Abstract
In all conducting polymers (CPs), polyaniline (PANI) is one of the most thoroughly studied CPs. An essential feature of PANI is that its repeating units have two different moieties in different weights: oxidized and reduced state. In light of this element, PANI might be doped to get new molecular structures with various properties. It is considered as a (p-type) material, since it has excellent mechanical flexibility and environmental stability, and its conductivity could be controlled with acid/base (doping/undoping), it has potential applications in numerous fields, for example, lightweight battery electrodes, electromagnetic shielding devices, anti-corrosion coatings, and sensors. This chapter is focused on PANI as a leading polymer and brief synthesis of PANI thin films by the diverse strategies pursued by various applications in different fields.