Recent development in Electrets, Ferroelectrets, Ferroelectrics and related devices [editorial]

The 23 papers in this special issue focus on recent developments in electrets, ferroelectrets, ferroelectrics and related devices. The papers are extended forms of some of the papers presented at the 13th International Symposium on Electrets (ISE 13), held from 15 to 17 September 2008 in Tokyo, Japan.