分立活塞式MEMS微变形镜的系统级设计

利用实验室自主研发的集成设计平台,搭建了分立活塞式MEMS微变形镜的系统级行为模型,并对其有效性和准确性进行了验证;在此基础上完成了微变形镜的结构设计,并由仿真得到了结构的性能参数.研究结果表明,采用系统级方法进行MEMS器件的设计能够在确保求解精度的前提下,显著提高设计效率,缩短设计周期,减小设计成本;所设计的MEMS微变形镜的各项性能指标完全能满足一般自适应光学系统的应用要求.     

微型MEMS皮拉尼计研究

介绍了一种用于检测真空密封腔体内真空度的器件——微型MEMS皮拉尼计。皮拉尼计是利用真空腔体内微小间隙间的热传导来检测真空度的[1]。本文设计了一种微型MEMS横向皮拉尼计,结构非常简单,并利用浓硼扩散和键合技术实现了该横向MEMS皮拉尼计,制造工艺仅需3张光刻版。其试验结果显示该皮拉尼计在10Pa～300Pa范围内热阻系数与真空度呈很好的线性关系。     

MEMS近红外光谱仪微镜驱动控制系统研发

针对微机电系统（MEMS）近红外光谱仪中MEMS微镜驱动系统的耦合与复杂扰动问题,提出了一种基于扰动观测器（DOB）与模型预测控制（MPC）的复合控制结构。通过分析MEMS微镜的驱动工作原理,建立MEMS微镜偏转角与驱动电压的传递函数模型,设计了MPC以消除系统耦合,通过分析系统扰动模型,设计了DOB实现对系统内部与外部扰动的集中监测。仿真研究与实验测试结果表明：基于DOB MPC复合结构的MEMS微镜驱动控制系统,既可以有效抑制系统的外部扰动,又可以抑制由模型失配和变量耦合导致的内部扰动。     

基于XML的MEMS设计过程描述语言

在分析和细化MEMS多种器件设计流程的基础上,建立了通用的MEMS Top-Down设计过程模型。参考工作流过程定义语言XPDL,并对其进行了扩展和修改,充分考虑微机械系统设计过程的特点,提出了一种基于XML的MEMS设计过程描述语言(MDPDL),介绍了其设计和实现的基本思想,用实例验证了该语言的有效性。     

带有凸条平板的MEMS结构压膜阻尼效应分析

针对带有凸条平板的MEMS结构压膜阻尼效应,利用基本Reynolds方程和特定的第一类边界条件,给出一种压膜阻尼系数的解析分析方法。在带有凸条平板的MEMS微开关设计与制作的基础上,利用引入该压膜阻尼系数的Simulink模型仿真分析了微开关的动态响应特性,得到的阈值加速度与其落锤测试结果是一致的,从而验证了所提出的带有凸条平板压膜阻尼效应理论分析的正确性。     

面向机载惯性稳定云台的微姿态参考系统的研究

基于MEMS传感器设计了面向机载惯性稳定云台的微姿态参考系统.首先,对磁力计受到的环境干扰磁场的影响进行了信号补偿;然后,在分析角速度陀螺、加速度计和磁力计等传感器特点的基础上,提出一种新的卡尔曼滤波算法模型;最后,通过性能测试,验证了微姿态参考模型具有较好的静态和动态性能,完全满足机载惯性稳定云台的需求.     

低驱动电压k波段电容耦合式RFMEMS开关的设计

设计了一种低驱动电压的电容耦合式射频微机械(RF MEMS)开关.RF MEMS开关采用共面波导传输线,双电极驱动,悬空金属膜采用弹性折叠梁支撑.使用MEMS CAD软件CoventorWare、微波CAD软件HFSS,分别仿真了开关的力学性能和电磁性能,仿真结果表明:开关的驱动电压为2.5V,满足低驱动电压的设计目标;开关开态的插入损耗约为0.23 dB@20 GHz,关态的隔离度约为18.1 dB@20 GHz.最后给出了这种RF MEMS开关的微制造工艺.     

