基于虚拟仪器的压电陶瓷驱动技术研究

针对压电陶瓷驱动器的非线性应变,以压电陶瓷微位移驱动原理为基础,分析了扫频激光器腔长控制原理;在硬件时钟的定时下,分析了压电陶瓷的驱动特性,并通过调整驱动信号的步长电压来调节压电陶瓷的非线性。设计了基于虚拟仪器的控制系统,并对线性化方法进行了原理分析和实验。实验结果表明,该测量系统可以使压电陶瓷在其伸长范围内线性地伸长。     

Determination of elastic, piezoelectric, and dielectric constants of an R:BaTiO3 single crystal by Brillouin scattering

From the sound velocity measured using the Brillouin scattering technique, the elastic, piezoelectric, and dielectric constants of a high-quality monodomain tetragonal Rh：BaTiO3 single crystal are determined at room temperature. The elastic constants are in fairly good agreement with those of the BaTiO3 single crystal, measured previously by Brillouin scattering and the low-frequency equivalent circuit methods. However, their electromeehanical properties are significantly different. Based on the sound propagation equations and these results, the directional dependence of the compressional modulus and the shear modulus of Rh：BaTiO3 in the （010） plane is investigated. Some properties of sound propagation and electromechanical coupling in the crystal are discussed.     

基于巯基和聚电解质双层自组装膜的压电免疫传感器检测小鼠IgG气溶胶

本文结合自组装单分子层膜(SAMs)和聚电解质静电吸附组装技术,提出了一种新的用于气相压电免疫检测的生物分子固定化方法,研制了一种用于检测小鼠IgG抗体的压电免疫传感器。首先在石英晶片的金电极表面自组装了一层L-胱氨酸SAMs,再在膜上组装带相反电荷的海藻酸钠,最后通过调节pH值定向固定羊抗鼠纯化抗体,优化了固定条件。通过超声雾化法产生的小鼠IgG气溶胶,研制成了直接气相检测小鼠IgG的压电免疫系统。结果表明,该方法对所固定的生物分子活性影响较小,传感器对小鼠IgG的响应快,灵敏度高,在0.14~6μg.μL-1范围内具有良好的线性关系,精密度好,再生方便。     

指数形压电声笔的设计和应用

压电声笔是各种声坐标录取装置的重要组成部分,高性能的声笔对于该装置的接收机和其它信号处理部分的研制会带来很大的方便,对装置的有效工作面积有直接的影响,对整机的精度有重要的作用。本文主要介绍从波动方程入手,根据变幅杆原理进行超声笔设计的方法。并根据实用要求测试了声笔的性能:工作频率为200kHz,垂直于工作面的水平指向性为360°,可以在与工作面的夹角为30°—90°的任何正常书写角度上使用,它发出的声信号强度比普通声笔(非变幅杆型)大6倍以上,并测定了几个典型点的振幅值,振幅放大系数大于6。符合设计要求,已在某些声坐标录取装置上获得了满意的应用。如按半波长振子的原理并配以简单的结构,能够很方便地获得当笔尖发射超声的同时,还能在传输介质的表面上留下笔迹,使用方便自由,外形和尺寸与普通钢笔相似。     

新书评介

电子陶瓷情报网编的《压电陶瓷应用》一书,于1985年8月由山东大学出版社出版.压电陶瓷是声学中广泛应用的电-声换能材料,由压电陶瓷做成的各种声学器件,是一些声学仪器、设备中的关键部件.该书从实用角度出发,对压电陶瓷在各类声学仪器中的作用、工作机理与方式等,给予了简要的说明;对一些典型的换能器,给出了设计的考虑原则、制做工艺、计算公式,并给出了具体结构的实例. 全书共分七章:第一章“在高电压发生装置中的应用”,介绍了压电陶瓷点火器、变压器、玩具遥控信号发生器、压电按扭开关等;第二章“在电声等设备上的     

PB-1型窄脉冲压电薄膜可逆式换能器

本文著者研制成PB-1型PVDF可逆式压电换能器。它的通频带较宽,中心频率500—900KHz,通带Q值1.5,发送电压响应[级]148.9dB(re:1μPa/V),灵敏度-210dB(re:1V/μPa)。在水中声脉冲持续时间7—10μs,并有足够的声功率输出,电声效率约10％。 本文介绍了该换能器的结构、理论分析、测量结果及应用效果。证明了理论与实验的一致性。可供电声、水声、超声等其它PVDF传感器设计时参考。     

新的压电薄膜——Ta2O5

据报道,日本Yasuhiko Nakagawa和Yasuo Gomi用磁控反应直流二极管溅射法将Ta_2O_5,沉积在石英基片上,得到了单晶薄膜,并且首次观察到了这种薄膜的压电现象.用叉指换能器在Ta_2O_5薄膜上成功地激发了声表面波.在Ta_2O_5/熔石英基片上,当薄膜厚度h在hk(=2πh/λ)=1.0时,其机电耦合系数k~2=0.5％,它可与熔石英基片上ZnO薄膜的机电耦合系数相比拟. 利用Ta_2O_5单晶的X射线衍射数据,推断出Ta_2O_5     

An investigation on optical microfiber reflector with low reflectance

The backscattering characteristics of optical microfiber(OM) are experimentally studied by controlling heating temperature and cooling method during the OM fabrication process.OM samples with various reflectances from 0.1% to 1% are achieved.An OM with waist length of 5 mm,waist diameter of 1 μm,and approximately 0.5% reflectance is used as the end reflector of a fiber Fabry-Perol(F-P) interferometer.A piezoelectric ceramic transducer(PZT) fiber phase modulator is used to test the sensing performance of the fiber F-P interferometer.Experimental results verify that the OM with low reflectance can be used as a reflector in the F-P interferometer.     

Broadband energy harvesting via magnetic coupling between two movable magnets

Harvesting energy from ambient mechanical vibrations by the piezoelectric effect has been proposed for powering microelectromechanical systems and replacing batteries that have a finite life span. A conventional piezoelectric energy harvester （PEH） is usually designed as a linear resonator, and suffers from a narrow operating bandwidth. To achieve broadband energy harvesting, in this paper we introduce a concept and describe the realization of a novel nonlinear PEH. The proposed PEH consists of a primary piezoelectric cantilever beam coupled to an auxiliary piezoelectric cantilever beam through two movable magnets. For predicting the nonlinear response from the proposed PEH, lumped parameter models are established for the two beams. Both simulation and experiment reveal that for the primary beam, the introduction of magnetic coupling can expand the operating bandwidth as well as improve the output voltage. For the auxiliary beam, the magnitude of the output voltage is slightly reduced, but additional output is observed at off-resonance frequencies. Therefore, broadband energy harvesting can be obtained from both the primary beam and the auxiliary beam.