TiO2 thin films were deposited on glass and polymer insulator substrates as self-cleaning coatings. TiO2 films were deposited at various RF powers by the unbalanced RF magnetron sputtering method using a TiO2 ceramic target. We investigated the tribological, structural, and electrical properties of the deposited TiO2 films at various RF powers. The result showed that the hardness and elastic modulus values of the TiO2 films increased with the increase of RF power. The surface roughness and contact angle values also increased with the increase of RF power. Also, the rms leakage currents of the TiO2 films were low for the insulator coating layer. The TiO2 films fabricated in this work are suitable for the protection of polymer insulators because of their low leakage current and good tribological properties. (C) 2014 Elsevier Ltd. All rights reserved.