Title: Physics Graduate Projects at UT Space Institute
1Physics Graduate Projects at UT Space Institute
- Professor Horace Crater
- Professor Lloyd Davis
- Associate Professor Christian Parigger
- Research Assistant Professor Ying Ling Chen
- Emeritus Professor Jim Lewis
- Adjunct Professor Charles Johnson
- Center for Laser Applications
- www.utsi.edu/ldavis ldavis_at_utsi.edu
UTSI
Physics 599 seminar class UT Knoxville, November
11, 2009
2Where is. ?
3Where is. ?
4Where is. ?
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8University of Tennessee Space Institute
- UTSI is a graduate campus of the UT Knoxville
- Graduate students may transfer between the
campuses - Students at UTSI obtain MS and PhD degrees from
the University of Tennessee Knoxville - Same degree requirements at UTSI and UTK
- UTSI has GRA positions, but no TA positions
- UTSI physics common practices
- PhD students have a committee member based in
Knoxville - Most students complete the MS degree en route to
the PhD - Some classes are offered at both campuses by
interactive distance education - Phys. 513, 514 606, 610, 643
9University of Tennessee Space Institute
- GRA and thesis/dissertation physics research
opportunities are available - with the Center for Laser Applications
- with research groups at the Air Force
Arnold Engineering
Development Center - and in selected areas of theoretical particle
physics - Opportunities are also available for
interdisciplinary research in Materials Science - Solid state / materials physics
10Theoretical Particle Physics with Professor
Horace W. Crater
- Relativistic Two-Body Dirac Equations
- Meson Spectroscopy and Decays
- Bound and Scattering States in Quantum
Electrodynamics - Nucleon Nucleon Scattering
- Bound States in Quark-Gluon Plasma
- Relativistic N-Body Problem Plus Fields
- Electrodynamics, General Relativity
- Relativistic Center of Mass
Matthew Duran-MS Physics, 2007 Modeling the
ground-state Baryon octet using a generalization
of the Lagrange triangle solution
11Kyle Peterson-PhD Physics, December
2003 Computational magnetohydrodynamic
investigation of flux compression and implosion
dynamics in a Z-pinch plasma with an azimuthally
opposed magnetic field configuration electronic
resource Karen Norton-MS Physics, August
2006 Ultraviolet image analysis of spacecraft
exhaust plumes
12Jesse Labello - MS Physics, 2007 Characterization
of the temperature dependence of optical
components in the 10V cryo-vacuum chamber
Howard Frederick MS Physics,
2008 Experimental determination of emissivity
and resistivity of Yttria stabilized Zirconia at
high temperatures
13University of Tennessee Space Institute Center
for Laser Applications
CLA lab
Tennessee Higher Education Commission Center of
Excellence
14Laser Spectroscopy with
Professor Christian Parigger
- Laser-induced breakdown spectroscopy
- Atomic and molecular spectroscopy
- Computational
modeling of
laser breakdown
phenomena
Pavlina J. Jeleva-PhD Physics, 2005 Photo-acousti
c analysis of dental materials and tissue
15Research Interests Professor Lloyd M. Davis
- Single-molecule spectroscopy, nanophotonics,
biophotonics, biophysics, chemical physics - Non-linear optics, quantum optics, ultrafast
spectroscopy - Femtosecond laser material and laser plasma
interactions - Numerical physics, Monte Carlo simulations
David Ball-PhD Physics, December
2006 Single-molecule detection with active
control
- Present position Postdoctoral fellow,
Virginia
Bioinformatics Center, 5-yr NIH funding
16Davis GRA Students (spring 08)
- Justin Crawford
- You Li
- Jason King
- James Germann
- Jesse Ogle (AEDC)
- Will Robinson
- Isaac Lescano (EE)
Larissa Wenren
17Outreach OSA student chapter
18Single-molecule detection in solution was first
achieved
by using pulsed laser excitation and time-gated
photon counting to reject the Raman scatter that
overlaps the fluorescence band
19Maximum likelihood data analysis
Measurements with small numbers of photons Eg.,
Fluorescence Lifetime of a single molecule
Find ? such that Prob(Data ? ) is a maximum
Error in lifetime ? ? ? number of photons
Least-squares curve fitting fails because it
assumes a Gaussian distribution of errors
20Maximum-likelihood multi-channel photon-counting
microscopy
Justin Crawford
count-rate dependent time-walk
We have improved the sensitivity of time and
spectrally-resolved imaging for applications that
require resolving the signal contributions from
fluorescent species with overlapping spectra
NIH/NIBIB R03 grant
New MPD Modified Module
21High-throughput modular microfluidic systems for
drug discovery/development
- NIH R01-grant 2007-2011
- Collaborators Louisiana State University, Tulane
University - UTSI
- Develop of a set of ultra-sensitive near-infrared
fluorescence readout methods for determining
molecular species concentrations within plastic
(PMMA) microfluidic devices - Goal is to determine changes in enzyme activity
in response to a library of 100,000 compounds - Parallelized assays of enzyme activity with
nanoliter samples by use of CCD camera - Demonstrate the developed platform by searching
for inhibitors of L1-endonuclease, an enzyme
implicated in cancer
22Use of diode laser for detection of near-infrared
phthalocyanine dyes
You Li
Raman notch transmission
We are developing custom instrumentation for
ultrasensitive detection of deep-red fluorophores
for application to pharmaceutical drug screening
within PMMA microfluidic devices.
