Improving the d33 and g33 properties of 0-3 piezoelectric composites by dielectrophoresis

Composites of piezoelectric particles in a polymer matrix with enhanced properties in the poling direction were prepared by dielectrophoretic alignment of the particles. The effect of processing parameters such as the amplitude and frequency of the applied electric field and the viscosity of the matrix on the dielectric and piezoelectric properties of the cured composite were demonstrated for a composite with a PZT volume fraction of 0.2. The amount of structuring could be correlated to the dielectric and piezoelectric properties of the composite through the (P-2) over bar order parameter for the average particle chain orientation, which was derived from image analysis of the microstructure. The piezoelectric properties of the aligned composites can be described with a new model for composites containing particles arranged into chains. The model predictions are in good agreement with the experimental results. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3291131]