Quantification of mechanical deformations induced by an electric field in a semicrystalline organic insulator

We studied mechanical deformations induced when an insulating material was subjected to a gradual increase in a direct‐current electric field. Poly(ethylene terephthalate) film was studied with an optical technique, which was nondestructive and involved no physical contact. The experimental results indicated that the level of the induced mechanical deformation depended on the strength of the applied electric stress, the linear dimensions of the area under study, and the thickness of the film. When the studied area was relatively small, the level of the mechanical deformation seemed to be more important. The relationship between the induced mechanical deformation and the electric conduction phenomenon was also examined.