In the 1990s, Antoine Naaman, a concrete composites expert at the University of Michigan, invented toothpick-sized steel "fibers" that when added to concrete, generated a high-strength concrete, or "super-concrete," but it was not commercially viable. That has changed. Polytorx now sells those fibers under the brand name Helix. They can be added to a concrete mix and can remove the need for rebar and steel mesh reinforcement. The material, in various concentrations, has been used in projects from "sidewalks to hurricane-resistant housing to bank vaults."