Polymer Foam Based Piezoelectric Materials Manufactured in an Environmentally Benign Novel Process

FSU researchers have developed thermally stable piezoelectric polymer foams (ferroelectrets) with high piezoelectric activity for sensing and actuation, with tailored morphology, cell structure and mechanical and electro-mechanical properties. These piezoelectric foams have extremely high piezoelectric coefficients and very high thermal stability up to two orders of magnitude higher than other published results.

Thermoelectric (TE) materials generate energy in the presence of temperature differential by virtue of converting thermal energy to electrical energy. Combination of different semiconductors are the dominant thermoelectric materials. Currently all research on TE materials focus on inorganic substance and the applications of most TE materials are limited to high temperature regime (> 200 oC) to achieve meaningful figure of merit, which restricts application area. In this technology, COC ferroelectrets can harvest thermal energy operated at low temperature with high figure of merit.

Commercially available ferroelectrets are based on porous polypropylene films which has been applied in various devices, i.e., audio devices as microphones, force sensors, actuators and respiration detectors. However, these devices lack sufficient thermal and UV stability. Our foams overcome these limitations.