基于钎焊的MEMS陀螺真空封装设计与实验研究

对于线振动硅微机电系统(MEMS)陀螺,真空封装是减小其振动阻尼、提高振动品质因数,进而提高性能的一种有效的措施。设计了一种基于钎焊的硅MEMS陀螺真空封装方案,该方案因不采用吸气剂,故可实现真空度可控。理论计算表明:该封装形式可以保持1 Pa以下的真空度;经过对真空封装后的陀螺实验测试结果表明:设计的陀螺驱动轴品质因数为1500,实际封装后的陀螺驱动轴品质因数为1700,满足真空度设计目标。经过对封装后的陀螺品质因数进行186 d的跟踪测试,品质因数基本保持不变,验证了该真空封装方案的可靠性。     

基于MEMS的航天器表面新型测温传感器设计与实现

鉴于微机械电子系统（Micro-Electro-Mechanical-Systems,MEMS）技术及其在航空航天用传感器设计中的优势,本文根据航天器表面测温的需要,设计了一款新型表面瞬态测温热电偶传感器,重点研究了其线条和热结点图形制作工艺及其优化过程。通过物理试验验证,该型薄膜热电偶比普通热电偶响应时间较短,相对误差较小,满足返回式航天器表面高温的瞬态测温需求。     

基于近似模型的y轴微机械陀螺系统级优化

提出一种基于近似模型的MEMS系统级优化方法,给出具体实现流程,并结合一个y轴微机械陀螺进行优化。该方法解决了如何得到近似优化目标函数表达式的关键问题。所得的y轴微机械陀螺优化参数,使得陀螺驱动模态谐振频率fx和检测模态谐振频率fz分别为3 074 Hz和2 998 Hz,两者之间相差7 6 Hz,较好的实现了模态匹配,且都在3 000 Hz的设计要求附近,约束条件也得到了满足。该优化方法为在MEMS设计中快速获得系统级优化方案提供较好参考。     

Modeling of a three-layer piezoelectric bimorph beam withhysteresis

Piezoelectric actuators are usually stacked or bimorph in configuration. In this paper the mechanics of a three-layer piezoelectric bimorph is discussed and its dynamic model with hysteresis is presented. The results can be used to analyze piezoelectric actuators constructed with three-layer piezoelectric bimorphs. A piezoelectric bimorph actuator has been fabricated and experiments have been carried out to verify the model. The calculated results of this model closely matched the tested results. This model can also be used with other types of piezoelectric actuators with a slight modification     

Deflection of coupled elasticity–electrostatic bimorph PVDF material: theoretical,FEM and experimental verification

Piezoelectric materials have wide applications in the field of mechanical, aerospace and civil engineering because of its voltage dependent actuation. Piezoelectric material goes through voltage generation whenever deflection is induced in it and vice versa. Piezoelectric bimorph beam has been widely used for sensing and actuating. In the actuation mode, an electric field is applied across the beam thickness, one layer contracts while the other expands. This results in the bending of the entire structure and tip deflection. In the sensing mode, the bimorph is used to measure an external load by monitoring the piezoelectric induced electrode voltages. In this research work, a 2D bimorph piezoelectric actuator model having two layers made of polyvinylidene fluoride (PVDF) material was developed to examine the inverse piezoelectric effect. Finite element analysis (FEA) was carried out on specially designed actuator model by using MATLAB Partial Differential Equation (PDE) Toolbox™. Theoretical analysis has been carried out to measure the tip deflection under applied electric field. The laboratory test was performed to investigate the deformation behavior of piezoelectric actuator. It is observed that, more the electric field applied, more the material would be deformed in a particular direction. The experimental results are in good agreement with numerical results.

     

压电扭转驱动器的有限元分析

为研究压电陶瓷的扭转驱动能力,制作了压电扭转驱动器,应用有限元分析方法,使用三维六面体耦合单元对压电扭转驱动器进行了力学和电学分析。根据压电陶瓷的基本方程,利用有限元分析软件ANSYS进行直接耦合分析求解。分析结果与试验结果取得了良好的一致,证实了利用压电陶瓷双晶片弯曲制作压电扭转驱动器结构设计的可行性。该分析方法与结论对压电驱动器的设计、制造与优化具有一定的指导意义。     

基于压电双晶片的微型无人机增稳驱动系统研究

研究了一种,基于压电双晶片的微型无人机增稳驱动系统,并设计了一种基于升压电路原理的压电驱动电源,该驱动电源采用机载电池供电,通过 0～5V 控制信号控制其运动,对驱动电源的动态特性进行了测试.同时为实现对整个驱动系统的自适应控制,采用光纤 Bragg 光栅(FBG)传感器对压电双晶片的位移变化特性进行了测量.研究结果表...     

