Inventor of an improved liquid crystal display, Fergason made his seminal discovery of the twisted nematic cell — a low-power, field-operated LC display — in 1969 while at the Liquid Crystal Institute at Kent State University, which he had joined in June 1966 as its associate director. These displays were superior to the earlier dynamic scattering displays, and soon became widespread.
The technology was patented in the United States in 1971, while Martin Schadt and Wolfgang Helfrich of Hoffmann-LaRoche patented similar technology in Europe. Also while at LCI, Fergason was part of an effort to use cholesteric liquid crystals for thermal mapping used, in particular, to screen for breast cancer. He participated in the discovery of the smectic C liquid crystal phase.
