共查询到19条相似文献,搜索用时 78 毫秒
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研制了一种无湿敏材料的纺织基底无芯片RFID 湿度传感器用于检测环境湿度。通过射频仿真软件
HFSS,获得谐振频率在2. 45 GHz 具有较高品质因数的纺织基底谐振器模型,对以谐振频率偏移量作为灵敏度指标
的检测原理进行了仿真。利用丝网印刷工艺和刻绘工艺分别在不同类型纺织物上制作了无芯片RFID 湿度传感器,
系统研究了制作工艺、纺织品类型和厚度对传感器湿敏特性的影响。结果表明,0. 5 mm 厚度下不同基底类型湿度传
感器的灵敏度由高至低依次为:棉基底、亚麻基底、聚酯纤维基底,恢复特性呈相反顺序,其中棉基底传感器在高湿
范围内平均灵敏度达3. 8 MHz/ %RH,聚酯纤维基底传感器恢复度达86%;相同类型的棉纺织基底下基底厚度越大,
平均湿度灵敏度越高,恢复特性越差。传感器稳定性测试表明传感器具有较好的中长期稳定性。对纺织基底湿度
传感器的感湿机理进行了分析,纺织纤维中的亲水基团与水分子间形成氢键,改变了基底的介电参数,传感器的湿
敏特性与组成纺织品的纤维成分、纤维细度、编织方式有关。 相似文献
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大气中含水汽的多少.常用湿度来表示。要控制湿度,就要对湿度进行检测,关键元件就是湿敏器件。湿敏器件的性能指标有湿度量程、灵敏度、温度系数、响应时间、湿滞回差、感湿特征量——相对湿度特性曲线等。例如作为湿敏器件之一的湿敏半导体陶瓷,按其阻值随环境湿度的变化规律,又可分为两大类:负感湿特性的半导体陶瓷。其阻值随环境湿度的增加而减小;正感湿特性的半导体陶瓷,其阻值随环境湿度的增加而增加。从结构上分,又可分为烧结型、涂覆膜型、多孔氧化物型、结型和MOS型半导体湿敏器件等。湿敏器件的应用是一种非电物理量的电气测量。湿敏电阻即其中的一种。它在一定的电源驱动下,将湿度量转换成电量,然后直接通过仪表读出或调节控湿 相似文献
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基于CAN总线的分布式车间温湿度检测系统 总被引:1,自引:0,他引:1
阐述了一种基于CAN总线温湿度检测系统的方法,重点介绍了通信与温湿度检测部分的实现。该系统以PIC18F25K80单片机为主控器,选用集成温度传感器与湿度传感器。高集成度的元器件使得项目开发周期大大缩短,经试运行证实,该系统具有性能稳定、通信距离远的优势。 相似文献
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Microsensors for chemical measurement microsystems exploit a wide variety of chemical and physical transduction principles and a correspondingly wide variety of practical electrical and electronic implementation technologies. To keep this article's scope manageable, the devices discussed in detail are limited to specialized electrical circuit components - resistors and capacitors - whose parametric values depend on their chemical environment; furthermore, the discussion and examples focus on chemical sensors for gas phase versus liquid phase or biological environments. The article looked in detail at chemiresistors, resistors fabricated of materials whose resistivity changes dramatically with their atmospheric environment, and humidity sensors, which are especially interesting because it is possible to compare commonly available devices based on resistive, capacitive, and thermal conductivity principles. Since many of the most practically important of these sensors are currently at a stage of their miniaturization path that makes it more accurate to call them "minisensors" than "microsensors," devices at this scale are also discussed. 相似文献
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Rachele Castaldo Giuseppe Cesare Lama Paolo Aprea Gennaro Gentile Veronica Ambrogi Marino Lavorgna Pierfrancesco Cerruti 《Advanced functional materials》2019,29(14)
Humidity‐driven and electrically responsive graphene/cloisite hybrid films are obtained by casting water dispersions of graphene oxide and cloisite Na+. Coupling hydrophilicity and a high water vapor barrier in a homogenous film enables to realize humidity‐driven actuators which exploit the water gradient generated across the film section under asymmetric exposure to humidity. The hybrid films are self‐standing, flexible, and exhibit fast humidity‐triggered bidirectional bending up to 75°, which is tuned by varying the relative amount of the two components. Up to 60% of the bending angle can be preserved at the steady state, providing a large and reliable response to humidity. Moreover, thermal treatment results in the reduction of graphene oxide, endowing the films with humidity‐dependent electrical conductivity, which increases from 1.5 × 10?6 S at 20% relative humidity (RH) up to 2.7 × 10?5 S at 90% RH. The films are used to realize a humidity‐sensitive electrical switching system in which the reversible actuation is due to water desorption induced by the Joule effect. Due to their ease of preparation and tunable properties, this new class of graphene‐based materials is suitable for the realization of humidity‐driven and electrically responsive actuators and sensors. 相似文献
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Maxwell T. Robinson Julie Tung Meysam Heydari Gharahcheshmeh Karen K. Gleason 《Advanced functional materials》2021,31(22):2101310
A new volatile organic compounds (VOCs) sensing concept called humidity-initiated gas (HIG) sensors is described and demonstrated. HIG sensors employ the impedance of water assembled at sensor interfaces when exposed to humidity to sense VOCs at low concentrations. Here, two HIG sensor variants are studied—Type I and Type II. Type I sensors benefit from simplicity, but are less attractive in terms of key performance metrics, including response time and detection limits. Type II sensors are more complex, but are more attractive in terms of key performance metrics. Notably, it is observed that the best-in-class Type II HIG sensors achieve <2 min response times and <10 ppb detection limit for geranyl acetone, a VOC linked to the asymptomatic form of Huanglongbing (HLB) citrus disease. Both Type I and Type II sensors are assembled from off-the-shelf materials and demonstrate remarkable stability at high humidity. HIG sensors are proposed as an attractive alternative to existing VOCs sensors for remote field detection tasks, including VOCs detection to diagnose HLB citrus disease. 相似文献