共查询到20条相似文献,搜索用时 156 毫秒
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为了研究拉伸和大形变弯曲共存状态下硅纳米悬臂梁传感结构的压阻特性,采用CMOS工艺制作了硅纳米悬臂梁传感测试结构,结合原子力显微镜和半导体参数测试仪对其电学参数进行了测量,其位移灵敏度高达1.58216×10-4/nm。在电阻相对变化率实验测量和ANSYS有限元平均应力仿真的基础之上,进而提出了一个非线性压阻模型来提取大弯曲硅纳米悬臂梁的一阶和二阶压阻系数。研究结果表明:其一阶压阻系数约为体硅的5倍,该巨压阻效应为利用硅纳米压阻传感结构来实现超高灵敏度的纳米压力传感器提供了可能的途径。研究结果同时也揭示了要获得高的灵敏度和好的可靠性,硅纳米悬臂梁的长度设计需要折衷考虑。 相似文献
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悬臂梁大变形的向量式有限元分析 总被引:1,自引:0,他引:1
为分析悬臂梁的几何非线性行为,用向量式有限元法将结构离散成质点系以及质点间的连接单元.根据牛顿第二定律得到每个质点在内力和外载荷作用下的运动方程以及悬臂梁在每个时刻的变形用该时刻质点系的运动表示.结合刚架元的节点内力和等效质量得出质点位移的迭代计算公式,采用FORTRAN编制计算程序,对悬臂梁分别承受集中载荷和弯矩下的大变形进行算例分析.计算结果与理论解吻合较好,表明该方法能很好地模拟分析悬臂梁的大变形. 相似文献
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针对磁场对传感器工作性能的影响,借助等强度标准悬臂梁,研究光纤光栅和电阻应变片在磁场环境下的应变测量特性。给出2种传感器的应变传感方程,搭建磁场工作环境,分别采用电阻应变片和光纤光栅对磁场下悬臂梁的应变进行测量。结果表明:在有周期变化磁场工况下,电阻应变片的时域波形产生周期性的脉冲,脉冲大小与变化磁场的强度成正相关关系;光纤光栅传感器的测量结果则始终维持在理论计算值左右,不随磁场的变化而产生较大波动,证明了光纤光栅的抗电磁干扰特性。 相似文献
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单光纤光栅实现位移、温度同时区分测量 总被引:10,自引:1,他引:9
结合光纤光栅悬臂梁调谐的特点,采用悬臂梁矩形梁结构,将光纤光栅粘贴在悬臂梁侧面,利用反射波的带宽对应变敏感而对温度不敏感的特性解调悬臂梁自由端的垂直位移,和反射波的中心波长对温度敏感而对应变不敏感的特性解调温度,成功地实现了对位移和温度的同时测量.基于光谱分析仪0.1 nm的光谱分辨率,实验可得到位移、温度同时区分测量系统的带宽随位移变化的灵敏度为0.153 nm/mm,位移分辨率为0.193 mm,位移测量范围可达6.15 mm;中心波长随温度变化的灵敏度为0.029 nm/℃,温度分辨率为3.4℃,温度测量范围为45℃.实验结果与理论分析基本一致. 相似文献
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本文采用金属电阻应变片作为传感器,研究了悬臂梁在动荷载的作用下的若干动态参数的测量,包括固有频率、阻尼系数等。详细叙述了用电阻应变计测试技术测定悬臂梁在动荷载的作用下的若干动态参数的过程以及数据处理的方法;并对所测定悬臂梁的动态参数的准确性进行讨论,指出方案中的优点和不足。 相似文献
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超薄平面结构电涡流传感器的研究 总被引:1,自引:0,他引:1
介绍用集成电路微细加工技术研制出的一种新型超薄平面结构的电涡流传感器探头。用理论模拟对线圈半径与绕向进行设计,并配制了适宜的二次电路,制造出微位移测试样机。同传统结构的电涡传感器探头相比,灵敏度提高了16%,线性度改善2%。 相似文献
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Chia-Yen Lee Chih-Yung Wen Hui-Hsiung Hou Ruey-Jen Yang Chien-Hsiung Tsai Lung-Ming Fu 《Microfluidics and nanofluidics》2009,6(3):363-371
This study designs and characterizes a novel MEMS-based flow-rate micro-sensor consisting of a platinum resistor deposited
on a silicon nitride-coated silicon cantilever beam. Due to the difference between the thermal conductivities of the silicon
nitride film and the silicon beam, the tip of the cantilever structure bends slightly in the upward direction. As air travels
across the upper surface of the sensor, it interferes with the curved tip and displaces the beam in either the upward or the
downward direction. The resulting change in the resistor signal is then used to calculate the velocity of the air. A flow-direction
micro-sensor is constructed by arranging eight cantilever structures on an octagonal platform. Each cantilever is separated
from its neighbors by a tapered baffle plate connected to a central octagonal pillar designed to attenuate the aerodynamic
force acting on the cantilever beams. By measuring the resistor signals of each of the cantilever beams, the micro-sensor
is capable of measuring both the flow rate and the flow direction of the air passing over the sensor. A numerical investigation
is performed to examine the effects of the pillar height and pillar-to-tip gap on the airflow distribution, the pressure distribution,
the bending moment acting on each beam, and the sensor sensitivity. The results show that the optimum sensor performance is
