Polyaniline nanocomposites for smart electrorheological fluid applications

Electrorheological (ER) fluid is a smart suspension, which consists of the solid particles of high dielectric constant and low conductivity dispersed in insulating oil. When an external electric field is applied, ER fluid exhibits a drastic and reversible change in rheological properties (i.e., ER effect) due to the field-induced ordering of particulate phases. This rapid and reversible electric field-controlled mechanical response makes ER fluid useful for potential applications in various devices such as dampers, brakes, actuators, and so on. Due to insufficient performance of ER fluid, researches on high-active ER fluid for practical technical applications have been continuously carried out. In this chapter, we focus on the recent researches on electrorheology of various polyaniline (PANI) nanocomposite-based suspen-sions. Especially, the advantages of using anisotropic nanostructured PANI materials as ER dispersal phase have been highlighted.