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INVENTION AND OUTREACH
The
Center for the Science and Engineering of Materials
Fall
2001
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THE
CENTER FOR THE SCIENCE AND ENGINEERING OF MATERIALS
(CSEM), under the direction of Professor of Chemical Engineering
Julia Kornfield (BS '83, MS '84), celebrated its first anniversary
this past September. Established with a $9.6 million multi-year
grant from the National Science Foundation, the Center addresses
both research and educational aspects of polymeric, structural,
photonic, and ferroelectric materials that will be necessary to
solve critical societal needs of the twenty-first century. The
Center pioneers a number of exotic and futuristic materials and
applications such as liquid metals, responsive gels, and tiny
medical sensors.
The
Center draws its researchers principally from EAS—but also
from the Division of Chemistry and Chemical Engineering. The four
major research thrusts are in the areas of biological synthesis
and assembly of macromolecular materials; bulk metallic glasses
and composites; mesophotonic materials; and ferroelectric thin
films. "I have really enjoyed catalyzing connections,"
notes Professor Kornfield. "It has been wonderful to watch
relationships develop between scientists that had little interaction
before the Center existed. It's impossible to predict now how
these connections will develop, but they will almost certainly
lead to unique and unanticipated collaborations as the Center
moves forward."
 CSEM
Director, Julia Kornfield, and a student at the March outreach
program for high-school minority youth. More than 100 students
attended. |
The
biosynthesis initiative is led by David Tirrell, McCollum-Corcoran
Professor and Professor
of Chemistry and Chemical Engineering, and Chair of the Division
of Chemistry and Chemical Engineering. Research efforts include
the use of artificial proteins to make polymers with exquisite
control of properties, and responsive polymers and gels for biomedical
and industrial applications, including materials for entrapment
of cells in tissue engineering or biosensors.
The
team investigating glassy metallic alloys is led by Bill Johnson
(PhD '75), the Ruben F. and Donna Mettler Professor of Engineering
and Applied Science. This group pursues basic science and new
engineering strategies that will lead to custom-designed materials
with desirable characteristics such as ultrahigh strength, exceptional
elasticity, and ease of fabrication into complex parts.
The
effort toward mesophotonics is led by Harry Atwater, Professor
of Applied Physics and Materials Science. Mesophotonic devices
are optical components and devices sized at or below the wavelength
of light. Future applications include engineered optical probes
for biology and medicine, and photonic devices that could replace
certain electrical devices in telecommunications and computing.
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Everybody
knows that it is impossible to propagate light through structures
smaller than the wavelength of light... but CSEM researchers
have belied this conventional wisdom, showing propagation
of light along waveguides whose lateral dimensions are a
few nanometers (a few percent of the wavelength of light).
The key is to exploit the tendency for electromagnetic excitations
to "hop" between electric dipoles, such as fluorescent
dye molecules or metal nanoparticles.
Researchers
in the mesophotonics group, led by Professor of Applied
Physics Harry Atwater, have demonstrated propagation of
light through two types of subwavelength-scale waveguides.
The first is a DNA-based waveguide in which a fluorescence
excitation hops from an optical donor molecule bound to
one end of the DNA backbone to an acceptor molecule at the
other end through dye molecules tethered at intervals in
between. These fluorescence-resonant-energy-transfer waveguides
have so far demonstrated that light can take several hops
between molecules bound to DNA, and this "movement"
can be extended to many hops along a longer waveguide.
The
second nanoscale waveguide structure is called a "plasmon
wire," which is a chain of metal nanoparticles along
which light hops from one particle to another. Light can
even propagate around sharp corners and through nanoscale
networks—all of which are impossible in conventional
optical waveguides. So much for conventional optical wisdom!
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Kaushik
Bhattacharya, Professor of Applied Mechanics and Mechanical Engineering,
is leading research to create microactuators based on high-strain
ferroelectrics. The team's integrated simulation and experimental
approach promises to reveal the microscopic basis of large strain
behavior in this class of materials.
Along
with the flurry of research activities that the Center enhances,
major outreach efforts have been made to bring under-represented
minorities to campus for special seminars, tours, and learning
activities. The CSEM Undergraduate Research Fellowship Program
hosted seven students from California State University, Los Angeles
(CSULA) during the past year. These students, working with faculty
mentors from both CSULA and Caltech, have been pursuing research
in various laboratories.
 Valerie
Villareal is studying the stability of hydrogels (aggregated
fluoroalkyl-ended polyethyleneglycol) for applications in
capillary electrophoresis. She and her mentors (Professor
Julie Kornfield at Caltech and Professor Frank Gomez at CSULA)
are hoping to show that drugs (or other components) can be
immobilized in the hydrogel and that the hydrogel can also
serve as a sieving matrix. Rob Lammertink (a Caltech postdoc,
pictured at left) is also working on this project. |
In
March, CSEM hosted a two-day outreach program for high-school
minority youth. More than 100 high-school students from science
and technology programs throughout the Los Angeles area had a
stimulating first-hand exposure to cutting-edge work in materials
science, technology, and mathematics. Particularly exciting was
a pre-sentation created by CSEM scientist Mario Blanco and Native
American artist Rosemarie McKeon exploring the connections between
science and Native American life. Blanco and McKeon connected
scientific concepts and diagrams to art and cultural concepts,
interpreting from multiple perspectives how one might understand
the molecular representation of the structure of matter. "The
creation of the Center really jump-started campus-wide discussion
about outreach efforts that take advantage of Caltech's special
strengths and the demographics of the Southern California region,"
observes Kornfield. "It has allowed this NSF MRSEC [Materials
Research Science and Engineering Center] to be part of something
bigger. As the Center was growing up, there were numerous outreach
efforts on campus that did not connect. The Center was created
at a time when the situation was ripe for coordination of more
ambitious outreach efforts, which has enabled us to substantially
expand upon the programs we had proposed. For example, we had
proposed an annual workshop for a dozen high-school students and
it grew into a program for a hundred with help and support from
other organizations at Caltech." 
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