Publications

High-Order ΣΔ Interface for Micromachined Inertial Sensors

Vladimir Petkov
Bernhard E. Boser
Roger T. Howe
Roberto Horowitz
2004
Emerging automotive and consumer applications such as vehicle stability control, GPS backup and many others are generating a growing demand for inertial sensors with an increasing range of functionality including digital interfacing, built-in self-test, calibration and temperature compensation. Among various techniques for implementing inertial sensor interfaces, Σ∆ modulation provides the benefits of intrinsically linear, two-level force-feedback and analog-to-digital conversion....

CMOS Imaging Receivers for Free-Space Optical Communication

Brian Leibowitz
Kristofer S. J. Pister
Bernhard E. Boser
Andrew Packard
2004
Free-space optical communication is an attractive alternative to radio communication for low power, long-range communication between small devices, primarily because utilization of shorter radiation wavelengths allows for more directional transceivers. At the transmitter, increased directionality allows for reduced transmission power because a given receiver will collect a larger fraction of the radiated energy. At the receiver, increased directionality allows for greater...

Evolutionary Synthesis of MEMS

Raffi Kamalian
Alice M. Agogino
Albert P. Pisano
Kristofer S.J. Pister
2004
An evolutionary synthesis framework for Microelectrical Mechanical System (MEMS) design is presented. MEMS based technologies promise to bring a revolution to the world we live in just as the integrated circuit has done in recent decades; better design tools are critical to this revolution. More complex design objectives and constraints demand automation to generate successful devices. Genetic algorithms and other stochastic evolutionary synthesis approaches are used to design surface micromachined MEMS using...

Microfluidic Accumulator Driven by Capillary Forces

Eric Hobbs
Albert P. Pisano
Liwei Lin
Roya Maboudian
2003
Four million people died in 2002 due to diabetes related conditions[1]. Diabetes is the leading cause of adult blindness, end-stage kidney disease and amputations as a result of diabetic neuropathy. People with diabetes are two to four times more likely to have coronary heart disease and stroke than people who do not suffer from the disease. ...

Low-Power Portable Microfluidic Delivery System

Eric Hobbs
Albert P. Pisano
Liwei Lin
Daniel Fletcher
2004
Future, portable, continuously-monitoring micro-total-analysis-systems are likely to require low-power portable microfluidic delivery systems allowing the actuation of fluids with a minimum expenditure of electrical energy. One method to accomplish this is to utilize a micro-osmotic pum...

Lateral Etching of Silicon: The Hole-in-the-Wall Fabrication Processes

Jeremy Frank
Albert P. Pisano
Liwei Lin
Lydia L. Sohn
2004

This project details three derivatives of a fabrication process that gives the MEMS engineer increased freedom when designing planar microfluidic systems. This new family of processes was developed to laterally etch microfluidic channels in silicon and can be used to place an orifice (the “hole-in-the-wall”) in the center of the sidewall of a channel, Fig. 1.1. This creates improved valve seat geometry and has been used to create planar silicon microvalves that seal...

Planar Microfluidic Devices for Control of Pressure-Driven Flow

Jeremy Frank
Albert. P. Pisano
Liwei Lin
Daniel Fletcher
2004
Active and passive microfluidic valves, thermopneumatic pumps and low-power dosing systems have been fabricated using a new family of fabrication processes. These new processes are capable of producing integrated planar microfluidic systems with a one-thousand-fold increase in flow control over existing planar systems. The three ...

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...