Pb₅₂(Zr,Ti)₄₈O₃ ferroelectric dipole electret exploiting surface pillar array structure for electrostatic vibration energy harvesters

In this paper, we present ferroelectric dipole electrets (FDEs) with patterned Pb₅₂(Zr,Ti)₄₈O₃ (PZT) pillar arrays. Their output power generation capability was higher than that of flat FDEs when used for electrostatic vibration energy harvesters (e-VEHs). This excellent capability was achieved since the patterned pillar structure increased the electric field near the electret surface. The surface potential (V_s) became as high as 1035 V when the surface charge density was 6.9 mC/m². This surface charge density was 1.3-fold higher than that of flat FDEs and sixfold higher than that of conventional CYTOP polymer electrets (CPEs). Consequently, VEHs (20 × 20 × 1 mm³) showed a maximum power of 102 µW at an acceleration of 0.6 g (1 g = 9.8 m/s²) and a frequency of 20 Hz. These results will open a new strategy for the use of FDEs in e-VEHs.