Piezoelectric Polymers

A piezoelectric polymer is a plastic material with groups of molecules linked as orderly crystallites. The crystallites form in an amorphous matrix of chemically similar, but differently structured material. The relative population of crystallites strongly effects the piezoelectric behavior of the material. Polyvinylidene fluoride is the most popular piezoelectric polymer material for shock sensors. The designation PVDF refers to a class of materials based on the vinylidene fluoride monomer [-CH2-CF2-].

In order for PVDF to be used as a stress gauge, it is necessary to reproducibly manufacture poled piezoelectric transducer elements with defined homogeneity and stability. Since the gauge element is often destroyed in the calibration experiment, reproducibility in the manufacturing processes is paramount to the use of PVDF as an accurate stress gauge.

Ktech's PVDF Lab

Bauer, at the Institute Saint-Louis, developed a patented poling process. This process poles uniformly throughout the poled region, aligns crystallites, orients dipoles, and eliminates the ions and space charges resident in the unpoled material. The Bauer process has been shown to be capable of producing piezoelectric polymer transducer elements that have the uniform high volume fraction of beta-phase crystallites and relatively few crystallites of other phases, stability, and the reproducibility of polarization essential for accurate shock wave measurements. Ktech is the only company in North America licensed to manufacture PVDF sensors using the Bauer method.

Typical PVDF Applications

• Dynamic response testing of composite materials
• Pressure Pick Ups: distribution of pressure on surfaces, localization of impacts, accelerometers, keyboards
• Electrical Components: switches, miniature electric fan
• Acoustic Components: microphones, ultrasonic detectors, hydrophones, sonar
• Optical Devices: laser diameter measurement, variable mirrors

Ktech's PVDF Sensors

PVDF sensors are piezoelectric sensors uniquely suited for the measurement of induced stresses ranging from bars to hundreds of kilo-bars. They are thin (less than 25um), unobtrusive, self powered, adaptable to complex contours, and available in a variety of configurations. Ktech Corporation has demonstrated the use of thin-film piezoelectric polymer transducers over a wide range of stresses. PVDF gauges can measure transient pressures from KPa to 40GPa.

PVDF Sensor Dimensions

Please contact us for a full catalog, and for more information.

Jennifer Dubois
Ktech Corporation
1300 Eubank Blvd. S.E.
Albuquerque, NM 87123-3336
505-998-5830
505-998-5848-FAX
Email: jennifer@ktech.com