The Fabrication Process of Tunneling Vibratory Microgyroscopes

振动梁式微机械隧道陀螺仪是一种以悬臂梁作为换能构件,以电子隧道效应为输出敏感方式的高精度和高灵敏的角振动传感器,解决了传统机械陀螺仪因尺寸减小而导致的灵敏度降低的缺点。结合微机械隧道陀螺仪的尺寸特点:硅尖与下电极的距离为1μm,齿厚和齿间距之间的距离为4μm,梁的厚度为50μm,提出硅正面刻蚀—玻璃上电极制作—硅玻键合—硅背面减薄—硅背面刻蚀的DDSOG(DeepDrySiliconOnGlass)工艺方案,成功实现了整个器件的工艺制备。本文就DDSOG工艺中的关键工艺进行了一一论述,该工艺不仅能用于隧道陀螺仪的制备,同时也可以制作其它高深宽比传感器或执行器。Micro-machined tunneling gyroscope with cantilever is a kind of angular rate sensor with high sensitivity and resolution,in which cantilever works as transducer and electron tunneling effect is employed as sensor.It overcomes the traditional one's reduction in sensitivity when miniaturized.The Deep Dry Silicon On Glass(DDSOG)process,which includes the silicon front side etching,the technology of electrodes on the glass,the wafer bonding,the silicon thickness reduction and silicon deep etching on the back side,has been introduced to fabricate the microgyroscope based on its dimension characteristics:1μm gap between silicon tip and its underside electrode,4μm finger gap and width,50μm thickness of cantilever.This process can be used to fabricate not only the micro-machined tunneling gyroscope but also other sensor and actuators.国家自然科学基金资助(50675184);; 福建省科技计划重点项目资助(2002H022);; 回国留学人员基金资助;; 厦门大学新世纪优秀人才基金资

Time-varying predictive-LQG control for micromechanical tunneling gyroscope

为了降低微机械隧道陀螺仪系统的非线性,增大器件的带宽并提高系统的信噪比,隧尖与相应隧道电极之间的隧道间距应控制在1nM附近,且其必须在闭环模式下工作。本文鉴于线性二次高斯(lQg)控制理论的抗干扰特性和鲁棒性以及哥氏加速度的时变特征,采用时变卡尔曼滤波器和lQg最优控制器串联而成的lQg预测控制策略设计了隧道陀螺仪闭环控制系统。首先,根据隧道陀螺仪的工作原理设计了总体控制方案。然后,在建立隧道式陀螺仪的扩展动态方程的基础上,设计了lQg预测控制器的两个串联环节即时变卡尔曼滤波器和状态反馈调节器。最后,通过SIMulInk建立了隧道式陀螺仪的lQg预测控制系统并进行数值仿真。结果表明,即使输入角速度是缓变的随机信号,lQg预测控制器也能将隧道间距维持在1nM附近。控制系统能够精确地估计欲测量的输入角速度,估计精度达到10-4 rAd/S。In order to decrease the nonlinearity of a Micromechanical Tunneling Gyroscope(MTG),enlarge its band width and raise the signal-to-noise ratio of the system,the tunneling gap between the tunneling tip and the corresponding tunneling electrode should be controlled in 1 nm,moreover the MTG must operate in the closed-loop mode.Based on the anti-interference and robustness of the Linear Quadratic Gauss(LQG) control theory and time-varying characteristics of Coriolis acceleration,this paper uses the predictive-LQG control strategy formed by a series of time-varying Kalman filter and an optimal LQG controller to design a closed-loop control system for the MTG.First,the overall control scheme was designed according to the operating principle of the MTG.Then,the two series of the predictive-LQG controllers were designed on the basis of the establishment of the extended dynamic equation of the MTG.Finally,the predictive-LQG controller system of the MTG was built up by Simulink,and a numerical simulation was performed.The simulation results prove that the tunneling gap has been controlled in 1 nm and the measured input angular rate could be estimated accurately by the predictive-LQG controller even if the input angular rate is a slowly varying random signal.And the estimation accuracy can reach 10-4rad/s.国家自然科学基金资助项目(No.50875222/51035002);青年科学基金资助项目(No.51105320);中央高校基本科研业务费专项基金资助项目(No.2010121039

The Preliminary Study of Micromachined Tunneling Gyroscope with a Fan-shaped Comb Drive Electrode

