共查询到20条相似文献,搜索用时 0 毫秒
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Yin-Nee Yun Ching-Hsiang Chen Wallace Woon-Fong 《Sensors and actuators. A, Physical》2008,147(2):401-408
A novel fluidic strain sensor is proposed with the use of a mixture of glycerin with aqueous sodium chloride encapsulated within an elastomer as a mean for piezoresistive large strain measurement. Electrochemical impedance spectroscopy (EIS) is conducted for strain response measurement and equivalent circuit analysis is applied for explaining the strain-affected ion transportation behavior of the sensor. The applied strain has caused an increase in both the resistance to charge transfer (Rct) and the resistance of the salt solution which is reflected in an increase in the resistance of the system (Rsys). A parabolic relationship between the real part of the impedance (Zre) and the true strain () for an applied strain of up to about 30% is verified. In addition, a novel fluid encapsulation technique by applying oxygen plasma surface modification is introduced. Aqueous sodium chloride is successfully encapsulated within an elastomeric casing with a pattern and this sensor is capable of measuring large strain of even up to about 40%. This method is suggested as an industrial fabrication technique for the strain sensor. The use of ionic liquids for green chemistry has been suggested for years and its use as an electrical conductive media in large strain sensor technology is found to be direct and environmentally friendly. 相似文献
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A hydrogen sulphide (H2S)-sensitive optode film has been fabricated by immobilising tetraoctylammonium fluorescein mercury(II) acetate (TOFMA) and tri-n-butyl phosphate in a poly(vinyl chloride) (PVC) matrix. The optode film, coated on an overhead transparency film, was employed as a sensing device for fluorimetric detection of H2S. The fluorescence intensity monitored at 553 nm (excitation at 503 nm) increased with increasing H2S concentrations. The optode film showed a good, linear and reversible response to H2S from 0 to 15 ppm (v/v). It was optically stable and the reproducible response of the film on exposure to 10 ppm (v/v) H2S was extremely good. There was no sign of degradation after 8 h of continuous use. The response to H2S levelled off at about 27.5 ppm The response and recovery times of the optical H2S sensor were fast and less than 2 and 5 s, respectively. An optically-based sensor for H2S determination was successfully developed. It was anticipated that the system could be used to monitor H2S with a concentration range of 0–25 ppm (v/v) with satisfactory results. A proposed mechanism for the detection of H2S by the optode films is described. 相似文献
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热释电红外传感器噪声特性分析 总被引:3,自引:0,他引:3
采用噪声电流电压的En -In 模型对热释电红外传感器的噪声特性进行了定性分析 ,给出了热释电红外传感器的输出噪声电压公式及其低噪声设计的一般方法 相似文献
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J.D. Jeyaprakash S. Samuel P. Ruther H.-P. Frerichs M. Lehmann O. Paul J. Rühe 《Sensors and actuators. B, Chemical》2005,110(2):218-224
Surface conductivity caused by adsorbed water ions and molecules affects the performance of capacitive field effect transistor (FET) based gas sensors. Surface conduction leads to a slow decay of any voltage difference built-up between the sensitive surface and the gate electrode of the FET and thus to a drift in the sensor signal. In humid environments this problem becomes even more significant, as more water is becoming adsorbed. This leads to a cross-sensitivity of the sensor signal towards moisture. In this work we report on the application of a simple room temperature violet photochemical process to yield chemically anchored thin fluoropolymer films on the surface of such FET devices. The modified areas of the sensor surface were strongly water repellent. This led to a decrease in surface conductivity by more than three orders of magnitude at high relative humidities. Making the surface of the sensor chips hydrophobic resulted in elimination of the surface discharge caused by the leakage current even at high relative humidities. 相似文献
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Design of dual‐outputs‐single‐stage a‐Si:H TFT gate driver for high resolution TFT‐LCD application 下载免费PDF全文
Guang‐Ting Zheng Po‐Tsun Liu Meng‐Chyi Wu 《Journal of the Society for Information Display》2016,24(5):330-337
A new gate driver has been designed and fabricated by amorphous silicon technology. With utilizing the concept of sharing the noise free block in a single stage for gate driver, dual‐outputs signals could be generated in sequence. By increasing the number of output circuit block in proposed gate driver, number of outputs per stage could also be adding that improves the efficiency for area reduction. Besides, using single driving thin‐film‐transistor (TFT) for charging and discharging, the area of circuit is also decreased by diminishing the size of pulling down TFT. Moreover, the proposed gate driver has been successfully demonstrated in a 5.5‐inch Full HD (1080xRGBx1920) TFT‐liquid‐crystal display panel and passed reliability tests of the supporting foundry. 相似文献
