碳纳米管压阻微悬臂梁红外热探测器的研究

研究了压阻复合层微机械悬臂梁红外探测器的热挠曲理论模型。利用IC工艺和微机械加工技术设计制作了一种硅/铝/碳纳米管三层微机械悬臂梁红外探测器,该探测器基于硅和铝两种材料热膨胀系数的差异,存在双物质效应,不同温度下梁的挠度不同,其形变可通过梁根部的压敏电桥检测。为提高探测器的红外吸收特性,实验探索出了在微机械悬臂梁上涂敷碳纳米管吸热层的工艺方法。实验研究了具有碳纳米管薄膜吸热层的三层微机械悬臂梁红外热探测器对红外辐射的响应规律,结果表明涂敷碳纳米管吸热层使响应灵敏度提高近一倍。     

二氧化硅微球颗粒的解团聚研究

二氧化硅微球颗粒在无水和水相介质中都极易发生自组装现象,进而严重影响该颗粒的特性研究。为了更好地使用和研究二氧化硅微球颗粒,需要进行解团聚工艺研究。实验研究了不同尺度的颗粒的团聚特性和现象,提出了一种工艺,该工艺方法可以很好地实现大团聚的二氧化硅微球颗粒的解团聚。经过尼康显微镜观察,显示该工艺不仅很好地完成了二氧化硅微球的解团聚,而且提高了颗粒的分散性和稳定性。     

用于恶劣环境的耐高温压力传感器

为了解决如高温200℃等恶劣环境下的压力测量问题,基于微机电系统(MEMS)和高能氧离子注入(SIMOX)技术,研制了一种量程为0~120 kPa的压阻式压力传感器。该传感器芯片由硅基底、薄层二氧化硅、惠斯登电桥结构的硼离子注入层、氮化硅应力匹配层、钛-铂-金梁式引线层和由湿法刻蚀形成的空腔组成。在氧剂量1.4×10¹⁸/cm²和注入能量200 keV条件下,由高能氧离子注入技术形成厚度为367 nm的埋层二氧化硅层,从而将上部测量电路层和硅基底隔离开,解决了漏电流问题,使得传感器芯片可以在高温200 ℃以上的环境下使用。为了提高传感器在宽温度范围内的稳定性,对温度补偿工艺进行了研究,补偿后的传感器灵敏度温度系数和零位温度系数很容易控制在1×10^-4/℃·FS。实验标定结果表明:在200 ℃下,研发的耐高温压力传感器具有很好的工作性能,其线性度误差达0.12%FS、重复性误差为0.1%FS、迟滞误差为0.12%FS,精度达0.197%FS,满足油井、风洞、汽车和石化工业等现代工业的应用需求。     

谐振式MEMS温度传感器设计

为了实现以频率输出为信号的气象温度测量,提出了一种基于双层悬臂梁的谐振式微温度传感器。基于双悬臂梁不同材料热膨胀系数的差异会导致悬臂梁谐振频率偏移的原理,采用压电方式同时实现悬臂梁的驱动及其谐振频率的检测,从而实现温度的测量。根据硅基传感器的正面腐蚀工艺,设计了谐振悬臂梁的双层结构,采用有限元方法分析了悬臂梁的谐振模态、可利用的振型及其温度与各模态谐振频率的关系,并利用多普勒振动系统对悬臂梁的谐振特性进行了研究。实验发现悬臂梁的二阶弯曲振型Q值相对于其它振型是最大的,其Q值约为150;高阶振型特别是二阶弯曲振型适合用于以ZnO为压电材料的温度传感器的频率检测,并且具有相对较高的灵敏度(约为20Hz/℃)和频率温度系数(1.9×10-4/℃)。结果表明,微型温度传感器能够满足气象温度检测的要求,并具有抗干扰能力强、灵敏度高、信号传输接口简单等优点。     

人体温度数字式无线检测微机电系统的设计与研制

通过理论分析和实验研究,提出了一种用于人体温度数字式无线检测的微机电系统的设计方法。针对人体的特殊使用条件及环境,本着微体积可靠性高等设计原则,分别讨论了温度传感器的选择和设计、封装外壳的设计和无线温度信号发射与接收的设计,并研制出符合设计要求的微机电系统,对系统进行了体外温度测量实验,实验结果表明系统设计可行。     

一种测量Si/SiO2界面残余应力的微结构应变计

借鉴工程力学中测量残余应力的盲孔法,给出了一种测量半导体氧化工艺中形成的硅-二氧化硅界面残余应力的微结构应变计,并对其测量结果作了讨论.     

