Flexoelectricity

Flexoelectricity is a property of a dielectric material whereby it exhibits a spontaneous electrical polarization induced by a strain gradient. Flexoelectricity is not the same as Ferroelasticity.

The electric polarization due to mechanical stress in a dielectric is given by

where the first term corresponds to the direct piezoelectric effect and the second term corresponds to the flexoelectric polarization induced by the strain gradient.

Here, the flexoelectric coefficient, μ i j k l , is a fourth-rank polar tensor and d i j k is the coefficient corresponding to the direct piezoelectric effect.