The MOS nanowires have been synthesized by thermal oxidation technique. This technique has been successfully used for synthesizing ZnO or CuO by simply heating pure Zn and Cu material source, respectively. The process is usually conducted in a cylindrical furnace. For the synthesis of ZnO nanowire as shown in Fig. 5, Zn thin films or thick films were screened or evaporated on alumina substrate. Then, they were sintered at temperature in ranging of 500-700ºC to form the nanostructure. For the synthesis of CuO nanowire, the commercial grade copper plate with thickness of 0.1 mm was cut and cleaned by alcohol in an ultrasonic bath for 2 min and dried at room temperature. The copper plate was loaded into a center of a tube furnace at 600°C at normal atmosphere for oxidation reaction.