设计了一种扇形梳齿驱动式隧道陀螺仪,意在取代现有的平板驱动方式,以此来提高陀螺仪的灵敏度.从扇形梳齿驱动的工作原理出发,推导了该型陀螺仪的运动方程,分析了结构参数与其灵敏度的内在联系.在此基础上,对陀螺仪设计中与陀螺仪性能相关的机械耦合、静电驱动频率和敏感方向刚度等问题进行了有益的探讨,揭示了静电驱动频率的选择与敏感方向品质因子和驱动方向品质因子大小之间的内在联系,为陀螺仪的尺寸优化设计奠定了理论基础.A tunneling-based micromachined gyroscope with a fan-shaped comb drive electrode,instead of plate-drive electrodes at existing designs,is put forward in this paper.From the principle of the gyroscope,the dynamic equation of this model gyroscope is derived and the inherent relations between structure and sensitivity are also analyzed.Based on this result,the effects of the mechanical coupling,the electrostatic drive frequency and the spring constant of sensitive direction on the performance of the gyroscope are comprehensively discussed.The internal relations between the selection of the electrostatic drive frequency and Q-values of different directions are also found out.Thus,a theoretical foundation of optimal structure for micromachined gyroscope has been laid.国家自然科学基金(50275127);; 福建省自然科学基金(A0110003);; 福建省科技计划重点项目(2002H022)资

LQG control for sensing mode of micro tunneling gyroscope

为了将微隧穿式陀螺仪(MTg)的隧尖与检测电极之间的隧道间隙及其变动量分别维持在1nM和0.1nM并降低系统噪声和扩大带宽,本文为其检测模态设计了线性二次高斯(lQg)闭环反馈系统。在利用微小量法对呈指数规律的隧道效应进行线性化的基础上,建立了MTg检测模态的线性化模型,并将哥氏加速度和电子隧道1/f噪声分别当作主要的过程噪声和输出噪声,设计了由最优状态估计器和线性二次(lQ)状态调节器组成的lQg控制器。搭建了仿真系统和实际的lQg控制电路并进行动态测试。仿真结果显示,lQg控制在将系统的信噪比提高24db的同时,能够将两个隧道电极之间的间隙的变动量控制在10-4 nM。实验曲线表明,隧道电流噪声的峰峰值为0.4nA,lQg反馈控制系统在动态加速度信号的激励下可维持恒定隧道间隙为1nM。In order to maintain the tunneling gap and its fluctuation between a tunneling tip and a detecting electrode at the operation points of 1 nm and 0.1 nm respectively,a Linear Quadratic Gauss(LQG) closed-loop feedback control system was designed to reduce the system noise and to expand the bandwidth of the Micro Tunneling Gyroscope(MTG).Based on the linearization of the exponential tunneling effect using the minification method,the linearized model of the sensing mode of the MTG was deduced.By taking the Coriolis acceleration and electronic tunneling 1/f noise as the process noise and output noise of the sensing mode of the MTG,respectively,the LQG controller composed of a optimal state estimator and a Linear Quadratic(LQ)regulator was designed.The simulated system and the real LQG control circuit were established for the dynamic test.The simulation results show that the signal-to-noise ratio can be increased by 24 dB and the deviation of the tunneling gap between the two electrodes can be maintained at the value of 10-4 nm by the proposed LQG feedback controller.Furthermore,the testing curve indicates that the peak-to-peak amplitude of the tunneling current noise is 0.4 nA and the tunneling gap can be controlled to be 1 nm under the excitation of dynamic acceleration.国家自然科学基金资助项目(No.51035002);青年科学基金资助项目(No.51105320);中央高校基本科研业务费专项资金资助项目(No.2010121039

THE APPEARANCE FEATURES AND ENVIRONMENTAL INDICATION OF SURFACE SEDIMENTS IN CHUKCHI SEA AND CANADA BASIN

通过对中国首次和第二次北极科学考察采集的表层沉积物的观察,根据沉积物的颜色和气味、砾石分布、底栖生物及贝壳分布特征的分析,探讨了该海区表层沉积物表观特征变化与有机质输入、沉积物的氧化还原状态的关系、底栖生物分布范围、冰筏碎屑的分布区域及与海流的关系,指出在研究区软体动物生长的北界位于73.5°N,比浮游动物的北界约低2个纬度。冰筏碎屑的北界可作为融冰水的北界或永久冰区的南界,位置在77°24′N附近。通过对沉积物表观特征的综合分析,结合研究区的海流特征,指出研究区的海流分布对沉积物分布有重要影响,尤其是两股不同性质的海流相遇,对西南部与东部两个区域的沉积物组成及性质具有较强的控制作用。The apparent features of surface sediments collected during Chinese First and Second Arctic Research Expedition were observed.Based on the recognition of color and odor of the sediments,distribution of gravels or ice-rafted debris and molluscan remains in the surface sediments,we discuss the relation among the apparent features of surface sediments and the content of organic matters,oxidation-reduction status as well as the distribution range of benthos,ice-rafted detritus and the relation with ocean current.We find that the north boundary of mollusks is located at 73.5°N,which is 2° lower than that of zooplanktons.The north boundary of ice-rafted detritus which is also the north boundary of melting water and equals to the south boundary of permanent ice region,appears near 77°24'N.According to analysis of apparent features of sediments,combining with current characteristics in study area,we conclude that current plays an important role in distribution of sediments,especially for that within the southwest region and east region.国家自然科学基金项目(40576060,40376017

