1、传感器研发设计 模拟和数字电路 涡流压电电容传感器 AUTOCADDevelopment of a miniature abrasion-detecting device for a small precision latheSensors and ActuatorsThis paper describes the development of a miniature abrasion-detecting device for a small precision lathe. The device works by detecting the amplitude of the first na
2、tural frequency of the cutting tool, which increases with abrasion. By employing a small unimorph piezoelectric vibrator as a sensor and using an electric power control with an analog switch, a miniature, low power device for detecting abrasion is developed. The 30mm by 30mm device does not need a r
3、egulator in the electrical circuit and runs continuously for more than a week on a coin-sized battery.Development of temperature stable charge based piezoelectric composite quasi-static pressure sensorsIn this work piezoelectric composite charge based sensors are developed, aimed at quasi-static pre
4、ssure sensor or switch type applications. The use of piezoelectric composite materials allows for manufacturing robust devices which can easily be integrated with conventional polymer processing. Piezoelectric composites of lead zirconate titanate (PZT) and two types of polymers, polyamide-6 (PA6) a
5、nd a liquid crystalline thermosetting polymer (LCT) were used to manufacture sensor devices. The behavior of the output signal of different types of sensors was studied with focus on both temperature dependence of the output signal and the drift of the signal with time. The properties of the PA6 bas
6、ed composites and devices are highly temperature dependent while the output signal of LCT based composites and devices has a very low temperature dependence and drift, even outperforming the PZT reference device. The temperature dependence of the output signal of the composite devices is dependent o
7、n the device configuration as well as the material properties, such as polymer permittivity. The drift of the signal is strongly dependent on the resistivity of the PZTpolymer composite material used in the sensor.A new PZT piezoelectric sensor for gravimetric applications using the resonance-freque
8、ncy detectionSensors and Actuators B: ChemicalPiezoelectric sensors made of quartz, Pb(Zr,Ti)O3, Pb(La,Zr,Ti)O3, or Pb(Zr,Ti,Sn)Oy have rapidly been developed recently because of the potential applications in devices such as biosensors, accelerometers, pressure sensors, and ultrasonic transducers. H
9、owever, the development of devices with reduced size but with improved sensitivity is highly important. With this idea, the study aims to develop a lead zironate titanate (PZT) chip as a novel gravimetric biosensor using the resonance feature in biomolecule detection. The PZT thin film characterized
10、 by the X-ray diffractometer (XRD) has a perovskite structure. The fabricated PZT sensor was designed with 250m250m-sensing areas of electrodes, determined by the measured impedance at 98.5MHz frequency. The morphology and cross-section of scanning electron microscope (SEM) images show that the thic
11、kness of the spin-on PZT layer was about 500nm and the crystal grain size was less than 50nm. Moreover, an evaluation circuit consisted of a resonance circuit and a frequency-to-voltage circuit was established to detect bovine serum albumin (BSA) protein. The PZT sensor, combined with evaluation cir
12、cuit, showed a high sensitivity of 62.8Hzcm2/ng. The detection sensitivity was enhanced by 300 folds than that of traditional quartz crystal microbalance (QCM).Sensors and Actuators B: Chemical 化学传感器开发应用项目实例In this study, the regioregular poly (3-hexyl thiophene) (rr-P3HT) based piezoelectric sensor
13、s were developed and evaluated to detect alcoholic volatile organic compounds (VOCs) associated with spoiled and Salmonella typhimurium contaminated packaged beef headspace. The drop coating technique was used to deposit thin films of rr-P3HT on both sides of quartz crystal microbalance (QCM) electr
14、ode. The QCM polymer sensors were found to provide repeatable and reproducible sensor response to alcohol VOCs with a fast recovery ( 2min) at room temperature (25C). The principal component analysis on the sensors sensitivities was performed to discriminate the sensed alcohol VOCs, namely: 3-methyl
15、-1-butanol from 1-hexanol. The QCM polymer sensors demonstrated selective response to low concentration of 3-methyl-1-butanol (average estimated lowest detection limit (LDL): 4.35ppm) and to 1-hexanol (average estimated LDL: 3.20ppm). The 30 days storage study performed on QCM sensors showed identic
16、al sensitivity responses for sensing 3-methyl-1-butanol and 1-hexanol at low concentrations.Development of piezoelectric acoustic sensor with frequency selectivity for artificial cochleaSensors and Actuators A: Physical 物理传感器开发样例In this paper, we report a novel piezoelectric artificial cochlea which
17、 realizes both acoustic/electric conversion and frequency selectivity without an external energy supply. The device comprises an artificial basilar membrane (ABM) which is made of a 40m thick polyvinylidine difluoride (PVDF) membrane fixed on a substrate with a trapezoidal slit. The ABM over the sli