obtained using a pillar height of 0.75 mm and a pillar-to-tip gap of 5 mm. Moreover, the sensitivity of the octagonal sensing
platform is found to be approximately 90% that of a single cantilever beam. 相似文献
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为了改造24头轧机红外烤箱的温度系统,采用了软件和硬件相结合的自动控温设计方案。用热敏电阻器作温度传感器,87C51单片机作主控微机,加上放大器、模数转换器等组成主要硬件系统。软件上采用积分分离PID位置式算法控制温度超调,实现恒温控制。改造后的系统温度波动误差小于±0.5℃/30min,平均控温误差小于±1℃,很好地满足了全部流水设备的要求。 相似文献
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介绍了一种基于悬臂梁的匹配光栅测量和解调方案,在外界加速度作用下,一个光纤光栅受压,另一个光纤光栅受拉,使波长调谐的灵敏度增加了1倍。实验证明了该方法寓解调和温度补偿为一体的优越性,本解调方案的波长移动分辨力为0. 01pm,可实现高分辨力加速度测量。 相似文献
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This study applies conventional micro-electro-mechanical systems (MEMS) techniques to develop a novel low-cost humidity sensor comprising a silicon substrate, a freestanding cantilever and an integrated resistive thermal sensor. The cantilever has a composite structure comprising a thin layer of platinum (Pt) deposited on a silicon nitride layer and then covered with a polyimide sensing layer. The cantilever deflected in the upward direction as water molecules absorbed by the polyimide sensing layer. The humidity sensor chip caused a measurable change in the resistance of the platinum layer. By compensating the change in the measured resistance by the ambient temperature, the absolute value of the relative humidity can be directly derived. The experimental results show that the sensor has a time-response of 0.9 s when exposed to a sudden humidity change of 65%RH to 95%RH. The sensitivity of the sensors decreases as the temperature increases. Furthermore, the sensor with the longest Pt resistor has the greatest sensitivity. In additions, the temperature-calibrated resistance signal generated by the sensor varies linearly with the ambient humidity. 相似文献
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Microcantilever-based weather station for temperature,humidity and flow rate measurement 总被引:1,自引:1,他引:0
The current study develops a new process for the fabrication of Pt resistor temperature detectors (RTDs), cantilevers covered
with a water-absorbent polyimide layer for humidity measurement and the bending-up of cantilevers to determine the flow rate.
Pt RTDs are fabricated on the silicon substrate. The temperature measurement is based on the linear resistance variations
when temperature changes. The polyimide layer is spun on the cantilever to form a humidity sensing layer. A variation in humidity
causes moisture-dependent bending of the micro-cantilever, which changes the measured resistance of the resistor on the micro-cantilever.
The same type of micro-cantilever, without spinning on polyimide, is used to form an anemometer. It is found that the cantilever
bends slightly upward as a result of the released residual stress induced in the beam during the fabrication. When wind passes
over the cantilever beam, a small deformation occurs. Variations in the flow rate can therefore be determined by measuring
the changes in resistance caused by the beam deflection, using a LCR meter. 相似文献
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基于低分辨力编码器的高精度速度测量简化算法 总被引:2,自引:0,他引:2
采用编码器进行单片机速度测量时,数据运算时间较长,测量范围受到限制。通过对常用的速度测量方法和计算公式进行分析,结合低分辨力编码器的特点,提出了一种简化算法。对不同系数的编码器,采用测量时间可变的测量方法,将复杂的乘除运算变换为简单的乘法运算,减少计算工作量,彻底消除计算误差。测试数据表明:采用低分辨力编码器时,简化算法可测量的最大速度达13008m/h,速度分辨力可达到3m/h。 相似文献