W. Craig Carter - Faculty highlight W. Craig Carter
Materials science professor develops algorithms to solve problems across
disciplines, strengthens online teaching techniques, and contributes to
Denis Paiste | Materials Processing Center
June 1, 2015
he's tackling thermodynamics and kinetics of batteries, modeling
solid-state dewetting, or undertaking an artistic collaboration, MIT
Professor W. Craig Carter brings
a mathematical approach to solving problems and creating new work,
developing fresh algorithms for each venture. He also is developing new
paradigms for online materials science education, melding factual
instruction with critical thinking and programming skills.
"I've gone from topic to topic pretty rapidly, and it kind of stems
from an applied mathematical bent that I've always had in my career,"
says Carter, 54, the POSCO Professor of Materials Science and
Engineering. "That gives you the ability to jump into a topic, find what
problems are useful to be solved, and either do kind of a theoretical
development or do simulations which shed insight onto materials
On the scientific side, Carter collaborates closely with fellow
Department of Materials Science and Engineering (DMSE) Professor Yet-Ming Chiang,
whose experimental prowess complements Carter's computational skills,
while on the artistic side, Carter partners frequently with associate
professor of media arts and sciences Neri Oxman in creating nature-inspired sculptural objects.
Carter's recent projects include:
developing the Materials Science Curriculum 2.0, using Wolfram Mathematica
notebooks and the Wolfram Language as an integral part of proctored
tutorials that engage students and build skills interactively;
analyzing decision-making to integrate intermittent green-power sources such as wind and solar into the always-on power grid;
understanding battery fatigue, assisted by postdoc Giovanna Bucci's
work simulating the failure mechanisms in battery microstructures and
solid-oxide fuel cells;
modeling dewetting phenomena in thin films, supervising PhD student Rachel V. Zucker's creation of Wulffmaker and other software solutions; and
a personal project to restore a 14th-century structure in the Burgundy region of France.
Distance education can cover a range of needs, from the MIT student
continuing classes toward a degree while out of the country to the
online learner in a massive open online course (MOOC) seeking
enrichment. "MOOCs are very good for some things, but I don't think
they're very good for higher education or developing critical thinking
skills," Carter says. In contrast to MOOCs, Carter takes a different
approach for materials science by building courses around a "master
class" model of students interacting with an instructor. That means
enrollments are necessarily smaller and instructor time has to be
dedicated to proctoring the online class. His proctored scaffolding
framework for online coursework uses modules that
incorporate Wolfram Mathematica programming.
Carter has developed online tutorials for several material science courses, and this spring semester offered his 3.017 (Modeling, Problem Solving, Computing, and Visualization) course exclusively online to students at MIT.
Using a WebEx interface,
Carter says, builds student skills in video conferencing, while the
Mathematica component builds programming skills. Both are necessary
professional skills for today's engineering students, he says. "This
class combines programming, mathematics, visualization, and prototype
problems in materials science, and puts them all together and gives the
students very challenging problems to solve. I think that solving these
problems is a very effective way not only to learn the subject but to
develop skills which will transfer to into many different aspects of
their professional lives," Carter says.
"My goal is to develop a very holistic curriculum for materials
science and do a job that is the best I could possibly do," he says. "In
developing the methods for materials science, hopefully it'll create a
prototype for other STEM disciplines to follow."
Carter previously received a Wolfram Innovator Award for
his use of Mathematica in the classroom. "What he's trying to do is
really create a platform for learning that engages the students, makes
them think in that distance learning environment," says Wolfram business
development associate Adriana O'Brien. "We're always delighted to see
him, especially at our technology conferences. He always brings
something new to the table for other higher education users and
professors that are creating digital content with Mathematica."
Carter has been assisted by Rachel Zucker, who earned her PhD this
spring, and recently recruited Kyle Keane, a former Wolfram employee, to
work on the MSC 2.0 project.
Power grid management
With Yet-Ming Chiang and Throop Wilder, Carter co-founded 24M,
a company with a mission of making low-cost, high-energy-density
batteries for power grid and transportation markets. While 24M's flow
battery technology is based on innovations in semi-solid electrodes,
Carter has also has been developing economic models about how grid
operators should make efficient decisions.
"Most governments right now have a system where if a solar plant or a
wind plant puts power onto the grid, the utility, or the grid operator,
has to consume it. It creates havoc for the grid," Carter explains. The
drive toward renewable sources has paradoxically increased greenhouse
emissions from gas generators because cycling on and off frequently
raises their carbon footprint, Carter says.
