一种新型MEMS微驱动器的设计与仿真分析

提出并设计了具有双稳态功能的新型电磁型MEMS微驱动器结构形式。微驱动器由导磁的两端固支的扭梁、两端可自由摆动的悬臂梁,以及永磁体、下磁路和平面线圈组成。永磁体的使用,实现了器件的双稳态功能,从而可以得到低功耗的磁驱动器。通电线圈用来实现器件的姿态转换。对设计的器件进行了电磁仿真分析,验证了器件的双稳态机制,分析表明:铁芯的存在对器件功能有决定性的影响。     

应用于电磁驱动器的非线性平面微弹簧及其集成制造工艺研究

平面微弹簧是MEMS器件(如微驱动器、开关等)中一种常用的微结构。目前,平面非线性微弹簧的设计、制造与应用正日益成为关注的焦点。本文针对微机械电磁驱动器的需求,研制了一种变形量在100 μm左右,弹性变形力在5 mN附近的非线性变刚度微弹簧。研究包括通过仿真分析确定了弹簧的结构方案和影响因素,提出了配套的原位集成制造微加工工艺,并测试了所研制“V型”平面微弹簧的非线性特性,验证了所提出方案的可行性。为非线性弹簧的进一步设计和应用提供参考。     

用于硅基氮化镓可调微镜的静电梳齿型微驱动器设计

提出并设计了一种用于硅基氮化镓(GaN)可调微镜的静电梳齿型微驱动器.利用有限元软件建立了该器件的几何结构模型,对器件的结构进行了仿真优化.此外,采用微机电系统(MEMS)加工工艺,制作出了用于硅基氮化镓可调微镜的梳齿型微驱动器,并对其驱动特性进行测试.测试结果表明:所制作的微驱动器的位移随着电压的变化呈二次方关系,与仿真结果基本一致.当加载驱动电压为200 V时,微驱动器的驱动位移可达到1.08 μm.     

电磁发电微电源结构设计与输出电能的动态仿真分析*

首先研究了微型电磁发电微电源输出能量理论分析模型,通过理论分析得到感应线圈匝数及导线横截面半径的最优尺寸。然后利用AnsoftMaxwell软件建立了微电源结构仿真模型,通过仿真分析计算得到不同方向上电磁感应强度B的变化规律以及永磁体振子与感应线圈在不同相对位置下所产生感应电动势的变化曲线。仿真分析结果同时表明：当永磁体振子与感应线圈相对距离为1.25mm时,线圈产生最大感应电动势2.65mV,最大输出功率为0.6626滋W,本文的建模与仿真分析过程将为电磁发电微电源结构的整体结构设计和制作提供依据。     

基于电磁驱动的微扑翼飞行器驱动器振动特性

电磁驱动的微扑翼飞行器翼端拍打振幅受到驱动电压、磁感应强度、电流角频率等因素的影响。为了探究上述三个因素对微扑翼飞行器翼端拍打振幅的影响规律,提出一种新型电磁驱动器方案,并建立电磁场中微梁振动模型,为验证电磁驱动器方案的可行性及进一步探究相关因素对微梁振动的影响规律,设计开展电磁驱动的微梁振动试验。结合理论振动模型与试验结果,得到驱动电压、磁感应强度、电流角频率对于梁端拍打振幅的影响规律,研究结果对于后续微扑翼飞行器电磁驱动器的研究发展具有一定的指导意义。     

基于阻抗特性分析的电磁层析成像传感器优化

设计一种与电磁层析成像(MIT)系统的工作频率相匹配的传感器阵列对于提升图像重建的精度至关重要.针对MIT传感线圈结构,研究了频域内线圈结构参数的变化与其阻抗的对应关系,包括线圈匝数和线圈直径.实验结果表明:增加线圈匝数或扩大线圈直径均会导致线圈阻抗响应曲线向着频率较低的区域平移.在设计MIT传感器时,为了使得优化后的线圈结构与MIT系统的工作频率能够有效匹配,需要协同考虑线圈不同结构参数引起的效应.     

直线同步电机气隙检测的电磁分析

基于直线同步电机的气隙检测,对电涡流传感器线圈电感与矽钢叠片电磁特性之间关系分析和实验研究,认为线圈电感随间隙的变化电感效应起了主要作用,建立了基于磁场镜像法的电磁计算模型,计算了空载和矽钢叠片影响下的电感,与仿真结果对比和分析,并得出结论:间隙小于10mm时,计算和仿真结果误差比较小,为复杂结构线圈提供可行的近似计算方法。     

基于磁共振无线电能传输系统中三种结构线圈空间磁场分布研究

在磁耦合谐振无线电能传输研究中,采用何种线圈结构能使传输距离达到最远目前还没有一个定论。根据毕奥-萨伐尔定律理论推导了矩形、平面型和圆柱型等三种螺旋线圈的空间磁场分布表达式;提出一种求解磁场空间分布的新算法,并对结果进行了验证。绘出三种线圈在最大半径、匝间距及匝数一致时的空间分布三维图;比较三种不同结构线圈的空间磁场分布规律,为无线电能传输研究中采取何种结构线圈作为系统发送、接收线圈提供理论参考。     

