Hemispherical Piezoelectric Thick Film Printed By Electrohydrodynamic Jet Printing And Its Impact Sensor

Curved surface piezoelectric ceramics can be widely used in medical imaging,ocean monitoring and industrial control due to its function of increasing sensitive direction,focusing and amplifying signal.The thickness of PZT piezoelectric thick film is between thin film and bulk,which has the advantages of high sensitivity,strong driving ability and strong machinability.It is suitable for the fabrication of curved piezoelectric ceramics.In this paper,the model of hemispherical piezoelectric impact sensor is established.The stress,piezoelectricity,temperature and sensitive direction of the hemispherical piezoelectric impact sensor are simulated and analyzed.Hemispherical PZT piezoelectric thick films were prepared by electrohydrodynamic jet printing.The impact sensor test device is built.The sensitivity,amplitude linearity,sensitivity response range and direction of the impact sensor are tested.Finally,a hemispherical piezoelectric impact sensor with good sensitivity and linearity is obtained.Firstly,based on the basic principle of piezoelectric effect of piezoelectric materials,the simulation model of hemispherical piezoelectric impact sensor is established by using the finite element analysis method and COMSOL software.It is preliminarily determined that the hemispherical piezoelectric impact sensor will produce stress when it is impacted at multiple angles.The stress distribution of sensor and hemispherical piezoelectric thick film is simulated.The stress distribution of PZT thick film under different impact angles at-70?-200?was obtained.The relationship between the electrical signal of the sensor and the impact acceleration is simulated.The sensitivity direction of the sensor is analyzed,and the influence of electrode partition on the sensitivity direction of the sensor is obtained.These results provide a basis for the fabrication of PZT thick films.Secondly,a hemispherical piezoelectric thick film electrohydrodynamic jet printing platform was built.The trajectory in the process of hemispherical piezoelectric thick film electrohydrodynamic jet printing is studied.The hemispherical substrate of titanium alloy was prepared.Based on the electrohydrodynamic jet printing process,a hemispherical PZT piezoelectric thick film with thickness of 50?m was prepared by using PZT composite suspension on the printing platform.The printed piezoelectric thick film was annealed by sintering.The surface morphology of hemispherical piezoelectric thick films was characterized.The electrode was fabricated on the surface of PZT thick film by magnetron sputtering.The polarization platform of hemispherical piezoelectric thick film is constructed,and the polarization law of hemispherical piezoelectric thick film is analyzed.The d₃₃piezoelectric constant of the polarized hemispherical piezoelectric thick film is 65p C/N.Finally,the hemispherical piezoelectric impact sensor test device is built,and the impact height and impact block mass on the impact acceleration of the test device are analyzed.The sensitivity of the impact sensor is 2.89p C/g.The sensitivity and amplitude linearity of the hemispherical piezoelectric impact sensor are tested and analyzed.The results show that the sensitivity is 2.89pc/g,and the sensitivity amplitude linearity is 5.4%under 100g?8000g impact acceleration.In addition,the hemispherical piezoelectric sensor with six zone electrodes is fabricated,and the sensitivity uniformity is significantly improved compared with the single zone sensor.