08/03/2022
Over the years, thousands of female innovators have shaped the patent landscape in the fields of chemistry and materials science. Their research has not only advanced theoretical understanding in their field, but has led to many inventions that have a tangible impact on our everyday life. This International Women’s Day we wanted to celebrate the achievements of some of our favourites.
Stephanie Kwolek
Born in 1923, the Polish-American spent her career working for American chemical company DuPont. Following the success of the introduction of nylon by DuPont back in the 30s and 40s, Kwolek worked on the development of further polymer fibres. One of her first achievements came in 1959, in which she published a paper on the ‘Nylon rope trick’ in which a strand of nylon can be continuously drawn from a beaker of liquid precursors. The experiment is still conducted in school science labs to this day.
Her biggest breakthrough however was the development of Poly-p-phenylene terephthalamide, or to give it its commercial name, Kevlar. The novel polymer proved to be five times stronger than steel by weight, and so sensing suitability for a huge range of applications a patent for the production process was filed in 1963. The structural building block of Kevlar shown in US patent application US3287323A appears deceptively simple, yet the tensile properties that arise from its processing, and eventual alignment of polymer chains, means that the material is now found throughout society.
From body armour to bicycle tyres, and suspension bridges to string instruments, Kevlar, and Stephanie Kwolek, helped drive high performance materials innovation in the 20th century.
Helen Murray Free
Helen Murray Free began college in 1941, studying to become an English and Latin teacher. During this time, the population of male students declined as they were drafted for WWII. Women were encouraged to take up the empty seats in traditionally male-dominated science courses, so Free changed her major to chemistry.
Graduating in 1944, Free began working for Miles Laboratories in quality testing before moving to a position in the biochemistry division, developing diagnostic tests.
In 1956, Free co-invented a novel at-home dip-and-read glucose test for diagnosing diabetes and monitoring blood sugar. The dip-and-read test revolutionised glucose analysis and self-testing systems for people with diabetes.
Free’s invention was a glucose specific test composition, protected by US patent US2912309. The test used enzymes peroxidase and glucose oxidase, with an indicator such as o-tolidine dihydrochloride. A soluble protein like gelatine was used to stabilise and bind the active ingredients to a test strip.
Launched in 1956 and known commercially as Clinistix®, the chemically coated dip-and read strip measured glucose levels and changed colour when dipped into a urine sample.
Clinistix® formed the blueprint for urine strip testing that became standard practice for patients worldwide as an initial indicator of metabolic, kidney, and liver disorders.
Katharine Blodgett
Born in 1898, Katharine Blodgett pursued a scientific career with General Electric after graduating from the University of Chicago. Her work as a student focussed on the adsorption of gases onto solid substrates, and similar surface-chemistry research was conducted during her time with General Electric.
Between 1924 and 1926 Blodgett took time out to become the first woman to receive a PhD in physics from the University of Cambridge. Upon returning to industry, she continued her work on monomolecular coatings.
Filed in June 1937, her patent application for a ‘Film Structure and Method of Preparation’ would disclose a glass coating that reflected almost no light.
The production of such a coating involved the repeated raising and lowering of a glass substrate into a trough containing an aqueous solution of organic molecules. Each subsequent pass through the trough deposited a single monolayer of molecules, and so a film of exact depth could reliably be built up on the substrate surface.
This so called ‘invisible’ glass entered immediate use in both submarine periscopes and spy plane cameras during the period of World War II. Named in collaboration with her colleague, Irving Langmuir, the Langmuir–Blodgett film saw commercial uses in cinema too. The 1939 film Gone with the Wind was the first significant production to utilise the technology, and its clarity of cinematography was met with critical acclaim.
Esther Sans Takeuchi
Esther Sans Takeuchi is a researcher in the field of energy storage and power sources. She is a named inventor on over 150 patent families for her innovative developments concerning battery technology. Takeuchi’s work has focused on batteries for a wide range of applications, from medical devices to electric cars.
Takeuchi’s most well-known inventions are related to improved batteries for use in implantable cardiac defibrillators (ICDs).
ICDs are required by millions of patients worldwide. Once a ICD is surgically fitted in a patient it detects abnormal heart rhythms and reacts by sending electrical pulses to the patient’s heart. The first ICD was implanted in 1980, but it was so bulky it had to be implanted in the abdominal region and had a battery life of only 12-18 months.
Takeuchi developed lithium/silver vanadium oxide (Li/SVO) batteries using a novel cathode material, a highly conductive electrolyte, and a new cell design that enables high power delivery. The Li/SVO batteries have a lifetime of around 5 years, and are small enough to be used in ICDs while providing the high voltage of around 600-900 volts needed to deliver the required “shock” to a patient’s heart.
First implanted in 1987, and continuously developed and refined since, Takeuchi’s patented technology is still the dominant battery type used in the 300,000 ICDs implanted each year.
Perhaps therefore, you have worn Kevlar gloves whilst gardening, or know someone who know someone with an ICD. It is only right that these women who have pioneered the development of such influential products are known and celebrated for their innovation.
This article is for general information only. Its content is not a statement of the law on any subject and does not constitute advice. Please contact Reddie & Grose LLP for advice before taking any action in reliance on it.
