Carbon nanotube fibers beat copper conductivity at one-sixth the weight, Spanish researchers show

Spanish researchers have developed carbon nanotube fibers with electrical conductivity reaching 24.5 MS/m, nearly half that of copper but at only one-sixth the weight. The breakthrough, published in Science, uses a gas phase intercalation process that boosts conductivity by a factor of 17 without sacrificing the fibers' mechanical strength. For power grids, these fibers could enable overhead transmission lines that are five times stronger and twice as light as conventional cables, reducing sag and improving grid resilience. In electric vehicles and aircraft, replacing copper wiring with these lightweight fibers could directly improve range and efficiency by cutting weight.