Virginia Space Grant Consortium
2012 Student Research Conference
April 5, 2012

Luncheon Sponsored by the College of William and Mary at the Williamsburg Hospitality House, Williamsburg, Virginia

Undergraduate Research Scholars
Poster Presentations - Foyer Outside of Empire Room


Oral Presentations
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UNDERSTANDING PLASMON ENHANCEMENT FOR NEXT-GENERATION SOLAR
CELLS FOR AEROSPACE TECHNOLOGY

Jacqueline Blake-Hedges, College of William & Mary
Photovoltaic cells that harness solar energy and convert it to electricity are essential to NASA’s
work in outer space, as wired electricity does not exist. However, current solar cells are
inefficient and inflexible. Dye-sensitized solar cells (DSSCs), a type of organic-based solar cell,
show promise as a potential solution to this problem. DSSCs are novel technologies though, and
their inefficiency makes them currently economically infeasible. Research on the molecular
mechanisms of DSSCs could lead to improvements on their efficiency and a possible marketable
commercial product. This paper discusses research involving the introduction of silver
nanoparticles into DSSCs to enhance their efficiency through plasmon enhancement, the
improved absorbance of a dye molecule due to the enhanced electromagnetic field surrounding a
photoexcited metal particle. The plasmonic effect is distance dependent, so it will be studied
using silica-encapsulated silver nanoparticles with dyes attached at varying lengths. The
structures will be studied using single molecule fluorescence, a technique that will allow the
study of single particles rather than the average of a group. This research will hopefully lead to a
more efficient model for the DSSC.


ASTEROID CAPTURE USING A BINARY EXCHANGE MECHANISM
Andy Borum, Virginia Tech
A new method of capturing an asteroid in an orbit around the Earth is proposed, inspired by the
theory that the irregular satellites of Jupiter and Neptune may have at one time been members of
a binary asteroid. After a close approach with the planet, the binary asteroid was disrupted, and
one member was captured into a permanent orbit. A parametric study was conducted by
simulating binary-Earth encounters. The total mass of the binary system and the velocity of the
binary asteroid relative to the Earth were found to be the two dominant parameters affecting
capture. These results were used to select a candidate near-Earth binary asteroid, 1999 HF1,
with which additional simulations were conducted. It was found that the candidate asteroid
could only be captured with a high probability at low velocities, and the resulting orbits were
larger than the Earth’s Hill sphere. However, larger non-near-Earth binary asteroids could be
captured within the Hill sphere. The effect of treating the larger member of the binary system as
an extended body and the effect of the moon were also considered. A close approach with the
moon sometimes resulted in one or both binary members being captured within the Hill sphere.


ON-BOARD INERT GAS GENERATION SYSTEMS
Justin Bright, Hampton University
The world is more environmentally conscious than ever before. This is clearly indicated by how
much government funding is invested in environmental research, conservation efforts, pollution
reduction, and so forth. For aviation to maintain its place as a leading industry, airlines and
manufacturers, alike, must make environmental concerns a priority. Currently, the Boeing
Company and the Honeywell Company have produced On-Board Inert Gas Generation Systems
(OBIGGS) that help prevent the probability of fuel tank explosions by use of nitrogen.
However, there yet exists an OBIGGS system that actually extinguishes a fire. Halon 1211
extinguishers are still used to put out fires that might occur within the aircraft cabin or flight
deck, and Halon 1301extinguishers are still used for hold fires. These extinguishers can be
broken down into harmful, corrosive by-products when in contact with fire and thus have ozone
depleting and global warming potential. As an ecological alternative, an OBIGGS can be paired
with a Water Mist System (WMS). An FAA study proved this combination to be much more
efficient than Halon 1301 and Halon 1211 extinguishers. This project will therefore focus on
finding the proper placement of this OBIGGS/WMS combination system to provide for a safer
flight environment.


EXPLORING THE PERFORMANCE OF THE IROBOT CREATE FOR OBJECT
RELOCATION IN OUTER SPACE

Hasani Burns, Hampton University
This research explores the performance of the iRobot Create machine for optimizing object
relocation in an outer space environment. From our efforts with this robot, we hope to have it
become a symbol of innovation for robots that are sent into outer space. Functioning as a toolbot,
and an active assistant, this robot aims to assist in small duties and respond to commands.
With its arm and color blob recognition capabilities, this robot has the potentiality to receive a
request, register and associate it with existing objects in its line of sight, and maneuver the arm to
act accordingly, grabbing the correct object and giving it to a worker or engineer. This poster and
presentation explains current progress and implementation of the iRobot Create for this purpose.


POTENTIAL USE OF MOLECULAR ABSORPTION FILTERS IN PARTICLE IMAGE
VELOCIMETRY OF A MACH 2 SCRAMJET TEST SECTION AT THE UNIVERSITY
OF VIRGINIA

J. Ryan Clubb, University of Virginia
The Aerospace Research Laboratory at the University of Virginia currently uses Particle Image
Velocimetry (PIV) to measure the velocity fields of flow through a Mach 2 Scramjet Test
Section. PIV is the method of tracking seed particles as they are carried through the flow, and
using their velocities to create a velocity field. This method is limited by seed particles coating
the windows, known as window fouling, making seed particle tracking within the flow
impossible. This paper will discuss a potential improvement to the PIV system that will attempt
to reduce the effect of window fouling. The potential improvement will involve the use of a
molecular iodine absorption filter, as in Planar Doppler Velocimetry (PDV), to separate out the
signals of moving particles from those with little to no velocity coating the window. This paper
will discuss the feasibility of this potential improvement, and describe how the improvements
may be implemented.