基于剩磁原理的微功耗脉冲励磁方法研究

针对目前因恒流源励磁方法功耗过大而无法满足电磁水表微功耗要求的问题,提出了基于剩磁原理的微功耗脉冲励磁方法。通过对电磁流量传感器磁场的工作方式进行分析,选择具有高剩磁、低矫顽力的矩形磁滞材料制作磁路,采用双向窄脉冲电压为励磁线圈供电,使磁场稳定反转。根据这一原理,设计了脉冲励磁磁路和双向脉冲发生电路,并进行试验测试。测试结果表明,相对于恒流励磁方法,基于剩磁原理的脉冲励磁方法可以大幅度降低励磁功耗,并且得到稳定的工作磁场,有利于提高电磁水表的使用寿命和流量信号的稳定性。     

一种间隙传感器的线圈设计

设计分析了一种悬浮间隙传感器的测量线圈,分析了测量线圈与被测导体之间作用后的磁感强度的分布,调整结构使距离测量线圈相同间隙位移处的磁感强度分布接近为恒定值,实验结果验证它可以有效降低由被测物体齿槽结构所引起的测量信号波动,降低齿槽效应.     

Design, fabrication and testing of sandwich coupled inductors

A planar coupled inductor having sandwich coil structure is fabricated using MEMS microfabrication techniques. The structure of the inductor coil is designed to achieve high coupling and high winding number with a relatively small coil area. In this work, the structure is fabricated by bonding two planar on-chip coil fabricated on two different substrates. This method can replace the conventional via connections that cause various problems in output pads interconnection. The functionality of the fabricated device was tested, while the basic characteristics of the fabricated coil were measured at wide range of operating frequency using cascade GSG probe and compared with the simulation. For measurements up to 1?GHz, three resonance frequencies, inductance of 35?nH and resistance of as low as 25?Ω were observed. The results show that the proposed technique is a promising alternative method for fabricating a simple and cost effective 3-D coupled inductors.     

低频振动能量收集装置的设计和数值模拟

针对低频振动条件,设计了一种高效的振动能量收集装置。该装置形成闭合磁路,大幅度提高了能量获取能力;同时利用多齿结构,提高装置中线圈磁场变化的频率,使其适应于低频振动环境。论文在介绍了装置的结构和工作原理后,借助Ansoft Maxwell软件进行了数值仿真。利用静态仿真对比了不同相对磁导率的导磁材料以及不同气隙宽度对线圈最大磁感应强度的影响;利用动态仿真给出感应电压和能量损耗。根据仿真数据计算了该振动能量收集装置在1 Hz低频振动下所能达到的最大平均功率,该功率远高于已见报道的同类装置的功率值,表明该装置能为无线传感器网络节点供电。     

Enhancement of metal coil quality on selective p-silicon based planar electromagnetic coil by thermal annealing process

In this paper we report an optimization of metal quality of planar MEMS electromagnetic coil through thermal annealing process. The study aims to see the effects of annealing process on the quality of metal layer deposited on localized p-type silicon regions. Two annealing process parameters namely isothermal (annealing under time variations in constant temperature) and isochronal (annealing under temperature variations at constant time) were performed on metal contact on highly doped Si substrate and characterized using transfer length method method by measuring the specific contact resistance ρ _C of the metal traces. The measurement results showed that the annealing process have significant influence on physical and electrical characteristics of the metal layer. Analysis showed that the quality of metal layer was significantly improved through the annealing process after treatment at temperature variations between 425–550 °C. An optimum annealing at 525 °C for 15 min was observed and the contact resistance can be reduced significantly up to 400 %. The results also showed that the surface roughness improves while metal contact resistance decreases 40 times when the metal is annealed for more than 10 min. The planar coil structure was designed to reduce the device density of a compact magnetic micro-sensor system.     

基于超导量子干涉仪的磁性颗粒检测单元分析

带有磁化退磁样品处理单元的扫描超导量子干涉仪（SQUID）显微镜系统,配合样品移动定位平台,可以实现生物样品内源磁性颗粒磁学特性和磁场分布的测量。基于SQUID的磁场检测单元为系统重要组成部分,介绍检测单元基本结构、检测原理,推导磁通、磁场和电压间的转换公式,建立磁性颗粒模型。通过仿真分析线圈参数对系统磁场灵敏度和空间分辨率的影响,设计绕制了直径500μm,30匝的超导接收线圈,系统磁场灵敏度为1.46×10-13 T/（Hz）^1/2,空间分辨率为500μm。磁性颗粒模型和仿真分析为系统设计、实验数据分析提供了理论依据。     

平面精密磁悬浮轴承的悬浮位置控制

介绍了一种新型平面磁悬浮轴承.该轴承采用3套悬浮线圈实现悬浮,3套推力线圈实现水平驱动.针对其悬浮部分具有参数摄动、多变量、非线性、强耦合的特点,提出一种改进的自抗扰控制器,以克服常规自抗扰控制器非线性误差反馈控制律中非线性函数的不平滑性,并提高了控制品质.仿真对比分析和实验结果表明,应用改进的自抗扰控制器后,平面磁轴承悬浮控制系统具有较好的动、静态特性和鲁棒性.     

