Stacked layers of graphene could make effective shields...
"Despite being just one atom thick, graphene is a strong absorber of electromagnetic radiation over a wide range of wavelengths – particularly in the far infrared and terahertz parts of the spectrum. This is extraordinary because conventional materials normally need to be thousands of atoms thick to be as effective."
"Phaedon Avouris and colleagues at IBM's TJ Watson Research Center in New York have created a film comprising alternating layers of graphene and an insulator. The team has shown that a film containing just five layers of each material can shield electromagnetic radiation in the terahertz and microwave ranges by up to 97.5%, while remaining transparent to visible light."
"Graphene could be used as a transparent terahertz and microwave shielding material and so help prevent external electromagnetic interference in high-accuracy electronic equipment," he said. "Such a shield could even help protect people from radiation at these wavelengths, which are hazardous to human health, according to the World Health Organization."