基于面内补偿的微机电系统离面运动测试

将频闪成像技术和相移显微干涉技术相结合,提出了一种基于面内补偿的微机电系统(MEMS)离面运动测试方法。首先通过相移显微干涉技术自动采集MEMS结构运动周期内不同准静态位置处的数帧相移干涉图像;然后通过图像处理得到每个准静态位置的亮场图像,进行面内位移测试;最后利用面内位移测试结果对离面位移测试进行补偿,即双相位展开算法,完成对于MEMS结构的离面运动测试。实验结果表明:面内运动的测试的精度可达0.01 pixel,静态离面高度测试的重复精度可达0.52 nm,可以完成伴随着面内位移的MEMS离面位移测试。     

大位移、低电压驱动MEMS静电梳齿驱动器的设计与研究

分析了MEMS静电梳齿驱动工作原理,以梳齿结构和弹性梁结构为基础,综合考虑了动态特性、可靠性以及加工工艺可行性要求。提出了非等高结构、变形曲臂梁结构、位移放大驱动器、垂直Z向位移静电梳齿驱动器等四种大尺度、低电压驱动线性MEMS静电梳齿驱动器结构设计。利用CAD采用FEA法分别建模、仿真,进行了大位移、低电压驱动MEMS静电梳齿驱动器的动态与静态的研究,并获得20V直流偏置、位移80～130μm、驱动器面积小于2mm×2mm的结果。     

硅微机械梳齿静电谐振器的建模与分析

基于参数化的计算机辅助设计（CAD）软件，对硅微机械梳齿静电谐振器进行了实体建模，以有限元分析软件为工具，进行了谐振器的模态分析，静态分析和谐响应分析，初步揭示了谐振器的静、动态特性，有助于改善设计效率和质量，展示了计算机辅助工程（CAE）技术在微机电系统（MEMS）研究中的重要作用。     

Si MEMS陀螺仪的正交耦合补偿技术

为了减小正交耦合误差对硅微电子机械系统(MEMS)陀螺仪性能的影响,提高陀螺仪零偏精度,对MEMS陀螺仪正交耦合补偿技术进行研究.建立MEMS陀螺仪动力学模型,分析正交耦合产生的原因,介绍了各类正交耦合补偿机理.设计了一款可实现静电刚度补偿的MEMS陀螺仪,并利用绝缘体上硅(SOI)工艺进行制备.利用现场可编程门阵列(...     

双层亚波长光栅微位移传感系统结构优化设计与性能仿真

随着MEMS惯性传感器件对微位移检测精度的要求越来越高,微位移检测技术已经成为MEMS惯性传感领域的研究热点。亚波长光栅以其超高的位移检测灵敏度成为一个极具发展前景的高精度位移传感平台。利用Rsoft软件模拟分析了双层亚波长光栅共面、离面相对运动时系统零级衍射光透射率与光栅位移量之间的关系及系统关键结构参数对位移检测灵敏度的影响,并对这两种亚波长光栅微位移传感系统进行了结构优化与性能仿真及对比,理论验证了亚波长光栅位移检测的高灵敏度优势。     

静电悬浮转子微陀螺五自由度位置检测研究

给出了一种基于微机电系统(MEMS)技术的静电悬浮转子微陀螺,为了实现对静电悬浮转子微陀螺转子的五自由度(5-DOF)悬浮控制,需要对转子进行五自由度位置检测,首先介绍了微位移检测原理,提出了一种基于频分复用技术和开关解调技术的微位移检测方法,设计了基于直接数字频率合成(DDS)技术的多频率信号发生器、前置放大器及锁相放大器组成的位置测试系统,位移检测电路的各项性能指标能满足静电悬浮转子微陀螺的五自由度控制需要.     

可调谐VCSEL的低应力MEMS悬臂结构设计

针对GaAs基和InP基材料的波长可调谐垂直腔面发射激光器（VCSEL）中微机电系统（MEMS）应力集中引起结构损坏的问题开展研究。设计了蝴蝶结状MEMS悬臂结构,在保证最大位移不变的情况下,降低了悬臂固定端所受的米塞斯应力,提高了器件的可靠性。采用COMSOL软件对蝴蝶结状悬臂结构的各项参数对力学特性的影响进行了优化与分析。结果表明:优化后的蝴蝶结状MEMS悬臂结构固定端的最大米塞斯应力相比于等截面状悬臂结构最大降低了64%,对于GaAs基材料的蝴蝶结状MEMS波长可调谐VCSEL自由光谱范围可达45 nm。     

微进给刀架中位移放大机构的优化设计

基于压电陶瓷驱动的刀具微进给机构是满足精密加工的重要途径,为进一步增加微进给刀架驱动位移,在微进给刀架中增加一种柔性铰链微位移放大机构,增加压电陶瓷驱动器输出位移。该文设计了4种微位移放大机构,理论计算了静态刚度,利用ANSYS软件对4种微位移放大机构进行了建模和有限元数值仿真分析,对比了不同类型的微位移放大机构的放大倍数、负载能力和应力情况等静态特性,为优化设计刀具微进给机构打下良好基础。     

