Scientists in the United Kingdom have made a significant advance in using nano-devices to create accurate electrical currents. They have developed a nano-size electron pump that picks these electrons up one at a time and moves them across a barrier, creating a very well-defined electrical current. The device drives electrical current by manipulating individual electrons, one-by-one at very high speed. This technique could replace the traditional definition of electrical current, the ampere, which relies on measurements of mechanical forces on current-carrying wires.