Piezo-, Pyro- and Ferroelectric Polymers

Abstract

Piezo, pyro, and ferroelectric polymers are known since 30 years. With piezo- and pyroelectric coefficients being less than that of crystalline or ceramic piezoelectrics, polymers have found niche applications in diverse fields, ranging from sensor systems and nondestructive testing to fundamental research applications, such as photopyroelectric spectroscopy and microcalorimetry. This survey discusses the technologically important polymers polyvinylidene fluoride {PVDF} and its copolymers with trifluoroethylene {P(VDF-TrFE)}. Recent developments include the preparation and characterization of ultra-thin ferroelectric polymer films and relaxor-type ferroelectric polymers with large electrostrictive responses. Special emphasis is given to techniques for measuring the piezo- and pyroelectric activity, and to their use for the nondestructive probing of nonuniform space-charge and polarization distributions in polymer films. A few recent applications are selected which display the large potential of exploiting ferroelectric polymers.