nano material 311.
(photo credit: Courtesy)
A revolutionary new ball-shaped nanostructure – fully derived from very simple
organic elements yet strong as steel – has been developed and characterized at
the laboratories of Prof. Ehud Gazit of Tel Aviv University, Dr. Itay
Rousso and Nitzan Kol of the Weizmann Institute of Science in Rehovot and David
Barlam and Roni Shneck at Ben-Gurion University of the Negev in
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These promising bio-inspired nanospheres have innumerable
potential uses – from durable composite materials and bullet-proof vests to
medical implants that are not metallic and reinforced plastics for tooth
implants. They could also be used in the space, aviation and transportation
industries. The groundbreaking work has just been published in
Wiley-VCH’s leading journal Angewandte Chemie.
Organic nanostructures are
key elements of nanotechnology because these building blocks can be made with
tailored chemical properties. Their disadvantage has been that their
mechanical properties have so far been significantly inferior to those of
metallic nanostructures. But the Israeli team managed to produce biocomposite
nanospheres that are as rigid as metal.
The team used a simple dipeptide,
a molecule consisting of only two amino acids, to form spherical nanostructures.
They assembled themselves into the first bio-inspired nanomaterial known to date
– and without any heating or manipulation. The material is mechanically
equal and even superior to many metallic substances, they said.
demonstrating chemical properties similar to those of the ultra-rigid Kevlar
polymer, already used for bullet-proof vests, the new substance is built from
much simpler building blocks, enabling some important advantages: manipulation
and deposition at the nanoscale, the fabrication of nano-materials of tubular,
spherical and other geometries, and spontaneous formation by
Thus, said the team, it is a perfect building block for
Using an atomic force microscope, the scientists
examined the mechanical properties of their nanospheres.
This device uses
a nanotip (cantilever), a tiny flexible lever arm with a very fine tip at the
end. When the tip is pressed against a sample, the deflection of the lever
indicates whether the tip of the needle can press into the sample object, and
how far in it can go. A metal needle was not able to make any impression on the
nanospheres; only a needle made of diamond was able to do it.
researchers used these measurements to calculate the elasticity modulus for the
nanospheres, which is a measure of the material’s stiffness. The larger the
value, the more resistance a material has to its deformation. By using a
high-resolution scanning electron microscope equipped with a nanomanipulator, it
was possible to directly observe the deformation of the spheres.
nanotechnology development now emerging from Tel Aviv University is based on
extensive research which began in Gazit’s laboratory seven years ago. In an
earlier achievement, the team was able to fabricate tubular nanostructures that
assemble themselves into vast “forests” featuring exceptional mechanical and
physical properties. This earlier work, based on the doctoral thesis of Dr. Lihi
Adler- Abramovich and published last year in the prestigious journal Nature
Nanotechnology, may eventually generate self-cleaning windows and solar panels,
as well as supreme energy storage devices with exceptionally