基于功率MOSFET的超磁致伸缩执行器驱动电源

在分析超磁致伸缩材料的驱动特性及超磁伸缩执行器驱动电源特点的基础上,采用连续调整型恒流源的原理,并选用功率MOSFET作为功率放大元件,研制出－3－＋3A连续可调的高精度超微致伸缩执行器驱动电源。实际测试的结果表明其性能良好,可以满足驱动超微致伸缩材料的要求。     

高压氧治疗29例一氧化碳中毒致迟发脑病的效果分析

论述了超磁致伸缩材料在电液控制元件中的应用研究现状,基于超磁致伸缩材料的特点和未来航空航天领域对高频大流量伺服阀的迫切需求,提出了一种由超磁致伸缩执行器驱动的新型射流伺服阀的结构,分析了其工作原理与特点,同时对该新结构伺服阀涉及的温度控制、热补偿、预压力施加与零位调节与驱动磁场均匀化等关键技术进行了详细分析并给出了具体实施方法.     

超磁致伸缩薄膜性能测试系统研究

针对超磁致伸缩薄膜制备过程中所关心的性能测试问题,提出了利用外加磁场引起薄膜变形,运用微位移传感器测试薄膜变形的新方法,以此为基础,建立了超磁致伸缩薄膜性能测试系统,并通过本系统测试比较了不同条件下制备的Tbo.27 Dy0.73 Fe2 薄膜的磁性能.结果表明,在制备磁致伸缩薄膜材料过程中施加一个平行于薄膜长度方向的磁场,可得到更好的磁致伸缩性能.     

光致弯曲薄膜微执行器的研究

光致弯曲薄膜是一种可遥控供能的新型微执行器驱动元件.介绍了光致弯曲薄膜的驱动原理,综述了光致弯曲薄膜微执行器的开发和研究现状,重点介绍了光致弯曲薄膜微执行器在微液体控制系统和微马达中的应用,并对光致弯曲薄膜在微执行器中的应用进行了展望.     

肺心病患者急性发作期血液流变学和D-二聚体测定的临床意义

光致弯曲薄膜是一种可遥控供能的新型微执行器驱动元件.介绍了光致弯曲薄膜的驱动原理,综述了光致弯曲薄膜微执行器的开发和研究现状,重点介绍了光致弯曲薄膜微执行器在微液体控制系统和微马达中的应用,并对光致弯曲薄膜在微执行器中的应用进行了展望.     

磁性薄膜磁致伸缩效应及传感器的应用

磁性薄膜的磁致伸缩效应是磁性材料中普遍存在的现象，是磁性薄膜应力各向异性的主要表现。文中对磁性薄膜的磁致伸缩效应进行了理论分析与计算，并就磁致伸缩位移传感器介绍了磁致伸缩效应的应用原理，给出了其具体应用的例子。     

超磁致微位移直线驱动器

超磁致材料TbxDy1-xFey(GMM)是A.E.Clark于70年代发现的新型稀土－铁系功能材料，近几年来，作为高科技功能材料得到了迅速发展，这种材料由于具有很大的室温超磁致伸缩应变量，高的电（磁）能－机械能转换率，高能量密度，伸缩应力大，机械响应快等优异特性，因而有着广泛的应用前景。该文设计了一种高出力，快响应，可控性好的超磁致微位移直线驱动器，文中对超磁致微位移直线驱动机理进行了探讨，并在MATLAB平台上，以有限元分析（FEM）为基础研制了CAD软件，示出了采用椭圆模态驱动的超磁致振子组合结构的微位移直线驱动器。     

超磁致伸缩伺服阀用伺服放大器的设计及分析

为驱动超磁致伸缩伺服阀,结合超磁致伸缩执行器驱动电源与伺服阀用伺服放大器的性能要求设计了超磁致伸缩伺服阀用伺服放大器,并建立了其电路模型,仿真分析了功率运算放大器的开环增益对其输出性能的影响.仿真结果表明,在功率运算放大器开环增益大于80 dB时,电路特性可满足设计要求.在驱动负载为额定值时,测试结果表明,样机的输出电流线性度为3％;输出电流2A时,其阶跃响应的调节时间小于0.5 ms,幅频宽可达2 kHz;在驱动频率小于1 kHz时,输出电流失真小且无相位滞后.     

