An Optical Technique Based Mark Tracking for Electrical Field Induced Mechanical Strain Measurement in Thin Polymer Films

Abstract

An optical non contact measurement technique based on the tracking of successive positions of computerized markers has been developed which enables one to characterize the electric field induced strain response of the plane gold-metalized surfaces in thin organic insulating films. The present study was made on two microstructures of films: a virgin amorphous material and some semi-crystalline samples 70µm thick were obtained by annealing the amorphous one at annealing temperatures of 170°C at 5, 60 and 120 minutes using Differential Scanning Calorimetry (DSC). The test results demonstrate that the newly developed method is capable of detecting displacement of selected markers when the sample is subjected to the application of a dc high voltage. The field-induced mechanical strain measurements have been performed as a function of time and then analyzed with respect to the applied electric field. The observed strain levels varied from ~ 10⁻³ to 10⁻² . Moreover the influence of crystallinity on the electric field induced strain mechanical response is discussed.