Nanopores in aluminum oxide film served as vessels for corrosion inhibitor to add self-healing ability. Aluminum oxide films were immersed into a solution containing corrosion inhibitor to fill the nanopores. To monitor polarization resistance, the aluminum oxide film was coated with polymer, which was then scratched with a knife-edge. Uniform and large nanopores demonstrated a higher level of polarization resistance. The corrosion inhibitor was released in two steps: a large release due to dissolution was followed by a more sustained release due to corrosion inhibitor desorption. (C) 2018 Elsevier Ltd. All rights reserved.