(Na1/2Bi1/2)TiO3‐based lead‐free co‐fired multilayer actuators with large strain and high fatigue resistance

Large‐strain multilayer actuators (MLAs) were fabricated by tape‐casting 0.91(Na1/2Bi1/2)TiO3–0.06BaTiO3–0.03AgNbO3 (NBT‐BT–3AN) lead‐free incipient piezoceramics co‐fired with Pt inner electrodes. Microstructures, dielectric properties, unipolar and bipolar strain, as well as fatigue properties of the MLAs were investigated. It was found that the actuator consisting of 15 ceramic layers with individual thicknesses of 114 μm could output a large unipolar strain of 0.3% and a dynamic displacementof 5 μm at 6 kV/mm at room temperature. It exhibited excellent cyclingstability and provided a high strain of 0.23% after 107 cycles at 6 kV/mm. Moreover,these MLAs still can deliver a strain of 0.20% at 125°C.