Publications

Electrostatic Transduction for MEMS Resonators

Sunil Bhave
Roger T. Howe
Tsu-Jae King
Oliver M. O’Reilly
2005
The vast majority of RF systems currently in production use some form of the heterodyning architecture developed by Edwin Armstrong 75 years ago. Today, this architecture relies on discrete components such as quartz crystals and ceramic filters to provide frequency selection and stable references. However, quartz and ceramics cannot be easily integrated with on-chip circuitry, which precludes a fully monolithic wireless transceiver. In recent years, high quality factor (Q) electrostatically transduced micromechanical resonators have emerged as a possible...

Electronics for Resonant Sensors

Kenneth Wojciechowski
Bernhard E. Boser
Liwei Lin
Roger T. Howe
2005
Resonant force or displacement sensing based on observing the change in resonant frequency is attractive because of its relative insensitivity to 1/f noise, high resolution and bandwidth, and “quasi-digital” output. Applications include inertial and strain sensors, biosensors based on mass-loading, and atomic force microscopy. The main contributions of this dissertation are Design of low-noise high fidelity MEMS resonators for sensing, ...

Ultra-Low Power Wireless Technologies for Sensor Networks

Brian Otis
Jan Rabaey
Roger T. Howe
2005

The new field of wireless sensor networks presents manmy opportunities and just as many challenges. One particularly difficult aspect of wireless sensing is the implementation of the radio link. To enable energy scavenging, a technique that harvests ambient energy to pwoer the sensor node indefinitely, sub-mW power levels are necessary for the reciever. To allow a small node form-factor, all external surface-mount components must be eliminated. Traditionial RF transceiver design techniques are not suitable for achieving complete integration since they rely on frequency synthesis, requiring...

Apex Seal Design for the Mems Rotary Engine Power System

Fabian Martinez
Albert P. Pisano
Carlos Fernandez-Pello
2003
Design, modeling, and analysis of a novel in-plane cantilever apex seal for maintaining high compression ratios in a MEMS-based rotary internal combustion engine are presented. This work is part of an effort to create a portable, MEMS-based Rotary Engine Power System (MEMS REPS) capable of producing power on the order of tens...

Optimized Fabrication of Ultra-Deep Reactive Ion Etched Silicon Components for the MEMS Rotary Engine Power System

Fabian Martinez
Albert P. Pisano
A. Carlos Fernandez-Pello
Seth Sanders
2005
Results from the research and development of an ultra-deep reactive ion etching (Ultra-DRIE) process are presented here. The driving motivation of this process development is the manufacturing of high aspect ratio (HAR) Silicon microelectromechanical systems (MEMS), and specifically components for the MEMS Rotary Engine Power System (MEMS REPS). The ultimate goal of the MEMS REPS project is to develop a system capable of producing portable elec...

Pick and Place Silicon on Insulator Microassembly

Matthew Last
Kristofer S.J. Pister
Ming C. Wu
Liwei Lin
2005
Deep reactive ion etching into Silicon on Insulator (SOI) wafers is a popular method of fabricating high-performance MEMS devices. These include electrostatic and thermal actuators, flexures that guide very precise motion, and ultra-flat and smooth reflectors to make micro-mirrors. An important limitation of SOI-based MEMS is that it is not easy to achieve a large range of out-of-plane motion without a complex fabrication process. This is because of the difficulty in...

The Design and Evaluation of Network Power Scheduling for Sensor Networks

Barbara Hohlt
Eric A. Brewer
David E. Culler
Paul K. Wright
2005

The combination of technological advances in integrated circuitry, micro-electro-mechanical systems, communication, and energy storage has driven the development of low-cost, low-power sensor nodes. Networking many nodes through radio communication allows for data collection via multihop routing, but the practical limits on available resources and the lack of global control present challenges. Constraints imposed by the limited energy stores on individual nodes require planned use of resources, particularly the radio.

In this dissertation we present Flexible Power Scheduling (FPS...

Localized Synthesis, Assembly and Application of Carbon Nanotubes

Dane Christensen
Liwei Lin
Albert P. Pisano
Alexander Zettl
2005
This report describes the localized synthesis, orientation, assembly and application of carbon nanotubes. Synthesis by chemical vapor deposition is activated by means of resistively heating a MEMS structure in a room temperature reaction chamber. Catalyst nanoparticles, created by heating a thin film of NiFe (80%-20% by...

Microfluidic Devices for Quantitative Cell Biology

Philip Lee
Luke P. Lee
David Sretavan
Jay Groves
2006
As cell biology transitions into a quantitative science, it is critically important to develop experimental tools capable of precisely controlling the cellular microenvironment. In the emerging field of cellular systems biology, scientists hope to describe the complex behavior of living organisms by understanding the intricate relationships between molecular components. In order to confront this...

Modularly Integrated MEMS Technology

Marie-Ange Eyoum
Tsu-Jae King
Roger T. Howe
Sanjay Govindje
2006
Process design, development and integration to fabricate reliable MEMS devices on top of VLSI-CMOS electronics without damaging the underlying circuitry have been investigated throughout this dissertation. Experimental and theoretical results that utilize two “Post-CMOS” integration approaches will be presented. The first integration approach uses SiGe MEMS technology for the “Post-CMOS” monolithic integration of the MEMS devices...