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

用于减少高性能旋转微致动器和PowerMEMS器件摩擦磨损的摩擦学增强封装微球轴承提案号：0901411马里兰大学ParkPI: Reza Ghodssi， Co-PI: Matthew mccarthy摘要摘要本工作的目标是使用摩擦学增强薄膜涂层开发用于微机电系统（MEMS）的高性能旋转球轴承。特别强调的是设计、制造和实验表征超晶金刚石（UNCD）、碳化硅（SiC）、氮化钛（TiN）和氮化硼（BN）薄膜作为硬涂层，以减少微尺度滚动接触中的摩擦和磨损。这一成果将在用于旋转微致动器和PowerMEMS器件的低摩擦、低磨损、长生命周期微球轴承中实现。这些支持机构将能够以超过100,000转/分钟的速度连续运行，并为实现高速微型涡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。本文提出的工作是对微加工滚珠轴承支撑机制的科学和工程基础研究，包括硬质涂层对减少摩擦和磨损的影响。它将特别导致在各种旋转MEMS器件中使用的可靠支持机制。使用硬涂层的mems制造球轴承的设计和工程将使这些技术实现高性能应用。本文提出的原位实验研究将全面解决材料、载荷和操作对微加工旋转轴承的影响。这将通过(1)使用薄膜涂层设计和制造轴承，(2)使用集成微涡轮驱动进行原位实验表征，以及(3)在微制造旋转致动器和PowerMEMS器件中实现优化轴承来实现。更广泛的影响研究这项技术将产生低摩擦/磨损的微球支撑机构，这是实现几种高性能旋转微机械所必需的。目前正在进行的研究是开发用于小规模经济高效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内的可靠演示将对分布式自主系统（如微型飞行器、便携式电源系统和传感器网络）产生重大影响。这项研究将对大学起到补充作用。美国在材料科学和MEMS领域建立了完善的研究和教育项目。拟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，让大四本科生和研究生参与材料工程及其对MEMS领域的广泛影响的硕士和博士水平的研究。PI已经开发了一个为期两个学期的多学科研究生水平课程，其中包括一个活跃的实验室组件（MEMS和微系统的设计，制造和测试）。拟议的研究将加强正在进行的工作，开发球轴承支持的微型机械在PI？MEMS传感器和执行器实验室（MSAL），以及马里兰纳米中心。PI指导一些本科生和研究生，其中大多数是美国公民。他是前NSF GK-12教学研究员，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、优秀学生的招聘以及通过会议和评审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