共查询到20条相似文献,搜索用时 109 毫秒
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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。 相似文献
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超磁致微位移直线驱动器 总被引:2,自引:0,他引:2
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。 相似文献
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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. 相似文献
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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。 相似文献
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微驱动器的原理与应用 总被引:8,自引:0,他引:8
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。 相似文献
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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. 相似文献
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以PZT薄膜为驱动和传感的微型陀螺研制 总被引:5,自引:0,他引:5
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。 相似文献
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《Mechatronics》2000,10(4-5):431-455
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. 相似文献
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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。 相似文献
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Luca Pilia Michele Serri Michio M. Matsushita Kunio Awaga Sandrine Heutz Neil Robertson 《Advanced functional materials》2014,24(16):2383-2388
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. 相似文献
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Versatile Microfluidic Platforms Enabled by Novel Magnetorheological Elastomer Microactuators
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Shi‐Yang Tang Xuchun Zhang Shuaishuai Sun Dan Yuan Qianbin Zhao Sheng Yan Lei Deng Guolin Yun Jun Zhang Shiwu Zhang Weihua Li 《Advanced functional materials》2018,28(8)
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. 相似文献
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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。 相似文献
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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。 相似文献