Pyroelectric polymer electrets

Pyroelectricity is the electrical response of a material to a change in temperature. It exists in polymers which contain spontaneous or frozen polarization resulting from oriented dipoles. This review describes the physical basis for the existence of the pyroelectric effect and discusses its behavior in a number of amorphous, semicrystalline, crystalline and liquid crystalline polymers. Some of the techniques for measurement of the pyroelectric effect are presented and its use in pyroelectric relaxation spectroscopy and thermal analysis is described. The spatial distribution of polarization and space charge through the thickness of polymer films can be determined by several thermal pyroelectric techniques. Recent developments in the integration of pyroelectric polymer infrared detectors with solid-state silicon devices are described. One of the most important recent applications of polymers is in photopyroelectric spectroscopy which can be used for the determination of a number of thermal and optical properties of materials. Finally, some miscellaneous applications in physics, chemistry and biology are presented.