Ferroelectric dipole electrets for output power enhancement in electrostatic vibration energy harvesters

We propose a ferroelectric dipole electret composed of polarized lead zirconate titanate. Deep insight into the physics behind the parallel plate capacitor theoretically predicts that we can extract large electric field near the surface of the ferroelectric dipole electret by increasing its surface charge density and thickness. Experiment for ferroelectric dipole electret shows good agreement with the theory. The maximum output power density of electrostatic vibration energy harvesters using the ferroelectric dipole electret was 78 μW/cm³, a three-fold increase over a conventional polymer electret. Our results will pave the way for use of ferroelectrics as electrets.