一种新型PZT压薄膜应力传感器的设计仿真

针对目前应力传感器不能兼顾柔性、动态测量及无法测量曲面接触应力特征信息等难题,设计了一种新型的PZT压电薄膜柔性应力传感器。主要有由PZT压电薄膜、导线、特殊的压敏涂层等构成。传感器的受力信息可以通过检测PZT压电薄膜传感器的电荷变化来获取,可应用于测量各种接触面之间的应力。为研究测量轮胎路面等具有复杂曲面接触结构的应力分布提供了新的思路和方法,分析了压电传式感器的工作原理,压电薄膜的传感特性,建立有限元分析模型,进行仿真分析,结果表明该传感器结构简单、体积小,相对于传统测量方法更加可靠,适用于曲面应力的测量。     

基于激光多普勒技术的PZT薄膜压电性能测试研究

应用基于激光多普勒技术的微小形变分析方法,并引入数字锁相技术,成功实现了PZT(Pb(Zr,Ti)O₃)铁电薄膜的压电性能测试。对商用压电陶瓷在小信号激励下的压电性能测试表明,数字锁相技术的引入能有效抑制系统噪声,并提高激光多普勒系统的位移检测分辨率,使其达到皮米量级。此外,研究了用溶胶-凝胶技术和溶胶-电雾化技术制备得到的PZT薄膜的电压-位移曲线和压电位移"蝴蝶线",实验结果表明:在5 V直流偏置下测得两种方法制备得到的PZT薄膜的d₃₃压电系数分别为218.7 pC/N和215.8 pC/N,相应的标准偏差分别为12.7和28.6。     

Development of RF magnetron sputtering method to fabricate PZT thin film actuator

PZT piezoelectric very thin films suitable for a microactuator have been deposited onto Invar alloy substrate using a high-temperature RF magnetron sputtering technique. PZT thin films must be deposited onto conductive substrate for a monomorph or a bimorph actuator. The chemical composition and the crystalline structure of these films were measured by ESCA and XRD, respectively. The chemical composition of PZT deposited stoichiometrically was almost the same as commercially-produced bulk PZT. Crystal planes (1 1 0) and (1 1 1) of PZT perovskite structure were observed in XRD analysis. When the substrate was heated to above 600 °C, SEM revealed only a very small number of pinholes on the surface. A thin (500 nm) film actuator has been characterized by measuring the piezoelectric property using a Laser Doppler Vibrograph. It was confirmed that the piezoelectric property has a linear relationship with the grain size, which also increased with the substrate temperature. The piezoelectric property of deposited PZT thin films showed a good agreement with a quoted value of bulk PZT, when the substrates were heated to 600 °C.     

Quantitative measurement of piezoelectric coefficient of thin film using a scanning evanescent microwave microscope

This article describes a new approach to quantitatively measure the piezoelectric coefficients of thin films at the microscopic level using a scanning evanescent microwave microscope. This technique can resolve 10 pm deformation caused by the piezoelectric effect and has the advantages of high scanning speed, large scanning area, submicron spatial resolution, and a simultaneous accessibility to many other related properties. Results from the test measurements on the longitudinal piezoelectric coefficient of PZT thin film agree well with those from other techniques listed in literatures.     

压电智能悬臂梁的压电片位置、尺寸及控制融合优化设计

对压电智能悬臂梁振动控制中的压电片的位置、尺寸及其控制参数进行研究.在对压电片和基板的耦合特性进行分析的基础上,建立智能悬臂梁的压电传感、致动方程及基于闭环控制系统的状态方程,并以系统的存留能量作为目标函数,建立压电智能悬臂梁压电片的位置、尺寸和控制参数的优化模型及一阶灵敏度分析表达式,并采用移动渐进线法(Method of moving asymptotes,MMA)对模型进行求解.采用Simulink对优化结果的动态响应特性进行仿真分析,仿真结果表明,采用提出的优化模型及算法对悬臂梁压电片的位置、尺寸和控制参数进行优化是合理的.     

