With innovative measurement techniques and new ways to position the molecules, NIST researchers reported at the March Meeting of the American Physical Society how they have improved manipulation of so-called block copolymers—polymers made of a mixture of two or more different molecule building blocks that are tethered at a junction point—which can form arrays of tiny dots that could be used as the basis for electronic components that pack terabytes (1000 gigabytes) of memory in something as small as a pack of gum.
One of the challenges in polymer nanotechnology is how to control their self-assembly—a hard-to-control process for materials which require precision. An important recent NIST accomplishment has been in developing accurate measurements of thin film polymeric nanostructure in 3-D. (Ironically, while determining atomic structure is well-established, measuring the slightly larger internal structure of the polymers—on the order of 10 to 20 nanometers—is much harder.) Ron Jones, together with colleagues from NIST, the University of Maryland and IBM, has used NIST’s neutron scattering and reflectivity facility to deflect neutrons off block copolymer films from many different angles. By combining the many 2-D neutron scattering pictures into a single composite scattering pattern, this technique provides the first quantitative method for imaging the 3-D internal structure of thin film polymeric nanostructures using neutron scattering—a crucial tool to see if the nanoscale polymer structures are in their required positions.1
NIST researchers also have developed new insights on how best to nudge these self-assembling material into those positions. August Bosse will report on computer simulations that model how the polymers assemble when they are placed on templates lined with troughs separated by crests.2 When a heated zone is swept across the template, the polymer molecules assemble into almost defect free, well-aligned lines faster over the entire template, an important feature for nanotech manufacturing applications.3 Sangcheol Kim (working with a team that included researchers from the University of Maryland and IBM) has found that changing the surface chemistry of the template by making some parts hydrophillic and some parts hydrophobic also can elegantly control the dimension of the block-copolymer pattern relative to the chemical template.4
And last, with all this emphasis on precise placement, NIST researcher Kevin Yager, has learned that sometimes sloppier is better. By purposely roughening up his templates with a sprinkling of chemically modified nanoparticle silica, he has forced block copolymers into standing perpendicular to the template—a feat that is generally considered tough to manage but important for nanotech applications.5 Of course, the inner structure of the polymers are not orderly with this technique, but for those applications where only the surface needs to be smooth, this is an ideal, inexpensive way to achieve vertical structures.
Michael Baum | EurekAlert!
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The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
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