Publications

Liquid to Vapor Phase Change in Constant Cross-Section Silicon Microchannels

Brenda Haendler
Albert P. Pisano
Dorian Liepmann
Kristofer S.J. Pister
2003
This paper presents research on the evaporation of methanol/water mixtures in uniformly heated, constant cross-section, serpentine silicon microchannels for potential application as a fuel injection system for a MEMS rotary engine. The phase change of a variety of mixtures of methanol and water was observed, characterized and compared to the phase change both of pure water and pure methanol. Seven different fluids were tested: pure water, pure methanol and five different molar fractions of methanol mixed with water....

Solid Propellant Microrockets

Dana Teasdale
Kristofer S.J. Pister
Albert P. Pisano
2000

This paper details the design, fabrication and testing of millimeter scale solid propellant rockets for use as one-time deployment platforms carrying communication-equipped MEMS sensor systems, known as Smart Dust. Each rocket assembly is an integrated system, incorporating a combustion chamber, composite propellant grain, nozzle, igniter, and thermoelectric power converter. Solid propellant is advantageous for a millimeter-scale single-use device because of its simple implementation, unlike liquid propellants, which...

Sputter Deposition of Piezoelectric Lead Zirconate Titanate Thin Films for Use in MEMS Sensors and Actuators

Clifford Frederick Knollenberg
Timothy D. Sands
Richard M. White
Eugene, E. Haller
2001
This thesis describes the development of sputter-deposited piezoelectric lead zirconate titanate for sensing and actuation in microelectromechanical systems (MEMS). Piezoelectricity, the coupling of mechanical stress or strain and electric polarization observed in certain dielectric ceramics, is attractive for converting between electrical and mechanical energy in MEMS devices. While piezoelectric ZnO is currently used in MEMS devices such as the flexural plate wave device (FPW), replacing this layer with...

Algorithms for Position and Data Recovery in Wireless Sensor Networks

Lance Doherty
Kristofer S.J. Pister
Kannan Ramchandran
2000

Networks of hundreds or thousands of sensor nodes equipped with sensing, computing and communicationability are conceivable with recent technological advancement. Methods are presented in this report to recover and visualize data from wireless sensor networks, as well as to estimate node positions. Acommunication system is assumed wherein information from sensor nodes can be transferred to acentralized computer for data processing, though suggestions are made for extensions to distributed computation. Specifically, this...

Batch-Fabricated Ferromagnetic Microactuators with Silicon Flexures

Jack William Judy
Richard S. Muller
Richard M. White
Timothy D. Sands
1996
This manuscript investigates the use of magnetism and ferromagnetic materials in microelectromechanical systems (MEMS) and describes ways to integrate ferromagnetic materials with conventional silicon-based surface micromachining. Surface-microma-chined, batch-fabricated structures that combine plated-nickel and nickel-iron films with polysilicon mechanical flexures, are studied. The microstructures are constructed in a batch-fabrication process that uses electroplating and conventional lithography, materials,...

Optical MEMS for Free-Space Communication

Lixia Zhou
Kristofer S.J. Pister
Joseph M. Kahn
Roger T. Howe
Alice M. Agogino
2004
The convergence of MEMS technology with communication and digital circuitry makes high-speed, low power, free-space communication links over distances up to several km possible. MEMS corner cube retroreflectors (CCRs) are proposed to work as a passive optical transmitter, sending collected information back to an interrogating center. MEMS scanning microm...

Water-Powered Microfluidic Devices for Diagnostic and Drug Delivery Systems

Yu-Chuan Su
Liwei Lin
Albert P. Pisano
Luke P. Lee
2003
This dissertation presents the development of water-powered microfluidic devices, including actuators, pumps, pressure-sensitive valves, and flow discretizers, by integrating osmosis, capillarity, microfabrication, and polymer processing technologies at the microscale. By harvesting and coordinating the mechanical actuations driven by chemical potentials and interfacial forces, these water-powered devices can transport flows in pre-...

Electromagnetic Effects in MEMS Application: Actuators, Relay and Packaging

Andrew Cao
Liwei Lin
Albert P. Pisano
Luke P. Lee
2004
Two electromagnetic effects are utilized in MEMS applications: electromagnetic Lorentz force for bi-directional actuator/relay operations, and electromagnetic induction heating for MEMS bonding and packaging processes. As a proof-of-concept demonstration, a liquid-metal wetted contact process is developed to reduce the contact resistance in MEMS relay applications. Electromagnetic Lorenz force...

Electromagnetic Generators for Portable Power Applications

Matthew Kurt Senesky
Seth R. Sanders
Albert P. Pisano
Dennis K. Lieu
2005
The power source that is common to almost all electrically powered portable devices— the electrochemical battery — has failed to shrink at the same rate as circuits and sensors. While this growing disparity has been partially mitigated by the decreasing power requirements of many electronic circuits, the size and weight of portable electronic devices are increasingly dominated by electrochemical batteries. An obvious set of candidates for energy storage with...

MEMS Microbial Fuel Cells and Photosynthetic Electrochemical Cells

Kien-Bang Lam
Liwei Lin
Albert P. Pisano
Kevin E. Healy
2005
In this dissertation, we present three MEMS (Micro-electro-mechanical Systems) biological electrochemical cells: (1) a microbial fuel cell (μMFC) utilizing glucose as the bio-fuel and live baker’s yeast as the bio-catalyst; (2) a photosynthetic electrochemical cell (μPEC1) based on unicellular bacteria Anabaena as the biological photo-electrical converter; and (3) a second photosynthetic electrochemical cell (μPEC2)...