Pyroelectrically Rechargeable Electret for Continuous Vibration Energy Harvester

Abstract

In this manuscript, the first pyroelectric-based rechargeable electret for continuous energy harvester is reported. The proposed pyroelectric-based electret preparation provides two main advantages 1) Wafer-scale electret production with uniform surface charge density and 2) On-chip rechargeable option for the electret-based energy harvesters and sensors. Pyroelectrically generated surface charges are transferred to the dielectric material placed in contact with the polarized surface of the pyroelectric crystal. A 5 mm thick lithium niobate crystal is used as a pyroelectric material with a temperature gradient of 2.3°C/sec. A Teflon dielectric is used as an electret material with a surface area of 1 cm2 and thickness of $75\mu m$. Obtained results from the pyroelectrically prepared electret showed a surface potential of ∼540V with a charging efficiency of 8.9% from the pyroelectric surface potential of 6060V. Obtained results were in good agreement with repeatability and charge stability for >15 days. Our preliminary experiment of energy harvester showed an average power of $1.29\mu W$ at 4Hz.