Publications

MicroElectroMechanical Devices and Fabrication Technologies for Radio-Frequency Analog Signal Processing

Darrin Young
Bernhard E. Boser
Robert G. Meyer
Albert P. Pisano
1999
The proliferation of wireless services creates a pressing need for compact and low cost RF transceivers. Modern sub-micron technologies provide the active components needed for miniaturization but fail to deliver high quality passives needed in ...

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...

Microfabricated Microneedles for Minimally Invasive Drug Delivery, Sampling and Analysis

Jeffrey Zahn
Dorian Liepmann
Albert P. Pisano
Frank Tendick
2001

Utilizing current Micro Electro Mechanical Systems (MEMS) technologies, different microneedle designs have been fabricated and integrated with various microfabricated microfluidic devices. microneedle technology promises to revolutionize health care by allowing the precise injection of therapeutic agents to prescribed locations below the skin. In addition, microneedles can be used for sample collection for biological analysis, delivery of cell or cellular extract based vaccines, and sample handling providing interconnection between the microscopic and macroscopic world. Microneedsl are...

Micro-Fabricated Shells for Mechanical and Fluidic Interconnects

Phillip Stupar
Albert P. Pisano
Liwei Lin
Luke P. Lee
2001
Three micro-fabricated shell processes are developed in this work, each tailored to a specific application. The first is a two-wafer molding process used to fabricate polysilicon shell suspensions that are very light and stiff. The second is a single crystal silicon...

Microfabricated Parylene Microneedles and Pneumatic/Hydraulic Actuators for Use in Interventional, Transvascular Drug Delivery

Kirk Seward
Albert P. Pisano
Kristofer S.J. Pister
Liwei Lin
2001
A method for performing interventional surgery has been developed. Transvascular delivery of therapeutic and diagnostic agents into perivascular space is desirable for various cardiovascular treatments and applications. The dosing of perivascular space requires the perpendicular actuation of a microneedle to slide through the layers...

Bubble-Actuated Planar Microvalves

Alexandros Papavasiliou
Albert P. Pisano
Dorian Liepmann
Luke P. Lee
2001

This work describes the development of low-power bubble-actuated planar micro gate valves. The work includes the design of the gate valve, the development of electrolysis bubbles as a low power actuator, and a novel fabrication procedure that allows these valves to be integrated with other planar fluidic devices and controlling circuitry. The operation of the valves is demonstrated and valve performance is measured in terms of leakage, power consumption, and cycle time.

The low-power, bubble-actuated, planar micro gate valves consist of a silicon gate that is thrust across a...

Hybrid Surface-/Bulk-Micromachining Processes for Scanning Micro-Optical Components

Jocelyn Nee
Kam Y. Lau
Richard S. Muller
Paul Wright
2001

This dissertation discusses the design and fabrication of micro-optical scanners that have high-quality optical-surface properties and are capable of previously unattainable high scanning rates. Scanners having high-quality optical surfaces are fabricated and characterized in both diffractive and reflective applications.

A first project investigates methods of creating scanning rectangular diffraction gratings using well-established fabrication methods of silicon surface-micromachining in a foundry process. We then introduce new methods to form an actuated blazed grating, a...

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...

Mechanical Analysis and Design of Vibratory Micromachined Gyroscopes

Wyatt Davis
Albert P. Pisano
Oliver M. O'Reilly
Kristofer S.J. Pister
2001
Vibratory micromachined gyroscopes typically exhibit certain undesirable behaviors that impede the angular rate measurement, such as nonlinearity, cross-axis sensitivity, scale factor offset, and quadrature error. These errors have sources in both the mechanical and electrical ...

Effect of Devitrification Temperature on the Microstructure of NiTi Films

Michael Vestel
Ronald Gronsky
Albert P. Pisano
2002

Crystalline nickel titanium (NiTi) films are known to possess superelastic properties offering superior advantages in engineering applications where resilient mechanical response is essential. One such application of increasing importance in the biomedical field is the fabrication of micro-needles for transdermal or subdermal fluid transport, including the integration of micro-needles with silicon structures such as bio-MEMS assemblies. Unfortunately, the direct deposition of Ni-Ti alloys onto silicon is sometimes compromised by grossly mismatched thermal expansion coefficients...