Carbon Dioxide Separation - NETL of DOE Sponsored
Virtual Material Design with CMU
The goal of this effort is to significantly reduce the greenhouse gas carbon dioxide emitted in flue gas. This is a
vital transition technology required to minimize the adverse environmental effects inherent in coal based energy while our
country transitions to more appropriate, renewable energy sources. The approach involves the development of an
electrochemical separation device for carbon dioxide separation. The team includes John Kitchen of CMU and a team from
DOE's National Energy Technology Lab (NETL). The primary emphases of the device development are (1) carbonate
electrochemistry (electrode development which transforms the carbon dioxide and excess oxygen into carbonate ions for
separation), (2) ion transport (ionic polymer development and characterization), and (3) device construction and testing.
Pitt's contributions to this effort include multiscale modeling with experimental validation of the ionic polymer
mechanical and transport properties. The figure illustrates the carbonate selectivity of the membrane (top right);
experimental validation of this selective carbonate transport (top left); and experimental and theorectical details of
the selective membrane itself (bottom right and left respectively). Current program dates are
August 2006 - April 2008, with extensions subject to routine review.
Enabling Miniature Ionomeric Sensors - Sponsored by NSF
Validating the Mechanism of Streaming Potential. In Collaboration with Virginia Tech
The work is motivated by current limitations in implementing ionomeric sensors, which have superior sensitivity as
compared to other active materials, because of an inadequate understanding of the physics responsible for the observed
sensing response. Moreover, the transduction properties which make this material a superior sensor also enable it as a
energy harvesting material. This work presents and tests the hypothesis that the sensing mechanism of ionic polymers is
directly analogous to streaming potential. The proposed effort will enable the reliable use of this novel class of polymer
material to function in combined sensing and energy scavenging applications. Team members include Barbar Akle and
Don Leo of Virginia Tech. While both Virginia Tech and Pitt will engaged in experimentation and modeling, Virginia Tech
will lead the experimental aspect of the program while Pitt will focus on developing models appropriate to validating the
hypothesis of streaming potential. Program date July 2007 - June 2010.
Hydrokinetic Energy Harvest - Sponsored by the Heinz Foundation
Hydrokinetic Energy: Our Untapped Renewable Energy Resource - Performed by Pitt's Student Chapter of Engineers for a
Sustainable World in collaboration with the town of Vandergrift, PA
Traditional high head hydropower harnesses potential energy (falling water), usually incorporating a turbine with a
dam and/or penstock; this represents the overwhelming majority of hydropower technology to date. Conversely, hydrokinetic
energy harvesting relies on the high kinetic energy of fast flowing water. In October 2005, the DOE hosted a workshop on
hydrokinetic energy. The goal of the workshop was to identify existing hydrokinetic concepts, natural resources,
environmental impacts, and development needs. The workshop proceedings describe hydrokinetic energy generation potential
as “gargantuan.?The majority of the technologies discussed in that workshop harness ocean based tidal energy and/or employ
various turbine configurations. Aside from the recognition that fast flowing rivers represent a significant natural
hydrokinetic resource, the DOE workshop failed to identify an existing technology base for translating river flow to
electric power. This represents a clear and important technology gap.
The fast flowing Kiski river wraps around 3 sides of the town of Vandergrift, PA. Vandergrift civic leaders seek
to introduce hydrokinetic energy harvest to power their downtown district. The goal is to offset power costs as an economic
incentive for new businesses to come to Vandergrift, while promoting environmentally friendly practices. In this program
Vandergrift civic leaders handle all river access related details and offer important feedback for the general acceptance
of hydrokinetic design concepts. Program start date July 1, 2007. Program end date June 30, 2008.
