Piezoelectric/electrostrictive multimaterial PMN-PT monomorph actuators

Fused deposition of multimaterials (FDMM), a CAD-based layered manufacturing technique, was utilized to fabricate monolithic piezoelectric/electrostrictive multimaterial monomorphs. The samples, comprised of piezoelectric 0.65Pb(Mg1/3Nb2/3)O3-0.35PbTiO3 and electrostrictive 0.90Pb(Mg1/3Nb2/3)O3-0.1PbTiO3, have been successfully prototyped and co-sintered. Bimorphs, that are isometric with the co-fired samples, have also been prepared by attaching individual piezoelectric and electrostrictive layers with conductive epoxy, and were used as a comparison for displacement properties. The dielectric permittivity, displacement, and polarization hysteresis were investigated. The permittivity of the multimaterial co-sintered samples followed the two-capacitors in-series model, showing a dielectric constant of 5800 at room temperature. The P–E loop of the multimaterial samples exhibited a saturation polarization, remnant polarization, and hysteresis between that of the single material electrostrictive 0.9PMN-0.1PT and the single material piezoelectric 0.65PMN-0.35PT. Displacement hysteresis was shown to be lower for the monolithic monomorph as compared to the bimorph and reached ∼11 μm at ∼3 kV/cm.