GOALI: Stable Nanomechanical Oscillators with Large f*Q Product

1.提案标题：GOALI：具有大f*Q产量的稳定纳米机械振荡器2.项目目标简介：将在钻石中制造纳米级的电光机械系统，并探索其在精密测量(如质量、力)中的应用。3.摘要：a)非技术摘要：钻石是一种迷人的材料，具有许多显著的性能。事实上，在许多方面，它都是终极工程材料--工程师最好的朋友！例如，钻石具有很高的机械硬度，是最好的导热材料之一。它从紫外光到远红外线都是光学透明的，并具有高折射率(n=2.4)。最后，它是生物相容的，化学上是惰性的。这些特性使钻石成为许多应用领域非常理想的材料，包括生命科学、石油勘探和工业传感。其中许多应用需要实现高频(F)、高品质因数(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灵敏的质量测量，并且可以在恶劣的环境(由于钻石的化学惰性)和生物医学环境(由于钻石的生物兼容性)下工作。然而，尽管单晶金刚石具有独特的性质，但它在NEMS和NOMS中还没有得到广泛的应用！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，这种衬底可以被牺牲地移除。单晶钻石是众多材料中的一个例子，其中许多材料具有吸引人的材料特性，而这种薄膜平台是不存在的。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)，允许在块状钻石衬底上实现功能器件，以及由工业合作伙伴(Element 6)提供的最先进的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调查单晶钻石作为NEMS/NOM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，将探索在钻石中实现高f*Q乘积机械振荡器的潜力及其在精密测量(质量、力)和作为稳定的定时基准方面的应用。这将通过角度刻蚀技术在单晶金刚石衬底上实现悬臂梁、轮廓谐振器、声波回声走廊模谐振器和光机晶体(光子-声子晶格)。哈佛大学团队最近展示的角度刻蚀技术是基于自上而下的刻蚀技术的组合，其中RIE室中的离子垂直撞击钻石表面，然后进行角度刻蚀，其中离子指向刻蚀特征上的某个角度。在随后的蚀刻步骤中，样品被插入法拉第笼中，其几何形状定义了离子在蚀刻衬底上的入射角。学术研究实验室和工业伙伴之间的合作是互惠互利的：工业伙伴(第六元素)将提供最先进的钻石衬底、块状钻石加工(包括抛光和退火)，并在适当的情况下支持商业发展；另一方面，哈佛团队将提供对尖端NEMS和NOM研究的洞察，并开发业界感兴趣的新型纳米制造和表征技术。该项目具有强大的理论和实验内容，涉及纳米力学和光学的基础和工程方面，为本科生、研究生和研究生提供了一个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波士顿科学博物馆进行公开演讲，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.