Preliminary study of multi-layer space-charge electrets with piezoelectric properties from porous and non-porous Teflon films

摘要

Non-uniform electrets consisting of at least one "soft" porous and at least one "hard" nonporous Teflon PTFE film were investigated for their piezoelectric properties. Two, three, or four films were corona-charged and assembled in various multi-layer stacks. Quasi-static piezoelectric responses of the same order as in ferroelectric fluoropolymers could be obtained in the best cases. As expected, the observed piezoelectric coefficients scale linearly with the charge density and also strongly depend on the respective layer geometry.