Electric element capable of controlling the electric conductivity of .pi.-conjugated macromolecular materials

An electric element which comprises:

• a .pi.-conjugated macromolecular material which is liable to increase its conductivity when it is put in an excited state by polarization of a dielectric substance;
• a ferroelectric material disposed so close to said .pi.-conjugated macromolecular material that excitation of said .pi.-conjugated macromolecular material occurs in response to polarization of said ferroelectric material;
• a pair of input and output electrodes disposed at the opposite ends of said .pi.-conjugated macromolecular material to make their respective ohmic-contacts therewith;
• and
• a pair of control electrodes disposed so as to sandwich said .pi.-conjugated macromolecular material in the direction perpendicular to the direction in which said input and output electrodes are laid, the conductivity of said electric element between input and output electrodes varying corresponding to the voltage of the electric field when an electric field is applied between said control electrodes.