Recent approaches in electret research in India and study of polarization in new advanced materials

From the very beginning, electret research in India was pursued with two fold objectives; development of human resources and search for new advanced materials. Major thrust of electret research in 1970s & 1980s was on organic-dielectrics; polymers, their blends and composites; piezo and pyro-electric materials; bio-polymers and electro-optic materials. Thermally stimulated depolarization current studies have provided a valuable contribution to the understanding of mechanism of charge production and its persistence in new polymeric materials. In 1990s, studies on opto-electronic interaction in non-linear optical and piezoelectric polymer composites have been carried out for developing tailor-made nano-materials. In the present paper, results obtained by different groups are briefly reviewed.