MEMS悬臂梁的静态力学模型研究

研究分析了MEMS悬臂梁的静态力学特性。对比分析了集总式静力学模型和枢纽式静力学模型。对于集总式静力学模型,将MEMS悬臂梁的下拉位移假设为处处相等的普通电容极板,得到悬臂梁下拉位移和下拉电压。对于枢纽式静力学模型,将MEMS悬臂梁假设为下拉位移处处不等的转轴,通过寻找悬臂梁在下拉过程中的等效受力点,得到下拉位移和下拉电压。比较了两种模型的静电力学下拉位移与下拉电压的相对误差。结果表明,集总式静力学模型的误差为20.5%,枢纽式静力学模型的误差仅有5.3%。这表明,枢纽式静力学模型的特性优于集总式静力学模型。     

MEMS三维静动态测试系统

采用集成频闪成像、计算机微视觉和显微干涉技术,研制了微机电系统(MEMS)三维静动态测试系统。系统可进行MEMS面内刚体运动、表面形貌、垂向变形和离面运动的测量。对于面内运动测量,提出了基于立方样条插值的亚像素步长相关模板匹配算法,从MEMS视觉图中提取面内位移,匹配精度为0．02pixels。对于离面运动测量,采用Hariharan 5步相移干涉(PSI)算法和去包裹算法,离面运动测量分辨率可达1nm。通过对Si微压力传感器膜和Si微陀螺仪的静动态测试,验证了系统的适用性和可靠性。     

静电梳齿驱动器薄膜变形反射镜

提出一种大冲程静电梳齿驱动器微机械薄膜变形反射镜,理论上研究了静电梳齿驱动器微机械薄膜变形反射镜的静电驱动力和变形位移与驱动电压的关系,分析了变形反射镜的驱动稳定性,比较了平板电容驱动器与纵向梳齿驱动器的驱动能力.结果表明,变形反射镜的静电驱动力和变形位移没有关系;在相同的面积下,纵向梳齿驱动器的驱动力比平板电容驱动器的驱动力大很多.     

Optimal design and development of a five-bar finger with redundant actuation

In order to develop a human hand mechanism, a five-bar finger with redundant actuation is designed and implemented. Each joint of the finger is driven by a compact actuator mechanism having an ultrasonic motor and a gear set with a potentiometer, and controlled by a VME bus-based control system. Optimal sets of actuator locations and link lengths for cases of a minimum actuator, one-, two-, and three-redundant actuators are obtained by employing a composite design index which simultaneously considers several performance indices, such as workspace, isotropic index, and force transmission ratio. According to the optimization result, several finger-configurations optimized for a special performance index are illustrated, and it is concluded that the case of one redundant actuator is the most effective in comparison to the cases of more redundant actuators, and that the case of two redundant actuators is the most effective in multi-fingered operation in which the force characteristic is relatively important, as compared to the kinematic isotropy and the workspace of the system.     

Dynamic characteristics of planar bending actuator embedded with shape memory alloy

Planar bending actuators embedded with a shape memory alloy (SMA) are a novel type of actuator capable of outputting high bending angle and bending moment. This actuator has a simple structure and high power–weight ratio, which enable it to have wide-ranging applications in the field of biomimetic robots, including biomimetic fish fins and soft robots. However, the existing mechanical model of planar bending actuators embedded with SMA is still quasi-static. Thus, the dynamic characteristics of this kind of actuator cannot be effectively described. Therefore, actuators are difficult to control during the deflection process. To effectively describe this process, a dynamic model of the actuator must be built. This paper aims to identify the dynamic characteristics of the actuator. First, a dynamic model for planar bending actuators embedded with a single SMA wire is established. Second, before SMA wire application, the constitutive characteristics are identified to obtain the necessary parameters for simulation. Third, stable planar bending actuators are fabricated for experiments on characteristics, and then the process flow chart of the planar bending actuator is developed to ensure consistency of the properties of all actuators. Finally, the actuator characteristics obtained experimentally are presented in comparison with those obtained by theoretical simulation. Analysis of the experimental data and simulation results indicates that the planar bending actuator performs better in pulse current heating mode, and that bending angle can be accurately predicted.     

A new preload mechanism for a high-speed piezoelectric stack nanopositioner

Piezoelectric stack actuators are the actuator of choice for many ultra-high precision systems owning to its fast responses and high pushing force capabilities. These actuators are constructed by bonding multiple piezoelectric layers together. An inevitable drawback of these actuators is that there are highly intolerant to tensile and shear forces. During high-speed operations, inertial forces due to effective mass of the system cause the actuators to experience excessive tensile forces. To avoid damage to the actuators, preload must be applied to compensate for these forces. In many nanopositioning systems, flexures are used to provide preload to the piezoelectric stack actuators. However, for high-speed systems with stiff flexures, displacing the flexures and sliding the actuators in place to preload them is a difficult task. One may reduce the stiffness of the flexures to make the preload process more feasible; however, this reduces the mechanical bandwidth of the system. This paper presents a novel preload mechanism that tackles the limitations mentioned above. The preload stage, which is connected in parallel mechanically to a high-speed vertical nanopositioner, allows the piezoelectric stack actuator to be installed and preloaded easily without significantly trading of the stiffness and speed of the nanopositioning system. The proposed vertical nanopositioner has a travel range of 10.6 μ m. Its first resonant mode appears at about 24 kHz along the actuation direction.     