Design and static modeling of a semiconductor polymericpiezoelectric microactuator

The design of a semicircular polymeric piezoelectric actuator is presented, the models for its deflection and force are derived, and the results of the experiments used to verify the models are reported. The design is a polymeric piezoelectric bimorph formed in a semicircular shape instead of the standard straight cantilever beam bimorph design. The deflection model is adopted from the straight cantilever beam model and relates the free deflection as a function of the applied voltage field. The force model is developed using Castigliano's second theorem. Two experiments were conducted to verify the model: force-voltage and force-deflection. The models show that a bimorph formed in a semicircular shape produces significantly more force than a straight cantilever beam bimorph of the same length without a significant sacrifice in deflection     

Planate conducting polymer actuator based on polypyrrole and its application

In this study, we propose a planate actuator which can transform only its central part locally. We have developed a planate conducting polymer actuator based on polypyrrole (PPy) and two types of acids, such as p-phenol sulfonic acid and dodecylbenzene sulfonic acid, by electrodeposition. Its structure was patterned bimorph structure with anion-driven, cation-driven and bimorph layers. The planate conducting polymer actuator could deform only its central part locally. Moreover, we introduce a micro-pump that operates by planate conducting polymer actuator as the drive source. The water level in the flow channel of micro-pump shows the reciprocating motion measuring ±2 mm in accordance with the oscillation of the bimorph conducting polymer actuator which was approximately 28 μl/min. The oscillating volume can be controlled by the application of electrochemical potential and its scan rate applied to the actuator.     

气动薄膜执行机构模型优化及参数辨识

在气动调节阀中,针对智能电气阀门定位器控制算法的开发通常需以气动薄膜执行机构模型为基础;本研究对应用于气动薄膜执行机构的传统Karnopp摩擦模型进行了优化,对动静摩擦判断条件DV(临界速度)进行修改,修改后的模型解决了DV如何选取这一问题。同时对传统气动薄膜执行机构模型的参数辨识方法进行改进,将多元线性回归和最小二乘法应用于估算气动薄膜执行机构中移动部件质量,弹簧刚度系数,预紧力,库伦摩擦和粘滞摩擦系数,通过实际气室压力和估计气室压力的标准误差、相关系数与参数向量中每个参数对应的p-value三个指标来决定参数的选取结果。将摩擦模型整合进气动薄膜执行机构动力学模型中,通过仿真和实验验证了参数辨识方法有效性。在开环不同幅值的阶跃信号和随机信号激励下进行仿真和实验对比,结果表明,整合后的摩擦模型能准确模拟气动薄膜执行机构的动态过程,该模型和参数辨识方法同样适用于其它机械装备。     

悬臂梁式压电双晶片振动能量采集器的模型与实验研究

针对悬臂梁式双压电晶片振动能量采集器的质量效应问题,通过幅值修正方法建立了能量采集器的集总参数修正模型,利用阻抗分析和导纳圆法对模型参数进行了识别,得到了采集器在简谐基础激励作用下的机电耦合输出传递函数表达式;建立了悬臂梁压电振动能量采集器的实验系统,实验与仿真分析了悬臂梁末端质量、负载电阻等对能量采集器输出特性的影响,结果表明理论仿真结果与实验结果具有很好的吻合度,证明本文模型有利于提高压电振动能量采集器输出性能的分析预测精度。     

Optimization of clamped circular piezoelectric composite actuators

This paper addresses the design of clamped circular piezoceramic composite unimorph and bimorph configurations, specifically the conflicting requirements of maximum volume displacement for a prescribed bandwidth. An optimization problem is formulated that implements analytical solutions for unimorph and bimorph configurations using laminated plate theory, including the use of oppositely polarized piezoceramic patches. A range of actuator geometric parameters are studied, and bounds for volume displacement and natural frequency of optimal designs are determined and presented via design curves. In the selected design space, Pareto optimization results for unimorph and bimorph configurations show that optimal volume displacement is related to the bandwidth by a universal power law such that the product of the square of the natural frequency and the displaced volume, a “gain-bandwidth” product, is a constant. Characteristic trends are also described that are independent of the actuator radius for the Pareto optimal piezoceramic patch thickness and radius versus normalized bandwidth. The results are relevant, for example, in the design of zero-net mass-flux or synthetic jet actuators used in flow control applications.     

A piezoelectric inertia rotary actuator based on asymmetric clamping mechanism

A newly piezoelectric inertia rotary actuator is presented by using asymmetric mechanical structure to produce asymmetric inertia impact force when the symmetric electrical signal is applied to the piezoelectric bimorph Mechanical analysis was derived and simulation model of asymmetric clamping mechanism was established to determine the influence of structural parameters to the output performance. A prototype was developed and a series of experiments were conducted to evaluate the performance in terms of angular displacement, speed, and load characteristic. The experimental results show that the angular displacement of the actuator is approximately proportional to the amplitude of driving voltage, and an angular displacement resolution of 12 µrad is obtained with a square wave of 15 V_p?p at a frequency of 4 Hz. The maximum torque can reach 3.96 N mm at 70 V_p?p applied voltage and 2 Hz driving frequency. The rotary actuator characterized with an asymmetric clamping mechanism will provide new references for the further research on piezoelectric inertia drive mechanism.