Multilayer piezoelectric haptic actuator with CuO-modified PZT-PZNN ceramics

A piezoelectric haptic actuator composed of a multilayered ceramic (MLC) of 0.5 mol% CuO-modified 0.69Pb(Zr0.47Ti0.53)O3-0.31[Pb(Zn0.4Ni0.6)1/3Nb2/3]O3 (0.5CPZT-PZNN) ceramic was developed and characterized. The 0.5CPZT-PZNN ceramic was well-sintered at 900 °C. This ceramic showed a small εT33/εo of 1801 and a large d33 of 570 pC/N, necessary characteristics for high-performance actuators operating at low voltages. This ceramic also showed a high field-induced strain, maintained after 106 fatigue cycles. A three-layer MLC was synthesized at 900 °C using this ceramic. Ag metal was used as the electrode for the MLC actuator. No inter diffusion between the Ag electrode and the 0.5CPZT-PZNN ceramic layer was observed. The MLC actuator exhibited a high free stroke of ± 300 μm even after 106 bending cycles. The piezoelectric haptic actuator fabricated using this MLC showed a large vibration acceleration of 2.1 G with a low capacitance of 20 nF. This demonstrates the suitability of the 0.5CPZT-PZNN ceramic for applications in piezoelectric haptic actuator.