The electrification of an electrolyte solution in a nanoporous alloy is investigated through a mechanoelectricity measurement experiment. As the liquid flows across the nanoporous electrode, charge separation occurs over the large nanopore surface, resulting in a significant output voltage, which is in-phase with the actuator motion. This phenomenon is different from the conventional streaming current effect, since the solid phase is conductive and no voltage can be developed along its surface. (c) 2006 Elsevier B.V. All rights reserved.