In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTi...In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary （MPB）. LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.展开更多
Lead-free piezoelectric ceramics of (Bi1/2Na1/2)TiO3-BaTiO3(BNT-BT) were prepared by the conventional piezoelectric ceramic preparation technique (free air atmosphere sintering). The influence of BaTiO3 additive amoun...Lead-free piezoelectric ceramics of (Bi1/2Na1/2)TiO3-BaTiO3(BNT-BT) were prepared by the conventional piezoelectric ceramic preparation technique (free air atmosphere sintering). The influence of BaTiO3 additive amount and La2O3 additive amount on the properties of BNT-BT lead-free piezoceramics were investigated. The results show that the dielectric constant(ε) and piezoelectric strain constant(d33) of materials start increasing and then decreasing while BaTiO3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1650, d33 = 120 PC·N -1 ) while x (BaTiO3) =0.06 mol. Theεand d33 of materials start increasing and then decreasing while La2O3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1684, d33 = 153 PC·N-1) while w(La2O3) =0.3% . The influence of La2O3 additive amount on the microstructure of BNT-BT piezoelectric ceramics was analysed by SEM( scanning electron microscope). The influence mechanism of La2O3 additive amount on the properties of BNT-BT piezoelectric ceramics was discussed. The BNT-BT ceramics with optimum comprehensive properties were obtained.展开更多
To improve the efficiency of MEMS piezoelectric vibration energy harvesters(PVEHs), the bulk lead zirconate titanate(PZT) has been used to substitute the thin film PZT for the higher mechanical-electrical coupling coe...To improve the efficiency of MEMS piezoelectric vibration energy harvesters(PVEHs), the bulk lead zirconate titanate(PZT) has been used to substitute the thin film PZT for the higher mechanical-electrical coupling coefficients. The expensive equipment of micromachining set a high entry barrier on the research of PVEHs with high efficiency. To solve this issue, this paper developed an efficient PVEH with bulk PZT using common precision machining, whose dimensions and electrical outputs are comparable to the MEMS devices. After numerically analyzing the effects of the length ratio of the proof mass to the harvester on the output power, a compact PVEH consisting of a cantilevered uni-morph and a tungsten proof mass was designed. Simulations show that the mechanical damping ratio and the thickness have little effects on the optimized length ratio. By using a uni-morph with the copper structural layer of about 80-90μm and the bulk PZT-5 H layer of 139μm, a low-cost harvester prototype was assembled. The key parameters of the prototype were experimentally identified and compared with the theoretical predictions. Under the harmonic base excitation of 0.4 g(where g = 9.8 m/s^2) at 160 Hz, the maximum output power of the prototype is about 76.7μW, with the normalized power density of about 3.35 mW/cm^3/g^2. Under base excitation of 0.4 g at 159 Hz, the prototype charged a 680μF capacitor from 0 to 4.84 V in about 154 seconds.展开更多
The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohed...The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohedral coexistent phases, was studied. A series of piezoelectric ceramics with good properties was obtained, having dielectric constants (ε= 1500 ~ 2500), plane electromechanical coupling factor(Kp = 0.45 ~ 0.65), mechanical quality factor( Qm = 500 ~ 1600). These materials are used for making ultrasonic sensor and filter, and marine acoustic launching and receiving device, and so on. It has been explored that the influence of composition on the lattice constant and phase composition of La2O3-doped PNSZT piezoelectric ceramics by XRD(X-ray diffraction) . The character of dielectric constant changing of La2O3-doped PNSZT piezoelectric ceramics before polarization and after polarization was studied. The affecting mechanism about composition on the electric machine properties of phase coexistent La2O3-doped PNSZT piezoelectric ceramics was analyzed and discussed.展开更多
To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics ...To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact areas.Increasing the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated voltage.Decreasing contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT ceramic.On the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT ceramic.From this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50675025)Scientific Research Foundation of Ministry of Education,Dalian City for the Returned Overseas Chinese ScholarsDoctoral Startup Fund of Liaoning Province of China (No.20051080).
文摘In order to describe the characteristics of piezoelectric bimorph, properties of lead zirconate titanate （LZT） film are studied by X-ray diffraction （XRD） and scanning eletron microscope （SEM）. The ratio of PbTiOJPbZrO3 in LZT is 53/47, which is around morphotropic phase boundary （MPB）. LZT film is composed of cubic particles with the average size of 5 ~ma. Density of thin film is figured out through the datum measured in experiments. The displacement model used to analyze the driving ability of bimorph is set up, and the effect of elastic intermediate layer is taken into account. Piezoelectric coefficient of LZT film is worked out by using the displacement model. Experiments of driving ability show that deformation of bimorph free end does not increase with times of crystal growth processes and the maximum deformation is obtained after two times crystal growth processes. Finally, the ferroelectric property of the bimorph is investigated and coercive voltage of the bimorph is obtained.
