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  • richardmitnick 1:47 pm on August 15, 2016 Permalink | Reply
    Tags: , Graphene nanoribbons in solutions mimic nature, Nanotechnology,   

    From Rice: “Nanoribbons in solutions mimic nature” 

    Rice U bloc

    Rice University

    August 15, 2016
    Mike Williams

    Rice University scientists test graphene ribbons’ abilities to integrate with biological systems

    1
    The tip of an atomic force microscope on a cantilevered arm is used to pull a graphene nanoribbon the same way it would be used to pull apart a protein or a strand of DNA in a Rice University lab. The microscope can be used to measure properties like rigidity in a material as it’s manipulated by the tip. (Credit: Kiang Research Group/Rice University)

    Graphene nanoribbons (GNRs) bend and twist easily in solution, making them adaptable for biological uses like DNA analysis, drug delivery and biomimetic applications, according to scientists at Rice University.

    Knowing the details of how GNRs behave in a solution will help make them suitable for wide use in biomimetics, according to Rice physicist Ching-Hwa Kiang, whose lab employed its unique capabilities to probe nanoscale materials like cells and proteins in wet environments. Biomimetic materials are those that imitate the forms and properties of natural materials.

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    Rice University physicist Ching-Hwa Kiang, left, and graduate student Jingqiang Li analyze readings at the atomic force microscope in her lab. The researchers analyzed the properties of carbon nanoribbons in solutions with the equipment they normally use to analyze DNA, proteins and cells. (Credit: Rice University)

    The research led by recent Rice graduate Sithara Wijeratne, now a postdoctoral researcher at Harvard University, appears in the Nature journal Scientific Reports.

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    Rice University physicist Ching-Hwa Kiang, left, and alumna Sithara Wijeratne led a study to determine the mechanical properties of graphene nanoribbons in solution. They found the nanoribbons mimic the properties of natural polymers like proteins and DNA and may be suitable for biomimetic applications. (Credit: Jeff Fitlow/Rice University)

    Graphene nanoribbons can be thousands of times longer than they are wide. They can be produced in bulk by chemically “unzipping” carbon nanotubes, a process invented by Rice chemist and co-author James Tour and his lab.

    Their size means they can operate on the scale of biological components like proteins and DNA, Kiang said. “We study the mechanical properties of all different kinds of materials, from proteins to cells, but a little different from the way other people do,” she said. “We like to see how materials behave in solution, because that’s where biological things are.” Kiang is a pioneer in developing methods to probe the energy states of proteins as they fold and unfold.

    She said Tour suggested her lab have a look at the mechanical properties of GNRs. “It’s a little extra work to study these things in solution rather than dry, but that’s our specialty,” she said.

    Nanoribbons are known for adding strength but not weight to solid-state composites, like bicycle frames and tennis rackets, and forming an electrically active matrix. A recent Rice project infused them into an efficient de-icer coating for aircraft.

    But in a squishier environment, their ability to conform to surfaces, carry current and strengthen composites could also be valuable.

    “It turns out that graphene behaves reasonably well, somewhat similar to other biological materials. But the interesting part is that it behaves differently in a solution than it does in air,” she said. The researchers found that like DNA and proteins, nanoribbons in solution naturally form folds and loops, but can also form helicoids, wrinkles and spirals.

    Kiang, Wijeratne and Jingqiang Li, a co-author and student in the Kiang lab, used atomic force microscopy to test their properties. Atomic force microscopy can not only gather high-resolution images but also take sensitive force measurements of nanomaterials by pulling on them. The researchers probed GNRs and their precursors, graphene oxide nanoribbons.

    The researchers discovered that all nanoribbons become rigid under stress, but their rigidity increases as oxide molecules are removed to turn graphene oxide nanoribbons into GNRs. They suggested this ability to tune their rigidity should help with the design and fabrication of GNR-biomimetic interfaces.

    “Graphene and graphene oxide materials can be functionalized (or modified) to integrate with various biological systems, such as DNA, protein and even cells,” Kiang said. “These have been realized in biological devices, biomolecule detection and molecular medicine. The sensitivity of graphene bio-devices can be improved by using narrow graphene materials like nanoribbons.”

    Wijeratne noted graphene nanoribbons are already being tested for use in DNA sequencing, in which strands of DNA are pulled through a nanopore in an electrified material. The base components of DNA affect the electric field, which can be read to identify the bases.

    The researchers saw nanoribbons’ biocompatibility as potentially useful for sensors that could travel through the body and report on what they find, not unlike the Tour lab’s nanoreporters that retrieve information from oil wells.

    Further studies will focus on the effect of the nanoribbons’ width, which range from 10 to 100 nanometers, on their properties.

    Co-authors are Rice research scientist Evgeni Penev; graduate student Wei Lu; alumna Amanda Duque, now a scientist at Los Alamos National Laboratory; and Boris Yakobson, the Karl F. Hasselmann Professor of Materials Science and NanoEngineering and a professor of chemistry. Tour is the T.T. and W.F. Chao Professor of Chemistry as well as a professor of computer science and of materials science and nanoengineering. Kiang is an associate professor of physics and astronomy and of bioengineering.

    The Welch Foundation and the National Science Foundation supported the research. The researchers used the NSF’s Extreme Science and Engineering Discovery Environment and the NSF-supported DAVinCI supercomputer administered by Rice’s Center for Research Computing and procured in a partnership with Rice’s Ken Kennedy Institute.

