STM and Flake (IMAGE) DOE/Lawrence Berkeley National Laboratory Caption Under the STM tip a flake of graphene 50 microns (millionths of a meter) long rests on a substrate of silicon with a thin layer of silicon dioxide insulation (upper left). The graphene is contacted by gold electrodes, connected to outside experimental equipment and to the underlying silicon electrode, which is used to apply a gate voltage. At lower right, a topographical image of the graphene flake, 10 nanometers (billionths of a meter) across. Variations in height of one or two angstroms (ten-billionths of a meter) are likely caused by the roughness of the substrate. Credit Lawrence Berkeley National Laboratory 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.