Electronic Roughness (IMAGE) University of Pennsylvania Caption On the macroscale, adding fluorine atoms to carbon-based materials makes for water-repellant, non-stick surfaces, such as Teflon. However, on the nanoscale, adding fluorine to graphene had been reported to vastly increase the friction experienced when sliding against the material. Through a combination of physical experiments and atomistic simulations, a Penn team has discovered the mechanism behind this surprising finding. Using atomic force microscopy, they found that the fluorine atoms add "electronic roughness" to the graphene; these graphs show a comparison between the energy corrugation of graphene (above) and fluorinated graphene (below). Credit University of Pennsylvania Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.