The single-molecule electric motor is an electrically operated synthetic molecular motor made from a single butyl methyl sulphide molecule.[1] The molecule is adsorbed onto a copper (111) single-crystal piece by chemisorption.[1] The motor, the world's smallest electric motor,[2] is just a nanometer (billionth of a meter) across[3] (60 000 times smaller than the thickness of a human hair). It was developed by the Sykes group and scientists at the Tufts University School of Arts and Sciences and published online September 4, 2011.[4]