多晶硅纳米薄膜压阻和电学修正特性

本文制备了不同掺杂浓度的多晶硅纳米薄膜,研究了掺杂浓度对多晶硅纳米薄膜压阻和电学修正特性的影响。利用低压化学气相淀积法制备了不同掺杂浓度的多晶硅纳米薄膜,掺杂浓度分别为1.0*10^20cm-3、2.0*10^20cm-3、4.1*10^20cm-3和7.1*10^20cm-3。利用应变系数测量装置对不同掺杂浓度多晶硅纳米薄膜的应变系数进行了测量,利用恒流源和万用表测量 不同掺杂浓度多晶硅纳米薄膜的电学修正特性。实验结果表明:多晶硅纳米薄膜的应变系数与掺杂浓度有关,应变系数范围:33.38~38.41,利用电学方法能够修正多晶硅纳米薄膜的电阻,最大修正范围可达15.4%,多晶硅纳米薄膜具有较高的应变系数,适用于制作压阻式传感器,电学修正可用来调整多晶硅纳米薄膜的电阻,进而降低传感器的失调。     

基于钯纳米颗粒导电沟道的室温型氢气传感器的研究

随着氢能的广泛应用,检测氢气(H₂)泄漏十分必要。采用溶剂热法合成钯(Pd)纳米颗粒,结合旋涂法从极大程度上简化了覆盖敏感层工艺,在利用微机电系统(MEMS)工艺制备的硅基金(Au)叉指电极上研究了基于“氢致Pd晶格膨胀效应(HILE)”的裂结式H₂传感器的敏感特性,为低成本批量化制备室温型氢气传感器提供了可行性研究。结果表明该传感器对H₂的响应值与Pd纳米颗粒在基底上的覆盖率密切相关：覆盖率在一定范围内越大,响应值越小。在室温下,该类传感器对500×10^-6～2 500×10^-6H₂表现出了较快的响应速度：响应时间在5 s左右,恢复时间在25 s左右,具有较高的响应值：在2 500×10^-6H₂气氛下高达83%,有较好的选择性和稳定性。     

基于柔性打印技术的纳米湿度传感器

研制了一种基于柔性打印技术的纳米湿度传感器,利用氧化石墨烯水溶液对富勒烯粉末进行分散并制成湿敏薄膜,用于修饰打印在聚酯基板上的银叉指电极.考察了频率对传感器灵敏度的影响,研究了传感器的动态响应特性和稳定性,并通过复阻抗谱图分析了传感器的湿敏响应机制.采用打印技术构建的纳米湿度传感器具有成本低、响应时间短、可在柔性衬底上...     

含Pd纳米线SAW气体传感器氢敏特性分析

基于COMSOL Muhiphysics软件,建立了含Pd纳米线的声表面波(SAW)传感器三维模型,以YZ铌酸锂为压电基底,叉指电极固定于基底表面,分析了Pd纳米线长度对模型本征频率的影响.对电极施加20V电压得到了不同氢气体积分数下电极上电导纳值和本征频率偏移值.通过磁控溅射制作了Pd薄膜,设计了SAW传感器测试夹具,得到了传感器氢敏特性.将仿真值与实验值进行对比,得到了含Pd纳米线氢敏材料的SAW传感器具有比含面形Pd膜传感器更高的灵敏度.     

基于 ＧＮＰｓ/ ＰＤＭＳ 复合薄膜的柔性压阻传感器制备及性能研究

目前柔性压力传感器已被用于众多领域,其中压阻薄膜是柔性压力传感器的核心。本文将石墨烯纳米片（GNPs）与聚二甲基硅氧烷（PDMS）复合,通过倒模的方法制备压阻薄膜,经测试,GNPs浓度为8%时,材料具有较好的性能。以此为基础,制备了压敏结构间距为1.2 mm,直径大小为1.0 mm的GNPs/PDMS基压阻传感器,经测试,所制备的传感器加载响应为340 ms,卸载响应速度为260 ms,并具有较好的稳定性,同时,基于该压阻式柔性压力传感器实现了人体手腕关节处压力信号的测试。     

纳米钯基氢传感材料

介绍了纳米Pd基氢传感材料的研究进展.根据传感材料和结构的不同,对Pd/Pd合金膜,Pd/Pd合金纳米线状结构氢传感器的制备和传感性能进行了总结,介绍了Pd-碳管氢传感器的研究成果.使读者较为全面地了解纳米Pd基氢传感材料的现状与研究动向.     

薄膜高温热流测量技术研究

薄膜热流传感器具有响应时间快,体积小等优势,可用于航空、航天等领域高速飞行器表面短时间的高温热流瞬态测量。热流传感器原理基于不同热障层薄膜下薄膜热电偶温度变化量的大小,通过离子束溅射镀膜工艺成功制备快速响应薄膜高温热流传感器。试验结果表明:该传感器热响应时间可达0.1s,温度可达900℃。     

纳米硅薄膜超微压力传感器设计与性能研究

利用纳米硅薄膜良好的力学与电学特性,设计出超微压压力传感器芯片结构:双岛-梁-膜结构.利用ANSYS进行了静力分析、模态分析、谐反应分析、瞬态分析,结果表明:该结构具有灵敏度高、线性度好、动态响应快等优点.     

