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Book explores bio-inspired nanomaterials
In a new book, An Experimental Study on Adhesive
or Anti-Adhesive, Bio-Inspired Experimental Nanomate-
rials, published by De Gruyter, Italian scientists Emil-
iano Lepore and Nicola Pugno explore the potential of
three categories of bio-inspired materials: Adhesives,
anti-adhesives, and materials. In each area, the tech-
nologies are described in relation to how they were in-
spired by nature in an attempt to optimize their physical
characteristics and performance in operation, with an
aim to design and develop innovative products. The au-
thors investigate a wide range of natural systems and use
original experimental procedures to take a rigorous look
at biomaterials. Special attention is given to bonding
dissimilar materials, which due to their physical proper-
ties prohibit the application of more conventional join-
ing techniques. In this field, inspiration comes from
investigating the adhesive abilities of insects, spiders, and reptiles. .
Nanotube-graphene material aims to simplify manufacturing
Carbon nanotubes (CNTs) are reinforcing bars that make 2D graphene much easier to
handle in a new hybrid material grown by researchers at Rice University, Houston. In James
Tour’s chemistry lab, nanotubes are set into graphene in a way that not only mimics how
steel rebar is used in concrete, but also preserves and even improves the electrical and me-
chanical qualities of both. To create the rebar graphene, researchers spin-coat and then
heat and cool functionalized single- or multi-walled CNTs on copper foils, using the nan-
otubes as the carbon source. When heated, functional carbon groups decompose and form
graphene, while nanotubes partially split and form
covalent junctions with the new graphene layer. The
interconnected, embedded nanotubes strengthen the
graphene. “We can see in our images how well the
nanotubes bear the load. When we stretch the mate-
rial, the tubes get thinner,” says Tour. For more infor-
mation: James Tour, , .
A square-cm sheet of rebar graphene floats in water.
Rebar allows the sheet to be transferred from one surface
to another without using polymers in an intermediate
step. Courtesy of Tour Group/Rice University.
Nanowire phenomenon seen for the first time
Scientists at IBM Research – Zurich and the Norwegian University of Science and Tech-
nology demonstrated that both efficient light emission and detection functionalities can be
achieved in the same nanowire material by applying mechanical
strain. Using this new physical phenomenon, scientists might be
able to integrate light emitter and detector functions in the same
material. This would drastically reduce the complexity of future sil-
icon nanophotonic chips, say researchers. IBM scientist Giorgio
Signorello explains, “When you pull the nanowire along its length,
it is in a state that we call ‘direct bandgap’ and it can emit light very
efficiently. When you compress the length of the wire instead, its
electronic properties change and the material stops emitting light.
We call this state pseudo-direct—the III-V material behaves simi-
larly to silicon or germanium and becomes a good light detector.”
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ADVANCED MATERIALS & PROCESSES • JUNE 2014 16
NANOTECHNOLOGY
briefs
Researchers from the Near Field
NanoPhotonics Research Team
at the RIKEN Center for
Advanced Photonics, Japan,
developed a high-resolution
microscopy technique that can
resolve individual carbon
nanotubes under ambient
conditions. The technique involves
replacing the atomic force
microscope (AFM) tip on tip-
enhanced Raman spectroscopy
(TERS) with a scanning tunneling
microscope (STM). A resolution of
1.7 nm was achieved using the
new system, allowing carbon
nanotubes to be visualized at the
dimensions of their diameters. This
makes it possible to extract the
local property of the nanotubes
optically without averaging.
Researchers at Pacific Northwest
National Laboratory, Richland,
Wash., added a powdered metal
organic framework (MOF) to an
electric battery’s cathode to
capture problematic polysulfides
that cause lithium-sulfur batteries
to fail after a few charges. During
lab tests, the new battery
maintained 89% of its initial power
capacity after 100 charge-
discharge cycles. Researchers plan
to improve the cathode’s materials
mixture so it can hold more energy
and also must develop a larger
prototype and test it for longer
periods of time to evaluate
performance in real-world
applications.
Researchers at University of the Basque Country, Spain, and the
French National Centre for Scientific Research (CNRS) studied
contacts of carbon nanostructures with atoms of different chemical
natures. A prototype carbon-based molecule made from 60 carbon
atoms arranged in a sphere (a graphene sheet rolled into a tiny ball)
was attached to the apex of an extremely tiny metal needle of a scan-
ning tunneling microscope. This needle was then attached to individ-
ual metallic atoms to form a robust connection. By simultaneously
measuring the electrical current passing through these connections,
researchers deduced which individual metallic atom injected charges
into the carbon-made molecule with the greatest efficiency.
, .