Gold and aluminum foils with nano-structured edges were investigated as electrodes for corona discharges in nitrogen and ambient air. Low onset voltages were observed due to the field enhancement near the edges of the foil. The lowest onset voltage was determined to be about 1.2 kV in ambient air and about 1.1 kV in nitrogen for a 5mm inter-electrode spacing. This is significantly smaller than the values reported in the literature for sharp tips with similar electrode spacing. The foil-based electrode tips are extremely simple to produce, making them candidates for low-cost, low power consumption and easily available corona-discharge technology. (C) 2013 AIP Publishing LLC.