Study of 1-3 PZT fibre/epoxy composite force sensor

Lead zirconate titanate (PZT) fibres were prepared by a powder-based extrusion method. Pre-sintered PZT powder mixed with poly(acrylic acid) was spun in a spinnerette to produce fibres. The fibre of similar to 400 mu m diameter was used to fabricate 1-3 PZT fibre/epoxy composite discs with different volume fractions (phi) of PZT. Since the ceramic fibres are rather brittle, their elastic properties cannot be measured directly. In order to determine the properties of the ceramic fibres, effective properties of the fibres/epoxy 1-3 composite were measured. By using a modified series and parallel model, the properties of 1-3 composites can be calculated. Then, the elastic coefficient s(33,fibre)(E), relative permittivity epsilon(T)(33,fibre) and piezoelectric strain coefficient d(33,fibre) of the ceramic fibre could be found. Ring-shaped PZT fibre/epoxy materials composites with different phi were fabricated to be used as the sensing material in force sensor applications. The ring-shape composite with phi = 0.5 was installed into a housing and the sensor was calibrated by different methods and its sensitivity was found to be 144 pC/N within the frequency range of 0.5-6.4 kHz which is much higher than that of a quartz force sensor with a similar structure.