Optical temperature sensor based on ZnO thin film's temperature-dependent optical properties

A reflective fiber temperature sensor system based on the ZnO thin film is proposed. The transmittance spectra and temperature dependent optical property of the sensing head with ZnO thin film is investigated theoretically and experimentally, and the temperature resolution of ～1?°C is obtained in the temperature region of 300-773 K. The temperature sensing system is only related to the wavelength shift of transmittance spectra, and has a high stability without depending on the incident light intensity. This research results also indicate a fiber optical sensor with a broad temperature measurement range (10-1800 K) can be gained as a promising temperature sensing device, and can be applied into some extremely environments, such as aircraft, nuclear power station and power transmission system, and so on.     

硅基PZT压电功能结构研究

PZT压电薄（厚）膜是制备MEMS传感元件和执行元件重要的功能材料,对近年PZT薄（厚）膜在MEMS领域的研究现状进行了分析,提出了一种新型的双杯PZT/Si膜片式功能结构;采用有限元方法对双杯PZT/Si膜片进行了结构优化,得到PZT和上、下硅杯的结构优化值为DPZT: D1:D2 =0.75:1.1:1;一阶模态谐振频率为13.2KHz;以氧化、双面光刻、各向异性刻蚀,以及PZT厚膜丝网印刷等工艺技术制作了双杯硅基PZT压电厚膜膜片,该膜片具有压电驱动功能。双杯PZT/Si膜片式功能结构的MEMS技术兼容性好,对芯片内其它元件或电路的影响小,适合作为MEMS片内执行元件的驱动机构。     

Enhanced magnetoelectric effect in heterostructure of magnetostrictive alloy bars and piezoelectric single-crystal transformer

We report an enhanced magnetoelectric (ME) effect in a heterostructure consisting of a long-type, longitudinally-longitudinally polarized 0.71Pb(Mg(1∕3)Nb(2∕3))O(3)-0.29PbTiO(3) (PMN-PT) piezoelectric single-crystal transformer with its input part sandwiched between two longitudinally magnetized Tb(0.3)Dy(0.7)Fe(1.92) (Terfenol-D) magnetostrictive alloy bars. The observed ME effect has two independent operational modes: namely, ME sensing mode and ME transduction mode. The ME sensing mode features a large ME voltage coefficient (α(V)) of ～0.32 V∕Oe over a flat frequency range of 1-50 kHz, while the ME transduction mode possesses two colossal resonance α(V) of 7.6 and 7.9 V∕Oe, corresponding to the first and second longitudinal resonances, at 56.2 and 127.9 kHz, respectively. This enhanced dual-mode ME effect not only enables the application potential of the heterostructure, but also advances the technology of power-free ME sensors and transducers.     

Dynamic characteristics and optimization research on PVDF piezoelectric film force sensor for steel ball cold heading machine

According to cold heading process with overloaded craft, high-impact dynamic real-time measurement requirements, this paper presents researches on dynamic characteristics and optimization of PVDF piezoelectric film force sensor for steel ball cold heading forming quality monitoring, through the combination method of mechanism analysis, mathematical modeling, numerical simulation and experimental validation. The motivation and strategic objectives are to breakthrough dynamic time-varying impacting load measuring fundamental technologies in steel ball forging process. The structure of piezoelectric film force sensor is proposed. The theoretical calculation formula of natural frequency is deduced and calculated by using MATLAB software. The mechanical performance analysis on dynamic model and structural optimization simulation by FEM is carried out. In order to study the validity of the proposed method, a prototype of the sensor is fabricated. The static and dynamic calibration devices are designed to realize calibration experiments on the fabricated PVDF piezoelectric film force sensor. The differences among experimental value, simulation value and the theoretical value are given. The nonlinear error of the fabricated sensor is 0.197%. The sensor’s first order natural frequency value is 5238 Hz. It is proved that the PVDF piezoelectric film force sensor has superior dynamic performance and high accuracy for measuring deformation in steel ball. The paper will provide important scientific basis and technical foundation to achieve superior performance steel ball.     

