Roger T. Howe (Advisor)

Adaptive Servo Schemes using Micromachined Accelerometers for Increased Disturbance Rejection for Magnetic Hard Disk Drives

Satinderpall Pannu

Roberto Horowitz

Albert P. Pisano

Roger T. Howe

1998

Hard disk drive track widths of 1 um are needed to achieve 10 GBit/in^2. Since it is desired to keep the tracking error below an eigth of the track width, the magnetic hard disk drive servo must maintain the tracking error below 0.12um at the above track width. In a low disturbance environment, some hard disk drive manufactures believe that they can achieve this tracking error accuracy without the addition of new sensors and/or actuators. However, conventional hard disk drives are used in a wide variety of environemtns which subject them to a significant amount of shock and vibrations....

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MEMS Microshells for Microneedles, Microscale Fluid Visualization, and Vacuum Packaging of Microdevices

Kyle Lebouitz

Albert P. Pisano

Roger T. Howe

Dorian Liepmann

1998

Three MEMS microshell devices are developed in this work. The first device is an isotropically etched microhypodermic injection needle (microneedle); the second device is a transparent, silicon nitride flow tube for fluid flow visualization; and the third...

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Planar Microfluidics: Toward Large Scale Integration of Channels, Pumps, Valves, and Fluid Mixers in Microelectromechanical Systems (MEMS)

John Evans

Dorian Liepmann

Albert P. Pisano

Roger T. Howe

1999

A cost effective, manufacturable technology for the large scale integration of microfluidic processing components would find wide application in drug delivery, drug development, micro-biology, genetics, printing and associated fields. This dissertation outlines a design paradigm...

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An SOI Based, Fully Integrated Fabrication Process for High-Aspect-Ratio Microelectromechanical Systems

Timothy Brosnihan

Albert P. Pisano

Roger T. Howe

David Dornfeld

1998

A low-cost, SOI-based, fully integrated fabrication process for high-aspect-ratio MEMS has been developed and demonstrated. The fully integrated SOI MEMS process uses only two MEMS masking steps plus a standard foundry CMOS process to form sensors and actuators with on-chip electronics. The test vehicle for this process was a 50um tall, in-plane, linear accelerometer with sigma-delta force balanced, capacitive sense electronics. The accelerometer had 25uG/Hz noise floor and +/- 1.75 G full range.

Using a modular process approach, fully integrated MEMS devices...

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Microrelay Design, Performance, and Systems

Ezekiel Kruglick

Kristofer S.J. Pister

Roger T. Howe

Richard M. White

Dorian Liepmann

1999

Surface micromachined four terminal relays have been fabricated, tested, and packaged. The relays are implemented in a foundry process with minimal post-processing. They show on resistances as low as 20mW, current carrying capacities as highas 0.48 Amps, and lifetimes in the millions of cycles while hot switching 80mA. These devices are thus competitive with commercial macroscopic relays.

Achieving these high performance and reliability levels required exploring the physics and tribology of microrelays and using novel physical experiments to outline a...

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Uthara Srinivasan

Alumni

Electrical Engineering and Computer Sciences

Professor Roger T. Howe (Advisor)

Ph.D. 2001

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Polycrystalline Silicon Germanium for Fabrication, Release, and Packaging of Microelectromechanical Systems

John Heck

Roger T. Howe

Tsu-Jae King

George Johnson

2001

Polycrystalline silicon germanium has recently proven to be a compelling alternative to polysilicon for micromachining. Low temperature fabrication of micromechanical structures is possible, which enables their modular integration with conventional electronics. The deposition and crystallization temperatures are significantly lower than for polysilicon, and low-stress, low-resistivity structural films can be achieved with little or no annealing. Poly-Ge can be used as a hydrogen peroxide-soluble sacrificial layer, so a...