Current Research
Interests
My work
in general revolves around micromachining technologies
and their application to medicine and biology (BioMEMS). Micromachining technologies include the fabrication,
modeling, and characterization of nanometer to millimeter
size sensors, actuators, and structures. I have extensive
experience using designing, modeling, fabricating, and
characterizing MEMS devices and structures. I
also have extensive knowledge of the equipment,
laboratory devices, clean rooms, and machinery required
for BioMEMS fabrication and testing. While my
interest in micromachining is broad and applicable to
several areas, my most basic interests lie in the area of
micro total analysis systems (m-TAS) and includes sample
preparation systems, microchromatography systems,
detection systems, miniature biosensors, microstructured
substrates for tissue engineering, and microfluidics. In depth
information on my research can be found at the Center
for Biomedical Microfluidics, as well as a list of publications.
I am currently the director of the Center for Biomedical Microfluidics at the
University
of Utah.
The Center currently focuses on applying microfabrication technologies to the development
and understanding of microfluidic systems for biological applications.
Summaries of some of the primary projects follow. More detail can be found
on each project's page.
Microscale Field Flow Fractionation
Field flow fractionation (FFF) is a family of techniques used for the separation
of nanoparticles, proteins, DNA, viruses, and other materials based on size,
charge, or other physical properties. We have primarily explored how
miniaturization effects these systems. We have explored microscale
electrical and thermal systems, as well as the SPLITT versions. We are
also developing techniques using cyclical fields for these systems.
Specific projects included in this area:
| Microscale Electrical FFF
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| Microscale Thermal FFF
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| Microscale Thermal Electrial FFF
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| Cyclical Electrical FFF
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| Microscale Electrical SPLITT
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| Reduction of End Effects in FFF |
Microscale Chromatography Detectors
To complement the Center's separation capabilities, the Center has developed
several microscale particle detectors that can be integrated into microfluidic
systems. These detectors rely on either electrical impedance or optics for
detection.
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DC Conductivity Detector
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| AC Conductivity Detector
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| Impedance Spectroscopy Detector
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| Optical absorbance detection
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| Evanescent optical detection
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| Microscale NMR for particle identification |
Optical Chemical Sensing Systems
Using electrostatic layer by layer assembly to deposit sensing materials on
polymer waveguides, the Center has developed nanoscale sensors for oxygen, glucose,
cholesterol, and other biochemicals. Projects in this area include:
| Electrostatic layer-by-layer assembly of sensors
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| Monolithic PDMS waveguides
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| Dissolved oxygen sensors
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| Gaseous oxygen sensors
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| Glucose sensors based on oxygen sensitive ruthenium dyes
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| Glucose sensors based on peroxide sensitive amplex red
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Integrated Microfluidic
Devices for Diagnostics
The Center is working with researchers in the health sciences to create
microfluidic systems for diagnostic purposes based on other technologies
developed at the Center. The focus of these projects is on integrating
sample preparation steps and automating complex and expensive tasks typically
performed by hand. Projects include:
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DNA extraction and amplification
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| Homogenous DNA assays in array format
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| Smith-Lemli-Opitz Syndrome (SLOS) diagnosis from body fluids.
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Micropumps
In collaboration with other labs, the Center is working on several types
of pumps including: low flow pumps for drug delivery and microscale separation
systems, and rotary micropumps for high flow rate applications.
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Rotary disk pump
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| Rotary shaft pump
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| Osmotic pumps
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| Pressure and temperature compensation
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General Microfluidics
The Center has several projects related to using microfluidics for delivery of
biopolymers, the physics of microflows, and ways to minimize unwanted
microfluidic (or macroscopic) effects. For example, we have recently
developed a promising technique for the manufacture of microneedles.
| Protein and biomolecule spotting for array fabrication
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| Fundamentals of protein laden flows
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| Microneedles for drug delivery and sample collection
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| Integrated microfluidics and microoptics |
| Packaging of microfluidic systems
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Discontinued Research
The Center has been involved in a number of research projects that are no longer
ongoing or no longer involve the Center. Some of these projects include:
| Microstructure effects on cell and tissue growth |
| Platelet activation and binding in microchannels |
| Fundamentals of microfluidic flows |
MEMS, BioMEMS, and Microfluidics Education
I have a great interest in MEMS,
BioMEMS, and
microfluidics education, not only because of the need to develop
individuals capable of performing research in this area, but
because of the significant demand from students for MEMS and
microfluidics education. I have explored
MEMS
education for both graduate and undergraduate students
and am developing classes, labs, and other techniques
relevant to this area of education. I am continuing
to develop teaching materials and other resources for the
furtherance of the MEMS field and would like to
continue developing classes and labs in this area.
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