This paper investigates the effect of different nanoinclusions and polymers of varying dipole moment on the actuation response of polymer nanocomposites. Single walled carbon nanotubes (SWNTs)-based nanocomposites above percolation show a bending actuation response to applied electric fields. The actuation response increases with the nanoinclusion content and amount of dipoles in the system. Dielectric relaxation spectroscopy shows that enhanced polarization drives the actuation response which is determined as electrostriction. The coefficient of electrostriction is calculated at different SWNT content and for different polymer matrices. SWNTs, polymer dipoles and SWNT-polymer interaction is thought to drive the enhanced polarization and hence the electrostrictive response.