The Maxwell stress and theoretical models of electric field effects in nematics

(Received 17 April 1992, revised 24 June 1992, accepted 6 October 1992)

Abstract
This communication seeks to analyze the expression of the body force per unit volume arising out of the Maxwell stress caused by the application of an external electric field (E). Despite some assumptions which have been made in the derivation it appears that in addition to the term describing the effect of the electric field on the free charge density, the term corresponding to spatial variations of the electric field may also be important, especially in mathermatical models attempting non-linear analyses. In cholesterics a body force caused by flexoelectricity may become important even for linear perturbations.