Publications

Effects of Abrupt Changes in Microfluidic Geometry on Complex Biological Fluid Flows

Shelly Gulati
Dorian Liepmann
Susan J. Muller
Andrew J. Szeri
David Saloner
David Trebotich
2006
Direct measurement techniques are employed to quantify the kinematics of λDNA flows in three microfluidic components with abruptly changing geometries. Flow through these geometries subjects the fluid to large spatial gradients in velocity, leading to viscoelastic effects. The effects on DNA transport in microscale flows are significant because flow behavior may be influenced by elasticity of individual molecules, ...

Enclosed Microfluidic Platform Realizing Enhanced Stem-cell Survival (EMPRESS)

Yue Zhang
Matthew V. Tirrell
Albert P. Pisano
Tejal A. Desai
2011

Here we present a microfluidic culture platform for enhancing single stem cell survival. Traditional plate culture is inadequate for large scale single cell studies because of (1) less than 40% single stem cell survival leading to (2) possible inaccuracies in the biostatistics in single cell studies from lack of sufficient data. This platform mitigates these issues by doubling overall survival rates as well as increasing the available data points by...

Electrochemical Approaches to Renewable Energy

Peter Lobaccaro
Joel Ager
Roya Maboudian
Alexis Bell
Ali Javey
2016
Renewable energy is becoming an increasingly important component of the world’s energy supply as the threat of global warming continues to rise. There is a need to reduce the cost of this renewable energy and a future challenge to deal with the strain intermittent power sources like renewables place on the power grid. In this dissertation, electrochemistry is harnessed to address possible solutions to both of these issues. First, it is used to develop a low...

Design and Implementation of Sigma-Delta Force-Balance Microaccelerometers

Crist Lu
Bernhard E. Boser
Roger T. Howe
1994

The first goal of this research is to investigate the issues involved in the design of a sigma-delta force- balance surface-micromachined accelerometer. The second goal is to successfully design, fabricate, and test a monolithic m...

Design and Control of Micro-actuators for High Density Disk Drives

Sanjay K. Aggarwal
Roberto Horowitz
1997

A brief discussion of a previously designed parallel plate micro-actuator is provided. Theoretical models for the parallel plate design are then developed to motivate models used in the control design and to illustrate non-linear effects of the parallel plate design. Electrostatic simulations are performed for a...

Design and Analysis of High Quality Factor Chemical Vapor Deposition (CVD) Diamond Micromechanical Resonators

Mohammad Hadi Motieian Najar
David A. Horsley
M. Saif Islam
Rajeevan Amirtharajah
2014
Diamond is an excellent material for Microelectromechanical Systems (MEMS) due to its superlative material properties compared to commonly used materials such as silicon. In its single crystalline form, diamond offers properties such as very high Young’s modulus, low thermal coefficient of expansion, and very high thermal conductivity as well as being chemically inert. Specifically, diamond’s high thermal conductivity offers the potential for ...

Direct-Write Piezoelectric Nanogenerator by Near-Field Electrospinning

Chieh Chang
Liwei Lin
Albert P. Pisano
Seung-Wuk Lee
2009

Electrospinning technology based on the electrostatic driving mechanism can construct long and continuous polymeric nanofibers with diameters less than 100 nm. However, conventional electrospinning process is chaotic by nature. The chaos is manifested in the difficulty to control the deposition position and amount of electrospun nanofibers. In this dissertation, a near-field electrospinning (NFES) process has been developed to deposit solid...

Development of a Free-Space Optical Switch for Fiber Communications Based on Actuated, Silicon Surface-Micromachined Mirrors

Alois Friedberger
Richard S. Muller
1996
Optical communication networks require switches for fiber links. Free-space optical switches have the potential of high coupling efficiencies and are investigated for fabrication by silicon surface-micromachining. Due to batch processing, this technology can provide large...

Design and Analysis of Closed-loop Controlled Parallel-Plate Electrostatic MicroGrippers

Patrick Breckow Chu
Kristofer S.J. Pister
1994

This work describes the design and analysis of a class of sub-millimeter scale grippers. These electrostatically-driven devices are fabricated from polysilicon using an IC-based surface micromachining process and have been designed to handle objects...

Design of Moderate Resolution High Speed Pipeline ADCs in Fine Line Technologies

Dimitrios Katsis
Bernhard E. Boser
Kristofer S.J. Pister
2006

In this work the issues involved in designing pipeline Analog to Digital Converters in fine line technologies are discussed. In particular, we focus on the design of the interstage amplifier within the pipeline. We compare open loop voltage and current mode approaches to amplifier design and suggest solutions to common current mode design problems. Further, we propose...