THE DEVELOPMENT OF A TUNABLE DIODE LASER ABSORPTION
TOMOGRAPHY SYSTEM ON A DIRECT-CONNECT SUPERSONIC COMBUSTION
WIND TUNNEL

Erik Ellison, University of Virginia
A Tunable Diode Laser Absorption Tomography (TDLAT) system been developed and is being
tested on a supersonic wind tunnel at NASA Langley. TDLAT is a diagnostic technique that is
designed to measure water vapor concentration and temperature at the exit plane of the wind
tunnel. Prior to this project TDLAT had already been used on the smaller supersonic wind
tunnel at the University of Virginia. The differences between the two wind tunnels resulted in
several challenges. This paper explains how these challenges were addressed and presents the
progress to-date, as of mid March as well as plans for the near future. The author’s role in this
project is mainly focused on the software system including: motion control, laser control, and
data acquisition. The changes to these three components resulted in a system designed for a
larger test section with a reduced runtime for implementation on the NASA tunnel, compared to
the UVa tunnel.


DESIGN AND SYNTHESIS OF NOVEL HYDROGEN-RICH POLYIMIDES FOR
RADIATION SHIELDING

David Hill, University of Virginia
In space, there are several types of radiation, including solar radiation and galactic cosmic
radiation (GCR), that can be harmful to both living beings and machines. The current radiation
shielding available on spacecraft is insufficient to protect astronauts and sensitive equipment for
long-duration space flight or extraterrestrial habitation, and terrestrial shielding techniques are
too heavy to be practical for spacecraft. The use of polymers, specifically hydrogen-rich,
aromatic polyimides, as radiation shielding provides a method of slowing radiation in space and
preventing the damaging cascade of radiation that results from its collision with spacecraft. This
research focuses on the development of novel aromatic-ether dianhydrides for use in
polymerization with similarly structured diamines to produce hydrogen-rich polyimides for use
as radiation shielding.


LONG-TERM POTENTIATION IN MEMRISTIVE NEUROMORPHIC SYSTEMS
Joshua Holt, College of William & Mary
Abstract: The memristor, a recently developed electronic component, behaves analogously to
synapses in biological neural networks. Neuromorphic systems, which model biological neurons
as electronic circuits, can implement memristors as synapses. Memristive devices were
fabricated at the University of Michigan using tungsten oxide. These devices were to be used in
neuromorphic systems, but they did not survive to circuit implementation. Instead, memristive
synapses were modeled using a field-programmable gate array (FPGA). These modeled
synapses exhibited LTP, and could be replaced by a working memristive device in the circuit.


DETERMINATION OF THE MICROSTRUCTURE PARAMETERS WHICH CONTROL
INTERGRANULAR STRESS CORROSION CRACKING

Carl Mayer, University of Virginia
This paper outlines an approach for investigating the aspects of mechanical deformation which
are relevant to intergranular stress corrosion cracking. A combination of electron backscatter
diffraction (EBSD) and optical microscopy techniques is used to investigate the difference in
mechanical behavior between lightly sensitized (1 hour at 600 oC) and heavily sensitized (50
hours at 600 oC) at elevated temperature. Additionally, the difference in mechanical behavior at
room temperature and elevated temperatures is characterized. Slip trace analysis revealed no
significant variation in slip distribution due to sensitization or deformation temperature.
However, these differences in sample condition did result in qualitative changes in the grain
boundary sliding behavior. This work has developed an experimental method for analyzing the
deformation behavior which can be employed for further research.


ANALYZING THE EFFICIENCY OF DYE SENSITIZED SOLAR CELLS USING SINGLE MOLECULE SPECTROSCOPY
Alana Ogata, The College of William and Mary

Dye sensitized solar cells (DSSCs) have shown great potential for clean, efficient, and inexpensive solar energy technology. DSSCs produce electricity by electron transfer between a dye and semiconductor. Unfortunately, the complex electron transfer mechanisms of are hypothesized to be a major cause in inefficiency. To model a typical DSSC structure, blinking is used to probe electron transfer between a dye molecule and a semiconductor. Blinking, a phenomenon observed in dye molecules upon photoexcitiation, is transitional jumps between quantum states that can be seen as emissive and non emissive events. We examine the blinking behaviors of two flourophores Rhodamine B(RB) and Rhodamine 6 G(R6G) using single molecule spectroscopy (SMS). These experiments allow for statistical analysis of electron transfer events, giving insight into the underlying photophysics of the dyes. Inconsistent with past studies, power law distributions showed to be insufficient for describing much of the observed blinking behaviors. Instead, lognormal distributions characterize non-emissive events, corresponding to the transition from a dark state to the molecular ground state. Lognormal dispersive kinetics describe a distribution of activation barriers which physical origins are yet to be explored

