Highlights
Aug 31, 2011
University of Pennsylvania
Protein Assembly at the Air-Water Interface
Tobias Baumgart and Ivan J. Dmochowski
Protein assembly at the air-water interface (AWI) occurs naturally in
many biological processes, and provides a method for creating ordered
biomaterials. However, the factors that control protein self-assembly at
the AWI are generally not well understood. Here, we describe the
behavior of a model protein, human serum albumin minimally labeled with
Texas Red dye (HSA-TR), using a new confocal microscopy technique
(Figure 1). Albumin was observed to form well-ordered, mesoscale
Aug 31, 2011
University of Pennsylvania
Nanostructured programmable matter for functional architectures and devices
Ritesh Agarwal, Russ Composto, Marija Drndic, Cherie Kagan, Jay Kikkawa, Jennifer Lukes, Chris Murray and So-Jung Park
The objective of this Seed is to understand cooperative electronic,
optical and electromagnetic phenomena emerging from the interactions of
nanoscale building blocks. Recent work encompasses synthesis of
nanoparticles (figure right) and nanowires, and the investigation of how
nanocrystals can drive geometrical rearrangement in polymersome
micelles (figure right). A second breakthrough (figure below), developed
a ligand exchange process that enables flexible electronic devices
(FETs) based on nanocrystal assemblies
Aug 31, 2011
Northwestern University
Pd Dispersion on Opposing Polar LiNbO3 Surfaces
Andy Rappe, John Vohs and Dawn Bonnell
Pioneering experiments reported [upper left] the ability of
ferroelectric domain orientation to switch surface chemistry on and off,
finding unambiguous evidence that the polarity of a ferroelectric
surface can have a strong impact on the energetics of physisorption.
Aug 31, 2011
University of Pennsylvania
Maquette protein engineering and construction for long-lived photo-induced charge separation
Les Dutton and Bohdana Discher
We have developed analytic methods that establish molecular
constraints to photochemical efficiency in the engineering and
construction of molecular photochemical materials and devices useful to
addressing the global energy challenge. The absence, to-date, of
analytic procedures has seriously handicapped progress in the
development of photochemical devices. The new methods will provide
important precise engineering guidelines to photochemical device
construction in the future.
Aug 31, 2011
University of Pennsylvania
Engineering a virus-like particle via protein design
Marija Drndic, Jay Kikkawa, Bill DeGrado, and Mike Klein (Temple University)
We have designed specialized protein molecules that organize around
carbon nanotubes into an atomistically-predefined pattern. Targeted
design of such self-organization is a powerful tool for engineering at
the nano scale. For example, we have shown that our protein/nanotube
hybrid can be used to generate a regularly-spaced array of gold
nano-particle. Shown here is an exciting new concept we are currently
pursuing. We believe that our nanotube/protein complexes can be used to
Aug 31, 2011
University of Pennsylvania
Patterning within Amphiphilic Self-Assemblies using Charge, Curvature, and Crystallinity
Dennis Discher, Randy Kamien, Michael Klein, Paul Janmey and Andrea Liu
Design & engineering of modern devices increasingly requires
complex nano- and micro-structures. One area of research now showing
promise for creating such structures through simple solution techniques
Aug 31, 2011
University of Pennsylvania
Colloidal Networks & Lattices at Threshold of Mechanical Stability
Tom Lubensky, Andrea Liu, Arjun Yodh, Shu Yang and Ju Li
An isostatic lattice is one at the threshold of mechanical stability.
The square and kagome lattices (see Figure 1a-b) in two dimensions are
examples of isostatic lattices. A 2D kagome lattice of N sites has of
order N1/2 zero-energy bulk modes under periodic boundary conditions.
Theoretical study shows that when neighboring triangles are counter
rotated through an arbitrary angle α shown in Figure 1c, the bulk
modulus vanishes, making the Poisson's ratio equal to -1, and all of the
Aug 30, 2011
Johns Hopkins University
High School Student Research Internships at The Johns Hopkins University
Background: The
JHU MRSEC conducts extensive K-12 educational outreach programs aimed at
promoting interest in and awareness of the importance of modern materials
research. High school students from the greater Baltimore area receive
four-week internships each July to conduct research in the laboratories of the
JHU MRSEC. The students are mentored by Center faculty, and also work closely
Aug 30, 2011
Johns Hopkins University
Dynamics of Magnetic Charges in Spin Ice
P. Mellado, O. Petrova, Y. C. Shen, and O. Tchernyshyov
Background: A bar magnet has two poles, denoted as +1
and -1 magnetic charges. Patterned
structures consist of many magnets (Fig. 1), where the square array (Fig. 1a)
does not, whereas the honeycomb (Fig. 1b) has, net magnetic charges (or magnetic
monopoles). Under a magnetic field these
local magnetic monopoles will move (Fig. 1c).
This latter structure is called “spin ice”, because it has a large
number of nearly degenerate configurations.
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