Electro-active solids are solids that are either infused with electrorheolo
gical fluids or embedded with electrically conducting particles, the body a
s a whole however conducting negligible current. In this paper, we provide
a mathematical framework, within the context of continuum mechanics, for th
e study of electro-active solids. The theory assumes that the body can be c
onsidered as a continuum, in the sense of homogenization, which is isotropi
c, incompressible, elastic and is capable of responding to an electric fiel
d. Appealing to standard techniques in continuum mechanics, we obtain a con
stitutive relation for the stresses in terms of the deformation and electri
c field. This is used in a study of triaxial extension, simple sheer and an
isotropy induced by the electric field.