Katharine Blodgett

Katharine Burr Blodgett
Blodgett demonstrating equipment in lab, 1938
Born	January 10, 1898 Schenectady, New York
Died	October 12, 1979(1979-10-12) (aged 81) Schenectady, New York
Occupation	inventor, physicist
Parent(s)	Katharine Burr George Blodgett
Awards	Garvan–Olin Medal (1951)

Katharine Burr Blodgett (January 10, 1898 – October 12, 1979) was an American scientific researcher. She was the first woman to be awarded a Ph.D. in physics from the University of Cambridge, in 1926. After receiving her master's degree, she was hired by General Electric, where she invented low-reflectance "invisible" glass.

Blodgett was born on January 10, 1898 in Schenectady, New York. She was the second child of Katharine Burr and George Blodgett. Her father was a patent attorney at General Electric where he headed that department. He was shot and killed in his home by a burglar just before she was born. GE offered a $5,000 reward for the arrest and conviction of the killer, but the suspected killer hanged himself in his jail cell in Salem, New York. Her mother was financially secure after her husband's death, and she moved to New York City with Katharine and her son George Jr. shortly after Katharine's birth. In 1901 the family moved to France.

In 1912, Blodgett returned to New York City with her family where she was enrolled in the Rayson School.

Blodgett was hired by General Electric as a research scientist as soon as she had received her master's degree. She was the first woman to work as a scientist for General Electric Laboratory in Schenectady, NY. She often worked with Langmuir, who had pioneered a technique for creating single-molecule thin films on the surface of water. Blodgett and Langmuir explored the application of similar techniques to lipids, polymers, and proteins, creating monomolecular coatings designed to cover surfaces of water, metal, or glass. These special coatings were oily and could be deposited in layers only a few nanometers thick.

In 1935, Blodgett extended Langmuir's work by devising a method to spread monomolecular coatings one at a time onto glass or metal. By repeatedly dipping a metal plate into water covered by a layer of oil, she was able to stack oil layers onto the plate with molecular precision. The apparatus which she used and refined is known as the Langmuir–Blodgett trough.

Using this technique, Blodgett developed practical uses for Langmuir’s gossamer films. Blodgett used a barium stearate film to cover glass with 44 monomolecular layers, making the glass more than 99% transmissive and creating "invisible" glass. The visible light reflected by the layers of film canceled the reflections created by the glass. This type of nonreflective coating is now called Langmuir-Blodgett film and is widely used. The first major cinematic production to use Blodgett's invisible glass was the popular film Gone with the Wind (1939), noted for its crystal-clear cinematography. Once introduced, nonreflective lenses were used for projectors and cameras by the post-war movie industry. Blodgett's glass was also used for submarine periscopes and airplane spy cameras during World War II.