A high-efficiency magnetic suspension actuator with reluctance-balanced permanent magnet biasing and flux-based control

To reduce power consumption of active magnetic bearings (AMBs), permanent magnets (PMs) may be employed to generate a bias flux through the magnetic circuits connecting the actuators with the rotor. In this way, control algorithms based on zero-current operating points and linearized models may be used. This paper describes a new modular design of PM-biased AMB actuator involving a balanced-reluctance topology where the bias flux is set by an auxiliary air gap within the magnetic circuit. A theoretical model and design methodology for achieving a specified range of actuation forces are also defined. Each actuator unit within an AMB suspension system may by positioned freely and operated independently because, unlike many previous PM-biased designs, there is no flux linkage between actuators. To improve the robustness of the actuator control to uncertainty in material properties and air gap sizes, a feedback control scheme is proposed based on inductive sensing of the mean flux density at the actuator pole faces. Testing of the actuator with a current-cancelling flux-based control scheme shows that stable suspension with very low power consumption can be achieved over a range of operating conditions involving both static loading and unbalance excitation.     

Six-axis nanopositioning device with precision magnetic levitation technology

In this paper, we present the design, control, and testing of a 6 degrees-of-freedom magnetically-levitated system with nanometer-precision positioning capability and several-hundred-micrometer travel range. This system levitates a triangular single-moving-part platen, and produces the six-axis motion with six single-axis linear actuators. One of the prominent advantages of this magnetic levitation (maglev) system is that there is no physical contact between the moving part and the stator, which eliminates friction, wear, backlash, and hysteresis. As compared to other traditional devices, the present system is very compact with the minimum number of actuators for six-axis motion generation. The maglev device presented herein shows the position resolution better than 5 nm with 2-nm rms position noise, and is capable of a velocity of 0.5 m/s and an acceleration of 30 m/s/sup 2/. The nominal power consumption is only 15 mW by each horizontal actuator, and 320 mW by each vertical actuator. The actuators are sized to be able to orient and position a maximum payload of 1 kg. The key application of this maglev device is the manipulation at nanoscale for microassemblies and manufacture of their parts. Other potential applications are stereolithography, vibration-free delicate instrumentation, and microscale rapid prototyping.     

一体双驱对称式压电悬臂梁微驱动器

设计了一种一体化加工的双驱对称式压电悬臂梁微驱动器。对压电驱动器工作原理、压电驱动器在准静态工况与共振工况下的输出特性进行了理论分析,确定压电驱动器几何尺寸。介绍了压电驱动器的多层复合结构与一体双驱的实现方式。制作了压电驱动器样机,并通过有限元仿真分析与测试实验相结合的方式得到压电驱动器的阻抗特性与输出特性曲线。将压电驱动器运用在轮式机器人,验证了设计的可行性。     

Performance Quantification of Conducting Polymer Actuators for Real Applications: A Microgripping System

In this paper, we report on modeling, characterization, and performance quantification of a conducting polymer actuator, driving a rigid link to form each finger of a two-finger gripping system, which is what we call a microgripping system. The actuator, which consists of five layers of three different materials, operates in a nonaquatic medium, i.e., air, as opposed to its predecessors. After the bending displacement and force outputs of a single finger are modeled and characterized including the effect of the magnitude and frequency of input voltages, the nonlinear behavior of the finger including hysteresis and creep effects is experimentally quantified, and then a viscoelastic model is employed to predict the creep behavior. The experimental and theoretical results presented demonstrate that while the hysteresis is negligibly small, the creep is significant enough so as not to be ignored. The response of the actuator and the finger under step input voltages is evaluated, and found that the actuator does not have any time delay, but only a large time constant. Two of the fingers are assembled to form a microgripping system, whose payload handling and positioning ability has been experimentally evaluated. It can lift up to 50 times its weight under 1.5 V. The payload handled was a spherical object covered with industrial type tissue paper. The friction coefficient between the object and the carbon fiber rigid link has been determined experimentally and used to estimate the contact force. All the theoretical and experimental performance quantification results presented demonstrate that conducting polymer actuators can be employed to make functional microsized robotic devices     

压电型精密位移驱动器的研究进展

把压电型精密驱动器按技术特点分为直动式、步进式／蠕动式和惯性式三类,列举了各类中的国内外典型机构,分析各类驱动机构的工作原理、优势、缺点、适用场合及研究的活跃点,对进一步研究多自由度精密位移驱动器具有指导意义。