Because of these issues, adding battery backup to the grid isn't a
plug-and-play operation. Operators need help in choosing the right-size
batteries for their needs and guidelines for operating them. Once he
recognized the problem, Carter says, he started constructing models for
how to purchase and operate a battery. "It's not really materials
science, but it is an application of algorithms and modeling, which is
my craft," he explains.
While 24M has developed some proprietary battery management code, a
number of academic problems remain that Carter is addressing through the
MIT-Skoltech Center for Electrochemical Energy Storage (CEES).
"What are the best algorithms in order to optimize battery usage? What
could we say about either mathematics or can we improve the algorithms
in order to make a much more efficient controller? Those are things that
24M is not interested in, and so it became a project that is part of
this Skoltech initiative to do some academic work on that," Carter says.
"At MIT, what we're trying to do is develop optimization techniques and
then create software based on the mathematics of optimization," Carter
adds. Lutao Xie, a graduate student in the interdisciplinary Center for Computational Engineering, is currently working on those optimization techniques for optimal dispatch.
Professors Carter, who specializes in modeling, and Chiang, who
specializes in experimental work, hold joint research group meetings.
"The students will have some part modeling, some part work in the
laboratory. We have these joint meetings, where modeling and experiments
and data are all discussed on the same footing," Carter explains. "The
modeling may include doing data analysis for experiments that are being
done or trying to construct models that help us understand that data and
what's happening in the experiment."
A current research thrust is understanding the effect of replacing
the liquid electrolyte in traditional batteries with solid electrolytes
for all solid-states batteries. "There is going to be a mechanical
problem associated with how the active electrode particles are
mechanically coupled to the electrolyte. One anticipates that the
failure modes are going to be delamination of the active battery
materials, which convey the ions from the anode to the cathode and
vice versa," Carter says. "We're anticipating that we're going to
need to quickly do models that are based on coupled physics,
electrostatics, mechanics, and chemistry, put these all together, and
begin to model how these batteries behave. The difficulty right now is
the experimental groups are just developing methods to get the
mechanical properties out, so the models right now are moving ahead. We
want to have the infrastructure in place that as soon as we have the
mechanical properties, we'll be able to plug that directly into the
model and start doing comparisons. In the meantime, we'll develop a lot
of intuition for how the batteries behave given a set of parameters that
describe the mechanical properties."
"The models will help give us a foundation on which we understand the
experiments," Carter predicts. "The experimental results, as they
develop, will help direct how we should push the model to look at
different kinds of effects. Eventually, there is a convergence where
data is coming up ready to plug into a model, and then, I think, we have
this nice, complete understanding of how these batteries behave, thus
perhaps have some design principles."
Lithium battery stresses
MIT postdoctoral associate Giovanna Bucci
is working on understanding battery fatigue by simulating failure
mechanisms in solid-state lithium battery microstructures and
solid-oxide fuel cells. Bucci's expertise in continuum scale simulation
enables her to model mechanical and chemical behavior of battery
charging and discharging. Her work shows that mechanical stress is an
important problem that cannot be ignored, Bucci says. With a strong
background in solid mechanics, Bucci developed non-linear continuum
mechanics-based simulations, using finite element analysis and writing
computer code, primarily in C++, to model these interactions.
Bucci's background in rational mechanics, a very theoretical and very
mathematical branch of mechanical engineering, makes her highly skilled
in understanding non-linear mechanics, Carter says. "She's learning
materials science very rapidly; I'm very impressed how rapidly she's
learning this. So she is becoming this new synthetic scientist, who
comes from a very strong mathematical, theoretical background, is
picking up materials science, and she's loving the fact that she's
working on these problems, which we know really matter."
Rachel Zucker, who receives her PhD on June 5, has developed a range
of mathematical solutions to explain various dewetting phenomena in thin
films. Working under co-advisors Carter and Carl V. Thompson, Zucker published a paper on
two-dimensional edge retraction for highly anisotropic, fully-faceted
thin films. She also created open-source code, Wulffmaker,
to calculate equilibrium shapes of faceted particles attached to
deformable surfaces as well as particles attached to rigid surfaces.
"Rachel is another good example of working with experimentalists, and
doing theory at the same time, because she was co-advised by Carl and
me," Carter says.
Modeling the anistropic surface tension that underlies dewetting
phenomena such as edge retraction in thin films is a mathematically hard
problem, Carter says. "What she's done is figure out how to formulate
many of these problems, solved many sub-problems associated with
retraction of a solid-state film, and then is beginning to synthesize
and put it all together so that we have enough understanding and enough
results that we can compare it to the experimental results that Carl
Thompson is getting in his group."
"There is a lot of work now on creating structures on a substrate
that are patterned that you can use to do two things. One is you either
use the pattern itself to do something interesting, or you can use the
pattern to grow something, like a forest of nanowires," Carter says.