基于Lamb波的压电陶瓷/环氧树脂复合材料传感器制备及应用

风力机叶片、飞机机翼等结构均为大面积曲面板类结构,基于Lamb波的结构健康检测技术对细微损伤比较敏感,是目前最具应用前景的技术之一。传统的Lamb波传感器大都采用PZT陶瓷制成,质地脆且硬度大,不能适应于曲面结构检测。将PZT陶瓷粉末与环氧树脂复合制备了一种新型柔性0-3型压电复合材料,研究了质量比、极化电场、极化温度和极化时间等因素对压电复合材料性能参数的影响,开展了多因素正交实验来确定材料制备的最优极化工艺参数。实验研究了该压电复合材料制成的传感器对Lamb波的传感响应特性,与现有的MFC、PVDF和传统压电片等传感元件的响应特性进行了对比分析。将制备的传感器应用于翼型曲面板,利用椭圆定位方法进行损伤检测。研究结果表明,PZT陶瓷/环氧树脂压电复合材料传感器具有良好的传感响应特性,能够很好地贴合于曲面板表面,与只能部分耦合于曲面板的传统压电片相比,采集的Lamb波信号更加准确,从而为曲面板类结构健康监测提供一种新型的柔性压电传感技术。     

GMM/PZT/GMM层合材料的纵振磁电响应

层状复合结构层间胶层和复合材料的机械损耗是影响层状磁电复合材料磁电响应的重要因素.为了考虑层间胶层的作用,包括其纵向变形和剪切变形产生的效果,应用Hamilton原理建立层状复合结构的运动方程,并用复柔顺系数来反映材料的机械损耗特性.结合层状复合结构的边界条件和磁致伸缩/压电本构方程,就可以得到考虑了胶层作用和材料损耗时,复合结构的固有频率和磁电响应.对GMM(超磁致伸缩材料)/PZT(压电材料)/GMM结构的磁电响应进行了数值计算,将计算结果与实验结果进行了比较,证明考虑胶层作用并引入材料的损耗能够更准确预测复合材料的磁电换能特性.     

Note: Utilizing Pb(Zr(0.95)Ti(0.05))O(3) ferroelectric ceramics to scale down autonomous explosive-driven shock-wave ferroelectric generators

Further miniaturization of recently designed autonomous ferroelectric generators (FEGs) [S. I. Shkuratov, J. Baird, and E. F. Talantsev, Rev. Sci. Instrum. 82, 086107 (2011)], which are based on the effect of explosive-shock-wave depolarization of poled ferroelectrics is achieved. The key miniaturization factor was the utilization of high-energy density Pb(Zr(0.95)Ti(0.05))O(3) (PZT 95∕5) ferroelectric ceramics as energy-carrying elements of FEGs instead of the previously used Pb(Zr(0.52)Ti(0.48))O(3) (PZT 52∕48). A series of experiments demonstrated that FEGs based on smaller PZT 95∕5 ferroelectric elements are capable of producing the same output voltage as those based on PZT 52∕48 elements twice as large. It follows from the experimental results that the FEG output voltage is directly proportional to the thickness of PZT 95∕5 samples. A comparison of the operation of FEGs based on PZT 95∕5 and on PZT 52∕48 ferroelectrics is presented.     

光谱吸收型光纤多气体传感系统

基于气体的近红外吸收机理，研究了一种可以检测多种气体的全光纤传感方法，采用光纤光栅波分复用技术．通过光纤光栅和压电陶瓷（PZT）对宽带光源LED进行波长调制，获得与相应气体吸收峰相对应的窄带反射出射光，检测二次谐波，实现对多种气体的较高灵敏度测量。利用二次谐波与光纤光栅透射光强的比值来消除光路干扰。建立了谐波检测的数学模型，进行了光纤C2H2和CO气体测量系统的实验研究。     

Study on the c-axis preferred orientation of ZnO film on various metal electrodes

ZnO thin film was deposited on various metal electrodes by reactive sputtering, and c-axis preferred orientation of the film has been studied. ZnO, which has high piezoelectricity, is promising for oscillators or filter devices such as surface acoustic wave (SAW) device, gas sensor, and film bulk acoustic resonator (FBAR). But, for the application of ZnO film for these devices, the film should be grown with c-axis normal to the electrode. In this study, Pt, Al, and Au were deposited on Si wafer, and the surface roughness and crystal structure of the ZnO film on the electrode were investigated using AFM, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Columnar structures of ZnO films were grown with c-axis normal to all electrodes, and among them Pt electrode showed the highest preferred orientation of ZnO film.     

