IEEE Women in Engineering Magazine - June 2016 - 22

tition and demand, suited
us-in the cars we drive,
motherhood very well.
the energy we generEveryone
Dresselhaus continate, the electronic
else
ued to be the same
devices that power
was studying
scrappy, pragmatour lives." All besemiconductors, but
ic scientist who
c a u s e o f her
Dresselhaus saw promise
had at one time
work with carbon.
Through difin the small effective masses built her own
equipment from
ferent crystal strof carbon materials and
a heap of war
uctures, carbon
carbon's widely spaced
surplus supplies.
makes up both
energy levels for
She knew that the
the hardest and the
MIT Magnet Lab had
softest natural mateelectrons.
the facilities to generate
rials known-diamond
fields to knock electrons up
and graphite. Carbon atoms
or down a level with a small amount
link nicely to each other, forming
of energy, the perfect stage for experistrong chains called polymers, and carbon
ments in studying the electronic struceasily bonds with other atoms, forming
ture of semimetals. She was especially
lattices. Millions of carbon compounds
interested in graphite.
have been discovered.
Graphite is built in flaky layers, and,
And still, decades ago, hardly anyone
while the layers easily break apart, the
was interested in carbon except for Dresselgraphite within each layer is very strong.
haus. Everyone else was studying semiconDresselhaus studied the properties of
ductors, but Dresselhaus saw promise in
graphite by inserting other molecules
the small effective masses of carbon materibetween the layers, essentially separating
als and carbon's widely spaced energy levels
the layers by a small gap in distance and
for electrons.
by a small energy gap that provided much
While in Cambridge, she would give
information about electronic and optical
birth to three more children, all boys,
properties that could be probed by varyand it turned out that this research niche
ing the magnetic field.
she had carved out, almost free of compe-

Dresselhaus sits among the books and papers in her office at MIT.

IEEE women in engineering magazine

june 2016

New-Age Nanotech
It's generally accepted t hat the idea
of nanotechnology began back in 1959
with the talk given by physicist Richard
Feynman, "There's Plenty of Room at
the Bottom," although the term nanotechnology would not be coined for
another decade, and practice wouldn't
really catch up with theory until the
1980s when two inventors at IBM Zurich
would invent the first scanning tunneling microscope that could "see" individual atoms. This new age of nanotechnology has brought about the ability to
make strong and lightweight materials
with applications across chemistry, biology, physics, engineering, and materials science.
Still, Dresselhaus has worked with nanotechnology for decades. Back in the 1960s
and 1970s, "People were thinking about
how to do nano, they just didn't have the
technology," she says. "The ideas, the environment, wasn't really there. I'm not the
only person who was working on nano.
Some of us discovered each other many
years later." Her early work with graphite laid the groundwork for this new era
of carbon nanotechnology, particularly
with graphene and carbon nanotubes,
and she has spent the last decades leading the way in researching these very
rich research areas.
Carbon nanotubes are more or less
like they sound-hollow tubes made out
of carbon with a diameter in the nanometers. They are in the fullerene family, like
the buckyball, and are incredibly strong,
good conductors, and can be either single- or multiwalled. Graphene is a sheet
of graphite that has a thickness of a single
atom. It is strong within this plane, perhaps the strongest material in the world,
yet it is flexible, ultralight, and conducts
electricity better than copper. We don't
know exactly where graphene and carbon
nanotubes will lead us, but unbreakable
touchscreens, water filters that make salt
water drinkable, nanoscale drug delivery,
and radioactive contaminant removal are
a few of the many new technologies.

Table of Contents for the Digital Edition of IEEE Women in Engineering Magazine - June 2016