Collaborative Research: Understanding Magnetostrictive Galfenol Physics for Micro- and Nano-Scale Devices

合作研究：了解微型和纳米级器件的磁致伸缩加酚物理

• 批准号: 1232218
• 负责人: Alison Flatau
• 金额: $ 27.76万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-08-15 至 2016-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1232218&HistoricalAwards=false
• 关键词: Collaborative; Research; Understanding; Magnetostrictive; Galfenol

The proposed research focuses on structured analytical and experimental analysis of magnetostriction in iron-gallium (Galfenol) thin films and nanowires to advance understanding of the magnetostrictive physics at this scale and to enable transformative new micro- and nano-scale device functionality. This alloy system has the distinct advantage of having high strains in response to magnetic fields (400ppm) while also exhibiting the mechanical ductility and strength of iron. The ability to electrodeposit this active material is possible due to preliminary work which overcame the difficulty of Ga oxidation in aqueous electrolytes, and which therefore enabled FeGa metallic alloys to be fabricated as thin films and nanowires. The intellectual merit of this research includes that insights from study of the proposed micro- and nano-scale test devices will lead to a deep understanding of the exciting device physics needed to facilitate utilizing magnetostriction at the nanoscale such as in artificial cilia sensors and actuators that mimic biological transducers in nature. As the only highly responsive material possible as ductile nanowires and conformal (nonplanar) thick films, this research is also expected to lead to the creative, new concepts for transformative sensors and actuators at the micro- and nano-scale. This work proceeds with an original plan to make the leap from materials science to devices with four important goals. The first goal is a simple, yet critical, step of measuring magnetostriction of electrodeposited Galfenol thin films as a function of composition, crystallographic orientation and magnetic domain orientation. A capacitance bridge will be used to measure the magnetostriction of these films and the optimal deposition parameters will be used in the subsequent goals. The second goal is to make a non-contact torque sensor as a test device to study the device physics of Galfenol films. The torque sensors will be evaluated in an existing rotating shaft torque test stand. The third goal involves high-risk, high-payoff measurements of magnetostriction in nanoscale devices (10-100nm diameter Galfenol nanowires). Wires with the right composition, crystal structure, and even necessary segmentation have been previously made, but measuring magnetostriction at this scale is difficult due to unknown strains, very small magnetic fields (from single wires), and general size constraints. Here, measurements of giant magnetoresistance (GMR) in individual nanowires will be used to determine the effect of applied tensile and compressive strains. In addition, magnetic force microscopy will be used to observe magnetization rotation in bent nanowires to verify GMR results. The fourth and last goal will involve making high-resolution tactile sensors using Galfenol nanowires to learn more about their behavior and integration into devices. This research will have impact in a broad variety of fields including spintronics (FeGa on GaAs), vibration sensors, energy harvesters as cantilevers and/or nanowires, and a wide range of sensors and actuators using non-contact mechano-magneto coupling (e.g. conformal non-contact torque sensors and structural health monitoring sensors). This research will impact the education of undergraduates via REU programs at both universities, and especially underrepresented students via faculty mentoring programs. Graduate students will benefit from course development that will include the research results from this project and from interactions with industry via industrial centers with annual reviews, journal clubs, and seminars. Finally, the PIs' will train students in outreach to k-12 students to continue the broad impact in the next generation.

拟议的研究着重于对铁 - 加酚（Galfenol）薄膜和纳米线中磁链的结构化分析和实验分析，以提高以这种规模的磁膜物理学的理解，并启用变换性新的微型和纳米尺度设备功能。该合金系统具有明显的优势，即响应磁场（400ppm），同时表现出铁的机械延展性和强度。由于初步工作克服了水性电解质中GA氧化的难度，因此可以进行电沉积的能力，因此使FEGA金属合金能够被制成薄膜和纳米线。这项研究的智力优点包括对拟议的微型和纳米尺度测试设备的研究的见解将使人们对促进在纳米级使用磁静脉所需的令人兴奋的设备物理学有深入的了解，例如在人工纤毛传感器和执行器中，可以模仿自然界的生物传输者。作为唯一可以作为延性纳米线和形成（非平面）厚膜的响应式材料，这项研究也有望导致微型和纳米尺度上的变换传感器和执行器的创造性，新的概念。这项工作制定了一项原始计划，以从材料科学飞向具有四个重要目标的设备。第一个目标是测量电沉积加腓酚薄膜的磁截图的简单但至关重要的步骤，这是组成，晶体学方向和磁性域方向的函数。电容桥将用于测量这些薄膜的磁截图，最佳沉积参数将用于后续目标。第二个目标是将非接触式扭矩传感器作为测试装置，以研究Galfenol膜的装置物理。将在现有的旋转轴扭矩测试台中评估扭矩传感器。第三个目标涉及纳米级设备（直径10-100nm galfenol纳米线）中磁磁体的高风险测量值。以前已经进行了正确组成，晶体结构甚至必要分割的电线，但是由于未知应变，非常小的磁场（来自单线电线）和一般尺寸约束，在此规模上测量磁截图很困难。在这里，将使用单个纳米线中巨磁阻（GMR）的测量来确定施加的拉伸和压缩菌株的效果。另外，磁力显微镜将用于观察弯曲纳米线的磁化旋转以验证GMR结果。第四个也是最后一个目标将涉及使用加法尔纳米线制作高分辨率触觉传感器，以更多地了解其行为和集成到设备中的信息。这项研究将对包括Spintronics（GAAS的FEGA），振动传感器，悬臂和/或纳米线的能量收割机以及多种传感器和执行器在内的各种领域产生影响，并使用非接触机械机械型机械手机耦合（例如，连接型非接触式扭矩传感器和结构型监测器）。这项研究将通过两所大学的REU课程，尤其是通过教师指导计划中的代表性不足的学生来影响本科生的教育。研究生将从课程发展中受益，包括该项目的研究结果以及与工业中心通过年度评论，期刊俱乐部和研讨会的互动。最后，PIS将培训学生与K-12学生的宣传，以继续在下一代中产生广泛的影响。