Preparation, characterization and sensor properties of ferroelectric and porous fluoropolymers

Ferroelectric copolymers of vinylidene fluoride and trifluoroethylene [P(VDF/TrFE)] have a strong piezoelectric and pyroelectric effect with a high potential for sensor and transducer applications. Porous polytetrafluoroethylene (PTFE) exhibits excellent electret properties and is suitable for transducer applications based on its macroscopic piezoelectricity. In this work the preparation of piezoelectric P(VDF/TrFE) films onto flexible as well as on any shaped printed circuits achieved through a spray technique from the polymer solution is reported. Results on array sensors, measuring dynamic pressure in air flow field monitoring as well as dynamic force measurements, are presented. Electret transducers made by porous PTFE are prepared and their sensor properties are described.