James Fergason just wanted to know if his thermal sensor was actually working. In 1958, the young researcher at Westinghouse Research Laboratories began experimenting with liquid crystals and ended up paving the way for innovations like forehead thermometers, mood rings, digital watches, computer monitors, three-dimensional video systems and flat panel TVs. Fergason, who now holds more than 130 US patents and more than 500 foreign patents, is being honored today with the $500,000 Lemelson-MIT Prize, the largest cash prize given in the US for invention. The award will be presented during a private ceremony at the Museum of Contemporary Art Chicago.James Fergason was awarded the $500,000 2006 Lemelson-MIT Prize, the largest cash prize in the US for invention. In 1963, Fergason patented the first practical application of liquid crystals. A few years later, he discovered the twisted nematic field effect of liquid crystals, which led to the creation of LCDs, now commonly used in laptop computer monitors, large-screen TVs, calculators, digital watches and medical devices. (Photo: Chris Conroy, courtesy Lemelson-MIT Program) "James Fergason's inventions are directly responsible for the creation of a multibillion dollar liquid crystal display industry that employs millions of people around the world," said Merton Flemings, director of the Lemelson-MIT Program. "But those are not his only contributions to society. He is also a staunch advocate for independent inventors and has dedicated countless hours to this cause. We recognize his outstanding achievements in the awarding of this year's $500,000 Lemelson-MIT Prize." Saw their potentialFergason did not discover liquid crystals, nor was he the first to experiment with them. He said he was "the first guy who saw what they were really good for."As a young researcher, Fergason needed a way to measure the accuracy of a temperature-measuring device and he thought liquid crystals might be useful because of their sensitivity to temperature fluctuations and their ability to reflect colors. At that time, liquid crystals were a little-known academic curiosity with no clear purpose.Fergason noticed other interesting properties of the materials as his experiments progressed. "When I started looking at liquid crystals, their optical activity caught my eye," he said in an MIT press releases. "They were intriguing as I got more and more into them. I found all kinds of things people hadn't thought about. They were the opposite of a mirror in terms of polarized light. It was great fun."He was issued his first patent in December 1963 for his use of cholesteric liquid crystals in temperature-sensing applications. This technique is still used today in products such as forehead thermometers and mood rings.Naturally twistedA few years later, in 1966, Fergason was recruited to join the Liquid Crystal Institute at Kent State University, where he discovered the twisted nematic field effect of liquid crystals -- the key discovery that led to the creation of today's LCDs.Fergason observed that liquid crystals are naturally twisted but can be untwisted with an electric current. Without a charge, light can pass through the liquid crystal cell. When varying amounts of voltage are applied, the liquid crystals can twist up to 90 degrees, like a Venetian blind, to block the light's path.Earlier attempts to develop LCDs required lots of power that degraded the liquid crystal materials quickly."Nobody thought you could switch polarized light efficiently enough to make a display out of it," he said. He proved that shuttering a liquid crystal requires very little energy, making nematic LCDs a highly efficient way to control light.In 1970, Fergason published a paper that broadly defined approaches for manufacturing nematic liquid crystal displays. He left the Liquid Crystal Institute and founded the International Liquid Crystal Co. (Ilixco), based in Menlo Park, Calif., to pursue his research and to commercialize LCDs.Article 'struck a chord'Fergason's article struck a chord almost immediately in the electronics community. "I got 1,200 reprint requests, which is highly unusual for someone in my business," he said. Companies from medical devices manufacturers to photocopier manufacturers were interested in the possibilities afforded by a low-power, low-voltage display that was compatible with integrated circuit drivers and produced a good contrast.Calculators and watches were the first products to benefit from Fergason's LCDs. Until then, products with digital displays lost their battery life quickly, making them undesirable to most consumers. LCDs were ideal for these low-voltage applications.The Gruen Watch Co. was the first to use Fergason's technology and to produce a digital watch with his display. "Everybody wanted a James Bond watch," Fergason recalled, "but when they found out they had to change the battery every two weeks, they weren't too interested. When they found out they could have a digital watch and keep the battery for two years, it became one of the top sellers."Despite the popularity of early LCD devices, their mass-market penetration in other applications still took another decade."When I was getting started, I would go on airplanes and count the number of products with liquid crystal displays in the Sharper Image catalogs," Fergason said. "Twenty, thirty, forty products would have liquid crystal displays. Now you go to the store and all the games, all the telephones ... there are hundreds of millions of products made with them."Championed inventorsOver the years, Fergason invented a number of other LCD applications. In 1983, he was issued a patent for surface-mode LCDs, which are used in products such as welding helmets and 3-D video viewing systems. The following year, he licensed a patent for polymer-dispersed liquid crystals (PDLCs) to Raychem Corp. These displays are used to make privacy windows that can change from clear to opaque with the flip of a switch.In 2001, Fergason founded Fergason Patent Properties, a company that broadly licenses his intellectual property on a nonexclusive basis to expand and enable new markets for electronic displays.The company -- also based in Menlo Park -- is currently developing three new LCD-based technologies. System synchronized brightness control (SSBC) improves the contrast and dynamic range of LCDs in flat-panel televisions, desktop and laptop computer monitors, rear-projection televisions and presentation projectors. StereoMirror 3-D monitors bring a new level of brightness, color saturation and sharpness to stereo 3-D desktop monitors. The RetroVue head-mounted projector is a sophisticated simulation system for in-vehicle training.In addition to his influence on the consumer electronics industry, Fergason champions the interests of independent inventors.In 2000, the Secretary of Commerce appointed him to the first Patent Public Advisory Committee. He advised the US Patent and Trademark Office on policy and operational issues, and he helped develop a quality improvement program that is still in effect.Nicholas Godici, a former commissioner for patents and acting undersecretary of commerce for intellectual property at the USPTO, vividly recalled Fergason's reception at the agency's Independent Inventor Conferences. "I can still picture Dr. Fergason standing before a packed house of aspiring inventors telling his story of hard work and success and the audience reacting as if he were a rock star," Godici said. "In fact, Jim Fergason is much more than that, he is an American hero."The Lemelson-MIT Program will also honor Sidney Pestka, inventor of disease-fighting interferons, with the $100,000 Lemelson-MIT Lifetime Achievement Award today.For more information, visit: web.mit.edu/invent