高载荷条件下的材料表面摩擦因数测量

针对材料表面高载荷条件的要求，提出了测量摩擦因数的方法，并进行了相应测试装置的设计，该测试装置由正向加载装置、侧向加载装置和数据处理装置3部分组成。可以用来测量高载荷条件下材料表面的静摩擦因数和滑动摩擦因数，同时得到整个滑动过程中摩擦因数变化情况。利用该装置对某国防减摩涂层进行了测试，结果表明在高载荷条件下该涂层对碳钢表面具有较好的减摩效果。     

Study on the c-axis preferred orientation of ZnO film on various metal electrodes

ZnO thin film was deposited on various metal electrodes by reactive sputtering, and c-axis preferred orientation of the film has been studied. ZnO, which has high piezoelectricity, is promising for oscillators or filter devices such as surface acoustic wave (SAW) device, gas sensor, and film bulk acoustic resonator (FBAR). But, for the application of ZnO film for these devices, the film should be grown with c-axis normal to the electrode. In this study, Pt, Al, and Au were deposited on Si wafer, and the surface roughness and crystal structure of the ZnO film on the electrode were investigated using AFM, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Columnar structures of ZnO films were grown with c-axis normal to all electrodes, and among them Pt electrode showed the highest preferred orientation of ZnO film.     

Coded Control of a Multilayer Piezo Actuator Producing Nano- and Micromotion

The mechanical and control characteristics of a multilayer piezo actuator producing nano- and micromotion are derived, in the case of coded control. The static and dynamic characteristics of such actuators with longitudinal, transverse, and shear piezoelectric effects are determined.     

激励电压对压电阻抗法检测灵敏度的影响

研究了锆钛酸铅压电陶瓷(lead zirconate titanate piezoelectric ceramic,简称PZT)传感器的激励电压与压电阻抗法(electro-mechanical impedance,简称EMI)结构健康监测技术灵敏度之间的关系.借助WK 6500B精密阻抗分析仪及自行搭建的高激励电压电阻抗测试系统(high excitation voltage electrical impedance measurement system,简称HEVEIMS),在0.01～20 V之间8种不同激励电压下,对尺寸为1250 mm×100 mm×3 mm铝梁结构上距离PZT传感器1 000 mm的直径为1.2,2.5和3.5 mm的通孔损伤进行了检测.研究结果表明,激励电压与检测灵敏度之间的关系是非单调的.在1～10 V范围内,提高激励电压能够显著增大EMI方法的检测灵敏度.高激励电压下PZT电阻抗信号中非线性成分增多是导致EMI方法检测灵敏度升高的主要原因.研究结果不但为EMI检测中激励电压的选取提供了参考,也为明确激励电压与检测灵敏度之间的相关关系提供了数据支持.     

Measurement of elastic constants of limited-size piezoelectric ceramic sample by ultrasonic method

Measurement of material elastic constants for limited-size samples by ultrasonic method is described and validated. Based on acoustic microscope technology, the material elastic constants are determined by longitudinal wave and leak surface wave velocities simultaneously measured by developed ultrasonic system with a line-focus PVDF transducer. In this paper, the elastic constants of limited-size Cr₂O₃ doping on 0.2 PZN–0.8 PZT piezoelectric ceramic wafer sample are determined and the measurement errors are analyzed. The experimental results show this ultrasonic system can be used for measurement of material elastic constants for limited-size samples with high measurement precision, and the relative errors for Poisson’s ratio and Young’s module measurements are, respectively, less than 1% and 3%. It can satisfy the requirement of engineering and science research. Furthermore, it is suitable to measure elastic constants of both isotropic and anisotropic materials by ultrasonic method with help of developed ultrasonic system.     

PZT铁电薄膜介电性能的数字锁相测试技术

在DSP上实现的数字锁相测试系统,采用数字锁相算法来完成对信号的锁相测试。基于该系统开发出了简单、可靠、可调性好并具有较高精度的PZT铁电薄膜介电性能测试系统。实验表明,使用该系统测得的样品介电常数的相对误差小于1 %,能够满足PZT铁电薄膜制备技术以及微机电系统中器件设计对薄膜性能测试的要求。