The EMP-proof concrete has actually been adapted from Tuan and Nguyen's previous -- and slightly more pedestrian -- breakthrough: self-warming concrete that can melt ice and snow with a safe, low-level electrical current. The pair was originally working on a way to build safer roads and bridges when they realized their new concrete could also block electromagnetic energy.
That microwave-blocking property comes from a key ingredient in the concrete mix called magnetite -- an iron ore with magnetic properties that allow it to soak up radiation. Tuan and Nguyen also added in more carbon and metal elements than traditional concrete in order to boost the absorption even further. Compared to building expensive metal enclosures or faraday cages, the University of Nebraska-Lincoln says the new conductive concrete is much cheaper and easier to deploy, and a prototype structure built with the material exceeded the military's own shielding requirements. As part of a licensing agreement with American Business Continuity Group, the University has even developed a commercially available, spray-on "shotcrete" version, so the material can easily be used to retrofit older buildings and potentially vulnerable infrastructure.