超磁致伸缩执行器磁滞模型的参数辨识

准确辨识磁滞模型参数是保证超磁致伸缩执行器位移控制精度的关键,而单一算法难以实现对超磁致非线性模型参数的精确辨识。该文提出了一种新型混合优化策略,即改进的遗传退火算法,并将其应用于对超磁致伸缩执行器位移磁滞模型参数的辨识。该算法兼顾了遗传算法和模拟退火算法的优点,同时还引入了机器学习原理,将模拟退火算法作为遗传算法中的种群变异算子,并将模拟退火算法中的抽样过程与遗传算法相结合。此算法不仅充分发挥了遗传算法并行搜索能力强的特点,且增强和改进了遗传算法的进化能力,同时提高了系统的收敛性和收敛速度,避免最优解的丢失。通过仿真和试验研究表明,该算法相对于遗传算法有更高的精度,可有效精确辨识超磁致伸缩执行器磁滞模型的参数。     

Ni-Mn-Ga铁磁性形状记忆薄膜研究进展

Ni-Mn-Ga合金兼有铁磁性和形状记忆效应,有望成为继压电陶瓷和磁致伸缩材料之后的新一代驱动与传感材料。但是由于合金脆性较大,难以切割,限制了其在微机电系统中的应用。系统阐述了薄膜的化学成分、组织结构、相转变、形状记忆效应及其影响因素,指出目前Ni-Mn-Ga合金薄膜研究中,各个元素对性能影响的探索存在不足,制备出的薄膜主要存在磁性能、磁致应变量偏低以及磁致形状记忆效应不可逆等缺点。可以通过调整薄膜化学成分、热处理工艺、膜厚或者元素替换来提高薄膜的性能。     

微驱动器的原理与应用

为了优化设计微驱动器,笔者通过对比近年来各种微驱动器的研究和发展,系统地概括总结了微驱动器所采用的主要的驱动原理、驱动方式和加工技术及其存在的优缺点等。并在此基础上,首次将微驱动器按功能进行了分类。     

微执行器的研究与展望

在微机电系统中,微执行器是核心部件。为了优化设计微执行器,通过对比近年来各种微执行器的研究和发展,系统地总结了线性位移微执行器所采用的驱动原理、驱动方式和应用以及存在的优缺点等。针对热执行器,提出了个人的一些见解。     

Plasmonic‐Assisted Graphene Oxide Films with Enhanced Photothermal Actuation for Soft Robots

Carbon‐based materials are widely used as light‐driven soft actuators relying on their thermal desorption or expansion. However, applying a passive layer in such film construction greatly limits the actuating efficiency, e.g., bending amplitude and speed. In this work, a dual active layer strengthened bilayer composite film made of graphene oxide (GO)–polydopamine (PDA)–gold nanoparticles (Au NPs)/polydimethylsiloxane (PDMS) is developed. In this film, the conventional passive layer is replaced by another AuNPs‐enhanced thermal responsive layer. When applying NIR light exposure, the whole film deforms controllably resulting from the water loss in the GO–PDA–Au NPs layer and thermal expansion in the PDMS layer. Benefiting from the dual active bilayer mechanism, the thin film's actuating efficiency is dramatically improved compared with that of conventional methods. Specifically, the bending amplitude is enhanced up to 173%, and the actuating speed is improved to 3.5‐fold. The soft actuator can act as an artificial arm with high actuating strength and can be used as a wireless gripper. Moreover, the film can be designed as soft robots with various locomotion modes including linear, rolling, and steering motions. The developed composite film offers new opportunities for biomimetic soft robotics as well as future applications.     

以PZT薄膜为驱动和传感的微型陀螺研制

利用压电陶瓷PZT的正反压电位效应,将PZT薄膜同时作为驱动及传感材料,设计并制造了两种新颖的以IC兼容技术制作在硅片上的压电薄膜微型陀螺。高质量的PZT薄膜是在Pt/Ti/SiO2/Si基底上以溶胶－凝胶技术铺设的。基于反压电效应,微型陀螺在其谐振频率上被输入的交流信号驱动,由其正压电效应,可检测到与转动角速度成正比的输出信号。文章分别介绍了两种微型陀螺的设计原理,详述了制作方法,并对制出的压电微型陀螺进行了检测,得到了的结果与预测结果相符。     

Microactuators and their technologies

This paper gives a brief overview of microactuators, focussing on devices made by microfabrication technologies which are based on silicon processes like photolithography, etching, thin film deposition etc. These technologies enable the miniaturization of electrical devices as well as micromechanisms and microactuators. They can be batch fabricated on large area silicon substrates and represent the smallest available in a vast field of actuators. Mentioning the activation principles and the three main fabrication technologies: bulk micromachining, surface macromachining and moulding, the paper focusses on devices, which made their way into industrial applications or prototypes. The far most developed micro electro-mechanical systems (MEMS) are found in micro-fluidic systems (printheads, microvalves and -pumps) and micro-optical systems (micromirrors, -scanners, -shutters and -switches). They can be combined with microelectronics and microsensors to form an integrated on-chip or hybrid-assembled system. Other MEMS-actuators like microgrippers, microrelays, AFM heads or data storage devices, are promising devices for future medical, biological and technical applications like minimal invasive surgery or the vast field of information storage and distribution.     