23You Li Photon bursts from single near-ir dye
molecules
24Single Protein Studies
25Single-molecule detection in a nanochannel
- Goal
- To detect and trap single molecules of
fluorescently-labeled proteins in solution with
high photon count rate for studies of protein
interactions and conformational changes with time
resolution of tens of microseconds - Approach
- Confocal fluorescence microscope
- Confine molecules in nanofluidic channel
- Custom electronics to actively
control
electrokinetic transport
for positioning each molecule in
confocal
volume - Excite fluorophore to saturation
using intense
laser - Replace molecule after bleaching
26Nanofluidics fabrication strategies
- Approach 1 EBL/RIE Nanochannels and Bonding
- Electron Beam Lithography
- Photolithography
- Bonding with Fused-Silica
- Approach 2 Sacrificial Nanochannels and Bonding
- Electron Beam Lithography
- Wet Etching of Sacrificial Lines
- Approach 3 FIB Machining and Bonding
- Focused Ion Beam
- Bonding with Fused-Silica
- Approach 4 Femtosecond Laser Direct Writing
- High-Aspect Vertical Nanoholes
- Possibility of enhanced light collection from
a single molecule in a vertical nanochannel
27Single microjoule femtosecond laser-pulse
fabrication of 10-micron deep nano-holes
photodiode
ultrafast mirror
3D piezo
- Nikon CF Plan Achromat 79173
- 150 mm conjugate
- Dry, NA 0.85, WD 0.410.45 mm
- cc for 0.110.22 mm, n 1.52
28Depth measure by SEM/FIB sectioning
Cross-section near top of holes
- Use of the DualBeam? SEM/FIB tool, CNMS, ORNL
- Diameters of 200-500 nm and depths exceeding 11
micron
29Possible mechanisms for high aspect holes
- Creation of similar long features internal to the
material has been attributed to - self-focusing due to Kerr nonlinearity of fused
silica EN Glezer E Mazur, Appl. Phys. Lett.
71, 882884 (1997) - interface-induced spherical aberration
self-focusing
Q Sun, et
al., J. Opt. A Pure Appl. Opt. 7, 655659
(2005) - long features only when gt 20 µm from the surface
- Focusing with spherical aberration
- objective correction collar for 0.110.22 mm, n
1.52
Air SiO2
cc.17
Zemax
30Possible mechanisms for high aspect holes
- Creation of similar long features internal to the
material has been attributed to - self-focusing due to Kerr nonlinearity of fused
silica EN Glezer E
Mazur, Appl. Phys. Lett. 71, 882884 (1997) - interface-induced spherical aberration
self-focusing
Q Sun, et
al., J. Opt. A Pure Appl. Opt. 7, 655659
(2005) - long features only when gt 20 µm from the surface
- Focusing with spherical aberration
- objective correction collar for 0.110.22 mm, n
1.52
Zemax
Single-pulse ultrafast-laser machining of high
aspect nano-holes at the surface of SiO2,
YV White X Li Z Sikorski LM Davis W
Hofmeister, Optics Express 16, 1441114420 (2008).
31Nanofluidic device fabrication
microchannels
4 inch, 500 mm SiO2 wafer
UV
nanochannels
coat 3 mm
e-beam
exposure
UV resist
exposure
develop
PMMA
50 nm
etch
develop
chrome
50 nm
reactive ion etch
SiO2
etch
cleaning CO2 laser hole punching wafer
dicing cleaning cover slip bonding
reactive ion etch ? PMMA removed
32Bonding of patterned chips
To avoid nanochannel collapse Low temperature
bonding lt100 ?C Surface cleaning in HF
solution Pressure1MPa Bonding time 12 hours
33SEM characterization of nanochannels
Dual Beam FIB/SEM
34Assembled nanofluidic device
electrodes
Plexiglass housing
nanofluidic chip
aluminum base
laser
351-D trap in a nanochannel
Irradiance profile
- Molecules are confined to 1-D within 100 nm
nanochannel - Two displaced laser beam foci pulse-interleaved
excitation - Irradiance at center constant
- Time-gated photon detection
- Electrophoretic/electro-osmotic motion along the
nanochannel
V2
nanochannel
immersion fluid
V1
V
microscope objective
nanochannel
laser
36The Laboratory
37Control of electrokinetic voltage
nanofluidic device
sync
1.2 NA objective
beam dump
pump laser 76 MHz 608 nm two beams, each 30 mW
with 6.6 ns delay
filters
custom FPGA board
sliding mirror
I-MAX ICCD camera
pinhole
NI PCI-6602 counter / timer
SPAD
38Numerical simulations of single-molecule trapping
William N. Robinson
First molecule enters at 70.8 ms
Molecule photobleaches
Laser beam positions 0.3 µm
Expected duration of capture before bleaching
(?10?5)
39Fluorescence autocorrelation
15 s
Nanochannel freshly loaded with 0.6 pM
streptavidin/Alexa 610 in 0.2 PBS
active electrokinetic control
?10 V
0 V
FPGA voltages seen on oscilloscope during trapping
40Other ongoing projects
- Single-Molecule Trapping
- 1-D in nano-fluidic device
- 3-D in micro-fluidic device
- Single-Molecule Tracking
414-Foci Fluorescence Microscope and Maximum
Likelihood Analysis
James Germann
Confocal microscope with 4 beams focused in
tetrahedon provides sub-micron position
trajectory information
42Microfluidic device for 3-D electrophoretic trap
Jason K. King
Platinum coated coverslip
-
Configuration 2.5V, 10mA
-
43Further information
- Contact ldavis_at_utsi.edu
-