Who Invented ‘Invisible’ Glass?

Have you ever peered through a microscope or gazed up through a telescope and wondered who made it possible to see through perfectly clear glass? From eyeglasses to windshields, “invisible” glass is everywhere — and we have National Inventors Hall of Fame^® Inductee Katharine Burr Blodgett to thank for it.

Read on to learn about this trailblazing chemist and physicist.

Studying Science

Blodgett was born in Schenectady, New York, on Jan. 10, 1898. At just 15, she earned a scholarship to Bryn Mawr College. In her senior year, she toured General Electric Co.’s labs and was encouraged by her tour guide — who happened to be future Nobel laureate and National Inventors Hall of Fame Inductee Irving Langmuir — to pursue graduate studies.

A chemistry major, Blodgett earned her bachelor’s degree from Bryn Mawr in 1917 and her master’s degree from the University of Chicago in 1918.

During her graduate studies, she contributed to the development of charcoal filtering applications for gas masks, which would be used in both World Wars.

Following her graduation, Blodgett became the first woman scientist at GE as she took on the role of research assistant to Langmuir.

She spent the next six years with the company, then chose to continue her education at the Cavendish Laboratory of the University of Cambridge. Here, she focused her research on the behavior of electrons in mercury vapor.

In 1926, Blodgett became the first woman to receive a doctorate in physics from the University of Cambridge. Following her graduation, Blodgett returned to GE as a research scientist.

Achieving Transparency

At GE in 1935, Blodgett made an important advance as she built on a discovery Langmuir had made years earlier. While Langmuir’s work had shown that a single water-surface monolayer could be transferred to a solid substrate, Blodgett’s research led her to discover that this process could be repeated to create multilayer films of any thickness. By creating multilayer, antireflective coatings on glass, Blodgett produced the world’s first completely transparent glass, or “invisible glass.”

Patented in 1938, this method, known as the Langmuir-Blodgett technique, essentially has remained unchanged since Blodgett's discovery. Eliminating distortion from reflected light in a variety of optical equipment, the technique has been used in products including eyeglasses, telescopes, microscopes, windshields, televisions, computer screens, and camera and projector lenses.

Additionally, growing uses for the Langmuir-Blodgett technique are found in scientific research and applications ranging from integrated circuit manufacturing to solar energy conversion.

Blodgett’s work has even made an impact on cinema. The 1939 film “Gone With the Wind,” known for its exceptionally clear cinematography, was the first major movie production to use Blodgett’s invisible glass.

During World War II, nonreflective lenses were used in submarine periscopes and airplane spy cameras. Blodgett also developed a “color gauge” to measure the thickness of coatings and continued to conduct more research on films until her retirement from GE in 1963.

Blodgett received many honors for her revolutionary research, including four honorary doctorates, the American Chemical Society’s Garvan Medal in 1951 and the Photographic Society of America’s Progress Medal in 1972.

When Blodgett passed away in 1979, her GE colleague Vincent J. Schaefer said of her legacy, “The methods she developed have become classical tools of the science and technology of surfaces and films. She will be long — and rightly — hailed for the simplicity, elegance, and the definitive way in which she presented them to the world."

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