The new electret charge recovery technique: a review

Physical details about a mechanism of charge decay of electrets introduced by the authors at the 5th International Symposium on Electrets (1985) are given. The suggested mechanism and the technique for charge reactivation are reviewed. The decay is due to compensating charges coming to the electret surfaces from the atmosphere and/or by electrical loading of the electret. The electret can be revived by repeatedly contacting the electret surfaces, one at a time, to a metal plate. At each contact some part of the compensating charge leaves the electret for the plate. In general, four to six such contact reversals are enough to fully reactivate the electret