Multilayer Piezoelectric Ceramics And Its Applications In Piezoelectric Actuators

The piezoelectric actuators transfer the electric energy into mechanical energy through the reverse piezoelectric effect of the piezoelectric ceramics.Compared to the traditional electromagnetic motor,it has the advantages of fast response speed,high energy density,no power consumption,no electromagnetic radiation and so on.It has been widely used in the fields of precision instruments,robots,medical devices and other fields.The development of technology provides higher requirements for the performance of piezoelectric actuators,such as higher resolution,smaller drive voltage,and smaller size structure.Based on the above issues,we summarized the researching status of the piezoelectric actuator at home and abroad,and studied the principle of piezoelectric actuator.The paper proposes a micro piezoelectric actuator to meet the demand for miniaturization drives.We innovate the driving mechanism and propose a piezoelectric actuator based on bending coupling modes.The miniature piezoelectric actuator based on the stick-slip principle is comprised of a T-shape zirconia drive foot and a multilayer PZT bimorph which consists of two parallel d₃₃ stacks,with overall dimensions of only 3 mm×3 mm×4 mm.Multi-layer piezoelectric ceramic structure makes micro-drive produce a significant displacement at lower drive voltage and non-resonant frequency,which is conductive to the drive and control.The test results of the output force and output step length of the actuator shows that the output step length is 1?m and the thrust force is 0.23 N,when the driving voltage is 50 V_pp and the holding force is 0.25 N.The L-type linear piezoelectric actuator,which is based on the coupling of two second-order bending coupling modes,form an elliptical motion locus at the driving tip.The mechanism analysis,structural design and optimization,and modal analysis of the actuator show that the driving frequency range of the driver is obviously increased due to the high coupling degree between the two bending vibrations,and the structure is simple.The mechanical performance shows that the working frequency is 89 kHz.At this frequency,the maximum speed of the forward movement is 53 mm/s,and the reverse maximum velocity is 44 mm/s,due to the uneven surface of the driving slider.