Composites of ferroelectric ceramic in polymer matrix have been developed and characterized for their ability to be employed as embedded sensors for the health monitoring of olymer composite structures. In this paper results illustrating the response of embedded composite sensors to dynamic loads are presented and discussed. Furthermore, the ability of the composite sensors to act as actuators, generating diagnostic waves in composite structures, has been investigated.

The incorporation of high dielectric constant filler particles into thermoplastics is an attractive approach to develop materials with high dielectric strength, low dielectric loss, and mechanical stiffness, for electronic packaging purposes. Herein, we report the preparation and properties of polystyrene (PS) based low loss 0-3 composites with inorganic PbZr 0.3 Ti 0.7 O 3 (PZT) filler particles in concentrations ranging from 0%-20% (w/w). The PZT particles were synthesized using the sol-gel process and the composites were prepared by a two-step, solvent-free approach: (1) melt mixing, followed by (2) hot press. The thermal and mechanical properties of the composite samples were investigated. The dielectric behavior of the as-synthesized composites showed pronounced improvement over pure PS, as is seen from the increased dielectric constant and extremely low loss tangent. For 20 wt.% PZT loading, the dielectric constant of the composite is as high as 12 at 1 MHz frequency, which is about five times greater than that of pure PS (ε = 2.5). All the PZT/PS composites exhibit remarkably low dielectric losses, even at lower frequencies (tan δ ≤ 0.04), which is better than reported literature values of PS based composites. The variation in dielectric constants of the samples with increasing temperatures was also recorded.

No abstract