Tribologically-Enhanced Encapsulated Microball Bearings for Reduced Friction and Wear in High-Performance Rotary Microactuators and PowerMEMS Devices

用于高性能旋转微致动器和PowerMEMS器件中用于减少摩擦和磨损的摩擦学增强型封装微球轴承建议编号：0901411马里兰大学帕克PI：Reza Ghodssi，Co-PI：Matthew McCarth摘要这项工作的目标是使用摩擦学增强型薄膜涂层为微机电系统(MEMS)开发高性能旋转球轴承。重点将着重于超纳米晶金刚石(UNCD)、碳化硅(SIC)、氮化钛(TiN)和氮化硼(BN)薄膜的设计、制造和实验表征，作为减少微尺度滚动接触中摩擦和磨损的硬涂层。这一成果将在用于旋转微执行器和PowerMEMS设备的低摩擦、低磨损和长生命周期的微球轴承中实现。这些支撑机构将能够在超过10万转/分的速度下连续运行，并为实现高速微型汽轮发电机以及方向传感器的精确旋转定位系统提供必要的稳定性和可靠性。本文提出的工作构成了对微细加工球轴承支撑机构的科学和工程基础研究，包括硬涂层减摩和磨损的效果。它将特别为各种旋转式MEMS器件提供可靠的支撑机构。使用硬涂层的MEMS制造的球轴承的设计和工程将使这些技术能够实现高性能应用。本文提出的现场实验研究将综合考虑材料、载荷和操作对微细加工旋转轴承的影响。这将通过(1)使用薄膜涂层的轴承设计和制造，(2)使用集成微型涡轮机驱动的现场实验表征，以及(3)在微制造的旋转执行器和PowerMEMS设备中实施优化的轴承来实现。目前正在进行研究，以开发用于小规模、成本效益高的发电的紧凑型微型涡轮发电机和用于定向传感器系统的旋转执行器平台。这种设备在长生命周期中的可靠演示将对微型飞行器、便携式电源系统和传感器网络等分布式自主系统产生重大影响。教育这项研究将补充S大学在材料科学和MEMS方面的成熟研究和教育项目。拟议研究的跨学科范围涵盖三个主要领域：材料、电气和机械工程。该项目提供了一个极好的机会，让高年级本科生和研究生参与材料工程及其对MEMS领域更广泛影响的硕士和博士水平的研究。该研究所开发了一门为期两个学期的多学科研究生水平课程，其中包括活跃的实验室组成部分(微机械和微系统的设计、制造和测试)。拟议中的研究将加强皮耶？S集团、MEMS传感器和执行器实验室以及马里兰州纳米中心正在进行的滚珠轴承支承微型机械的开发工作。PI管理着一批本科生和研究生，其中大多数是美国公民。这位合作者是前NSF GK-12教员，目前是博士后研究员。这些活动将直接影响跨学科研究课程的性质、招募优秀学生以及通过会议和参考期刊出版物传播知识。

Tribologically-Enhanced Encapsulated Microball Bearings for Reduced Friction and Wear in High-Performance Rotary Microactuators and PowerMEMS DevicesProposal Number: 0901411University of Maryland College ParkPI: Reza Ghodssi, Co-PI: Matthew McCarthyAbstractSummaryThe objective of this work is to develop high-performance rotary ball bearings for Microelectromechanical Systems (MEMS) using tribologically-enhanced thin-film coatings. Particular emphasis will be on the design, fabrication, and experimental characterization of UltraNanoCrystalline Diamond (UNCD), Silicon Carbide (SiC), Titanium Nitride (TiN), and Boron Nitride (BN) films as hard-coatings to reduce friction and wear in microscale rolling contacts. The results of this will be implemented in a low-friction, low-wear, and long-lifecycle microball bearing for rotary microactuators and PowerMEMS devices. These support mechanisms will be capable of continuous operation for speeds in excess of 100,000rpm and provide the stability and reliability necessary for the realization of high-speed micro-turbogenerators as well as accurate rotary positioning systems for directional sensors.Intellectual Merits The work proposed here constitutes fundamental research into the science and engineering of microfabricated ball bearing support mechanism including the effects of hard coatings to reduce friction and wear. It will specifically lead to reliable support mechanisms for use within various rotary MEMS devices. The design and engineering of MEMS-fabricated ball bearings using hard-coatings will allow the realization of these technologies for high-performance applications. The in-situ experimental investigation proposed here will comprehensively address the effects of materials, loading, and operation on microfabricated rotary bearings. This will be achieved through (1) bearing design and fabrication using thin-film coatings, (2) in-situ experimental characterization using integrated microturbine actuation, and (3) implementation of optimized bearings in microfabricated rotary actuators and PowerMEMS devices.Broader Impacts Research This technology will yield a low-friction/wear microball support mechanism necessary for the realization of several high-performance rotary micromachines. Ongoing research is being conducted on the development of compact micro-turbogenerators for small-scale cost-effective power generation and rotary actuator platforms for directional sensor systems. The reliable demonstration of such devices over long life-cycles would have a substantial impact on distributed autonomous systems such as micro-air-vehicles, portable power systems, and sensor networks.EducationThis research will complement the university?s well-established research and education programs in materials science and MEMS. The interdisciplinary scope of the proposed research covers three major areas: Materials, Electrical, and Mechanical Engineering. The project offers an excellent opportunity to engage senior undergraduate and graduate students in masters and doctoral-level research on materials engineering and its broader impact on the MEMS field. The PI has developed a two-semester multidisciplinary graduate-level course with an active laboratory component (Design, Fabrication, and Testing of MEMS and Microsystems). The proposed research will strengthen ongoing work developing ball-bearing supported micromachines in the PI?s group, the MEMS Sensors and Actuators Laboratory (MSAL), as well as the Maryland Nanocenter. The PI supervises a number of undergraduate and graduate students, the majority of whom are US citizens. The co-PI is a former NSF GK-12 Teaching Fellow, and currently a postdoctoral researcher. These activities will directly impact the nature of the interdisciplinary research curriculum, recruitment of outstanding students, and dissemination of knowledge through conferences and refereed journal publication