Soft dielectric elastomer is able to generate an
electromechanical response in terms of reversible shape
changing, which is a muscle-like behavior. The deformation
and electromechanical stability of dielectric elastomers,
classified by their deformation modes, uniaxial extension,
equal biaxial expansion and pure shear, are investigated.
Pull-in instability occurs in equal biaxial and uniaxial modes
at a small stretch ratio, while the pure shear mode features
wrinkling instability after a large stable deformation. The
coupled stiffness of the voltage-activated material is established
and studied for achieving the goal of high performance
stretchable dielectric actuators.

Applied Physics A DOI 10.1007/s00339-012-7457-6