Stephanie Kwolek, Chemist Who Invented Kevlar, Has Died

Stephanie Kwolek, the chemist who invented the incredibly tough fiber known as Kevlar, died yesterday at the age of 90. She was definitely a "true pioneer for women in science," as DuPont CEO Ellen Kullman noted, and her contributions to engineering and life-saving technology will ensure her memory lives on.

Despite primarily being known for bulletproof vests these days, Kevlar was invented with one primary purpose – to replace the steel in tires with something stronger and lighter, while still maintaining flexibility. In 1964, Kwolek was in her lab at DuPont, still trying to concoct a new fiber, when her latest attempt to re-invent the wheel ended with a thin, opaque liquid, rather than the thick, clear one that she wanted.

Discouraged but undeterred, her lab still spun the liquid into a fiber, and surprisingly found that the molecules in the liquid all managed to line up, producing an incredibly tough fiber when woven together. Pound-for-pound, it was five times stronger than steel, and fire-resistant to boot.

By the 1970s, Kwolek's invention had found its first commercial use, in racing tires.

Nowadays Kevlar and its descendants are used in everything from backpacks to bikes to boats to planes, and in F1 cars they're not only used in the tires, but to protect the drivers inside as well.

Oh, and bulletproof vests, of course. Kwolek and her invention has saved thousands of lives.

Stephanie Kwolek remains the only female employee to receive the Lavoisier Award for outstanding technical achievement from DuPont.

Photo credit: DuPont