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。     

Ansys在PZT压电薄膜微传感器压电分析中的应用

研究的PZT压电薄膜微传感器采用的弹性敏感元件为微悬臂梁结构,在压电原理和材料力学理论的基础上,采用简化的等效微器件结构建立了数学分析模型,将有限元方法发展应用于压电材料的结构分析中,并运用有限元软件Ansys7.0对PZT压电薄膜微悬臂梁结构的传感性能和线性度进行了模拟,同时分析了微悬臂梁结构的几何参数对输出电压的影响,这些分析结果和解析预测是一致的。     

一种柔性PVDF压电薄膜传感器的制备方案

利用性能优异的PVDF压电薄膜制备的新型柔性传感器柔性好、适应性强,可适应复杂曲面,其应用前景十分广阔。首先设计了具有柔性基底的PVDF压电薄膜传感器结构;其次,按照实验设计利用PVDF粉末制备了性能良好的PVDF压电薄膜,提出了一种柔性PVDF薄膜传感器的制备方案;最后总结了该传感器实验制备的主要工艺步骤,可为柔性PVDF传感器设计制备提供参考。     

新技术·新产品

P/C柔性复合压电薄膜 P/C柔性复合压电薄膜PVDF基压电聚合物与铁电陶瓷PZT等3—0型柔性复合压电PVDF/PZT薄膜系列。采用P/C柔性复合压电功能薄膜的压电换能传感器件,可极其广泛地应用于现代电子高新技术、生物医疗电子学与仿生学、工农业国民经济信息处理与自控自动化技术等领域,供作压电、     

压电薄膜力传感器及其牙咬力的测量应用研究

本文介绍一种用于测量牙咬力的传感器-压电簿膜力传感器.它应用压电薄膜受到机械应力产生电极化,从而产生电荷的原理来测量牙咬力.这种压电薄膜厚度仅25μm,用它来作为传感器测量牙咬力时无咬合间隙,测量的值能反映出牙齿真实的咬力.     

新技术·新产品

P/C 柔性复合压电薄膜P/C 柔性复合压电薄膜 PVDF 基压电聚合物与铁电陶瓷 PZT 等3—0型柔性复合压电 PVDF/PZT 薄膜系列。采用 P/C 柔性复合压电功能薄膜的压电换能传感器件,可极其广泛地应用于现代电子高新技术、生物医疗电子学与仿生学、工农业国民经济信息处理与自控自动化技术等领域,供作压电、压力、热电、超声和电声等换能、传感及监控处理。P/C 功能薄膜采用国际新型压电     

水热合成法制备PZT压电薄膜工艺研究

对水热合成法制备Pb(Zr1-xTix)O3(PZT)薄膜的原理进行了讨论,以钛、锆的醇盐和硝酸铅等为原料制备出PZT压电薄膜,利用X射线衍射对PZT压电薄膜的成分进行了分析,利用扫描电子显微镜(SEM)对PZT晶体形成过程的变化进行了分析.X射线衍射分析表明,晶体成核阶段,PbZrO3(PZ)成分较多,晶体生长阶段,PZ成分减少,PZT成分逐渐增多.2次重复生长过程后,SEM扫描图像所得为四方形PZT晶体,颗粒平均尺寸为5μm,与Shimomura和Kanda实验所得的PZT晶体颗粒在大小和形状上基本相同,为钙钛矿型结构.     

PT/PZT/PT薄膜微力传感器

提出了一种基于PT/PZT/PT压电薄膜微悬臂梁结构的微力传感器.运用Sol-Gel(溶胶-凝胶)法制作了PT和PZT薄膜,采用X射线衍射技术表征了PZT和PT/PZT/PT两种薄膜的成相特征,用阻抗分析仪测试了PZT和PT/PZT/PT薄膜的介电常数.结果表明,在PZT薄膜退火温度同为600℃时,PZT和PT/PZT/PT薄膜均为完整的钙钛矿结构,而且PT/PZT/PT薄膜沿(100)晶向强烈取向;在测试频率为1 kHz时,经600℃热处理条件下制备的PZT和PT/PZT/PT薄膜的相对介电常数分别为525和981.最后应用MEMS工艺制作了基于PT/PZT/PT压电薄膜微悬臂梁结构的微力传感器.在静态和准静态下对微力传感器的传感特性进行了测试.测试结果表明,力与位移或电荷具有良好的线性关系.两种尺寸微力传感器的灵敏度分别为0.045 mV/μN和0.007 mV/μN,力分辨率分别为3.7 μN和16.9μN,满足了微牛顿量级微小力的测量.     

