共查询到19条相似文献,搜索用时 125 毫秒
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为实现高灵敏度、低温漂的高性能电流传感器,提出将声表面波技术与磁致伸缩效应相结合的电流检测方法,分析了其敏感机理并改善其温度特性.这种声表面波电流传感器采用128°YX-LiNbO3作为压电基片,表面覆盖SiO2薄膜来改善器件温度稳定性,并溅射超磁致伸缩TbDyFe薄膜以响应电流.在电流作用下,TbDyFe薄膜会发生磁致伸缩效应和ΔE效应,引起声表面波相速度的改变.结合层状介质中声传播理论,分析了给定电流下层状结构中声表面波的传播特性,特别分析了TbDyFe和SiO2膜厚对传感器响应的影响.计算结果表明,TbDyFe和SiO2薄膜厚度分别为0.5μm、2μm时,该声表面波电流传感器具有最大检测灵敏度58.2 kHz/A,有良好温度稳定性和较高的灵敏度,从而为高性能声表面波电流传感器的研制奠定理论基础. 相似文献
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Chunbae LimAuthor VitaeWen WangAuthor Vitae Sangsik YangAuthor VitaeKeekeun LeeAuthor Vitae 《Sensors and actuators. B, Chemical》2011,154(1):9-16
A 440 MHz wireless and passive surface acoustic wave (SAW)-based multi-gas sensor integrated with a temperature sensor was developed on a 41° YX LiNbO3 piezoelectric substrate for the simultaneous detection of CO2, NO2, and temperature. The developed sensor was composed of a SAW reflective delay lines structured by an interdigital transducer (IDT), ten reflectors, a CO2 sensitive film (Teflon AF 2400), and a NO2 sensitive film (indium tin oxide). Teflon AF 2400 was used for the CO2 sensitive film because it provides a high CO2 solubility, with good permeability and selectivity. For the NO2 sensitive film, indium tin oxide (ITO) was used. Coupling of mode (COM) modeling was conducted to determine the optimal device parameters prior to fabrication. Using the parameters determined by the simulation results, the device was fabricated and then wirelessly measured using a network analyzer. The measured reflective coefficient S11 in the time domain showed high signal/noise (S/N) ratio, small signal attenuation, and few spurious peaks. The time positions of the reflection peaks were well matched with the predicted values from the simulation. High sensitivity and selectivity were observed at each target gas testing. The obtained sensitivity was 2.12°/ppm for CO2 and 51.5°/ppm for NO2, respectively. With the integrated temperature sensor, temperature compensation was also performed during gas sensitivity evaluation process. 相似文献
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限于传统涂敷敏感膜的声表面波(SAW)气敏传感器存在成膜困难和选择性差、重复性差以及再生性差等问题,本研究提出一种基于压电基底表面气体气液相转换效应机理的瑞利波传感器。在此基础上开发了一种基于瑞利声表面波传感器和气相色谱(GC)分离柱的便携式气体检测系统。最后实验论证了方案的可行性,初步的实验结果表明该系统具有分析时间短、选择性好、灵敏度高,可检测ppb(10^-9)浓度的混合VOCs以及成本低等优势,显示其在痕量挥发性有机气体检测和分析应用上有良好的潜力和前景。 相似文献
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A surface acoustic wave (SAW) piezoelectric device with a dual-path SAW delay line oscillator configuration has been developed to detect nitrogen dioxide (NO2) gas. One delay line is coated with a Langmuir-Blodgett (LB) film of copper tetrasulphonated phthalocyanine (CuTsPc), while the other is uncoated. NO2 gas can be selectively abosorbed by the CuTsPc LB film and then alters the SAW characteristics, which in turn causes the oscillation frequency to change. The concentration of NO2 can be detected by measuring the relative change in the frequency of the two oscillators. The CuTsPc LB film-coated SAW device has been demonstrated to be sensitive to low concentrations of NO2 gas. There is a linear relationship between NO2 concentration and frequency change under 12 ppm NO2 concentration. The sensitivity of the device is about 128 Hz/ppm NO2. The response time is 10 min, and the recovery is 40 min. It can be applied as a small, inexpensive and sensitive NO2 gas sensor. 相似文献
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采用MEMS技术制作了硅基微型NO2气体传感器,选用高分子金属酞菁聚合物酞菁铜作为敏感膜,从半导体理论出发解释了酞菁铜的敏感机理。阐述了该传感器的结构与工艺流程,并测试了传感器的气敏特性、温度特性、响应时间和恢复时间等敏感特性。实验结果验证了酞菁铜对NO2气体的敏感性,该传感器可以检测到10^-6量级的NO2气体,且响应时间快。 相似文献