Roll-Imprint Manufacturing of Three-Dimensional Nanomagnetic Arrays

这项资助通过探索滚印工艺背后的基本设计原则来促进科学进步，该工艺用于制造广泛应用的纳米磁阵列，包括个性化纳米医学和雷达，从而促进国家健康、繁荣和安全。目前的纳米医学将磁性氧化铁纳米颗粒用于癌症诊断和治疗的生物标记以及磁共振成像（MRI）。磁性薄膜在环行器中很有前途，它可以阻挡重新进入雷达源的反射，从而消除噪音并提高性能。该项目利用三维纳米磁阵列颠覆了这两种不同的技术。这些阵列本质上是一组条形码纳米线，可以想象成豪猪的皮毛——缩小到可以装在笔尖上。单独来看，这些“羽毛笔”非常小，以至于它们被细胞内化，从而导致有效的细胞条形码。作为一个阵列或“毛皮”，羽毛或纳米线组件就像雷达信号的单向反射镜。这里开发的制造工艺能够以每分钟10亿纳米线的产量生产3D纳米磁阵列卷。两名女性电气工程师对本科生和研究生进行培训，支持教育和多样性，使学生能够在医疗诊断和自动驾驶汽车雷达方面进行研究，以造福社会。建立了三维纳米磁阵列滚压制造的基本设计原则，包括纳米结构设计、工艺设计和质量控制设计。两个底层测试平台，射频识别（RFID）生物标签和自动驾驶汽车的高频循环器，用于验证设计。在纳米结构设计中，分层纳米结构是由零维（0D）纳米盘堆叠成一维（1D）纳米线组成的，这些纳米线位于二维（2D）柱状纳米孔阵列内部，形成三维（3D）结构。为了便于设计，对磁自旋结构进行了仿真，并进行了实验验证。该工艺设计包括在阳极氧化前对铝进行滚压，以生产含有长程有序柱状纳米孔的氧化铝模板。然后根据所需的纳米结构设计，使用电沉积方法用单组分铁磁性金属和多层材料填充这些纳米孔。质量控制设计涉及高频电路，包括测量铁磁共振的共面波导和定制设计的测量复合材料特性的循环器。重要的是，质量控制设计直接适用于测试平台的成功。以前的工作已经成功地展示了使用平方厘米面积的平面组件合成的3D纳米磁阵列。这项工作将生产规模扩大到每小时平方米的速度，采用步进连续的卷对卷工艺。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This grant promotes the progress of science by exploring the fundamental design principles behind the roll-imprint process for manufacturing nanomagnetic arrays for a wide range of applications, including individualized nanomedicine and radar thus advancing national health, prosperity and security. Current nanomedicine uses magnetic iron oxide nanoparticles in bio-labels for cancer diagnosis and therapy and for magnetic resonance imaging (MRI). Magnetic thin films are promising in circulators that block reflections from re-entering radar sources, hence eliminating noise and enhancing performance. This project disrupts both of these diverse technologies using three dimensional (3D) nanomagnetic arrays. The arrays are essentially groupings of barcoded nanowires that can be visualized as the pelt of a porcupine - shrunk to fit on the tip of a pen. Individually, the 'quills' are so small that they are internalized by cells, leading to effective cellular barcoding. As an array, or 'pelt', the quill or nanowire assembly acts like a one-way mirror for radar signals. The manufacturing process developed here enables rolls of 3D nanomagnetic arrays to be produced with a yield of one billion nanowires per minute. Undergraduate and graduate student training by two female electrical engineers supports education and diversity and enables students to conduct research in medical diagnosis and radar for self-driving cars for the benefit of society.Fundamental design principles are established for roll-imprint manufacturing of three dimensional (3D) nanomagnetic arrays, including nanostructure design, process design, and quality control design. Two underlying testbeds, radio-frequency identification (RFID) bio-labels and high frequency circulators for self-driving cars, are used to verify the designs. For nanostructure design, hierarchical nanostructures are composed of zero dimensional (0D) nanodisks stacked into one-dimensional (1D) nanowires that are inside two-dimensional (2D) arrays of columnar nanopores to make three-dimensional (3D) structures. The magnetic spin structures are simulated to facilitate design with experimental verification. The process design involves roll-imprinting of aluminum before anodization to produce aluminum oxide templates containing columnar nanopores with long range order. Electrodeposition is then used to fill these nanopores with single component ferromagnetic metals and multilayers according to the desired nanostructure designs. Quality control design involves high frequency circuits, including coplanar waveguides to measure ferromagnetic resonance and custom designed circulators to measure composite properties. Importantly, the quality control design is directly applicable for testbed success. Previous work has successfully demonstrated 3D nanomagnetic arrays that were synthesized using planar components with areas of square-centimeter. This work scales up manufacturing to square-meter per hour rates in a step-continuous roll-to-roll process.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.