To create the concrete semi-conductor, the team used a process called electron trapping to transform liquid cement into a glass-metal material. Glass-metal, a metal with properties similar to glass, is conductive, less brittle than glass, and easily molded. Mayenite, a component of cement, was melted by a laser at temperatures of 2000 degrees Celsius while suspended in an aerodynamic levitator. The levitator prevented the hot liquid from coming in contact with the surface of the container, which allowed it to cool to glassy state able to trap electrons and create a conductive surface.
Understanding the process of trapping electrons in cement could also lead to the development of other room temperature semi-condutors made from normally insulating materials.