Published online by Cambridge University Press: 03 March 2014
An electro-acoustic method for measuring volume charge distributions in dielectric films (50 μm–0.2 mm thick) is described. A high voltage (>1 kV) sinusoidal signal (frequency ∼ 2 kHz) is applied across the dielectric sample. The charges inside the dielectric material will mechanically respond to the input electric signal and excite acoustic waves. The acoustic waves can be detected and measured using a piezoelectric sensor. By analyzing the received acoustic signal, we are able to compare the amount of charge in various samples.