    See the full article here .

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    Rice U campus

    In his 1912 inaugural address, Rice University president Edgar Odell Lovett set forth an ambitious vision for a great research university in Houston, Texas; one dedicated to excellence across the range of human endeavor. With this bold beginning in mind, and with Rice’s centennial approaching, it is time to ask again what we aspire to in a dynamic and shrinking world in which education and the production of knowledge will play an even greater role. What shall our vision be for Rice as we prepare for its second century, and how ought we to advance over the next decade?

    This was the fundamental question posed in the Call to Conversation, a document released to the Rice community in summer 2005. The Call to Conversation asked us to reexamine many aspects of our enterprise, from our fundamental mission and aspirations to the manner in which we define and achieve excellence. It identified the pressures of a constantly changing and increasingly competitive landscape; it asked us to assess honestly Rice’s comparative strengths and weaknesses; and it called on us to define strategic priorities for the future, an effort that will be a focus of the next phase of this process.

     
  • richardmitnick 4:06 pm on August 8, 2016 Permalink | Reply
    Tags: , , Nanotechnology, Smarter Self-assembly Opens New Pathways for Nanotechnology   

    From BNL: “Smarter Self-assembly Opens New Pathways for Nanotechnology” 

    Brookhaven Lab

    August 8, 2016
    Justin Eure

    Brookhaven Lab scientists discover a way to create billionth-of-a-meter structures that snap together in complex patterns with unprecedented efficiency

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    Brookhaven physicist Aaron Stein, lead author on the study, in the cleanroom at the Center for Functional Nanomaterials (CFN) at Brookhaven National Laboratory. Stein and his co-authors used the electron beam lithography writer in the background to etch templates that drive the self-assembly of block copolymers in precisely controllable ways.

    To continue advancing, next-generation electronic devices must fully exploit the nanoscale, where materials span just billionths of a meter. But balancing complexity, precision, and manufacturing scalability on such fantastically small scales is inevitably difficult. Fortunately, some nanomaterials can be coaxed into snapping themselves into desired formations—a process called self-assembly.

    Scientists at the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory have just developed a way to direct the self-assembly of multiple molecular patterns within a single material, producing new nanoscale architectures. The results were published in the journal Nature Communications.

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    Electron beam lithography is used to adjust the spacing and thickness of line patterns etched onto a template (lower layer). These patterns drive a self-assembling block copolymer (top layer) to locally form different types of patterns, depending on the underlying template. Thus, a single material can be coaxed into forming distinct nanopatterns for example, lines or dots ‹ in close proximity. These mixed-configuration materials could lead to new applications in microelectronics.

    “This is a significant conceptual leap in self-assembly,” said Brookhaven Lab physicist Aaron Stein, lead author on the study. “In the past, we were limited to a single emergent pattern, but this technique breaks that barrier with relative ease. This is significant for basic research, certainly, but it could also change the way we design and manufacture electronics.”

    Microchips, for example, use meticulously patterned templates to produce the nanoscale structures that process and store information. Through self-assembly, however, these structures can spontaneously form without that exhaustive preliminary patterning. And now, self-assembly can generate multiple distinct patterns—greatly increasing the complexity of nanostructures that can be formed in a single step.

    “This technique fits quite easily into existing microchip fabrication workflows,” said study coauthor Kevin Yager, also a Brookhaven physicist. “It’s exciting to make a fundamental discovery that could one day find its way into our computers.”

    The experimental work was conducted entirely at Brookhaven Lab’s Center for Functional Nanomaterials (CFN), a DOE Office of Science User Facility, leveraging in-house expertise and instrumentation.

    Cooking up organized complexity

    The collaboration used block copolymers—chains of two distinct molecules linked together—because of their intrinsic ability to self-assemble.

    “As powerful as self-assembly is, we suspected that guiding the process would enhance it to create truly ‘responsive’ self-assembly,” said study coauthor Greg Doerk of Brookhaven. “That’s exactly where we pushed it.”

    2
    CFN researchers Gwen Wright and Aaron Stein at the electron beam lithography writer in the CFN cleanroom.

    To guide self-assembly, scientists create precise but simple substrate templates. Using a method called electron beam lithography—Stein’s specialty—they etch patterns thousands of times thinner than a human hair on the template surface. They then add a solution containing a set of block copolymers onto the template, spin the substrate to create a thin coating, and “bake” it all in an oven to kick the molecules into formation. Thermal energy drives interaction between the block copolymers and the template, setting the final configuration—in this instance, parallel lines or dots in a grid.

    “In conventional self-assembly, the final nanostructures follow the template’s guiding lines, but are of a single pattern type,” Stein said. “But that all just changed.”

    Lines and dots, living together

    The collaboration had previously discovered that mixing together different block copolymers allowed multiple, co-existing line and dot nanostructures to form.

    “We had discovered an exciting phenomenon, but couldn’t select which morphology would emerge,” Yager said. But then the team found that tweaking the substrate changed the structures that emerged. By simply adjusting the spacing and thickness of the lithographic line patterns—easy to fabricate using modern tools—the self-assembling blocks can be locally converted into ultra-thin lines, or high-density arrays of nano-dots.

    3
    Study co-author Kevin Yager measuring the self-assembling thin film layers.

    “We realized that combining our self-assembling materials with nanofabricated guides gave us that elusive control. And, of course, these new geometries are achieved on an incredibly small scale,” said Yager.

