Pressure-driven-flow of a dilute aqueous solution in a microchannel with charged walls generates streaming currents (ionic current) and streaming potentials across the microchannel. While generation of streaming currents can be performed in network of parallel circular microchannels or unstructured porous media, accurate measurements of such currents remain a challenge. In this study a gigantic amount of streaming current was successfully generated and measured using a glass microchannel array with special gold sputtered coatings on both its ends. Streaming current as high as 0.7 mA was obtained with moderate pressure drop (124 kPa) across the glass microchannel array that consists of approximately 11 250 000 parallel microchannels with radii of 2.5 mu m. Higher streaming currents are also possible to generate (scaled to 142 mu A/cm(2) of frontal area at a flow rate of 12 cm(3)/s) with potential applications in surface charge characterizations and electrokinetic power generation. In addition, apparent zeta potential of glass microchannel array surface was estimated with the aid of streaming current data and Levine-Olivare theories and an apparent zeta potential of -65 mV (0 M KCl, kappa a = 8) is reported. (C) 2016 Elsevier B.V. All rights reserved.