“…In order to ensure uniform charges deposition which results in the effective poling of the whole sample, the needle‐base distance which is approximately equal the radius of the electric field at the base of the corona poling setup, has to be set accordingly, in order for the area of electric field at the base to cover the top surface of the samples. [ 35 ] Given the fact that the samples have a cubic geometry with a top surface area of around 1.5 cm 2 , the needle base distance was set at 5 cm giving an active area of 78.5 cm 2 . No more than three samples were poled at the same time ensuring effective poling.…”