    “In essence,” said Stein, “we’ve created ‘smart’ templates for nanomaterial self-assembly. How far we can push the technique remains to be seen, but it opens some very promising pathways.”

    Gwen Wright, another CFN coauthor, added, “Many nano-fabrication labs should be able to do this tomorrow with their in-house tools—the trick was discovering it was even possible.”

    The scientists plan to increase the sophistication of the process, using more complex materials in order to move toward more device-like architectures.

    “The ongoing and open collaboration within the CFN made this possible,” said Charles Black, director of the CFN. “We had experts in self-assembly, electron beam lithography, and even electron microscopy to characterize the materials, all under one roof, all pushing the limits of nanoscience.”

    This work was funded by the DOE Office of Science.

    See the full article here .

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    One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. The Laboratory’s almost 3,000 scientists, engineers, and support staff are joined each year by more than 5,000 visiting researchers from around the world.Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.
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  • richardmitnick 12:20 pm on August 5, 2016 Permalink | Reply
    Tags: , Nanotechnology, Skyrmions, The future of data storage,   

    From Southampton: “Nanosize magnetic whirlpools could be the future of data storage” 

    U Southampton bloc

    University of Southampton

    3 August 2016
    No writer credit found

    1
    Skyrmions could be the future of data storage.

    The use of nanoscale magnetic whirlpools, known as magnetic skyrmions, to create novel and efficient ways to store data will be explored in a new £7M research programme involving University of Southampton researchers.

    Skyrmions, which are a new quantum mechanical state of matter, could be used to make our day-to-day gadgets, such as mobile phones and laptops, much smaller and cheaper whilst using less energy and generating less heat.

    It is hoped better and more in-depth knowledge of skyrmions could address society’s ever-increasing demands for processing and storing large amounts of data and improve current hard drive technology.

    Revolutionise data storage

    Scientists first predicted the existence of skyrmions in 1962 but they were only discovered experimentally in magnetic materials in 2009.

    The UK team, funded by the Engineering and Physical Sciences Research Council (EPSRC), now aims to make a step change in our understanding of skyrmions with the goal of producing a new type of demonstrator device in partnership with industry.

    Skyrmions, tiny swirling patterns in magnetic fields, can be created, manipulated and controlled in certain magnetic materials. Inside a skyrmion, magnetic moments point in different directions in a self-organised vortex. Skyrmions are only very weakly coupled to the underlying atoms in the material, and to each other, and their small size means they can be tightly packed together. Together with the strong forces that lock magnetic fields into the skyrmion pattern, the result is that the magnetic information encoded by skyrmions is very robust.

    Scientists can potentially move a skyrmion with 100,000 times less energy than is needed to move a ferromagnetic domain, the objects currently used in the memory of our computers and smartphones. Currently when we access information through the web, we remotely use hard disk drives that generate lots of heat and waste lots of energy. Skyrmionic technology could allow this to be done on smaller scale devices which would use much less energy.

    Skyrmions could therefore revolutionise the way we store data.

    Consortium of experts

    The Southampton researchers involved in the project are Professor Hans Fangohr and Dr Ondrej Hovorka from the University’s Computational Modelling Group. Professor Fangohr said: “Southampton will support this national grant into Skyrmion research by providing the computational science expertise and computational modelling to underpin, help understand and guide experimental work at our partner sites in Cambridge, Durham, Oxford and Warwick.

    “The skyrmions provide rich physics – this project will explore both the more fundamental physics questions that they raise and the potential for skyrmion use in applications.”

    The national consortium includes experts from the universities of Durham, Warwick, Oxford, Cambridge and Southampton, plus industry partners.

    World of opportunities

    The first prediction of a new type of stable configuration came from British physicist Tony Skyrme and has since opened up a whole variety of different sized and shaped skyrmion objects with different properties to conventional matter. However, numerous questions remain unanswered which focus on how best to exploit the unique magnetic properties of these magnetic excitations in devices.

    The three generic themes the team will look at are:

    • The development, discovery and growth of magnetic materials that host skyrmion spin textures;

    • A greater understanding of the physics of these objects;

    • Engineering of the materials to application.

    The research team will use state-of-the-art facilities such as synchrotron, neutron and muon sources both within the UK and internationally. The research is funded from summer 2016 until 2022.

    The research team is currently looking for five postdoctoral research associates to join the project. For more information about these opportunities, please visit http://www.skyrmions.co.uk

    More information about the Southampton post on computational modelling is available at http://www.southampton.ac.uk/~fangohr/vacancies/programmegrant.html

    See the full article here .

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    The University of Southampton is a world-class university built on the quality and diversity of our community. Our staff place a high value on excellence and creativity, supporting independence of thought, and the freedom to challenge existing knowledge and beliefs through critical research and scholarship. Through our education and research we transform people’s lives and change the world for the better.

    Vision 2020 is the basis of our strategy.

    Since publication of the previous University Strategy in 2010 we have achieved much of what we set out to do against a backdrop of a major economic downturn and radical change in higher education in the UK.

    Vision 2020 builds on these foundations, describing our future ambition and priorities. It presents a vision of the University as a confident, growing, outwardly-focused institution that has global impact. It describes a connected institution equally committed to education and research, providing a distinctive educational experience for its students, and confident in its place as a leading international research university, achieving world-wide impact.

