Piezoelectricity in electrically oriented films of poly-α-isobutyl-L-aspartate

Abstract
Highly piezoelectric films of poly (α‐isobutyl‐L‐aspartate) have been prepared from a solution in chloroform which was allowed to evaporate in a 2600‐V/cm electric field, with the field direction parallel to the casting surface. The resulting oriented film has a macroscopic symmetry ∞2 (D), as revealed by x‐ray diffraction, with a C axis along the direction of the applied electric field. The shear piezoelectric constant d14 has a value of 11.2 pC/N measured at a frequency of 4 Hz.