GOALI: Stable Nanomechanical Oscillators with Large f*Q Product

“1。题目：目标：具有大f*Q积的稳定纳米机械振荡器2。项目目标：将在金刚石中制造纳米级光电机械系统，并探索其在精密测量（例如质量，力）中的应用。3. 摘要：金刚石是一种令人着迷的材料，具有许多显著的性能。事实上，在许多方面，它是终极工程材料——工程师最好的朋友！例如，金刚石具有很高的机械硬度，是最好的导热体之一。它从紫外线到远红外都是透明的，并且具有高折射率（n = 2.4）。最后，它具有生物相容性和化学惰性。这些特性使金刚石成为许多应用领域非常理想的材料，包括生命科学、石油发现和工业传感。许多这些应用需要实现高频(f)，高质量因子(Q)，稳定的纳米级机电和光机械系统（NEMS和NOMS）。这些系统可以实现稳定的振荡器和敏感的质量测量，并且可以在恶劣环境（由于钻石的化学惰性）和生物医学环境（由于钻石的生物相容性）中运行。然而，尽管单晶金刚石具有独特的性能，但它在NEMS和NOMS中还没有找到很多应用！为什么?所有NEMS/ NOMS平台都有一个重要的共同点：它们由一个器件层组成，通常是由不同材料的衬底支撑的薄膜，可以牺牲去除。单晶金刚石是众多材料中的一个例子，许多材料具有吸引人的材料特性，而这种薄膜平台并不存在。为了克服这一障碍，该团队将利用角度蚀刻制造技术（由Loncar集团首创），该技术允许在大块金刚石衬底上实现功能器件，以及工业合作伙伴（Element 6）提供的最先进材料和材料专业知识。b)技术摘要：拟议的实验计划的目标是研究单晶金刚石作为NEMS/ NOMS材料的潜力。该计划将解决许多与晶体NEMS有关的基本问题，包括材料合成、纳米制造、性能限制等。特别是，在金刚石中实现高f*Q积机械振荡器的潜力及其在精密测量（质量，力）和作为稳定定时参考的应用将被探索。这将使用角刻蚀技术来实现单晶金刚石衬底上的悬臂梁、轮廓谐振器、声波低语通道模式谐振器和光机械晶体（光子-声子晶格）。哈佛团队最近展示的角度蚀刻技术，是基于自上而下蚀刻的结合，即离子在RIE腔内垂直撞击钻石表面，以及随后的角度蚀刻，即离子在蚀刻特征上以一定角度定向。在后面的蚀刻步骤中，将样品插入法拉第笼中，法拉第笼的几何形状决定了离子在蚀刻基底上的入射角。学术研究实验室和工业合作伙伴之间的合作是互惠互利的：工业合作伙伴（Element Six）将提供最先进的金刚石基板，批量金刚石加工（包括抛光和退火），并在适当的时候支持商业开发；另一方面，哈佛团队将提供最前沿的NEMS和NOMS研究的见解，并开发新的纳米制造和表征技术。该计划具有强大的理论和实验组成部分，解决纳米力学和光学的基础和工程方面的问题，并为本科生，研究生和研究生提供独特的研究和教育机会。与行业合作伙伴的合作将为学生提供实习机会。该团队将继续在当地学校和科学博物馆（波士顿）进行公开讲座，并指导对科学和技术感兴趣的高中生。

'1. Proposal Title: GOALI: Stable Nanomechanical Oscillators with Large f*Q Product2. Brief description of project Goals: Nanoscale electro-opto-mechanical systems will be fabricated in diamond, and their applications in precision measurements (e.g. mass, force) will be explored. 3. Abstract: a) Nontechnical Abstract:Diamond is a fascinating material with many remarkable properties. In fact, in many ways it is the ultimate engineering material - the engineer's best friend! For example, diamond has high mechanical hardness and is one of the best thermal conductors. It is optically transparent from the ultra-violet to far infra-red and has a high refractive index (n = 2.4). Finally, it is biocompatible and chemically inert. These properties make diamond a highly desirable material for many applications, including those in life sciences, oil discovery, and industrial sensing. Many of these applications require realization of high-frequency (f), high quality factor (Q), stable, nanoscale electro-mechanical and opto-mechanical systems (NEMS and NOMS). These systems could lead to realization of stable oscillators and sensitive mass measurements, and could operate in both harsh environments (due to diamond's chemical inertness) and in bio-medical setting (due to diamond's bio-compatibility). Despite its unique properties, however, single-crystal diamond has not found many applications in NEMS and NOMS yet! Why? All NEMS/ NOMS platforms have an important feature in common: they consist of a device layer typically a thin film supported by a substrate of a different material that can be sacrificially removed. Single-crystal diamond is one example from an extensive list of materials many with attractive material properties for which such thin film platform does not exist. To overcome this obstacle, the team will leverage angled-etching fabrication technique (pioneered by Loncar group) that allows for realization of functional devices in bulk diamond substrates, and state of the art materials and material expertise provided by industrial partner (Element 6).b) Technical Abstract:The goal of the proposed experimental program is to investigate the potential of single crystal diamond as a NEMS/ NOMS material. The program will address many fundamental questions that pertain to crystalline NEMS, including material synthesis, nanofabrication, performance limits, and so on. In particular, potential for realization of high f*Q product mechanical oscillators in diamond and their applications in precision measurements (mass, force) and as a stable timing reference will be explored. This will be accomplished using angled-etching technique to realize cantilevers, contour resonators, acoustic-wave whispering gallery mode resonators, and optomechanical crystals (photonic-phononic lattices) in single crystal diamond substrates. Angled-etching technique, recently demonstrated by Harvard team, is based on a combination of top-down etching, where ions in the RIE chamber impinge vertically on the diamond surface, with subsequent angled etching, where ions are directed at an angle on the etched features. In the later etch step, the sample is inserted in a Faraday cage, whose geometry defines the angle of incidence of ions on the etched substrate. Collaboration between academic research lab and industrial partner is mutually beneficial: industrial partner (Element Six) will provide state-of-the-art diamond substrates, bulk diamond processing (including polishing and annealing), and when appropriate support commercial development; on the other hand, Harvard team will provide insight into cutting edge NEMS and NOMS research, and develop novel nanofabrication and characterization techniques of interest to industry. The program has strong theoretical and experimental component, addresses both fundamental and engineering aspects of nanoscale mechanics and optics, and represents a unique research and educational opportunity for undergraduate, graduate and post-graduate students. Collaboration with industrial partner will enable internship opportunities for students. The team will continue giving public lectures at local schools and Museum of Science (Boston), and mentoring high school students interested in science and technology.