Abstract
Recent advances in the development of the theory of electret effects in polymers (except photo- and bio-electrets) are discussed: they include the phenomenological theory, the nature of the residual polarisation and of the injected charge, and the nature of the piezo- and pyro-effects in polymer electrets. Successful applications of electret-thermal analysis to the study of molecular mobility in polymers are discussed. The principal directions of the practical exploitation of polymer electrets are outlined. The goals of further studies and of technological developments are defined. 99 references.