Martin Schadt

In 1970, the physicists Martin Schadt and Wolfgang Helfrich invented the twisted nematic field effect (TN-effect) in the Central Research Laboratories of F. Hoffmann-La Roche Ltd, in Basel, Switzerland.

The resulting patent CH532261 was licensed worldwide to electronics and watch industries and thus initiated a paradigm change towards flat panel field effect liquid crystal (LC) displays.

His interdisciplinary approach involving physics and chemistry became the basis for modern industrial LC-materials research and led to the discovery and production of numerous new functional molecules and new electro-optical effects.

In 1970, shortly after the invention of the TN-effect, he developed the first commercial room temperature nematic liquid crystal mixture with positive dielectric anisotropy,[1] used in the displays of the first Japanese digital TN-LCD watches.

As a key technology it enables contact free alignment and photo-patterning of monomeric and polymeric liquid crystals by optical means instead of mechanically.

Martin Schadt (2007)
Early prototype of an alpha-numeric LCD based on the twisted nematic field-effect as realized in the laboratories of the Central Research Laboratories of F. Hoffmann-La Roche Ltd. by Martin Schadt and Wolfgang Helfrich. Photo by courtesy of M. Schadt.