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Graphene Frontiers LLC,
Philadelphia, received U.S. Patent
8,822,308—Methods and
Apparatus for Transfer of Films
among Substrates—which covers
the transfer of graphene films
between surfaces using roll-to-roll
manufacturing processes.
According to company officials,
this was the final hurdle in
creating a cost-effective
production process for graphene.
With the etch-free transfer
solution, manufacturers now have
the option of not dissolving or
consuming the substrate metal.
The company also entered into an
agreement with The Colleges of
Nanoscale Science and
Engineering at SUNY Polytechnic
Institute, Albany, N.Y., to increase
production. .
An international research group led
by Danny Porath of the Hebrew
University of Jerusalem reports
reproducible and quantitative
measurements of electricity flow
through long molecules made of
four DNA strands, signaling a
significant breakthrough toward
development of DNA-based
electrical circuits. Molecules were
produced by the group of
Alexander Kotlyar from Tel Aviv
University, who has been working
with Porath for 15 years.
Collaborators include groups from
Denmark, Spain, the U.S., Italy, and
Cyprus.
Prof. Danny Porath. Courtesy of
Hebrew University.
Body-degradable metals make headway
University of Pittsburgh researchers received an addi-
tional $1.5 million from the National Science Foundation
to continue a combined multi-university, private industry
effort to develop implantable medical devices made of
biodegradable metals. Body-degradable metals—usually
magnesium based—are not new, but according to project
director WilliamWagner, “The question comes when you
start to design medical devices for a specific application
and a clinical partner says they want it to be gone in a
month or they want it to be there for a year.”
To address these different requirements, the Pitt team
and collaborators at the University of Cincinnati (UC) and North Carolina Agricultural
and Technical State University (N.C. A&T) are creating new alloys and manufacturing
processes. The consortium seeks to design devices that can adapt to changes in a patient’s
body and dissolve once healing has occurred, reducing follow-up procedures and poten-
tial complications. So far, the group has created screws and plates for facial reconstruc-
tion, a stent for kidney dialysis, a nerve guide, and a ring to assist in pulling together
ruptured ligaments. The group also created a stent for pediatric patients whose tracheas
are underdeveloped at birth and prone to collapse. Wagner says once the stent is implanted
it will dissolve, avoiding a second procedure.
The original 2008 grant was for a total of $18.5 million over five years, shared by Pitt,
UC, and the project’s lead institution, N.C. A&T. The grant extension total is $4 million,
including the $1.5 million received by Pitt. .
Shape-shifting carbon fiber composites enable lightweight aircraft
Researchers at Airbus, France, and Massachusetts Insti-
tute of Technology (MIT), Cambridge, are developing
shape-shifting materials to make aircraft simpler and lighter,
potentially saving fuel. Made of carbon fiber composites,
materials can shift between two or more shapes in response
to changes in heat, air pressure, or other environmental fac-
tors. In addition, they can be easily integrated into aircraft,
replacing more complex actuators, motors, and hinges. Ini-
tial application might involve a jet engine air intake valve,
which must adjust as the plane changes altitude.
Although shape-changing materials have been around
for decades, many cannot handle demanding aerospace con-
ditions such as extreme temperature changes, says Christophe Cros, a technology program
leader at Airbus. In the MIT approach, carbon composites can be paired with a variety of
shape-shifting materials that respond to different environmental triggers. Another bene-
fit is that the new materials do not require the electrical connections that other shape-
changing composites need.
Skylar Tibbits, director of MIT’s Self-Assembly Laboratory, uses novel carbon fiber com-
posites developed by startup company Carbitex, Kennewick, Wash., which are made with a
variety of matrix materials that impart a range of properties. Some result in carbon compos-
ites that are floppy like a cotton sheet and others that are springy like a sheet of metal.
A 3D printer applies materials that are known to shrink or grow under certain conditions.
As they change, they force the carbon composite on which they are deposited to bend or twist
in various ways, depending on the pattern produced by the printer. Tibbits’ team is developing
software that simulates the way different patterns of these materials, printed onto different
kinds of composite materials, will behave under various conditions. So far, Tibbits has demon-
strated materials that respond to light, water, and heat, and says it should be possible to make
ones that respond to air pressure and other stimuli as well. , .
ADVANCED MATERIALS & PROCESSES • NOVEMBER-DECEMBER 2014 10
EMERGING TECHNOLOGY
Anterior cruciate ligament
(ACL) rings. Courtesy of The
Engineering Research Center
for Revolutionizing Metallic
Biomaterials.
Time-lapse photograph
shows a carbon fiber
composite bending in
response to heat. Courtesy
of MIT.