Recent developments and applications of functional thin films on metals, in some cases on semiconductors or glasses, are reviewed. Functional thin films can roughly be classified into three categories: 1) functional plating, 2) functional anodized alumina films, 3) modified electrodes. Functional plating encompasses dispersion or composite plating, alloy plating, and the other special type of plating. The aim of these plating methods is to improve the hardness, optical, electrical, thermal, adhesive, or the magnetic properties.
Anodized alumina films have many micropores on their surfaces, and various substances, acting as functional material, can be impregnated into the micropores. Metals and semiconductors can be coverd with a thin adsorbed layer of organic or inorganic functional groups, which give the substrate metal a special character, such as catalytic activity, ECD, selective reactivity, or photoelectrochemical activity.