共查询到19条相似文献,搜索用时 156 毫秒
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声表面波气体传感器的最终成功既取决于化学界面膜的性能,也取决于声表面波器件设计的最佳化。给出了声表面波气体传感器的设计考虑。 相似文献
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声表面波气体传感器的理论分析 总被引:1,自引:0,他引:1
声表面被气体传感器的敏感物质是在声表面波传播途径上覆盖一层具有选择性的吸附薄膜,这些薄膜在吸附对其敏感的气体物质后,质量密度,弹性参数。介电常数,导电率都将发生变化,通过理论分析,导出了该传感器的测量方程. 相似文献
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SAW气体传感器自动测试系统 总被引:1,自引:0,他引:1
声表面波气体传感器的性能在很大程度上取决于涂覆在其表面的化学界面膜的性能。因此,制作这种气体传感器的首要的任务是筛选制作这一界面膜的原材料。于是,对制成样膜的气敏性能要进行测试,诸如灵敏度、选择性、响应和恢复时间、可逆性、可重复性、可靠 相似文献
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为提高生化分析灵敏度,提出了一种快速富集悬液中微粒的新方法.它在127.68°旋转Y切割X传播方向的LiNbO3基片上采用微电子工艺制作了2×2叉指换能器阵列,在该叉指换能器阵列的一对对角叉指换能器上同时加经功率放大器放大后的RF信号,以激发两相向声表面波,采用微量进样器将待富集的微流体(微液滴)进样到两相向传播的声路径上,微液滴中的微粒在该两相向的声表面波作用下快速向心富集.淀粉溶液微液滴富集实验结果表明,两相向声表面波作用下,10秒内实现微液滴中淀粉微粒的快速富集. 相似文献
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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
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Towards a GC-based microsystem for benzene and 1,3 butadiene detection: Pre-concentrator characterization 总被引:1,自引:0,他引:1
H. LahlouAuthor Vitae J.-B. SanchezAuthor VitaeX. VilanovaAuthor Vitae F. BergerAuthor VitaeX. CorreigAuthor Vitae V. FierroAuthor VitaeA. CelzardAuthor Vitae 《Sensors and actuators. B, Chemical》2011,156(2):680-688
The performance of a gas pre-concentrator/gas chromatographic column/gas sensor system was studied step by step towards benzene vapor in presence of 1,3 butadiene vapor. The pre-concentrator, based on an activated carbon of high adsorption capacity, was first characterized using a GC/FID system. By this way, the adsorption capacity of each pollutant was evaluated, first separately, then mixed with different proportions in air. It was shown that the affinity of the pre-concentrator for benzene was higher than for butadiene. Once the optimal pre-concentration parameters were adjusted, we replaced the FID detector by a metal oxide gas sensor. The use of such gas pre-concentrator allowed decreasing the detection limit of the system towards benzene in presence of butadiene by at least ten times. 相似文献
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H. LahlouAuthor Vitae X. VilanovaAuthor VitaeV. FierroAuthor Vitae A. CelzardAuthor VitaeE. LlobetAuthor Vitae X. CorreigAuthor Vitae 《Sensors and actuators. B, Chemical》2011,154(2):213-219
A high area planar pre-concentrator based on various microporous activated carbons of different origins, granularities and preparation conditions, is studied. The adsorbing layer of different thicknesses was deposited on a self-heated planar substrate using the air-brushing technique. By coupling the pre-concentrator to a mass spectrometer, the thermo-desorption of benzene induced by application of a heat pulse was monitored with time. The effects of adsorbent layer thickness, grain size, origin, and activation conditions on the adsorption capacity and pre-concentration of the device are examined and discussed. Suggestions are given for preparing a planar pre-concentrator presenting the highest performances for the detection of benzene present as traces in a carrier gas. 相似文献
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A surface acoustic wave (SAW) device has been reported as a micro fluid device such as a pump of a water droplet so far (Renaudin et al. in μTAS, pp 599–601, 2004, 1:551–553, 2005; Sritharan et al. in Appl Phys Lett 88:054102, 2006; Wixforth in Anal Bioanal Chem 379:982–991, 2004; Yamamoto et al. in μTAS, pp 1072–1074, 2005). The SAW device is an interdigital transducer (IDT) fabricated on the piezoelectric substrate only. IDTs are advantageous in terms of integration, miniaturization, free position setting on the substrate and simple fabrication process because of their simple structure. Therefore, the SAW device is easy to apply to integrated chemical system such as lab-on-a-chip. The SAW drives the liquid homogenously by the transmission of surface vibrations of the substrate. Thus, both ends of the channel for pressure loading are not necessary to pump the liquid by using the SAW. The SAW can pump the liquid in both of a closed channel and an opened channel, although continuous flow pumping using an external pump is difficult for no loading pressure in the closed fluid channel. In this paper, we proposed and fabricated the micro fluid devices combined cyclical fluid channel and SAW actuator for liquid pumping. This device is fabricated on a piezoelectric substrate (LiNbO3) with UV photolithography and wet etching. Structure material of cyclical fluid channel is epoxy photoresist SU-8 100. Then, it is demonstrated to continuous flow pumping and reciprocal flow pumping in the channel. As a result of optimization of a SAW pump’s structural parameter, 32.5, 71.3 and 108.0 mm/s are achieved in the 500, 1,000 and 2,000 μm channel width as a maximum flow velocity. 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。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
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用于气体传感器的声表面波振荡器频率稳定性分析 总被引:1,自引:0,他引:1
作为声表面波(SAW)气体传感器的关键元件,SAW振荡器的频率稳定性直接影响到传感器的灵敏度和检测下限.因此,提高SAW振荡器的频率稳定度是传感器研究的关键.这里在ST石英基片上研制了一种具有低插入损耗(在10dB以内)、单一模式控制的SAW双延迟线型振荡器,并分析了作为频控元件的延迟线Q值以及系统温度对振荡器频率稳定性的影响,提出了改善方法.另外还研究了高频SAW延迟线型振荡器的频率稳定性,研制了一种300MHz频段上的SAW双延迟线型振荡器,其频率稳定度达到了0.066×10-6量级. 相似文献