     
  • richardmitnick 7:57 pm on August 4, 2016 Permalink | Reply
    Tags: , , Nanotechnology, ,   

    From SLAC: “Stanford-led team reveals nanoscale secrets of rechargeable batteries” 


    SLAC Lab

    August 4, 2016
    Andrew Myers

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    Artist’s rendition shows lithium-ion battery particles under the illumination of a finely focused X-ray beam. (Image credit: Courtesy Chueh Lab)

    An interdisciplinary team has developed a way to track how particles charge and discharge at the nanoscale, an advance that will lead to better batteries for all sorts of mobile applications.

    Better batteries that charge quickly and last a long time are a brass ring for engineers. But despite decades of research and innovation, a fundamental understanding of exactly how batteries work at the smallest of scales has remained elusive.

    In a paper published this week in the journal Science, a team led by William Chueh, an assistant professor of materials science and engineering at Stanford and a faculty scientist at the Department of Energy’s SLAC National Accelerator Laboratory, has devised a way to peer as never before into the electrochemical reaction that fuels the most common rechargeable cell in use today: the lithium-ion battery.

    By visualizing the fundamental building blocks of batteries – small particles typically measuring less than 1/100th of a human hair in size – the team members have illuminated a process that is far more complex than once thought. Both the method they developed to observe the battery in real time and their improved understanding of the electrochemistry could have far-reaching implications for battery design, management and beyond.

    “It gives us fundamental insights into how batteries work,” said Jongwoo Lim, a co-lead author of the paper and post-doctoral researcher at the Stanford Institute for Materials & Energy Sciences at SLAC. “Previously, most studies investigated the average behavior of the whole battery. Now, we can see and understand how individual battery particles charge and discharge.”

    The heart of a battery

    At the heart of every lithium-ion battery is a simple chemical reaction in which positively charged lithium ions nestle in the lattice-like structure of a crystal electrode as the battery is discharging, receiving negatively charged electrons in the process. In reversing the reaction by removing electrons, the ions are freed and the battery is charged.

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    An interdisciplinary research team has developed a new way to track how battery particles charge and discharge. Greatly magnified nanoscale particles are shown here charging (red to green) and discharging (green to red). The animation shows regions of faster and slower charge. (Image credit: SLAC National Accelerator Laboratory)

    These basic processes – known as lithiation (discharge) and delithiation (charge) – are hampered by an electrochemical Achilles heel. Rarely do the ions insert uniformly across the surface of the particles. Instead, certain areas take on more ions, and others fewer. These inconsistencies eventually lead to mechanical stress as areas of the crystal lattice become overburdened with ions and develop tiny fractures, sapping battery performance and shortening battery life.

    “Lithiation and delithiation should be homogenous and uniform,” said Yiyang Li, a doctoral candidate in Chueh’s lab and co-lead author of the paper. “In reality, however, they’re very non-uniform. In our better understanding of the process, this paper lays out a path toward suppressing the phenomenon.”

    For researchers hoping to improve batteries, like Chueh and his team, counteracting these detrimental forces could lead to batteries that charge faster and more fully, lasting much longer than today’s models.

    This study visualizes the charge/discharge reaction in real-time – something scientists refer to as operando – at fine detail and scale. The team utilized brilliant X-rays and cutting-edge microscopes at Lawrence Berkeley National Laboratory’s Advanced Light Source.

    LBL ALS interior
    LBL ALS

    “The phenomenon revealed by this technique, I thought would never be visualized in my lifetime. It’s quite game-changing in the battery field,” said Martin Bazant, a professor of chemical engineering and of mathematics at MIT who led the theoretical aspect of the study.

    Chueh and his team fashioned a transparent battery using the same active materials as ones found in smartphones and electric vehicles. It was designed and fabricated in collaboration with Hummingbird Scientific. It consists of two very thin, transparent silicon nitride “windows.” The battery electrode, made of a single layer of lithium iron phosphate nanoparticles, sits on the membrane inside the gap between the two windows. A salty fluid, known as an electrolyte, flows in the gap to deliver the lithium ions to the nanoparticles.

    “This was a very, very small battery, holding ten billion times less charge than a smartphone battery,” Chueh said. “But it allows us a clear view of what’s happening at the nanoscale.”

    Significant advances

    In their study, the researchers discovered that the charging process (delithiation) is significantly less uniform than discharge (lithiation). Intriguingly, the researchers also found that faster charging improves uniformity, which could lead to new and better battery designs and power management strategies.

    “The improved uniformity lowers the damaging mechanical stress on the electrodes and improves battery cyclability,” Chueh said. “Beyond batteries, this work could have far-reaching impact on many other electrochemical materials.” He pointed to catalysts, memory devices, and so-called smart glass, which transitions from translucent to transparent when electrically charged.

    In addition to the scientific knowledge gained, the other significant advancement from the study is the X-ray microscopy technique itself, which was developed in collaboration with Berkeley Lab Advanced Light Source scientists Young-sang Yu, David Shapiro, and Tolek Tyliszczak. The microscope, which is housed at the Advanced Light Source, could affect energy research across the board by revealing never-before-seen dynamics at the nanoscale.

    “What we’ve learned here is not just how to make a better battery, but offers us a profound new window on the science of electrochemical reactions at the nanoscale,” Bazant said.

    Funding for this work was provided in part by the U.S. Department of Energy, Office of Basic Energy Sciences, and by the Ford-Stanford Alliance. Bazant was a visiting professor at Stanford and was supported by the Global Climate and Energy Project.

    See the full article here .

