Katharine Burr Blodgett - invented low-reflectance glass or so called "invisible glass"
Katharine Burr Blodgett
(January 10, 1898 – October 12, 1979) was the first woman to get her Ph.D. in Physics from University of Cambridge in 1926. After receiving her master's degree, she was hired by General Electric, where she invented low-reflectance glass or so called "invisible glass".
Katharine Burr 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 own home by a burglar just before she was born. The suspected killer hung himself in his jail cell. After her birth, her mother moved to New York City with Katharine and her older brother George Jr. Her brother was two at the time. In 1901 the family moved to France, where she learned to speak French fluently.
In 1912 Blodgett returned to New York City with her family where she was enrolled in the Rayson School. This private school gave her the same quality of education that the boys her age were receiving. From an early age she had shown a great talent for Mathematics. Blodgett subsequently won a scholarship to Bryn Mawr women's College, where she excelled at mathematics and physics.
Blodgett decided to pursue scientific research and visited the Schenectady GE plant during Christmas break of her senior year. Her father's former colleagues there introduced her to research chemist Irving Langmuir . After a tour of his laboratory, Langmuir told the eighteen-year-old Blodgett that she needed to broaden her scientific education before coming to work for him.
Following his advice, Blodgett enrolled at the University of Chicago in 1918 to pursue her master's degree. Since a job awaited her in industrial research, she picked a related subject for her thesis: the chemical structure of gas masks. World War I was raging and gas masks were needed in order to protect troops against smoke and poison gases. Blodgett figured out almost all of the poisonous gases can be adsorbed by carbon molecules. She published a paper on gas mask materials in the scientific journal Physical Review at the age of 21.
Blodgett was hired by General Electric as a Research Scientist as soon as she had received her Master's degree in 1920. She was the first female scientist to work at the General Electric Laboratory in Schenectady, New York. During her research, she often worked with Dr. Langmuir, who had previously worked with her father. Blodgett and Langmuir worked on monomolecular coatings designed to cover surfaces of water, metal, or glass. These special coatings that they worked on were oily and could be spread in a thin layer. These layers were so thin that 35,000 of them stacked on top of each other are only as thick as a piece of paper. However it wasn’t until the 1930’s that she discovered uses for the coatings she had been working on.
In 1938, she figured out how to spread these monomolecular coatings one at a time onto glass or metal. She used a barium stereate film to cover glass with 44 monomolecular coatings to create the first "invisible" glass. Her invention made glass less distorted and more than 99% non-reflective. This coating is now called the Langmuir-Blodgett film. The Langmuir-Blodgett trough is also named after her. She had also invented the color gauge, which was a way to measure the tiny molecular coatings on the glass to the nearest one millionth of an inch.
The "color gauge" works on the idea that different thicknesses of coatings are different colors. She saw that soap bubbles were different colors and discovered that at each place that the soap bubble was a new color, it is of a different thickness. Before her invention, the best instruments were only accurate to a few thousandths of an inch. She made a glass "ruler" to show different colors corresponding to the thicknesses. Measuring a thickness now became as simple as matching colors. Other inventions for which she was credited were poison gas absorbents, methods for deicing aircraft wings, and improving smokescreens.
Dr. Blodgett was issued eight U.S. Patents during her career. She was the sole inventor on all but two of the patents. On those two she was the primary inventor with Vincent J. Schaefer as co-inventor. Blodgett also published over 30 technical papers in various scientific journals.
Social Life and Hobbies
Blodgett bought a home in Schenectady overlooking her birthplace where she spent most of her adult life. She was an actress in her town's little theater group and volunteered for civic and charitable organizations. Blodgett was the treasurer of the Travelers Aid Society there. She spent summers at a camp at Lake George in upstate New York, to pursue her love of gardening. Blodgett was also an avid amateur astronomer. She collected antiques, played bridge with friends and wrote funny poems in her spare time. 
She died in her home on October 12, 1979.
Blodgett received numerous awards during her lifetime but most of them were the "first woman" type. In 1951 she was chosen by the U.S. Chamber of Commerce as one of the 15 "women of achievement” Among many other awards she had received, the mayor of Schenectady honored her with Katharine Blodgett Day on June 13, 1951 because of all the honor she had brought to her community.
* U.S. Patent 2,220,860 issued Nov 5, 1940-"Film Structure and Method of Preparation"
* U.S. Patent 2,220,861 issued Nov 5, 1940-"Reduction of Surface Reflection"
* U.S. Patent 2,220,862 issued Nov 5, 1940-"Low-Reflectance Glass"
* U.S. Patent 2,493,745 issued Jan 10, 1950-"Electrical Indicator of Mechanical Expansion" (with Vincent J. Schaefer)
* U.S. Patent 2,587,282 issued Feb 26, 1952-"Step Gauge for Measuring Thickness of Thin Films"
* U.S. Patent 2,589,983 issued Mar 18, 1952-"Electrical Indicator of Mechanical Expansion" (with Vincent J. Schaefer)
* U.S. Patent 2,597,562 issued May 20, 1952-"Electrically Conducting Layer"
* U.S. Patent 2,636,832 issued Apr 28, 1953-"Method of Forming Semiconducting Layers on Glass and Article Formed Thereby"
1. ^ Bigraphical Information
2. ^ "Studies of the Adsorption of Gases by Charcoal. II," in Physical Review, Vol 14, Nov 1919, pp 394-402 (with Harvey B. Lemon)
3. ^ Edison Exploratorium, Katherine Blodgett (1898-1979)
4. ^ World of Chemistry on Katharine Burr Blodgett
For the complete inventors list please click here