变截面微管道的制作与气体流动特性分析

为提高硅微无阀泵和空间微推进器的性能，采用微电子机械工艺在硅片上加工出不同长度，不同喉部宽度、断面形状为矩形的变截面微管道，实验测量微管道内氮气的流量特性，分析不同因素对流动特性的影响，研究发现，相同变截面微管道，扩张方向的性能好于收缩方向，不同变截面微管道，随着扩张角，等直段长度，宽度的不断增加，流动性能逐渐提高。     

一种细胞分选芯片的设计、制作和实验

基于尺寸差异原理设计制作了一种-PDMS键合的细胞分选芯片。采用MEMS加工工艺,分别制作出特征尺寸都是20μm的3种不同形状分选孔阵列的硅基片和PDMS盖片,使用电晕放电仪实现硅－PDMS键合。用聚苯乙烯微球和MG-63人骨肉瘤细胞进行实验,微球实验说明了不同形状分选孔阵列的分选结果特征,细胞实验实现了不同大小MG－63细胞的分选,为最终实现不同种细胞分选打下了基础。     

基于MEMS技术的三维微力传感器

开发了一种基于MEMS技术制作的三维微力传感器,传感器为完全对称结构,由4根垂直放置和1根悬臂放置的硅梁连接而成。每根硅梁上设计了一个利用MEMS工艺制作的惠斯通电桥,该种电桥应变系数大,在很大程度上简化了电桥处理电路的设计。在弹性力学和材料力学基础上,利用SOLIDWORK软件对传感器进行了应变分析,得出了力和输出电压之间的关系。设计了传感器信号检测电路,确定了减小温度对检测精度影响的方法。测试表明:该传感器检测量程为±0.5 N,重复定位精度优于9.1 mN,分辨力优于0.95 mN.     

微加热板气体传感器的仿真及结构优化

针对微加热板气体传感器敏感薄膜上温度分布不均的缺点,在传统的微加热板传感器中加入了硅岛结构以均匀薄膜温度分布。利用有限元分析软件ANSYS对带有不同尺寸硅岛的传感器的温度分布进行了仿真和分析,得出了最佳的硅岛尺寸,并提出了一种新型的微加热板气体传感器结构设计,该传感器结构可以在性能不受影响的情况下简化制作工艺。     

铠装K型热电偶动态响应误差补偿研究

提出了一种利用同一可高频调制的高功率C02激光器发出的连续激光和脉冲激光作为激励热源,在同一系统中进行辐射温度计（红外探测器）静态校准和被校表面温度传感器动态校准的新方法,由于高速辐射温度计的频率响应特性优于被校温度传感器,因此以前者的响应作为真值来校准后者并获取系统误差的修正值,避免了因传感器安装环境差异及热物性的变化所产生的误差,解决了表面温度传感器动态校准的溯源难题。利用该方法对K型热电偶进行了动态校准实验,建立了数学模型,获得了该热电偶的频率特性和动态性能指标,对该传感器的动态特性进行补偿。     

光纤声发射传感器

一种用于状态监测和故障诊断的新型声发射传感器已经研制成功。它基于全光纤法布里—珀罗干涉仪原理。其分辨率高达埃级,频率范围为100kHz～1.4MHz。由于信号光束和参考光束在同一根光纤中通过,所以消除了温度变化、微弯效应以及电磁干扰等环境影响,并具有很高的测量稳定性。     

On a MEMS based dynamic remote temperature sensor using transverse vibration of a bi-layer micro-cantilever

In this paper a novel remote temperature sensor based on a bi-layer micro cantilever beam has been proposed, which can sense the temperature of a given heat source from a finite distance dynamically. Proposed sensor works based on radiation heat transfer and thermally induced vibration. In order to dispose a relationship between temperature of the heat source, and a sensible characteristic like as tunneling current or capacitance, thermo-mechanical behavior of such a structure has been investigated. Heat transfer equation of such a beam includes a nonlinear term due to the radiation heat transfer that has been solved numerically using Rung-Kutta explicit integration method. Galerkin based mode summation method has been utilized to solve the partial differential equation of the beam dynamics and the Houbolt implicit integrating method is used to solve obtained ordinary differential equations. Dynamic response to a step, and semi-harmonic excitations and frequency responses, for the proposed sensor with different geometrical or physical properties have been presented and discussed considering the temperature relaxation time of the sensor. In order to gain a semi explicit solution a perturbation method has been disposed and the results have been compared to the numerical direct integration ones, the accuracy and agreement are excellent.     