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    SLAC is a multi-program laboratory exploring frontier questions in photon science, astrophysics, particle physics and accelerator research. Located in Menlo Park, California, SLAC is operated by Stanford University for the DOE’s Office of Science.
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  • richardmitnick 11:41 am on August 3, 2016 Permalink | Reply
    Tags: , , IBM lab on a chip, , Nanotechnology   

    From phys.org: “IBM lab-on-a-chip breakthrough aims to help physicians detect cancer” 

    physdotorg
    phys.org

    August 2, 2016
    No writer credit found

    1
    A view of IBM’s lab-on-a-chip mounted in a microfluidic jig. IBM scientists have developed a new lab-on-a-chip technology that can, for the first time, separate biological particles at the nanoscale and could help enable physicians to detect diseases such as cancer before symptoms appear. The technology allows a liquid sample to be passed, in continuous flow, through a silicon chip containing an asymmetric nano-pillar array. Credit: IBM

    IBM scientists have developed a new lab-on-a-chip technology that can, for the first time, separate biological particles at the nanoscale and could enable physicians to detect diseases such as cancer before symptoms appear.

    As reported today in the journal Nature Nanotechnology, the IBM team’s results show size-based separation of bioparticles down to 20 nanometers (nm) in diameter, a scale that gives access to important particles such as DNA, viruses and exosomes. Once separated, these particles can potentially be analyzed by physicians to reveal signs of disease even before patients experience any physical symptoms and when the outcome from treatment is most positive. Until now, the smallest bioparticle that could be separated by size with on-chip technologies was about 50 times or larger, for example, separation of circulating tumor cells from other biological components.

    IBM is collaborating with a team from the Icahn School of Medicine at Mount Sinai to continue development of this lab-on-a-chip technology and plans to test it on prostate cancer, the most common cancer in men in the U.S.

    In the era of precision medicine, exosomes are increasingly being viewed as useful biomarkers for the diagnosis and prognosis of malignant tumors. Exosomes are released in easily accessible bodily fluids such as blood, saliva or urine. They represent a precious biomedical tool as they can be used in the context of less invasive liquid biopsies to reveal the origin and nature of a cancer.

    The IBM team targeted exosomes with their device as existing technologies face challenges for separating and purifying exosomes in liquid biopsies. Exosomes range in size from 20-140nm and contain information about the health of the originating cell that they are shed from. A determination of the size, surface proteins and nucleic acid cargo carried by exosomes can give essential information about the presence and state of developing cancer and other diseases.

    IBM’s results show they could separate and detect particles as small as 20 nm from smaller particles, that exosomes of size 100 nm and larger could be separated from smaller exosomes, and that separation can take place in spite of diffusion, a hallmark of particle dynamics at these small scales. With Mt. Sinai, the team plans to confirm their device is able to pick up exosomes with cancer-specific biomarkers from patient liquid biopsies.

    “The ability to sort and enrich biomarkers at the nanoscale in chip-based technologies opens the door to understanding diseases such as cancer as well as viruses like the flu or Zika,” said Gustavo Stolovitzky, Program Director of Translational Systems Biology and Nanobiotechnology at IBM Research. “Our lab-on-a-chip device could offer a simple, noninvasive and affordable option to potentially detect and monitor a disease even at its earliest stages, long before physical symptoms manifest. This extra amount of time allows physicians to make more informed decisions and when the prognosis for treatment options is most positive.”

    With the ability to sort bioparticles at the nanoscale, Mt. Sinai hopes that IBM’s technology can provide a new method to eavesdrop on the messages carried by exosomes for cell-to-cell communications. This can elucidate important questions about the biology of diseases as well as pave the way to noninvasive and eventually affordable point-of-care diagnostic tools. Monitoring this intercellular conversation more regularly could allow medical experts to track an individual’s state of health or progression of a disease.

    “When we are ahead of the disease we usually can address it well; but if the disease is ahead of us, the journey is usually much more difficult. One of the important developments that we are attempting in this collaboration is to have the basic grounds to identify exosome signatures that can be there very early on before symptoms appear or before a disease becomes worse,” said Dr. Carlos Cordon-Cardo, Professor and Chairman for the Mount Sinai Health System Department of Pathology. “By bringing together Mount Sinai’s domain expertise in cancer and pathology with IBM’s systems biology experience and its latest nanoscale separation technology, the hope is to look for specific, sensitive biomarkers in exosomes that represent a new frontier to offering clues that might hold the answer to whether a person has cancer or how to treat it.”

    Sorting bioparticles at the nanoscale

    3
    IBM scientists have developed a new lab-on-a-chip technology that can, for the first time, separate biological particles at the nanoscale and could enable physicians to detect diseases such as cancer before symptoms appear. The IBM team’s results show size-based separation of bioparticles down to 20 nanometers (nm) in diameter, a scale that gives access to important particles such as DNA, viruses and exosomes. Credit: IBM

    Lab-on-a-chip technologies have become an incredibly helpful diagnostic tool for physicians as they can be significantly faster, portable, easy to use and require less sample volume to help detect diseases. The goal is to shrink down to a single silicon chip all of the processes necessary to analyze a disease that would normally be carried out in a full-scale biochemistry lab.

