Publications

Articulated Mechanisms and Electrostatic Actuators for Autonomous Microrobots

Richard Yeh
Kristofer S.J. Pister
Roger T. Howe
Dorian Liepmann
2001

Enabled by advances in both integrated circuit technology and micro electromechanical systems (MEMS), the continuing miniaturization and integration of electronics, sensors, and actuators and mechanisms will make it feasible to create insect-sized autonomous microrobots. We propose to create a class of autonomous crawling microrobots the size on the order f 1cm^3 and equipped with a power source, low-power CMOS controller, sensors, wireless communications devices and motorized articulated legs. The work presented here demonstrates how articulated insect legs could be created from rigid...

A CMOS Magnetic Sensor Chip for Biomedical Applications

Peng Liu
Bernhard E. Boser
Seth Sanders
Yuri Suzuki
2012

The growing need for pointofcare applications in global health and personalized medicine motivates a significant reduction in the size and cost of present technologies. Current solutions use fluorescent or enzymatic labels with complex optical instrumentation that has proven difficult to miniaturize. Recently, magnetic bead labeling has emerged as an alternative solution enabling portable and low...

A Micro-Electro-Mechanical Systems (MEMS) Device to Measure the Fracture Strain of Polycrystalline Silicon

Peter Truxtun Jones
Roger T. Howe
1995

The past decade has witnessed the establishment of a new field of technology concerned with the manufacture of microscopic sensors and actuators, known as Micro-Electro-Mechanical-Systems (MEMS). The field of MEMS is based on the use of integrated circuit fabrication techniques to create...

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...

Miniature Gaseous Light Sources

Hsi-Jen Yeh
Richard S. Muller
Roger T. Howe
1991

This report describes miniature gas-filled plasma-discharge cavities fabricated using combined surface and subsurface micromachining. Starting with a bare silicon substrate, successive layers of polycrystalline silicon, low-stress silicon nitride, and low-temperature oxide layers were deposited to form the micro cavities. Polysilicon electrodes were patterned to serve as electrical connections to the gas. Low-stress silicon nitride formed the insulating layer and the cavity wall which confined neon at atmospheric pressure. Low-temperature oxide served as the sacrificial layer which defined...

Microstructure Micropackaging

Kristen M. McNair
Roger T. Howe
Richard M. White
1991

Two processes are developed to fabricate electrostatic comb drives hermetically encapsualted in a silicon nitride or polysilicon micropackage. To fabricate the silicon nitride micropackage, high-doped phosphosilicate glass is deposited, after the electrostatic comb-drive process is complete except for the release etch, and reflowed to form a mould for the silicon nitride microshell. The mould is patterned with a 5:1 BHF wet etch, and then the etch channel layer of phosphosilicate glass is deposited and patterned with a wt etch. The silicon nitride microshell layer is depositied, and holes...

Micromechanical Electrostatic Voltmeter

Charles Heng-Yuan Hsu
Richard S. Muller
Roger T. Howe
1991

A microminiature, noncontracting electrostatic voltmeter (ESV), produced by IC processes on a silicon wafer, is described. The ESV works on the principle of intermittent shuttering and exposing a sensing electrode to an electric field between a remote electrode at a different potential from the sensing electrode. The resultant time-varying field at the electrode produces an electrical signal. The principle of ESV measurements by intermittent shuttering is well establihsed and hybrid designs are presently used commerically. This invention teaches how the entire structure, and eventually the...

Growth Stresses in Undoped LPCVD Polycrystalline Silicon Films

Peter Krulevitch
1991
Thin films have applications in many technological fields, particularly in the area of electronics, where they form the basis of integrated circuits [l]. More recently, the techniques used to manufacture VLSI circuits have been applied to mechanical systems, such as...

Polysilicon Microstructures to Characterize State Friction

Martin Lim
Roger T. Howe
Roberto Horowitz
1990

A polysilicon microstucture to characterize static fiction has been developed. A normal force is applied to a displaced suspended structure by an underlying electrode. The tangential force to measure the frictional force is produced by a...