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Ceramics based on solid solutions of xBaTiO3–(100−x)(0.5Bi(Zn1/2Ti1/2)O3–0.5BiScO3), where x = 50, 55, and 60 were prepared by solid‐state reaction which resulted in a single perovskite phase with pseudocubic symmetry. Dielectric property measurements revealed a high relative permittivity (>1000), which could be modified with the addition of Bi(Zn1/2Ti1/2)O3 (BZT) and BiScO3 (BS) to engineer a temperature‐stable dielectric response with a temperature coefficient of permittivity (TCε) as low as −182 ppm/°C. By incorporating 2 mol% Ba vacancies into the stoichiometry, the resistivity increased significantly, especially at high temperatures (>200°C). Vogel–Fulcher analysis of the permittivity data showed that the materials exhibited freezing of polar nanoregions over the range of 100–150 K. An analysis of optical absorption near the band edge for the Ba‐deficient compositions suggested that the enhanced resistivity values were linked to a decrease in the concentration of defect states. An activation energy of ~1.4 eV was obtained from DC resistivity measurements suggesting that an intrinsic conduction mechanism played a major role in the high temperature conductivity. Finally, multilayer capacitors based on these compositions were fabricated, which exhibited dielectric properties comparable to the bulk material. Based on these results, this family of materials has great promise for high‐temperature capacitor applications.

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The use of thermoplastic elastomers with conductive fillers enables to produce strain sensors in a variety of shapes and forms by using thermoplastic processing routes. However, some methods of thermoplastic processing are costly and require long production time. Filament printing, an additive manufacturing route that still exhibits a high annual growth rate, is a cost and time-efficient method of additive processing. In this study a commercial conductive thermoplastic polyurethane (TPU) based fused deposition modelling (FDM) filament and a styrenic block co-polymer (TPS) compound were extruded through two different FDM based nozzles sizes, using an FDM 3D printer. The TPU material could only be extruded through a 0.5 mm orifice, using a lower nozzle diameter resulted in a none-elastic brittle filament. For the TPS material it was possible to produce filaments with diameter 0.3 mm and 0.5 mm. In all dynamic tests, the extruded commercial piezoresistive TPU filament either showed at higher elongation plastic deformation, which resulted in resistance uncertainty at low strain, or a secondary peak in the resistivity measurement. For the TPS material, mainly the relaxation of the material resulted in lagging of the resistive value at low strain, because of the buckling of the fiber. Using combined dynamic and static measurements, a reproducible signal could be achieved with the TPS based material, while the TPU based material could not be used as a sensor in this area of strains.

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Compositons in the pseudoquaternary system, 1-×(0.35Bi(Mg 1/2 Ti 1/2 )O 3 -0.30BiFeO 3 -0.35BiScO 3 )-× PbTiO 3 were fabricated and characterised at the morphotropic phase boundary (MPB) between ferroelectric rhombohedral and tetragonal phases. The MPB occurred at ×≈0.48 at which composition the ferreoelectric to paraelectric phase transition, T C =450°C, the piezoelectric constant, d 33 =328 pC/N and electromechanical coupling factor, k p =0.44. The piezoelectric properties are viable for actuator applications but lower than equivalent high T C piezoelectrics such as 0.36BiScO 3 -0.64PbTiO 3 (d 33 = 450 pC/N, T C =450°C). However, the relative reduction in the Sc 2 O 3 content gives a significant cost saving which may prove a commercial advantage.

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