    Using a technology called nanoscale deterministic lateral displacement, or nano-DLD, IBM scientists Dr. Joshua Smith and Dr. Benjamin Wunsch led development of a lab-on-a-chip technology that allows a liquid sample to be passed, in continuous flow, through a silicon chip containing an asymmetric pillar array. This array allows the system to sort a microscopic waterfall of nanoparticles, separating particles by size down to tens of nanometers resolution. IBM has already scaled down the chip size to 2cm by 2cm, while continuing development to increase the device density to improve functionality and throughput.

    Much like how a road through a small tunnel only allows smaller cars to pass while forcing bigger trucks to detour around, nano-DLD uses a set of pillars to deflect larger particles while allowing smaller particles to flow through the gaps of the pillar array unabated, effectively separating this particle “traffic” by size while not disrupting flow. Interestingly, IBM scientists noticed that nano-DLD arrays can also split a mixture of many different particle sizes into a spread of streams, much like a prism splits white light into different colors. The continuous flow nature of this technology circumvents stop-and-go batch processing typical of conventional separation techniques.

    Leveraging IBM’s vast semiconductor expertise with its growing capabilities in experimental biology, IBM scientists used manufacturable silicon processes to produce the nano-DLD arrays for their lab-on-a-chip device. As part of its on-going strategy, IBM researchers are working to increase the diversity of bioparticles that can be separated with their device, and improving the precision and specificity for real-world clinical applications.

    See the full article here .

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    Phys.org™ (formerly Physorg.com) is a leading web-based science, research and technology news service which covers a full range of topics. These include physics, earth science, medicine, nanotechnology, electronics, space, biology, chemistry, computer sciences, engineering, mathematics and other sciences and technologies. Launched in 2004, Phys.org’s readership has grown steadily to include 1.75 million scientists, researchers, and engineers every month. Phys.org publishes approximately 100 quality articles every day, offering some of the most comprehensive coverage of sci-tech developments world-wide. Quancast 2009 includes Phys.org in its list of the Global Top 2,000 Websites. Phys.org community members enjoy access to many personalized features such as social networking, a personal home page set-up, RSS/XML feeds, article comments and ranking, the ability to save favorite articles, a daily newsletter, and other options.

     
  • richardmitnick 2:28 pm on July 21, 2016 Permalink | Reply
    Tags: , , Engineering new technology at the molecular level, Nanotechnology, , University of Chicago’s Pritzker Nanofabrication Facility   

    From U Chicago: “Engineering new technology at the molecular level” 

    U Chicago bloc

    University of Chicago

    July 11, 2016 [Just made it to social media.]
    Steve Koppes

    1
    Photo by Robert Kozloff

    Academic and industrial researchers have begun working side-by-side at the University of Chicago’s Pritzker Nanofabrication Facility, using some of the world’s most advanced tools to exploit the atomic and molecular properties of matter for emerging applications in science and technology.

    “You can’t really do engineering systems from the molecular level up like we’re aiming to do without something like the Pritzker Nanofabrication Facility,” says Matthew Tirrell, dean and Pritzker Director of the Institute for Molecular Engineering.


    The Pritzker Nanofabrication Facility helps researchers exploit the atomic and molecular properties of matter for applications in science and technology. Video by UChicago Creative

    1
    Peter Duda, the technical director of the Pritzker Nanofabrication Facility, holds a pure, four-inch silicon wafer, a commonly used substrate material in the semiconductor world. “It’s about as close to 100 percent silicon as you can possibly get,” Duda says. (Photo by Robert Kozloff)

    Since the facility opened in February, its biggest users have been UChicago students in molecular engineering, physics, and chemistry working on their own projects and in collaboration with faculty members. There are also users from other university campuses as well as industry.

    “We have students working on a variety of different projects, including making devices for applications in quantum information, working on devices that use microfluidic technology, and developing detectors for astrophysical applications,” says Andrew Cleland, the John A. McClean Sr. Professor of Molecular Engineering Innovation and Enterprise and faculty director of the Pritzker facility.

    Microfluidic devices can be used to detect and measure the properties of single cells, viruses, or other biological components. In the astrophysical realm, researchers fabricate sensors for the South Pole Telescope to detect the cosmic microwave background radiation, the afterglow of the Big Bang.

    The facility’s tools offer the capability of manufacturing devices ranging in size from a few inches down to 10 nanometers—a size that compares to the width of a human hair as the width of that hair does to the height of a human.

    “Being able to craft objects on the nanometer scale with state-of-the-art equipment is going to enable extraordinary experiments on the campus,” says David Awschalom, the Liew Family Professor in Molecular Engineering and IME’s deputy director for space, infrastructure, and facilities.

    Large nanofacility

    Support for the 10,000-square-foot facility in the William Eckhardt Research Center came partly from a $15 million gift from the Pritzker Foundation. The National Science Foundation provided an additional $5 million to establish the Soft and Hybrid Nanotechnology Experimental Resource, a partnership between UChicago and Northwestern University. The NSF grant provides funding for support staff and training for external industrial and academic users who seek to develop nanostructure fabrication capabilities at the Pritzker facility and at Northwestern.

    “Today’s clean room is the machine shop of our time,” says Awschalom. “A generation ago it was all about state-of-the-art mills, lathes, making very tiny structures with wire-cutting tools. Today it’s the nanofabrication facility and advanced etching techniques.”

    But launching new technological products requires the involvement of industry, he notes.

    “Universities are fantastic at generating creative concepts and ideas and developing proof-of-concept prototypes. To transition these ideas into society, it will be vital to engage the expertise of startup companies and industry.”

