  While most previous developed metamaterials only consider a single physical
effect, we introduce a novel class of electro-mechanical metamaterials, which
allows a direct controllable reduction of the total stress by applying an
electric field counteracting the mechanical stress. The solution of the
resulting minimization problem yields a relation involving the eigenvalues of
the mechanical stress tensor. Additionally, we evaluate the constrained cases
allowing only tensile or compressive stresses, respectively, and consider the
plane stress problem. We show numerical results for all cases and discuss, to
what extent a stress reduction is possible.