THE DESIGN AND FABRICATION OF CAPILLARY FORCE MICROACTUATORS
FOR DEFORMABLE MIRRORS

Alexander Russomanno, University of Virginia
Adaptive optics (AO) is a revolutionary technology in astronomical imaging that enhances the
quality of astronomical images by correcting aberrations in them caused by atmospheric
turbulence and distortions in the primary mirrors of large telescopes. The technology relies on
manipulating arrays of microactuator devices mounted behind a deformable secondary mirror to
correct errors in wave-fronts of incoming light. Current microactuators used in deformable
mirrors lack sufficient force and stroke needed for higher resolution space imaging. This paper
focuses on the fabrication of a novel type of microactuator called a capillary force actuator that is
theoretically capable of producing 10 to 100 times more force than current actuators of similar
size. Prototype devices currently being fabricated at the University of Virginia are too large for
adaptive optics applications due to the subtractive fabrication process used. This paper discusses
the design and implementation of a new fabrication process that uses nickel electroplating to
manufacture capillary force actuators. The unique fabrication techniques developed allow the
actuators to be scaled down, while maintaining necessary force and stroke needed for adaptive
optics.

LIGHT WEIGHT, FLEXIBLE, NANOSTRUCTURED ORGANIC SOLAR CELLS FOR
SPACE APPLICATIONS

Matthew Samson, Old Dominion University
Improving the efficiency of organic solar cells (OSCs), which are far less efficient than inorganic
semiconductor solar cells, is of paramount importance to the field of polymer photovoltaics.
Current state-of-the-art bulk heterojunction (BHJ) OSCs utilize a homogeneous blend of the
semiconducting polymer poly(3-hexylthiophene) (P3HT) and the fullerene derivative [6,6]-
phenyl C61-butyric acid methylester (PCBM). Cells with this architecture exhibit only 6.5%
efficiency and suffer poor transport of free charge carriers due to charge trapping. Highly
ordered nanotechnologies can be used with vertically nanostructured active blends to ensure
paths to the electrodes and to reduce recombination resulting in increased efficiencies. This paper
details a facile solution based process to fabricate ZnO nanorods for the use of hybrid
nanostructured OSCs. Successful development of nanotechnologies to produce highly ordered
vertically arrayed nanostructures would have a tremendous impact on photovoltaic technology
resulting in cheap direct replacements for current Si solar cells in the form of solution
processable photovoltaic materials.


SELECTIVE ATTENTION AUDITORY BCI
Hilary Sandberg, Old Dominion University
A brain-computer interface (BCI) uses hardware and software to acquire and then translate brain
activity to control devices. Device control is achieved through neural signals alone, and does not
use muscle contractions or vocalizations. This study sought to develop a BCI that relied on a
subject's response to auditory stimuli, without the need for visual attention, by monitoring a
subject’s auditory attention during 16 different conditions. Eight healthy subjects with normal
hearing participated in the study. While neural signal classification accuracies for users across all
conditions averaged 75%, a specific condition did not emerge as an overall choice for use as a
selective auditory attention BCI. However, by first determining the condition with the greatest
classification for each user, this selective attention auditory BCI demonstrates a75% accuracy.


TECHNIQUE TO MEASURE DRAG ON THE MARS SCIENCE LABORATORY
AEROSHELL

Taylor Scholz, University of Virginia
The launch of the Mars Science Laboratory (MSL) marks the largest attempted landed mass for
interplanetary travel to date. At 850 kg, the MSL lander will utilize several novel Entry, Descent
and Landing (EDL) technologies and will land with a precision of 10 km and an altitude of 1 km
above the Mars Orbiter Laser Altimeter. Subsequent manned missions will likely require landed
masses on the order of 40 to 80 metric tons with landing precision on the order of tens of meters.
New EDL technologies are required to achieve these goals, such as propulsive deceleration jets,
which are currently being researched at the University of Virginia Aerospace Research Lab
(ARL). Although testing is underway, a direct measurement of the induced drag force is required
to validate the technology and confirm computer simulations of the flowpath. A new mounting
system has been developed to accomplish this, and will utilize an adjustable length cantilever
beam along with a capacitive sensor to determine the magnitude of the drag force acting on the
model. This mounting system was designed specifically for the facilities at the ARL, but the
underlying principle is widely applicable for small-scale force measurements.


SPACECRAFT APPLICATIONS USING THE MICROSOFT KINECT
Matthew Smith, Virginia Tech
This experimental study involves using the Microsoft Kinect as a Spacecraft Sensor. The Kinect
device has the ability to detect depth information along with RGB image data of any object
within its operational range. The goal of this project was to develop relative position and
orientation algorithms using the Kinect’s measurement data. Results include methods in which
three dimensional data of specified objects in the Kinect’s operational field can be determined. A
Matlab Graphical User Interface was also developed to exploit the uses of the Microsoft Kinect
Data. A thorough description of the GUI and an example of its functions are included in this
report.