    Facility users will complete training before using the cleanroom. They will pay an hourly fee for access, and may pay additional fees for the use of specific tools and equipment. The proceeds go to support the facility’s operations.

    “Our plans are that this facility will eventually be open 24/7, meaning that it will have access for graduate students as well as external users any time of the day or night,” Cleland says. “Industrial users will be an important part of our user base, and they will also tie in our graduate students to the industrial efforts that are related to their research.”

    Ultra-clean bays

    As an ISO Class 5 cleanroom, the Pritzker facility contains air with 100 or fewer particles measuring five microns (one tenth the width of a human hair) or larger per cubic foot. Outside air typically contains more than a million dust particles of this size per cubic foot.

    The facility sports a bay-and-chase design, with six bays (ultra-clean work spaces) alternating with chases (return-air spaces).

    “One positive impact of our gift from the Pritzker Foundation was our ability to purchase new equipment for the facility,” says Sally Wolcott, the facility’s business manager. “This allowed the PNF to design and plan tool purchases such that bay one is completely empty, giving us room for expansion. We have money already earmarked, and we will continue to acquire tools based on need.”

    The chases serve as giant vacuum cleaners, recirculating the air through nearly 1,000 filters to keep the facility clean. People working in the facility also must wear a special coverall, a hairnet, gloves, and covers for mouth and shoes.

    “In its simplest terms, the Pritzker facility is used for three primary activities,” said Peter Duda, its technical director. “We add materials, we remove materials, and we use different techniques to create patterns in those materials. By layering all of those patterned materials that you’ve added and subtracted, you can create devices.”

    The work is extremely precise. With the facility’s atomic-layer deposition tools, researchers can deposit a film one atomic layer at a time. One such material that can be grown this way is aluminum oxide, “a ceramic very similar to what your coffee cup is made of,” Duda says. But as an electrical insulator it is used in integrated circuits and in superconducting devices.

    Superconducting devices are among the interests of David Schuster, assistant professor in physics and an IME fellow. Schuster plans to install his multi-angle electron-beam evaporation system in the Pritzker facility.

    “It supports the evaporation of superconducting metals such as aluminum, niobium, and tantalum on wafers up to four inches in diameter,” Schuster says. The system can create high-quality superconducting Josephson junctions, which are a key element in superconducting circuits.

    Schuster’s collaboration with Awschalom and Cleland signals more synergy to come between IME and other departments.

    “Working with the Awschalom and Cleland groups has been wonderful, making UChicago one of the premier destinations in the world for quantum physics,” Schuster says.

    See the full article here .

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    U Chicago Campus

    An intellectual destination

    One of the world’s premier academic and research institutions, the University of Chicago has driven new ways of thinking since our 1890 founding. Today, UChicago is an intellectual destination that draws inspired scholars to our Hyde Park and international campuses, keeping UChicago at the nexus of ideas that challenge and change the world.

     
  • richardmitnick 4:49 am on July 14, 2016 Permalink | Reply
    Tags: , , Nanotechnology,   

    From New Scientist: “Graphene sheets open like a flower’s petals when poked” 

    NewScientist

    New Scientist

    13 July 2016
    Conor Gearin

    1
    Graphene holds promise in nanotechnology. Domhnall Malone

    Give graphene a diamond and you’ll get a flower in return. Researchers have found that poking a sheet of atom-thick graphene with a diamond tool causes tiny ribbons to peel away from the surface, like flower petals opening.

    “I don’t think anyone ever expected it,” says Graham Cross at Trinity College Dublin, Ireland, whose team made the discovery. Graphene sheets, which are made of a single layer of carbon atoms, are both superstrong and highly flexible. Other researchers have folded graphene into origami shapes using chemical reactions and tiny tools, but no one knew that a little prompting could cause graphene to tear and fold itself on its own.

    The find was an accident, discovered when the researchers were conducting an experiment to measure the friction of graphene by piercing it. Once their diamond tip punctured the sheet, they found that the energy from ambient heat was enough to cause the ribbons to keep tearing and unfolding into a tapered strip in less than a minute.

    “What for me is extraordinary is that it tears,” says Annalisa Fasolino at Radboud University in Nijmegen, the Netherlands. The atoms in a graphene sheet are bonded tightly, but there is only a weak attraction between sheets when stacked, she says. However, the researchers showed that after a layer started to tear, the weak attraction between the bottom of an unfolding ribbon and the sheet below was enough for the sheet’s internal bonds to keep ripping.

    Nanoscale control

    By changing the initial width of the tear, the researchers could control the length of the resulting ribbons, which tended to grow five times their initial width.

    “We’ve done crumpling, wrinkling and tearing of thin sheets, even one-atom-thin sheets like graphene, but not with such exquisite control,” says Scott Bunch at Boston University.

    2
    Graphene can be torn with a diamond tip, causing it to then self-fold – a property that could be useful in electronics. James Annett

    Graphene’s peculiar self-folding ability could be a big help in making better electronics, says Cross. By setting off ribbon formation in careful patterns, the sheets could be folded to make tiny sensors and even transistors. Such devices could allow for nanoscale electronics and fast-processing computers. “It would take a bit of work to do that, but it might be able to,” he says.

    Engineers could also prepare the sheets to tear at specific temperatures, says Cross. This could help in the food industry – for example, a graphene-based sensor on packaging could break a circuit if an item’s temperature rose above a safe level.