18、t, which mimics the biological system, is vibrated by acoustic waves and generates electric output due to the piezoelectric effect of PVDF. The width of ABM is linearly varied from 2.0 to 4.0mm along the longitudinal direction of 30mm to change its local resonant frequency with respect to the positi
19、on. A detecting electrode array with 24-elements of 0.501.0mm rectangles is made of an aluminum thin film on ABM, where they are located in a center line of longitudinal direction with the gaps of 0.50mm. Since the device will be implanted into a cochlea filled with lymph fluid in future, the basic
20、characteristics in terms of vibration and acoustic/electric conversion are investigated both in the air and in the silicone oil which is a model of lymph fluid. The in vitro optical measurements show that the local resonant frequency of vibration is varied along the longitudinal direction from 6.6 t
21、o 19.8kHz in the air and from 1.4 to 4.9kHz in the silicone oil, respectively. Since a resonating place vibrates with relatively large amplitude, the electric output there becomes high and that at the other electrodes remains to be low. Thus, the electric voltages from each electrode realize the fre
22、quency selectivity. Furthermore, the effect of surrounding fluid on the vibration is discussed in detail by comparing the experimental results with the theoretical predictions obtained by the WentzelKramersBrillouin asymptotic method. The theoretical prediction indicates that the surrounding fluid o
23、f the higher density induces the larger effective mass for the vibration that results in lower resonant frequency. From these findings, the feasibility of artificial cochlea is confirmed both experimentally and theoretically.Development of an Electrical Capacitance Tomography system using four rotat
24、ing electrodesAbstractThis paper presents an Electrical Capacitance Tomography (ECT) sensor scheme consisting of N segments linked in four groups, treated as single, extremely broad electrodes forming a 4-electrode sensor. This configuration is repeated along the pipe circumference, selecting differ
25、ent segments in order to form N/4 independent 4-electrode schemes. The response of this sensor is studied by means of Finite Element Method (FEM)-based simulations, and the results are compared to the response of a 12-electrode conventional sensor. The image reconstruction proved to have lower error
26、 when using the segmented sensor, and it is less sensitive to white noise affecting the measurements. A tomograph with 20 segments based on a FPGA core has been developed and tested using a test phantom. Results show that high values of inter-electrode capacitances and better image reconstruction ca
27、n be achieved.A finite element model for the analysis of 3D axisymmetric laminated shells with piezoelectric sensors and actuators 三维线性理论和有限元模型在传感器功能单元设计分析中的应用 Composite StructuresThis paper presents the development of a semi-analytical axisymmetric shell finite element model with piezoelectric laye
28、rs using the 3D linear elasticity theory. The piezoelectric effect of the material could be used as sensors and/or actuators in way to control shell deformation. In the present 3D axisymmetric model, the equations of motion are expressed by expanding the displacement field using Fourier series in th
29、e circumferential direction. Thus, the 3D elasticity equations of motion are reduced to 2D equations involving circumferential harmonics. In the finite element formulation the dependent variables, electric potential and loading are expanded in truncated Fourier series. Special emphasis is given to t
30、he coupling between symmetric and anti-symmetric terms for laminated materials with piezoelectric rings. Numerical results obtained with the present model are found to be in good agreement with other finite element solutions.Optimized piezoelectric sensor for a specific application: Detection of Lam
31、b wavesAbstractThis work is devoted to the development and the optimization of a new piezoelectric sensor using Lamb waves destined to aerospace structures health monitoring. In such systems, Lamb waves are usually excited and received by thin single piezoelectric transducers. One of the most critic
32、al tasks in health monitoring is to identify all the generated Lamb waves in order to ease the damage estimation. A possible solution is to measure the Lamb wave signal at different locations along the propagation direction. So, the development of a distributed sensing technology using metallic multi-electrode deposited on a piezoelectric substrate was a key element, which built the bridge between the sensors signals and the structural integrity interpretation. Firstly, the various manufacture stages of this new sensor by the tape casting technique were reported. Secondly, piezoelec
copyright@ 2008-2022 冰豆网网站版权所有
经营许可证编号:鄂ICP备2022015515号-1