压电传感器材料的铁电特性研究

本文采用溶胶-凝胶工艺制备了不同Mn离子掺杂浓度的PZT薄膜.研究了不同掺杂浓度对压电传感器薄膜铁电特性的影响.试验结果表明当Mn离子含量较少时,Mn在PZT中主要表现施主掺杂特性,薄膜铁电性能提高;而当浓度增大时,薄膜性能降低.     

利用光纤Bragg光栅测量压电晶体的特性曲线

应用逆压电效应 ,在低频直流条件下 ,提出利用光纤 Bragg光栅测量压电晶体的特性曲线。推导出了 Bragg反射波长λB随应力变化的关系式 ,并设计了合理的结构以直接测量 PZT的位移量。通过实际测量给出的 PZT电压—位移曲线表明 :该系统测量方法结构简单 ,测量精度高 ,能进行实时测量。     

Design and implementation of a versatile and variable-frequency piezoelectric coefficient measurement system

We present a simple but versatile piezoelectric coefficient measurement system, which can measure the longitudinal and transverse piezoelectric coefficients in the pressing and bending modes, respectively, at different applied forces and a wide range of frequencies. The functionality of this measurement system has been demonstrated on three samples, including a PbZr(0.52)Ti(0.48)O(3) (PZT) piezoelectric ceramic bulk, a ZnO thin film, and a laminated piezoelectric film sensor. The static longitudinal piezoelectric coefficients of the PZT bulk and the ZnO film are estimated to be around 210 and 8.1 pC∕N, respectively. The static transverse piezoelectric coefficients of the ZnO film and the piezoelectric film sensor are determined to be, respectively, -0.284 and -0.031 C∕m(2).     

Residual strain measurement of piezoelectric multilayers by spiral structure

A new structure is described to measure the residual strain of thin film of piezoelectric multi-layers. The spiral shaped structure consists of the four fixed-guided beams. Piezoelectric multilayers consisting of SiOx/Pt/PZT/Pt on SiNx substrate are used to evaluate the suggested structure. Finite element analysis predicts that the out-of-plane displacement of the spiral structure by residual stress depends linearly on the beam length, but there is little difference depending on the beam width. PZT is prepared by sol-gel method and multilayered spiral structures are released by microfabrication technique. Sensitivity analysis of the spiral structure with various layer stack shows that the high displacement of piezoelectric multilayers can be decreased by the application of SiOx layer with compressive stress over the piezoelectric multilayers.     

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.     

Research on the parallel load sharing principle of a novel self-decoupled piezoelectric six-dimensional force sensor

This paper presents a novel integrated piezoelectric six-dimensional force sensor which can realize dynamic measurement of multi-dimensional space load. Firstly, the composition of the sensor, the spatial layout of force-sensitive components, and measurement principle are analyzed and designed. There is no interference of piezoelectric six-dimensional force sensor in theoretical analysis. Based on the principle of actual work and deformation compatibility coherence, this paper deduces the parallel load sharing principle of the piezoelectric six-dimensional force sensor. The main effect factors which affect the load sharing ratio are obtained. The finite element model of the piezoelectric six-dimensional force sensor is established. In order to verify the load sharing principle of the sensor, a load sharing test device of piezoelectric force sensor is designed and fabricated. The load sharing experimental platform is set up. The experimental results are in accordance with the theoretical analysis and simulation results. The experiments show that the multi-dimensional and heavy force measurement can be realized by the parallel arrangement of the load sharing ring and the force sensitive element in the novel integrated piezoelectric six-dimensional force sensor. The ideal load sharing effect of the sensor can be achieved by appropriate size parameters. This paper has an important guide for the design of the force measuring device according to the load sharing mode.     

BIMORPH PIEZOELECTRIC ACTUATOR FOR SMALL PIPE ROBOT

An experimental bimorph piezoelectric element (PZT) actuator for small pipe robot is developed. The robot can move in φ20 mm pipe, and can carry a CCD camera for detecting cracks or fine holes on inner surface of pipe. The velocity of the robot can reach 17～22 mm/s for vertical pipe up/down, respectively. Moving principle and its performance characteristics are presented.     

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。     

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.     

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.