Zucker's contributions could help provide better control for patterning
wires, transistors and other components in thin films ranging from about
100 micrometers (microns) down to about 10 micrometers (equivalent to
about 4 thousandths of an inch to 4 ten-thousandths of an inch).
Innovative art works
Carter collaborated with Neri Oxman on a series of projects
that integrate her artistic visions with Carter's algorithms, 3-D
printing, and most recently computerized numerical control (CNC)
machining. "The first one was in MoMA and I think that must have been
six or seven years ago," Carter recalls. Their most recent project, the "Gemini"
chair, blended advanced manufacturing with mathematics, algorithms, and
art. It was shown in Paris as well as locally at Le Laboratoire
Cambridge this year.
"Craig's taste in thinking is incredibly unique: He combines
scientific rigor with open-ended artistic expressions," Oxman says. "His
codes are immaculate and, at the same time, he is a storyteller. He can
tell a good story: through his code, through his thinking, in the way
he teaches, in his gaze."
"I have learned many things through our collaborations; but mostly I
learned from Craig that in creative practice much like the physical
world strength of attitude is strength of character," Oxman explains.
"That innocence triumphs over strategy and that bottom-up research is
often more gratifying than top-down planning. Our initial conversations
about the relationship between material properties and their
microstructures have inspired me to think of design fabrication in the
same way prioritizing physical analysis of what is to generate
predictive frameworks for material (and structural) behavior, rather
than applying abstract and often reductive models on what can be.
That's how I fell in love with OOF, and how we came up with the new concept of Finite Element Synthesis as an approach for design."
"At its core is the very idea that we can design forms from the
bottom up by controlling relationships between intrinsic material
properties and extrinsic environmental stimuli. We started with
butterfly wings and today we're printing pavilions. OOF and Craig's
approach to materials science and engineering inspired in me a way of
seeing the world that overlapped with my values, as designer and
creator," Oxman says.
From Oxman's corset-like constructions through dresses and the recent
chair, Carter provided algorithms that patterned 3-D barnacle-like
surfaces lining, or covering, the objects of Oxman's creations. "The way
it works is Neri will get a commission and she'll develop something
that's conceptual, and usually maybe the basis of a form on which the
object will eventually be attached," Carter explains. "The art stuff is
something that is between an exercise of my scientific craft and a
hobby. It's been a great joy to work with her," he says.
Carter and Oxman will discuss a concept, for example the natural
textures of barnacles and extend the concept to something specific such
as barnacles clinging to the structure of a corset. "Mostly what I do is
think about the algorithms and the mathematics and then write code
which combines the original form, this new texture, and it's all done
with a very interesting dialogue between Neri, who is the creative force
behind the whole idea, and I hope to think that I add some creativity
associated with the development of an interesting algorithm and
eventually give the shape its final appearance," Carter says. For the
barnacle shapes, the algorithm incorporates a certain amount of
randomness but the algorithm develops ordered texture, so it becomes
readily identifiable as a continuous texture, but also has aspects where
it attaches. "So there is a lot of mathematics that goes into that,"
The Gemini chair combined CNC milling of a wood structure and 3-D
printing by Stratsys with Oxman's concepts and Carter's algorithms.
"I can say that without a doubt Craig's presence so early in my
career has been invaluable and meaningful to me in more than one way.
Craig taught me that naivetι is as precious (and perhaps as gentle) as
nature and encouraged me to operate across scales and disciplines
without any expectation for definitions. He taught me what I needed to
know, that questions are far more important than answers, and that
questioning is a way of being in the world, whether in art or in
science, whether in engineering or design. Throughout our
collaborations, we sought complete intellectual openness, one that
transcends boundaries and even language. In this sense Craig is a true
artist: one that constantly questions, that is not willing to take
anything for granted, that enjoys ambiguity, that considers any creative
pursuit whether through science, education, or art as a journey
without the need to define a destination," Oxman says.
Other personal interests
Carter and his wife, Martin Carter, who recently retired as an
associate dean at the Boston University School of Management, restored a
14th century structure in the Cτte de Chalonnais region of Burgundy, Notre Dame de Savigny-sur-Grosne,
near the cities Cluny and Taize. "It had no doors, no plumbing, no
electricity, no windows nothing; it was pretty much a roughly
organized pile of rocks," Carter says.
The Carters' have two cats, Pip and Squeak, and a dog, Berri.
Carter also has a famous brother, Chris Carter, creator and executive producer of the X-Files. "Sometimes, he would ask me to construct some equations that would appear on a blackboard on the show," Carter says.