On the Enormous Effect of Electric Field on the Crystalline Lattice of the Conductors with Charge-Density Waves

We discuss deformation of quasi 1-dimensional conductors with charge-density wave (CDW) under the electric field deforming the CDW. In case of ``strong'' CDW-lattice interaction the effect can be treated in terms of the converse piezoelectric effect with enormous piezomodulus, $\sim L_c/\lambda$ times larger than that in ionic crystals ($\lambda$ is the CDW wavelength, $L_c$ is the CDW coherence length, mm scale in the sliding state). The CDW-lattice interaction is likely to be defined by the interband charge transfer (rearrangement of the covalent bonds) with lattice deformation, possible in a number of CDW compounds. The resulting effects, observed or expected, are paving a way towards new-principle actuators, including nanosized ones.