纳米材料在生物传感器中的应用

将纳米材料应用于新型生物传感器的开发已成为研究热点。纳米材料的引入,拓宽了线性检测范围,缩短了响应时间,提高了稳定性,并降低了检测限等,实现了改善传感器性能的目的。概述了纳米颗粒、纳米纤维、纳米超薄膜等在酶、免疫、DNA等生物传感器中的应用,并对其发展前景作了展望。     

层层累积技术制备基于纳米碳管的葡萄糖生物传感器

以多壁纳米碳管(MWCNTs)为电子媒介体和酶的吸附载体,利用层层累积的自组装技术固定葡萄糖氧化酶(GOx)的多层(MWCNTs/GOx)n复合薄膜修饰电极,制备了一种新型葡萄糖生物传感器。结果表明:传感器对葡萄糖的响应电流值随着MWCNTs/GOx复合薄膜层数的不同而变化,当MWCNTs/GOx复合薄膜的层数为6时,响应电流值达到最大。(MWCNTs/GOx)6复合薄膜修饰的葡萄糖生物传感器对3×10-2mol/L葡萄糖的响应电流为1.63μA,响应时间仅为6.7 s。该生物传感器检测的线性范围为5×10-4~1.5×10-2mol/L,最低检测浓度可达0.9×10-4mol/L。     

流延共烧结制备极限电流式氧传感器的研究

以流延成型工艺制备钇稳氧化锆(YSZ)基片,采用丝网印刷、等静压叠层工艺,经1450℃共烧结制备极限电流式氧传感器。采用XRD,SEM对其物理性能进行表征,并在650℃、氧体积分数为0%～90%范围内对该陶瓷器件的伏—安特性、响应时间等输出特性进行研究,实验结果表明:该传感器在其体积分数范围内具有良好的极限电流平台,响应时间小于9 s(氧体积分数从20%～75%),准确度达到0.5%。     

Optochemical hydrogen peroxide sensor based on oxygen detection

A novel hydrogen peroxide sensor based on an optochemical oxygen sensor is presented. An oxygen sensitive membrane is covered with an additional layer containing inorganic catalysts which decompose hydrogen peroxide to water and oxygen. The oxygen is detected in the underlying oxygen sensitive membrane via luminescence quenching. The investigated concentration range for the reported sensor was between 0.1 and 2 wt.% hydrogen peroxide in water. Several catalysts were tested for this application with manganese dioxide being the preferred material. In addition to this, it was shown that by coating the sensor with a proper polymer layer, the hydrogen peroxide sensitivity could be improved up to five times compared to an uncoated sensor. The response times of the sensors depends on the type of covering layer, with the shortest response times being similar to that of uncoated sensors (t₉₅ was approximately 1 min for a change from 0 to 0.2 wt.% hydrogen peroxide in water).     

微型薄膜集成氢气敏感器件的研制

采用将类光激发二极管(即N-Si/Thin-SiO2/Thin-Ta/PdCr/Pt结构)、PdCr合金薄膜电阻、Pt加热和感温双电阻温控系统等集成的方式,研制了微型薄膜集成氢气敏感器件,能稳定测量0~2%体积分数的氢气,且具有较快的响应和恢复时间。     

Design and performance of a microcantilever-based hydrogen sensor

This paper describes the design of, and the effects of basic environmental parameters on, a microelectromechanical (MEMS) hydrogen sensor. The sensor contains an array of 10 micromachined cantilever beams. Each cantilever is 500 μm wide×267 μm long×2 μm thick and has a capacitance readout capable of measuring cantilever deflection to within 1 nm. A 20-nm-thick coating of 90% palladium–10% nickel bends some of the cantilevers in the presence of hydrogen. The palladium–nickel coatings are deposited in ultra-high-vacuum (UHV) to ensure freedom from a “relaxation” artifact apparently caused by oxidation of the coatings. The sensor consumes 84 mW of power in continuous operation, and can detect hydrogen concentrations between 0.1 and 100% with a roughly linear response between 10 and 90% hydrogen. The response magnitude decreases with increasing temperature, humidity, and oxygen concentration, and the response time decreases with increasing temperature and hydrogen concentration. The 0–90% response time of an unheated cantilever to 1% hydrogen in air is about 90 s at 25 °C and 0% humidity.     

Sensoring hydrogen gas concentration using electrolyte made of proton conductive manganese dioxide

Hydrogen gas promises to be a major clean fuel in the near future. Thus, sensors that can measure the concentrations of hydrogen gas over a wide dynamic range (e.g., 1-99.9%) are in demand for the production, storage, and utilization of hydrogen gas. However, it is difficult to directly measure hydrogen gas concentrations greater than 10% using conventional sensor [1], [2], [3], [4], [5], [6], [7], [8], [9], [10] and [11]. We report a simple sensor using an electrolyte made of proton conductive manganese dioxide that enables in situ measurements of hydrogen gas concentration over a wide range of 0.1-99.9% at room temperature.     