文摘Lead-free piezoelectric ceramics of (Bi1/2Na1/2)TiO3-BaTiO3(BNT-BT) were prepared by the conventional piezoelectric ceramic preparation technique (free air atmosphere sintering). The influence of BaTiO3 additive amount and La2O3 additive amount on the properties of BNT-BT lead-free piezoceramics were investigated. The results show that the dielectric constant(ε) and piezoelectric strain constant(d33) of materials start increasing and then decreasing while BaTiO3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1650, d33 = 120 PC·N -1 ) while x (BaTiO3) =0.06 mol. Theεand d33 of materials start increasing and then decreasing while La2O3 additive amount increasing, the e and d33 of materials have maximum value (ε= 1684, d33 = 153 PC·N-1) while w(La2O3) =0.3% . The influence of La2O3 additive amount on the microstructure of BNT-BT piezoelectric ceramics was analysed by SEM( scanning electron microscope). The influence mechanism of La2O3 additive amount on the properties of BNT-BT piezoelectric ceramics was discussed. The BNT-BT ceramics with optimum comprehensive properties were obtained.
基金financially supported by the National Natural Science Foundation of China(Nos.61774026 and61376116)
文摘To improve the efficiency of MEMS piezoelectric vibration energy harvesters(PVEHs), the bulk lead zirconate titanate(PZT) has been used to substitute the thin film PZT for the higher mechanical-electrical coupling coefficients. The expensive equipment of micromachining set a high entry barrier on the research of PVEHs with high efficiency. To solve this issue, this paper developed an efficient PVEH with bulk PZT using common precision machining, whose dimensions and electrical outputs are comparable to the MEMS devices. After numerically analyzing the effects of the length ratio of the proof mass to the harvester on the output power, a compact PVEH consisting of a cantilevered uni-morph and a tungsten proof mass was designed. Simulations show that the mechanical damping ratio and the thickness have little effects on the optimized length ratio. By using a uni-morph with the copper structural layer of about 80-90μm and the bulk PZT-5 H layer of 139μm, a low-cost harvester prototype was assembled. The key parameters of the prototype were experimentally identified and compared with the theoretical predictions. Under the harmonic base excitation of 0.4 g(where g = 9.8 m/s^2) at 160 Hz, the maximum output power of the prototype is about 76.7μW, with the normalized power density of about 3.35 mW/cm^3/g^2. Under base excitation of 0.4 g at 159 Hz, the prototype charged a 680μF capacitor from 0 to 4.84 V in about 154 seconds.
文摘The relationship between composition and the electric mechanical properties for La2O3-doped lead niobium stibium zirconate titanate(La2O3-doped PNSZT) piezoelectric ceramics,in which there are tetragonal and rhombohedral coexistent phases, was studied. A series of piezoelectric ceramics with good properties was obtained, having dielectric constants (ε= 1500 ~ 2500), plane electromechanical coupling factor(Kp = 0.45 ~ 0.65), mechanical quality factor( Qm = 500 ~ 1600). These materials are used for making ultrasonic sensor and filter, and marine acoustic launching and receiving device, and so on. It has been explored that the influence of composition on the lattice constant and phase composition of La2O3-doped PNSZT piezoelectric ceramics by XRD(X-ray diffraction) . The character of dielectric constant changing of La2O3-doped PNSZT piezoelectric ceramics before polarization and after polarization was studied. The affecting mechanism about composition on the electric machine properties of phase coexistent La2O3-doped PNSZT piezoelectric ceramics was analyzed and discussed.
文摘To better understand the generation of electric power for piezoelectric Pb Zr Ti O3(PZT)ceramic plate(?25 mm),an attempt was made to investigate experimentally and numerically electricpower generation characteristics during cyclic bending under various loading fixtures(?0–?20 mm),i.e.,different contact areas.Increasing the load-contact area on the PZT ceramic leads to a nonlinear decrease in the generated voltage.Decreasing contact area basically enhances the generated voltage,although the voltage saturates during loading when the contact area is less than?5 mm.A similar voltage is generated for?0 and?5 mm,which is attributed to strain status(ratio of compressive and tensile strain)and material failure due to different stress distribution in the PZT ceramic.On the basis of the obtained electric generation voltage,suitable loading conditions are clarified by loading with the?5 mm fixture,which generates a higher voltage and a longer lifetime of the PZT ceramic.From this approach,it is appeared that the area contact with the area ratio of 0.04(?5 mm/?20 mm)is suitable to obtain the high efficiency of the electric voltage.
