MEMS Rotary Actuator using an Integrated Ball Bearing and Air Turbine

Waits, C.M.; Jankowski, Nicholas R.; Geil, Bruce; Ghodssi, Reza

doi:10.1109/sensor.2007.4300334

Cited by 11 publications

(16 citation statements)

References 6 publications

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“…Fig. 2 shows the bearing and turbine designs from the authors' earlier work in encapsulated microball bearings [21], [22]. To minimize friction and wear, the encapsulated microball-bearing fabrication process developed by Waits et al [22] was modified to provide planar [ Fig.…”

Section: Microtribology Devicementioning

confidence: 99%

“…Friction increases with speed until the motors cannot generate enough force/torque to maintain synchronization with the moving element, corresponding to maximum linear and rotary speeds of 7 mm/s and 500 r/min, respectively. Similarly, microturbines supported on encapsulated microball-bearing structures have been demonstrated for speeds up to 37 000 r/min [21]- [23]. These devices, however, are prone to excessive wear, leading to particle contamination and deviations from the as-fabricated geometry.…”

Section: Introductionmentioning

confidence: 99%

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Dynamic Friction and Wear in a Planar-Contact Encapsulated Microball Bearing Using an Integrated Microturbine

McCarthy

Waits

Ghodssi

2009

J. Microelectromech. Syst.

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The demonstration and characterization of a novel planar-contact encapsulated microball bearing using a radial inflow microturbine are presented. Stable operation of the airdriven silicon microturbine is shown for over 1 000 000 revolutions at speeds, pressure drops, and flow rates of up to 10 000 r/min, 0.45 lbf/in 2 , and 3.5 slm, respectively. Incorporation of a gas thrust plenum using a novel packaging scheme has enabled comprehensive spin-down friction characterization of the encapsulated microball bearing. An empirical power-law model for dynamic friction has been developed for speeds of 250-5000 r/min and loads of 10-50 mN, corresponding to torques of 0.0625-2.5 μN · m and friction torque constants of 2.25-5.25 × 10 −4 μN · m/r/min. The onset and effect of wear and wear debris have been studied, showing negligible wear in the load bearing surfaces for the operating conditions considered.[2008-0109]

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Section: Microtribology Devicementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Dynamic Friction and Wear in a Planar-Contact Encapsulated Microball Bearing Using an Integrated Microturbine

McCarthy

Waits

Ghodssi

2009

J. Microelectromech. Syst.

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“…1). The development of the micro-turbine is presented in [22], while characterization of the device is presented among [23]- [25]. The RMD is fabricated using a 45-five step, 14 photolithography mask microfabrication process.…”

Section: A Testing Platformmentioning

confidence: 99%

Vibration-Based Diagnostics for Rotary MEMS

Feldman

Hanrahan

Misra

et al. 2015

J. Microelectromech. Syst.

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This paper demonstrates the use of low-cost off-the-shelf (OTS) microelectromechanical system (MEMS) technology to perform vibration-based in situ monitoring, diagnostics, and characterization of a MEMS microball bearing supported radial air turbine platform. A multimodal software suite for platform automation and sensor monitoring is demonstrated using a three-level heuristic software suite and sensor network. The vibration diagnostic methods used in the platform have applications in rotary microsystems for the early detection of failure, fault diagnosis, and integrated diagnostic systems for feedbackbased optimization to increase device performance, reliability, and operational lifetimes. The studied rotary microdevice used a dual OTS accelerometer configuration for dual range parallel redundant vibration analysis. The sensor suite has been used to monitor and detect multiple operational parameters measured optimally in time or frequency domains such as rotor instability, imbalance, wobble, and system resonance. This paper will lay the framework for active diagnostics in future MEMS devices through integrated systems.[2014-0236]

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“…An encapsulated bearing mechanism was developed to fully constrain the rotor without the need for external forces (23)(24)(25). In previous work, the microball bearing tribology mechanisms were studied and an empirical relationship between the bearing friction torque and the normal load/speed was developed (25).…”

Section: Introductionmentioning

confidence: 99%

A Low-wear Planar-contact Silicon Raceway for Microball Bearing Applications

Waits¹

2009

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Sensors and Electron Devices Directorate, ARLApproved for public release; distribution unlimited. ii REPORT DOCUMENTATION PAGEForm Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing the burden, to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. REPORT DATE (DD-MM-YYYY) April 20092. REPORT TYPE ARL-TR-4796 SPONSOR/MONITOR'S ACRONYM(S) 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) SPONSOR/MONITOR'S REPORT NUMBER(S) DISTRIBUTION/AVAILABILITY STATEMENTApproved for public release; distribution unlimited. SUPPLEMENTARY NOTES ABSTRACTAs silicon rotary micro-electromechanical systems (MEMS) devices become critical components to power generation and sensor platforms, it is crucial to develop bearing mechanisms that can achieve speed and reliability requirements without increasing cost and complexity. Microball bearings have proven simple to fabricate and capable of achieving high speeds. However, previous microball raceway implementations showed substantial degradation in performance and required cleaning steps to improve reliability. Furthermore, large surface roughness on the raceway thrust surface caused increased wear and friction. In this work, the silicon raceway is modified by shifting the rotor bond interface, minimizing both wear and debris generation within the bearing. We developed a modified fabrication process that eliminates the source of the raceway thrust surface roughness. These modifications led to continuous and repeatable operation for over 4,500,000 revolutions with no degradation in performance. Our testing demonstrated speeds in excess of 85,000 rpm, more than twice that of previous designs. SUBJECT TERMS

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MEMS Rotary Actuator using an Integrated Ball Bearing and Air Turbine

Cited by 11 publications

References 6 publications

Dynamic Friction and Wear in a Planar-Contact Encapsulated Microball Bearing Using an Integrated Microturbine

Dynamic Friction and Wear in a Planar-Contact Encapsulated Microball Bearing Using an Integrated Microturbine

Vibration-Based Diagnostics for Rotary MEMS

A Low-wear Planar-contact Silicon Raceway for Microball Bearing Applications

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