Selective detection of ethanol vapor and hydrogen using Cd-doped SnO2-based sensors

The effect of CdO doping on microstructure, conductance and gas-sensing properties of SnO₂-based sensors has been presented in this study. Precursor powders with Cd/Sn molar ratios ranging from 0 to 0.5 were prepared by chemical coprecipitation. X-ray diffraction (XRD) analysis indicates that the solid-state reaction in the CdO–SnO₂ system occurs and -CdSnO₃ with pervoskite structure is formed between 600 and 650°C. CdO doping suppresses SnO₂ crystallite growth effectively which has been confirmed by means of XRD, transmission electron microscopy (TEM) and BET method. The 10 mol% Cd-doped SnO₂-based sensor shows an excellent ethanol-sensing performance, such as high sensitivity (275 for 100 ppm C₂H₅OH), rapid response rate (12 s for 90% response time) and high selectivity over CO, H₂ and i-C₄H₁₀. On the other hand, this sensor has good H₂-sensing properties in the absence of ethanol vapor. The sensor operates at 300°C, the sensitivity to 1000 ppm H₂ is up to 98, but only 16 and 7 for 1000 ppm CO and i-C₄H₁₀, respectively.     

基于特殊形貌NiO电极的混合电位型C3 H6传感器研究

研究了特殊形貌NiO对基于该类敏感电极的混合电位C3 H6传感器的影响,实验数据显示：线型结构NiO敏感电极传感器在600℃下具有最好的响应值,达到了60 mV,其90%的响应和恢复分别为15,25 s。此传感器在600℃对0%～0.05% C3 H6具有较好敏感性能,且响应信号与气体体积分数对数之间有良好的线性关系,其灵敏度达－50.26 mV/decade。经气相催化分析,在400～600℃和0.01% C3 H6下,线型形貌NiO电极的平均气相催化效率最低,为31.4%（其余两种分别为42.7%,52.4%）,进而表现最优的传感器性能。     

Ceria-doped SnO2 sensor highly selective to ethanol in humid air

In our earlier study, we reported that at 300 °C, a 2.0 wt.% CeO₂-doped SnO₂ sensor is highly selective to ethanol in the presence of CO and CH₄ gases [F. Pourfayaz, A. Khodadadi, Y. Mortazavi, S.S. Mohajerzadeh, CeO₂ doped SnO₂ sensor selective to ethanol in presence of CO, LPG and CH₄, Sens. Actuators B 108 (2005) 172–176]. In the present investigation, we report the influence of ambient air humidity on the ethanol selective SnO₂ sensor doped with 2.0 wt.% CeO₂. Maximum response to ethanol occurs at 300 °C which decreases with the relative humidity. The relative humidity was changed from 0 to 80% for different ambient air temperatures of 30, 40 and 50 °C and the response of the sensor was monitored in a 250–450 °C temperature range. As the relative humidity in 50 °C air increased from 0 to 30%, a 15% reduction in the maximum response to ethanol was observed. A further increase in the relative humidity no longer reduced the response significantly. The presence of humidity improved the sensor response to both CO and CH₄ up to 350 °C after which the extent of improvement became smaller and at 450 °C was almost diminished. The sensor is shown to be quite selective to ethanol in the presence of humid air containing CO and CH₄. The selectivity passes a maximum at 300 °C; however it declines at higher operating temperatures.     

一种用于在体监测的新型钙离子传感器的研制

将钙离子敏感试剂(ETH129),DBP,NaTP,PVC按一定比例制成敏感膜,复合在高纯度铂丝基体电极上,制成了一种涂丝钙离子传感器。测试结果表明:该传感器的线性范围为10-6~10-2mol/L,响应斜率为20.35mV/Decup le,响应时间约为10 s。该传感器有好的选择性、稳定性及重现性,它的针状结构特点适于对生物体内的钙离子浓度进行在体动态监测。     

一种新型有机磷液晶传感器

提出了一种新型有机磷液晶传感器,其基底表面仅由Cu2+功能化。将液晶5CB滴凃其上,利用正交偏光显微镜对传感器的光学表征进行观察。传感器的光学表征随时间逐渐从亮转为暗,且其转为全暗态所需的时间与Cu2+的浓度呈反比;当通入甲基磷酸二甲脂(DMMP)气体时,传感器呈现出逐渐从暗到亮的光学表征变化,循环通入空气和DMMP气体时交替出现的暗与亮的光学表征转变显示了其对DMMP的光学响应具有可重复性;另外,水、乙醇、甲苯和丙酮等其他干扰气体的通入则不会引起光学表征的任何变化。同时,在实验范围内(0.1~10mmol/L),Cu2+的浓度越低,传感器对DMMP的光学响应灵敏度越高。结果表明了这种新型有机磷液晶传感器造价低廉,制作过程简易,可选择性、可重复性地应用于如DMMP等有机磷的检测中。