对孟烷-1,2,4-三醇的合成及对水稻稗草的除草活性研究

在1,2-二氯乙烷中,以30%H2O2为氧化剂,过氧磷钨酸季铵盐[π-C5H5N(CH2)11CH3]3PW4O32为催化剂,催化松油烯-4-醇的氧化反应生成对孟烷-1,2,4-三醇;该产物以白色粉末状固体析出,容易通过简单过滤方法分离,其结构经元素分析、红外光谱、1H NMR及13C NMR确证。本实验最佳合成工艺条件为:松油烯-4-醇12.3 mmol,1,2-二氯乙烷5 mL,过氧化氢与松油烯-4-醇的物质的量之比1.25∶1,催化剂用量为2.98%(以松油烯-4-醇的质量分数计),温度50℃,反应时间1.5 h;在此条件下,松油烯-4-醇的转化率和对孟烷-1,2,4-三醇的产率分别达到99.8%和58.0%,纯度达到98%以上。初步除草活性测试表明,对孟烷-1,2,4-三醇对水稻稗草种子萌发后胚根与幼芽的生长具有明显的影响,在10 mmol/L的浓度下,根长抑制率和芽长抑制率分别为100%和81.4%。广西科技攻关项目(1348006-10);广西自然科学基金(2011GXNSFA018057);广西民族大学引进人才科研启

Construction and Analysis of Probe Array Induced 3D Electrospun Nanofiber Structure

三维纳米纤维结构具有超高比表面积、可控孔径和孔密度,潜在应用非常广泛.以高度和位置可调的探针阵列为静电纺丝收集器,同时探针阵列通过控制开关与辅助电压相接,通过改变各探针高度、探针间距和与辅助电压的导通状态,制备所需的三维纳米纤维结构.初步实验结果表明,最大/最小探针间距随着电压的增大而减小,而随喷头与收集器间距的增大而增大.同时,增大探针高度差或减小喷头与收集器间距/探针间距将导致辅助电压变大.Three-dimensional(3D) nanofiber structure has vast potential applications due to its large surface area to volume ratio,controllable pore diameter and pore density.Probe array with adjustable height and position,which is controlled by switch controller to be connected with auxiliary voltage,is utilized as electrospinning collector.Desired 3D nanofiber structure can be fabricated by changing individual probe height,probe-to-probe distance and connectivity with auxiliary voltage.The preliminary experimental results show that the maximum/minimum of probe-to-probe distance decreases with the increase of applied voltage but increases with the increase of spinneret-to-collector distance.Meanwhile,auxiliary voltage decreases as spinneret-to-collector distance and probe-to-probe distance increase,but increases with the increase of height difference.国家自然科学基金重点项目(51035002);国家自然科学基金资助项目(50875222);福建省自然科学基金资助项目(2011J05139);中央高校基本业务费项目(51035002

Time-varying predictive-LQG control for micromechanical tunneling gyroscope

In order to decrease the nonlinearity of a Micromechanical Tunneling Gyroscope (MTG), enlarge its band width and raise the signal-to-noise ratio of the system, the tunneling gap between the tunneling tip and the corresponding tunneling electrode should be controlled in 1 nm, moreover the MTG must operate in the closed-loop mode. Based on the anti-interference and robustness of the Linear Quadratic Gauss (LQG) control theory and time-varying characteristics of Coriolis acceleration, this paper uses the predictive-LQG control strategy formed by a series of time-varying Kalman filter and an optimal LQG controller to design a closed-loop control system for the MTG. First, the overall control scheme was designed according to the operating principle of the MTG. Then, the two series of the predictive-LQG controllers were designed on the basis of the establishment of the extended dynamic equation of the MTG. Finally, the predictive-LQG controller system of the MTG was built up by Simulink, and a numerical simulation was performed. The simulation results prove that the tunneling gap has been controlled in 1 nm and the measured input angular rate could be estimated accurately by the predictive-LQG controller even if the input angular rate is a slowly varying random signal. And the estimation accuracy can reach 10-4 rad/s

兰州重离子研究装置的区域监测和安全系统

木文主要介绍了兰州重离子研究装置(HIRFL)的区域监测系统(包括中子和γ探测器及数据采集和处理系统)和辐射安全系统(包括报警系统和安全联锁系统)的设计和性能,以及它们在HIRFL调束中的应用