Stephanie Kwolek invented Kevlar, a tough durable material now used to make bulletproof vests. For years she'd worked on the process at DuPont and in 1963, she got the polymers or rod-like molecules in fibers to line up in one direction. This made the material stronger than others, where molecules were arranged in bundles. In fact, the new material was as strong as steel! Kwolek's technology also went on to be used for making suspension bridge cables, helmets, brake pads, skis, and camping gear.