Katharine Burr Blodgett – invisible revolution

Katharine Burr Blodgett was born on 10 January 1898 in a small town of Schenectady. The place was just like many other small towns, except for one thing – since 1892, it was the seat of General Electric (GE), the company we have already mentioned a few times, when presenting the biographies of prominent inventors such as Elihu Thomson, Ernst Alexanderson or Garrett Morgan. GE played a major role in the life of Katharine Burr Blodgett, too. Her father, patent attorney, worked there. Unfortunately, he died in a shooting and hadn’t even met his daughter. Little Katharine’s mother decided to move with her children, first to New York, then to France. Due to that, Katharine didn’t start school until she was 8, but at the same time travel made her curious about the world. The family left Europe and returned to the United States in 1912, and Blodgett was enrolled in the Rayson School, a private school, where her talent for mathematics and physics was revealed. Thanks to good grades, she earned a scholarship to Bryn Mawr College. In those times that would be the end of education for many women, but Irving Langmuir, a friend of late George Blodgett, Katharine’s father, encouraged her to go to university and graduate, thanks to which she could start work at GE. Katharine Blodgett followed his good advice and continued her education at the University of Chicago. She was an excellent student, so she not only satisfied Langmuir’s requirements, but also was able to continue her studies and she eventually became the first woman to earn a PhD in Physics from the University of Cambridge. Interestingly, Katherine Blodgett was equally successful at GE, where she was the first female engineer in the company’s laboratory.

Her scholarly work was mainly focused on multilayer films, which she studied with Langmuir. Using the so-called Langmuir-Blodgett trough, she discovered e.g. a very easy and exceptionally precise (to one-millionth part of an inch) manner of measuring these. Interestingly, this discovery was possible thanks to the observation of... soap bubbles. This research project, among other things, led Blodgett to her greatest discovery, one which we still use today. She created 99% transparent glass. Moreover, thanks to multilayer films, such glass does not reflect light. This is of great importance in the design of various optical instruments, e.g. telescopes. Anti-reflective glass is also applied in the movie industry, and it was first applied when filming the famous “Gone with the Wind”. Blodgett’s invention has also influenced our everyday life, although we would be able to notice it through our car windows or corrective lenses only if she had not made her discovery.

Of course, this was not the only achievement of the great physicist. During World War II, she contributed to the development of technologies for the army, for instance the technique of de-icing plane wings. She also made use of her knowledge gained when writing her thesis and designed an improved model of a gas mask. Altogether, she was granted eight patents in her career, six of which were exclusively hers.

Even though Katharine Blodgett’s inventions did not translate directly to optoelectronics, which we use on a daily basis, more and more frequently we encounter very precisely made lenses. It is not only in the case of video/smartphone cameras, but also in measurement instruments. The high precision of manufacture of optical elements is important in the case of industrial photoelectric sensors, but also laser emitters and receivers. It is also becoming increasingly significant due to the more and more popular implementation of photo modules in IoT devices (Internet of Things). These facts demonstrate perfectly how complex electronics is, when it employs purely theoretical inventions, such as mathematical models, right next to very practical improvements in the manufacturing technology of optical elements. You don’t need to know the intricacies of electronics to revolutionize it.