This is a coating or a thin film, so far Stronger than steel doesn't mean much of anything, it's just a catchy headline for non engineers. This finding is not important because it's 'stronger that steel' It's a big deal because it's the first time someone has produced a 2D polymer, a sheet polymer, instead of a strand, 1D. 1D polymers are used in everything: textiles, rope or anything with plastic fibers, paints and epoxy, etc