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针对Si基微结构气体传感器中Si基与敏感材料之间附着性较差的问题,提出在Si基与敏感材料之间引入纳米孔Al2 O3膜形成新型Si基微结构传感器,利用ANSYS分析软件对微结构进行热分析。采用薄膜工艺、光刻工艺、电化学阳极氧化工艺在Si衬底上制成Si基微结构,采用超声波的方法使聚苯胺敏感材料渗入纳米孔Al2 O3膜中制成气体传感器,并在室温下测试了传感器对氨气的检测特性。结果表明:将纳米孔Al2 O3膜移植到Si基上增加了敏感材料的附着性;传感器对响应时间约为40 s,恢复时间约为960 s,灵敏度随着氨气浓度的增加而增大,并且呈现出良好的线性关系。 相似文献
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Nur AksunerAuthor Vitae 《Sensors and actuators. B, Chemical》2011,157(1):162-168
A new sensor membrane based on a novel triazolo-thiadiazin derivative immobilized in polyvinyl chloride has been developed for the determination of Pb(II) ions that displays excellent performance. The parameters involved in the preparation of the optode and determination of Pb(II) were optimized. Under the optimal conditions, the proposed sensor displays a calibration response for Pb(II) over a wide concentration range of 5.0 × 10−8 to 3.8 × 10−4 M with the detection limit of 2.2 × 10−8 M. In addition to high reproducibility and reversibility of the fluorescence signal, the sensor also exhibits good selectivity over common metal ions. The optode membrane developed is easily prepared, stable, rapid, and simple for the determination of Pb(II). The accuracy of the proposed sensor was confirmed by analyzing standard reference materials of natural water and surface water. The sensor was successfully used for the determination of Pb(II) ions in water samples with satisfactory results. 相似文献
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Application of m-CNTs/NaClO4/Ppy to a fast response, room working temperature ethanol sensor 总被引:1,自引:1,他引:0
Ren-Jang Yu-Ching Ming-Ru Tzu Hsuan Shih-Lin 《Sensors and actuators. B, Chemical》2008,134(1):213-218
A new blended material, m-CNTs/NaClO4/Ppy, was developed as a gas sensor to detect ethanol concentrations at room temperature. The sensing material polypyrrole (Ppy) was synthesized in situ by UV-photo-polymerization. The multiwall carbon nanotubes (m-CNTs) added enhanced the short-term repeatability of the Ppy-sensing material. The relative resistance variation (Rethanol/Rair) of m-CNTs/NaClO4/Ppy was 1.193 when exposed to ethanol of 30,000 ppm. The sensor response and recovery times (both 20 s) were very short to this concentration. An unstable baseline of the sensor was explained by theoretical calculation of molecular dynamics made for ethanol adsorption on polypyrrole, which revealed formation of a new bond, N–HO. Adsorption energy decreased with increasing the number of ethanol molecules adsorbed and was 0.8 kcal/mol at eight adsorbed molecules. Sensor responses of three different Ppy samples were measured to ethanol concentrations of 18,000–40,000 ppm. 相似文献
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为了适应当前传感器网络中越来越多的图像压缩处理,提出了一种片上低存储离散小波变换(DWT)的超大规模集成电路(VLSI)结构.现今人们周围遍布各种图像采集设备,包括监视器、电脑、手机视频摄像头等,并且人们对图像精度的需求越来越高,使得传统软件处理图像压缩的速度逐渐无法满足人们的需求,这就需要考虑使用硬件处理来进行加速.小波变换常被用于图像的压缩,而采用5/3提升小波技术来进行硬件实现相对比较方便.为减少硬件的片上存储,通过特殊的调度运算方式进行行列并行运算有效降低片上存储需求.该设计进行RTL级仿真并使用SMIC的0.18μm工艺进行综合,结果表明:该调度方法可以大大节省缓存单元,并且在100 MHz时钟下就可以保证对高清图像的快速处理,可以满足当前传感器网络中图像压缩解码的需求. 相似文献
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多用户检测技术是第三代移动通信系统的关键技术,具备良好的抗多址干扰和远近效应性能。从移动通信系统抗干扰的角度出发,分析了CDMA系统中多址干扰(MAI)的产生原因,对多用户检测(MUD)技术的概念系统模型以及常用的MUD算法进行了阐述,并指出其局限性和研究方向。 相似文献
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针对物联网(IoT)传感器网络无线资源的稀缺和信道不完美带来的误差问题,提出了一种在不完美信道状态信息(CSI)下为次级IoT设备(SID)用户分配带宽和功率的方法。首先,基于次级系统和主级系统的不同情况,分别建立了次级系统发送端与主级系统接收端、次级系统发送端与接收端之间的不完美信道模型。其次,提出了为次级IoT设备用户分配带宽和功率的机制,并考虑了当前带宽不够分配时应采取的措施和相应的惩罚机制,目的是在充分利用现有无线资源的情况下,最大化整个次级系统的能量效率(EE)。最后,使用粒子群优化(PSO)算法和加权切比雪夫法进行分步求解,在降低问题复杂度的同时得到最优的分配方案。仿真结果表明,与均等分配和随机分配方法相比,所提方法在最大化系统总发送速率和最小化次基站平均发送功率方面提升了约75%,能有效提升整个网络的能量效率。 相似文献
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A microcantilever device has been used as a miniaturized sensor for the determination of total carbonate in soil samples. The method is based on the selective generation of CO2 (g) from samples and the measure of the pressure effect on the microcantilever sensor located in a closed system. The experimental set-up uses a manifold including the sample reaction minichamber and a dedicated flow-cell designed and built for housing the microcantilever. The response of this sensor was electronically and analytically characterized by using conductance signals. The analytical performance of the sensor was compared to that provided by the conventional quartz crystal microbalance (QCM), demonstrating advantages in terms of sensitivity, linear range of response and resolution. After the optimization of the method, it was validated for its use for direct determination of carbonate in soil samples. The method allowed the determination of carbonate in the 3–75 mg range, with a precision of 1.7%, expressed as relative standard deviation. It was applied to the analysis of different soil samples, obtaining results in agreement with those produced by the official method. 相似文献