Multiplex and simultaneous measurement of displacement and temperature using tapered fiber and fiber Bragg grating

A simple method to work out the multiplexing of tapered fiber based sensors is proposed and demonstrated. By cascading a tapered fiber with a fiber Bragg grating (FBG), the sensor head is provided with a wavelength identification, different FBGs provide the sensor heads with different reflective peaks and they can be distinguished in optical spectrum. By compositing several such sensor heads with a multi-channel beam splitter, a star-style topological structure sensor for multipoint sensing is achieved. At the same time, the output intensity at the peak wavelength is sensitive to one external physical parameter applied on the related FBG-cascaded tapered fiber and the central wavelength of the peak is only sensitive to temperature, so that that parameter and temperature can be measured simultaneously. A sensor for dual-point measurement of the displacement and temperature simultaneously is experimentally demonstrated by using a 2 × 2 coupler in this paper. Experiment results show that the sensor works well and the largest sensitivities reach to 0.11 dB/μm for displacement in the range of 0-400 μm, and ～0.0097 nm/°C for temperature between 20 °C and 70 °C.     

微机械氮化硅梁谐振式压力传感器

报导一种新型的电热激励、压阻拾振的氮化硅梁谐振式压力传感器。器件采用微电子机械加工技术和键合技术研制。谐振频率85kHz,空气中品质因素Q值接近1000,在真空中达到40000。采用闭环自激振荡方式测定压力传感器的压力特性,压力测试范围0－400kPa,灵敏度23．8Hz/kPa。     

振动功率流测量方法的研究

研究梁结构中功率流的测量中分别用加速度传感器和PVDF传感器进行功率流测量.通过压电加速度传感器与PVDF传感器测量进行实验比较,结果表明,设计制作的正弦形状和余弦形状传感器是适用可行的.     

APPLICATION OF FEA TO THE COLLOCATION OF ACTUATOR/SENSOR IN THE INTELLIGENT STRUCTURES

INTRODUCTIONThere are two characteristics of piezoelectriccomPOnents that permit them to be used as sensorsand actuators in advanced intelligent structure. Thefirst is called the direct piezoelectric effect that impliesthat when some mechanical force or pressure isapplied on a piezoelectric comPOnent, a charge/voltageis generated.The second is called the conversepiezoelectric effect that implies that when somecharge or voltage is imPOSed on a piezoelectriccomPOnent, the comPOnent will…     

Dynamic characteristics of a beam angular-rate sensor

This paper gives a bandwidth and sensitivity analysis for a vibrating square beam angular-rate sensor. A skew-symmetric gyroscopic inertia matrix results from rotating about an axis orthogonal to the plane of a forced-vibration elastic system giving unique characteristics permitting measurement of its rotation rate. The quality factor has a huge influence on the forced response at the resonant frequencies governing the dynamic operating range in its use as an angular-rate sensor. Fourier-type solution for the cantilever beam with electrostatic excitation reveals characteristics analogous to those occurring for more complex systems. The deflection-dependent nature of the electrostatic excitation induces the parametric excitation into the system, yielding a Hill-type equation. Although it causes the behavior to be more complex, linear sensitivity curves can be obtained, provided that the displacement of the beam is small compared with the gap in static equilibrium. Finally, it is seen that the system provides the applicability of the rotating beam for use as an angular-rate sensor within a certain small range of parametric excitation. Design rules are suggested by observing that sensor sensitivity decreases with increasing sensor bandwidth.     

Structural health monitoring using shaped sensors

This paper is concerned with distributed sensors to measure the response of beam and plate structures. The design of modal sensors for beam structures is well established. The design for plate structures with constant thickness sensors may be achieved by optimizing the shape of the sensor boundary, or by optimizing the effectiveness of the electrode. Most applications consider vibration control, but this paper is concerned with structural health monitoring, where the sensor output is made sensitive to changes in key stiffness parameters, for example in joints. The procedure is based on finite element models of the structures, and thus distributed transducers may be designed for arbitrary beam and plate structures. Simulated examples of a beam and a plate excited by a rotating machine are used to demonstrate the approach.