British Liquid Crystal Society and the Blaise Pascal Medal for Material Sciences of the European Academy of Sciences (2010). The Frederiks Medal, highest recognition award of the Russian Liquid Crystal Society (2011). The Charles Stark Draper Prize of the US National Academy of Sciences (known as the “Engineering Nobel Prize”) together with G. Heilmeier, W. Helfrich and P. Brody (2012). European Inventor Award 2013 for Lifetime Achievement (2013). Fellow of US National Academy of Inventors NAI (2013). Honorary Prof. of Sichuan University, Chengdu (2013). Honorary Prof. of Nanjing University, Nanjing (2013).

 

For more information:

SID UCF Student Branch Chair: Fenglin Peng, fenglin@knights.ucf.edu

SID UCF Student chapter advisor: Prof. Shin-Tson Wu, swu@mail.ucf.edu

IEEE Photonics Society Chair: Ruidong Zhu, ruidong.zhu@knights.ucf.edu