Stephanie Louise Kwolek (1923-2014), US chemist. Kwolek spent 40 years working as a research chemist at the DuPont Company. In 1965, she developed the first in a family of liquid crystal polymers that provided the basis for the Kevlar brand fibre. Kevlar has a high tensile strength-to-weight ratio, five times stronger than steel. Kwolek was inducted into the National Inventors Hall of Fame in 1995, and was awarded the DuPont Company's Lavoisier Medal (1995) and the National Medal of Technology (1996). Photographed in around 1980.