Flexible PZT/PI piezoelectric composite films with gamma radiation tolerance

Maintaining the electric properties of piezoelectric materials in irradiated environments is essential for the efficiency and reliability of piezoelectric devices on spacecraft. This study centers on the fabrication of flexible piezoelectric composite films and examines the effect of gamma irradiation and temperature on their structure and properties. A stable dispersion of lead zirconate titanate (PZT)/polyacrylic acid (PAA) precursor was prepared through mechanical grinding, followed by tape-casting and amidation to produce PZT/polyimide (PI) composite films with strong interfacial adhesion. The results show that an increase in the volume fraction of PZT correlates with enhancements in the dielectric constant, piezoelectric strain constant d₃₃, and remnant polarization of these films. Specifically, at a PZT volume fraction of 70%, the PZT/PI composite film demonstrated a dielectric constant of 104.97, a dielectric loss of 0.026 at 100 Hz, a piezoelectric strain constant of 38.9 pC/N, and a remnant polarization of 6.61 μC/cm², while retaining flexibility with a minimum bending radius of 3 mm. The output voltage signal was successfully generated at 1 Hz and 1 N within a temperature range of 20 °C to 150 °C. Notably, both the dielectric and piezoelectric properties exhibited stability, and the thermal stability of the PZT/PI composite films showed slight improvement following exposure to a cumulative gamma-ray dose of 50 kGy. This study of PZT/PI composite films presents a promising avenue for the application of flexible materials in harsh environments.