Latching micromagnetic relays

This paper describes the underlying principles, design and operation of a new type of latching micromagnetic relay. The device is based on preferential magnetization of a soft magnetic cantilever in a permanent external magnetic field. Switching between two stable states is accomplished by momentarily changing the direction of the cantilever's magnetization by passing a short current pulse through a planar coil situated under the cantilever. Once the relay is switched, it is held in this nonvolatile state by the permanent external magnetic field. Latching operation has been demonstrated for devices having two different cantilever geometries and a variety of sizes. Characterization has been performed under dc and ac conditions. The minimum (lead-to-lead) resistance through the switch is approximately 50 mΩ.. The switching current and minimum switching pulse width are 79 mA and 0.2 ms, respectively. The operating voltage is about 5 V. The switching energy consumption is <9.3 μJ     

Latching micromagnetic optical switch

In this paper, we report a new type of latching micromagnetic optical switch. The key component of this optical switch is a cantilever made of soft magnetic material with a reflective surface serving as a mirror. The cantilever has two stable positions, therefore two stable states for the device, with presence of an external magnetic field. Input optical signal to the device is switched selectively to one of the two output ports when the device transitions between the two states upon short electromagnetic actuations. The optical switch is bistable because the cantilever has a tendency to align with the external magnetic field, and the torque to align the cantilever can be bidirectional depending on the angle between the cantilever and the magnetic field. Switching between the two stable states is accomplished by momentarily changing the direction and/or the magnitude of the cantilever's magnetization by passing a short current pulse through a planar coil underneath the cantilever. In either of its stable state, the cantilever is held in position by the combined influence of the static external magnetic field and mechanical force, such as from a physical stopper or a mechanical torque produced by the torsion flexures supporting the cantilever. Stable vertical position for the cantilever is obtained by using a tilted external magnetic field. When the cantilever mirror is at this UP state, light is reflected to the desired output port. Large angle deflection and bistable latching operations have been demonstrated. The measured mechanical switching speed between the two states of the prototype is 3.2 ms. Optical insertion loss is -4 dB, and the energy consumption is 44 mJ for each switching event.     

Integrated electromagnetic microactuators with a large driving force

This paper describes a high power electromagnetic microactuator fabrication method that combines the hard magnetic Fe/Pt process, Ni/Fe permalloy magnetic circuit design, bulk micromachining, and excimer laser ablation. The hard magnetic material Fe/Pt is deposited under low temperature less than 350°C by sputter onto a suspension diaphragm to produce a perpendicular magnetic anisotropic field. The magnetic circuit with closed loop design is applied to concentrate the magnetic flux and increase the magnetic force. The magnetic field induced by the planar coil and Ni/Fe permalloy enhances the interaction with Fe/Pt to induce attractive and repulsive displacement, provide large output force, and operate at high frequency. This high power electromagnetic microactuator is demonstrated with minimum dimensions with a magnetic force two times greater than conventional magnetic micro-actuators.     

偏磁式消弧线圈在安钢220kV变电站的应用

分析偏磁式消弧线圈补偿装置的作用及工作原理,介绍偏磁式消弧线圈补偿装置在安钢某220kV变电站10kV系统的具体应用.     

Wireless magnetic resonant energy transfer system based on micro 3D flexible MEMS Litz coils

Wireless magnetic resonant energy transfer system shows more superiority in energy transfer efficiency and relative position parameters than that of inductive coupling system. It has been recognized as the best power supply method for implantable medical devices. The dimension and performance of the resonant coil is the key point that has great effect on the transfer efficiency and implantable applications. In this paper, high Q flexible planar and roll Litz coil is designed and implemented for the wireless energy transfer system. L and Q for 3D Litz coil is calculated and compared by theoretical model. The roll-Litz coil shows better performance in L and Q with smaller size comparing with the planar-Litz coil. Wireless energy transfer system based on two and four resonant coils is build up. The experimental results show that the energy transfer efficiency is improved by using the high Q 3D Litz coils. What’s more the roll-Litz four coil system shows priority in higher transfer efficiency with smaller size comparing with planar-Litz coil system. The efficiency of four-coil transfer system based on roll-Litz coils gets 48 % higher than the two-coil system with 1.0 cm transfer distance, and 10 % higher than the four-coil transfer system based on planar-Litz coils with 1.5 cm transfer distance.