Influence of porosity on stability of charge storage and piezoelectricity for porous PTFE film electrets

Abstract

In this paper, the influence of porosity on the piezoelectric d/sub 33/ coefficient, charge storage stability and thermal stability of piezoelectricity in porous PTFE electrets is studied. The results point out that with the increase of porosity, the piezoelectric coefficient of the film goes up, and the thermal stability of space charge storage and piezoelectricity is improved. The reasons for the influence of porosity on the piezoelectric coefficient, the charge storage stability and the thermal stability of piezoelectricity are also investigated. Our results also demonstrate that the improvement of the thermal stability of the piezoelectric coefficient at increasing porosity is due to improved thermal charge stability and the improved stability of the mechanical properties of the material.