共查询到18条相似文献,搜索用时 140 毫秒
1.
基于声表面波(SAW)技术的化学毒剂传感器在检测下限、响应速度以及减小温度、湿度交叉敏感等方面还需进一步提高。提出了在SAW双端口谐振器上涂敷超支化聚合物的方法提高传感器的检测下限和灵敏度。通过建立Van Dyke模型,分析了敏感膜对SAW化学毒剂传感器Q值、插入损耗以及电路阻抗匹配的影响。利用谐振器代替延迟线,确保了器件具有插入损耗、高Q值的特点。实验证实,在谐振器的中心栅结构上涂覆聚合物可以减小粘弹性聚合物对谐振器插损、Q值以及输入输出阻抗的影响。对设计的化学毒剂传感器进行了沙林毒剂检测实验,采用315MHz的SAW谐振器结合超支化聚合物膜,检测沙林气体浓度为5.0mg/m^3。实验表明:这种传感器的灵敏度可达到600Hz/mg/m^3,响应时间为50s,恢复时间约为60s。 相似文献
2.
3.
4.
5.
灵敏度是声表面波( SAW)纱线张力传感器成功检测纱线张力的关键。通过对SAW纱线张力传感器的灵敏度和基片应变率之间关系的研究,提出了通过增加基片应变率来提高传感器灵敏度的理论。以该理论为指导,给出了通过灵活设计基片尺寸来获得最佳基片应变率的设计方案。为了得到最佳基片应变率对应的基片尺寸,建立了基片应变率和基片尺寸之间的数学模型,提出了求解最大基片应变率所对应基片尺寸的线性规划模型,即最佳灵敏度所对应基片尺寸。实验表明:该方法可以有效提高SAW纱线张力传感器的灵敏度,灵敏度达3132.4 Hz/gf。 相似文献
6.
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。首先建立了挥发性有机气体(VOCs)液相凝聚体薄层负载下的SAW波传模型,并仿真计算了其波传频散和波传衰减。然后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浓度的混合VOCs)以及成本低等优势,因此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
7.
为解决声表面波(SAW)湿度传感器存在易被污染、不易清洁、稳定性差等问题,提出了一种新的基于改进的单端口SAW谐振器结构用于湿度检测。在此结构中,在ITO材料制作的叉指换能器和反射阵上溅射厚度为5pm Si3N4层以屏蔽各种腐蚀性物质如酸性、碱性等腐蚀性气体对SAW谐振器电极的侵蚀。相比常规谐振器,新结构加大了谐振器叉指换能器与一个反射阵之间距用于涂敷湿敏材料,同时在石英基片背面布设ITO材料脱湿电路。给出了基于此类结构SAW湿度传感器的制作工艺、感湿实验测试结果。实验验证了该结构SAW湿度传感器的可清洁性、耐腐蚀性及该结构的有效性。 相似文献
8.
设计了一种由超磁致伸缩材料Terfenol-D和SAW谐振器构成的复合磁传感器,在磁场作用下,Terfenol-D沿长度方向伸缩,并将应力应变传递至SAW谐振器,使其产生应变,造成谐振频率改变,通过测量SAW谐振器谐振频率的变化来测量磁场强度.分析了该磁传感器的传感原理,建立了该复合磁传感器的静态模型,对弹性敏感元件进行了受力分析,根据压磁方程和受力平衡得到该磁传感器的静态特性.实验结果表明:该复合磁传感器灵敏度可达341.6Hz/Oe,较Terfenol-D/SAW谐振器结构灵敏度提高了3倍;测量谐振频率的分辨率为1Hz,SAW谐振器频率稳定度为0.1×10-6时,该磁传感器对磁场的分辨率为10-6T. 相似文献
9.
10.
11.
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
12.
13.
14.
15.
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
16.
声表面波(SAW)传感器阵列具有体积小、功耗低、反应灵敏等优点,在食品检测、环境治理、气体鉴别等领域有广泛的应用前景。结合声表面波传感器阵列的原理及特点,建立和优化了声表面波传感器阵列的数学模型,并对数据进行预处理、主成分分析(PCA)以及BP神经网络分析处理,实现了对气体的鉴别分类,取得了好的实验结果。 相似文献
17.
18.
E. ChevallierAuthor Vitae E. ScorsoneAuthor VitaeP. BergonzoAuthor Vitae 《Sensors and actuators. B, Chemical》2011,154(2):238-244
A growing interest in diamond materials has been shown in the recent year for the design of smart chemical and biochemical sensors due to the remarkable physical and chemical properties of diamond. In this paper, modified diamond nanoparticles (DNPs) coatings are investigated as sensitive layers on surface acoustic wave sensor (SAW sensor) for the detection of volatile chemicals. DNPs are deposited onto SAW transducers by a layer-by-layer deposition method and then surface treated to fix them on the substrate and to enhance their affinity to specific compounds such as nitro-aromatic compounds, nerve-agent stimulants, or toxic gases. Homogeneous and reproducible coatings were achieved. The diamond coatings’ surface was either oxidised or reduced to see the effect on the response to ammonia gas, ethanol, DNT or DMMP vapours exposures. The sensors were generally very sensitive to the target chemicals and the response fully reversible. Oxidation of the surface promoted hydrogen-bond formation and therefore enhanced the response to most vapours under test. Even though the sensors were not very selective, we demonstrated the suitability of DNP coatings as stable and reliable sensing interface. This opens up wide opportunities for immobilizing more selective and highly sensitive chemical/biochemical receptors onto SAW transducer surfaces via strong covalent binding of those receptors on diamond nanoparticles deposited homogeneously on the SAW sensors surfaces. 相似文献