Mutable Materials - DARPA Sponsored
Materials with Electro-Controllable Mechanical Properties: In Collaboration with NextGen Aeronautics
One viable approach to the challenge of developing a morphing aircraft skin that is simultaneously compliant enough to
sustain large shape change but tough enough to withstand aerodynamic loads is the creation of a tough material that is soft
only upon command. This project is performed in collaboration with Dr. Tara Meyer of Chemistry (Pitt) and Dr. William Clark
of Mechanical Engineering and Materials Science (Pitt), and NextGen Aeronautics of Torrance, CA. Dr. Meyer's group will focus
on synthesis of a material which will soften in response to an electric stimulus. Dr. Clark's group will focus on system
design strategies appropriate to this morphing material. Our group is focused on developing appropriate experimental methods
to characterize material properties in each state, rate of response, and power consumption required to induce property
change; this characterization enables a synthesis feedback loop (with Meyer) and identification of macroscopic properties
requied in design development (with Clark). NextGen will provide implementation requirements for the mutable material on a
shape changing unmanned air vehicle (UAV). The figure illustrates the fundamental concepts; application and removal of
electric field results in the creation/destruction of crosslinks (top left); increased crosslinking results in increased
stiffness. The figure also illustrates one of the resulting polymer formulations (top right), as well as one of the
experimental strategies employed to characterize the property change of these materials (bottom). The set up includes a
mechanical shaker and a polytec laser vibrometer; the dynamic response of the sample, monitored by the laser vibrometer,
will change as the sample properties change. This Phase II program will conclude in August 2008.
Light Activated Shape Memory Polymer - DARPA Sponsored
Materials with Optically-Controllable Mechanical Properties: In Collaboration with Cornerstone Research Group (CRG)
Engineered polymers such as thermally stimulated shape memory polymers (SMPs) are being widely researched for their
capability to recover from large amounts of strain as well as their ability to switch between relatively low and high
moduli under a short temperature range. Their unique characteristics have made them attractive for several design concepts
from morphing aircraft, self-healing structures, automotive body panels, and numerous space and medical applications.
However, a thermal stimulus is inherently problematic in many applications. The goal of this work is to develop and
characterize a shape memory polymer that responds to specific wave lengths of light. The figure illustrates the complex
nature of the incident light stimulus (left) and a sample being stimulated by light (right); after application of the
light stimulus the material stiffness may increase by an order of magnitude. This work is performed in collaboration with CRG,
who fabricates the samples. Our contribution to the program is development of novel experimental techniques to characterize
this new class of active material and creation of multiscale material models to serve as a synthesis feedback loop.
Phase I+II Program Dates: October 2006-September 2009.
Nano-Scale Transport Optimization - DARPA Sponsored
A Generalized, Bio-inspired Active Transport Modeling Tool Enables Technologies Ranging From Hydrokinetic Device Development To Rapid Vaccine Production
This program seeks to develop a versatile computational tool that has the potential to optimize a broad range of systems
relying on nanoscale transport. Examples include proton transport in hydrogen fuel cells, accelerated flu pandemic vaccine
production, and biocide delivery. In the case of vaccine development, one of the significant barriers toward producing
large quantities of vaccine in a short time frame is the time associated with the passive transport processes currently
employed in most vaccine production methods (it might be helpful to envision an old style automatic drip coffee maker). If
instead a means to actively drive the process can be established, then considerably larger quantities of vaccine may be
produced in a given time span. In the case of biocide delivery, in the event that our troops are exposed to a bio-agent,
they will need immediate access to a neutralizing agent (or biocide). A means for active detection of the bio-agent, say on
the exterior of a tank, and rapid delivery of the countering biocide is another potential application for this tool. This
bio-inspired program seeks to employ active transport proteins present in all living things (from beets to humans). As
illustrated, these proteins penetrate intracellular membranes and selectively allow specific species (i.e., "S" and "X") to
pass through the membrane; in essence, these membranes selectively move the fuel we need into our cells, while waste is
selectively moved out. These biological transporters may alternatively be embedded in a polymeric membrane, enabling the
development of highly selective active transport membranes. Prediction of the transient response requires the simultaneous
solution of a very stiff system of differential equations (a few of which are provided in the figure); computationally
intensive methods are required to solve this system of equations. This program has established the means to solve this
system of equations and subsequently seeks to identify optimum membrane configurations. Program start date: January 2007; end date August 2008.
