Publications

Carbon Nanotube-based MEMS Energy Storage Devices

Yingqi Jiang
Liwei Lin
Albert P. Pisano
Constance Chang-Hasnain
2011
Carbon nanotube (CNT) forests have been utilized as electrodes in supercapacitors in this work for energy storage applications. High surface area to volume ratio, good electrical conductivity, and low contact resistance to a bottom metal electrode make CNT forests attractive as electrodes in supercapacitors. Several approaches have been investigated to improve the performances such as configurations, power and energy density of CNT-based supercapacitors, including the single layer architecture by utilizing...

CMOS Based Chemical Sensors

Dharmesh Bhalchandra Jani
Kristofer S.J. Pister
1995
Detection of chemical species using solid state sensors is of great practical importance. The niche for chemical microsensors exists in places where continuous measurement of a chemical concentration is required from a number of locations. Microsensors...

Chip-scale Lidar

Behnam Behroozpour Baghmisheh
Bernhard E. Boser
Ming C. Wu
Liwei Lin
2017

The superiority of lidar compared to radiofrequency and ultrasonic solutions in terms of depth and lateral resolution has been known for decades. In recent years, both application pull such as 3D vision for robotics, rapid prototyping, selfdriving cars, and medical diagnostics, as well as technology developments such as integrated optics and tunable lasers have resulted in new activities

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Crystal-Free Wireless Communication with Relaxation Oscillators and its Applications

David C. Burnett
Kristofer S.J. Pister
Ali M. Niknejad
Lance J. Kriegsfeld
2019

For the last decade, the size of complete 2.4GHz wireless modules containing everythingbut power have stagnated at ~1cm x 1cm. This is despite continued advances in semiconductorprocesses due to components needed by the core communication IC. Breaking this size barrier (which also sets a power and cost barrier) by eliminating all off-chip components is the goal of the Single-Chip Mote project, of which this dissertation is a part. The major componentsto be eliminated are antenna, battery, and crystal...

Biochemical Microflow System / Microfabricated Optical Chopper

Michael T. Ching
Richard M. White
Albert P. Pisano
1993

The application of micromechanics to biochemical instrumentation yields many improvements in size, efficiency, and power consumption. The microdevices have small volumes which are compatible with many biochemical reactions. With the addition of integrated sensors, ...

A MEMS Thin Film AlN Supercritical Carbon Dioxide Valve

Ya-Mei Chen
Albert P. Pisano
Liwei Lin
Tsu-Jae King Liu
Tarek Zohdi
2011
In this thesis, a new piezoelectric valve system with bi-chevron aluminum nitride (AlN) actuator is described. The intended application of the new piezoelectric valve is for the advanced printing technology with supercritical carbon dioxide as the solvent. With supercritical carbon dioxide as the solvent, the ink dissolved will start to nucleate with a micronozzle and generate extremely small and uniform ink particles due to rapid expansion of supercritical...

A Silicon-Based Microsensor to Measure Airborne Contaminants

Bharat M. Shah
Richard M. White
Albert P. Pisano
1994

In this reseach project the ability of a microfabricated acoustic-wave microsensor to detect volatile organic compounds in indoor air was studied. The microsensors were made in the Berkeley Microfabrication facility following designs developed at the Berkeley Sensor & Actuator Center. The devices were exposed in a four-liter chamber to vapor-phase concentrations of six representative VOCs one at a time: tetrachloroethylene, 1,1,1-trichloroethane, toluene, benzene, ethanol, and formaldehyde. The device sesnitivity to each VOC was computed from the measured oscillator frequency and...

Adaptive Control Strategies for MEMS Gyroscopes

Sungsu Park
Roberto Horowitz
Roger T. Howe
Bernhard E. Boser
2000
This dissertation presents adaptive control strategies for MEMS z-axis gyroscopes. Specifically, a unified methodology is proposed for designing and analyzing the performance of control algorithms that can identify and, in an adaptive fashion, compensate for most fabrication defects...

A Multi-Stage Micro-Tangential Flow Filtration System for BioMEMS Applications

Patrick Pak-Ho Leung
Dorian Liepmann
Luke P. Lee
Liwei Lin
2002

The micromachining technology that emerged in the 1980s has yielded an explosion of developments of micro electromeclianica1 systems (MEMS) in the past two decades. The developments have brought lives to many miniaturized sensors and...

A Micromachined Vibrating Ring Gyroscope

Michael William Putty
Khalil Najafi
Kensall D. Wise
Stella W. Pang
Noel Perkins
1995

A new micromachined gyroscope based on a vibrating ring is described. The device measures rotation rate or whole angle inertial rotation by monitorying the position of node lines in a vibrating ring. To sense rotation, the ring is electrostatically forced into an elliptically shaped vibration mode and the psoition of the node lines are capacitively monitored. When the device is rotated about the ring center, the node lines, lag behind the rotations due the the Coriolis force. The control and readout circuitry monitors this lag and develops a corrective voltage, that is proportional to the...