Giant enhancement in effective piezoelectric sensitivity by pyroelectric coupling

Abstract

We report stable two-layer composites that exhibit large enhancement of effective piezoelectric sensitivity to more than 20000 pC/N in the presence of a thermal gradient. They are based on coupled fields in the non-equilibrium presence of energy flux that is modulated by force. Thermal flux is modulated by a granular contact layer so that electric polarization of pyroelectric origin contributes to stress-generated electric polarization. Effective piezoelectric sensitivity is enhanced by at least two orders of magnitude and is higher than that of known commercial and research materials. The result illustrates the potential of relaxing the usual assumption of equilibrium in the presence of a coupled field to attain extremely high effective properties.