微驱动器的压电-弹性耦合分析(英文)

压电弹性耦合结构是实现MEMS微流体驱动的一种重要方式,掌握压电-弹性振动的耦合机理是微流体驱动协调控制的关键。针对压电与硅膜耦合微驱动结构,基于压电效应和弹性薄板理论,采用Rayleigh-Ritz能量法建立了周边固支边界条件下,弹性振动硅膜与压电驱动膜片耦合振动的理论模型,推导并计算了该微驱动结构的耦合振型及谐振频率。基于激光测振仪进行了该压电微驱动结构的振动测试实验,经实验模态分析获得了实测的谐振频率。理论计算结果与实验测试结果的对比分析表明,两者基本相符,验证了理论分析模型的正确性,为MEMS微流体的驱动与控制提供了一定的理论基础和实验依据。     

Giant Magnetoresistance in a Molecular Thin Film as an Intrinsic Property

The magnetic, thin‐film structural, conductivity, and magnetoresistance properties of [Ni(quinoline‐8‐thiolate)₂] ([Ni(qt)₂]) are studied. The conducting and magnetoresistance properties are studied in single crystals and in evaporated thin films through deposition on an interdigitated electrode array. Non‐linear conductivity interpreted through a space‐charge limited conduction mechanism with charges injected from the electrodes is observed. Under applied magnetic field, the material displays giant negative magnetoresistance above 50% at 2 K in both single crystals and in evaporated thin films. The effect can still be observed at 200 K and is interpreted in terms of a double exchange mechanism with the shape of the curve determined by the magnetic anisotropy. The unique observation of giant magnetoresistance (GMR) as an intrinsic effect in an evaporated thin film of paramagnetic molecules opens up new possibilities in organic spintronics.     

Versatile Microfluidic Platforms Enabled by Novel Magnetorheological Elastomer Microactuators

Microfluidic systems enable rapid diagnosis of diseases, biological analysis, drug screening, and high‐precision materials synthesis. In spite of these remarkable abilities, conventional microfluidic systems are microfabricated monolithically on a single platform and their operations rely on bulky expensive external equipment. This restricts their applications outside of research laboratories and prevents development and assembly of truly versatile and complex systems. Here, novel magnetorheological elastomer (MRE) microactuators are presented including pumps and mixers using an innovative actuation mechanism without the need of delicate elements such as thin membranes. Modularized elements are realized using such actuators, which can be easily integrated and actuated using a single self‐contained driving unit to create a modular, miniaturized, and robust platform. The performance of the microactuators is investigated via a series of experiments and a proof‐of‐concept modular system is developed to demonstrate the viability of the platform for self‐contained applications. The presented MRE microactuators are small size, simple, and efficient, offering a great potential to significantly advance the current research on complex microfluidic systems.     

基于硅片的SMA薄膜微驱动器驱动原理与模拟

建立了ＳＭＡ 薄膜／基片的耦合数学模型,对溅射在基片上的ＳＭＡ 薄膜产生驱动的过程进行了仿真模拟,结果表明ＳＭＡ 薄膜／ 基片的耦合驱动是双金属效应和形状记忆效应的双重结果,该驱动力比单纯双金属效应产生的驱动力大得多。该模型对于实际应用ＳＭＡ 薄膜／基片结构进行微驱动的器件设计具有理论指导意义。     

La—Ca—Mn—O薄膜的巨磁效应

报道了Ｃａ掺杂量对Ｌａ－Ｃａ－Ｍｎ－Ｏ巨磁薄膜材料的巨磁效应影响，测量薄膜电阻（外磁场强度Ｈ＝０．５Ｔ）磁化强度，温度关系曲线，认为Ｌａ１－ｘＣａｘＭｎＯ３体系中Ｍｎ＾４＋的含量是由于掺杂量Ｃａ的调制Ｍｎ＾４＋的含量变化导致磁性结构转变，用双交换模型解释了该象现，对实验给出满意的解释。