The incorporation of permanent charges in polymer films (e.g. by corona charging), is a long-known effect that has many applications, such as in the electret microphone. Despite the widespread use of these materials there remain many open questions. In collaboration with the chair of Macromolecular Chemistry II (Prof. H. W. Schmidt, UBT), we use micro-structuring techniques and scanning probe methods to further elucidate how charges are stored and transported in these materials, especially on the nm-level. We determine also how environmental factors, such as humidity and temperature, influence the charging state of these materials. We plan to apply the micro-structuring techniques for applications like self-assembly or electrostotatic motors.