Stephanie Kwolek

On the long list of happy accidents in science, some discoveries prove to be more monumental than others. Stephanie Kwolek’s was one of them. In the mid-1960s, Kwolek, who died June 18 at 90, was working at DuPont–a rare exception in the male-dominated world of chemistry–looking for a new synthetic fiber to use in tires. As she toiled in the lab, she noticed that one mixture of a polymer and a solvent looked different from the rest. Instead of assuming she’d made a mistake, she was curious and followed up on her observation. When her formula was spun into fiber, it proved to be five times as strong as steel. DuPont called it Kevlar.

Kevlar is famous for its protective powers, and thanks to its application in bulletproof vests and body armor, it has saved countless lives. But that’s not the only reason it landed Kwolek in the National Inventors Hall of Fame. The Kevlar gloves Kwolek wears in the photo above, for example, help workers avoid cuts. Kevlar has also been used to strengthen items from boats and baseball bats to shoelaces and cell phones. And in a nice full-circle twist, it’s used in tires too.

–LILY ROTHMAN