    Itai Cohen at Cornell University in Ithaca, New York, does not think graphene will replace silicon in electronic chips, but says graphene sheets could be used to manufacture very small robots. “Folding atomically thin sheets like graphene is a way of packing many, many features into a small 3D volume,” he says.

    Journal reference: Nature, DOI: 10:1038/nature18304

    See the full article here .

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  • richardmitnick 10:10 am on June 29, 2016 Permalink | Reply
    Tags: , Nanotechnology, NeuroFab, , New Stanford engineering tools record electrical activity of cells, , Stanford Neurosciences Institute   

    From Stanford: “New Stanford engineering tools record electrical activity of cells” 

    Stanford University Name
    Stanford University

    June 28, 2016
    Amy Adams

    When asked for the biggest idea that would transform neuroscience, Stanford mechanical engineer Nicholas Melosh came up with this: using engineering tools he and his colleagues were developing to record the electrical activity of cells.

    1
    Stanford researchers Greg Pitner and Matt Abramian finalize sample preparation in the Neurofab, mounting the cell culture vessel to the suspended wafer. (Image credit: L.A. Cicero)

    If it works, Melosh’s big idea could help neuroscientists improve on devices that interface with the brain – such as those currently used to relieve symptoms of Parkinson’s disease – screen drugs for electrophysiology side effects, and understand with greater precision the electrical currents that underlie our thoughts, behaviors and memories.

    To make this idea a reality, Melosh, an associate professor of materials science, engineering and photon science, founded the NeuroFab as an initiative of the Stanford Neurosciences Institute. It was one of seven interdisciplinary “Big Ideas” initiatives intended to tackle fundamental problems in neuroscience.

    “Eventually we’d like to create a toolset that would impact many neuroscience labs,” he said.

    Building a bridge

    The NeuroFab serves as both a physical space where engineers and neuroscientists can collaborate on new tools and an intellectual space with regular meetings to discuss ideas.

    Melosh said neuroscience and engineering have a lot in common.

    “Neural activity is electrical in nature and is a natural fit for engineers,” he said. But the language, cultures and skills of the two groups have been hard to bridge.

    John Huguenard is one of the neuroscientists on the other side of that bridge.

    “There is a cultural difference between engineers and biologists,” said Huguenard, a Stanford professor of neurology and neurological sciences.

    “When they start talking about device characteristics, it is lost on us. Similarly, when we say there are different types of neurons with very different properties, it’s lost on them.”

    Huguenard studies widespread neural activity in the brain, such as what occurs in sleep patterns or epilepsy.

    “This work requires us to record from many parts of the brain simultaneously,” he said, something that has been challenging with existing technology.

    Currently, neuroscientists have two primary methods to record cellular electrical activity. One is highly accurate, but can only record from one cell at a time, inevitably killing the cell within about two hours. The other can record long-term from an array of cells, but is not very sensitive.

    So far, teams within the NeuroFab are experimenting with a variety of approaches for reading electrical signals. Two of the more well-developed ones involve conductive nanomaterials, either in the form of nanopillars, which poke up into cells from below, or arrays of linear nanotubes that pass through cells like a bead on a string.

    Other approaches involve the optical recording of electrical fields, massively parallel interfaces based on computer chips, and membrane-fusing electrodes.

    Nanotubes

    Early in the NeuroFab’s existence, Melosh started talking with Philip Wong, a Stanford professor of electrical engineering, whose lab is developing ways of using highly conductive carbon nanotubes for next-generation computer chips. Wong brought in graduate student Gregory Pitner, who had experience with techniques for making those carbon nanotubes in a variety of configurations.

    “We grow them aligned, we grow them dense, we grow them consistently and reproducibly,” Pitner said, who believes that the dense, aligned nanotubes could provide a conductive surface for cells to grow on.

    That initial design changed when Pitner got a lesson in cell biology from Matthew Abramian, a postdoctoral fellow in Huguenard’s lab.

    Cells, Abramian explained, are surrounded by a halo of sugars and proteins and it’s these molecules that are in contact with a lab dish, not the cell itself. To get access to electrical changes within the cell, Pitner learned that his nanotubes needed to be suspended in a way that would allow the cell to encompass and incorporate the tube.

    “There are all sorts of practical details to understand about cell behavior that go way beyond high school biology,” Pitner said.

    The new design has small troughs for the cells to grow in, containing a single nanotube leading out to a recording station. With that new design, the pair needed to find that right cell type to test whether the idea works.

    If it succeeds, they envision being able to record from any kind of conductive cell including different types of neurons or heart muscle.

    “This would be a device where you can get data on hundreds of neurons at one time,” Abramian said.

    Cultural surprises

    Abramian said the pace of biology came as a surprise to engineers.

    “Engineers just think we’ll grow some cells and the next day we’re going to record,” he said. “That’s not how it works at all.”

    Cells can take up to weeks to grow, and then they don’t always have the anticipated properties, he added.

    By contrast, Abramian said he was amazed by the amount of control engineers have over their designs.

    “They have methods for building really intricate devices, and they can test them right way,” he said.

    By including faculty and students from many disciplines, Pitner said. the NeuroFab helps bridge these gaps in knowledge and expertise.

    “These kinds of relationships are almost impossible to create in a vacuum,” he said.

    Melosh said he hopes tools developed in the NeuroFab will enable bidirectional communication with neurons in a dish, and eventually the brain, which may start to unlock secrets of the brain by measuring from many places at once.

    See the full article here .

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    Leland and Jane Stanford founded the University to “promote the public welfare by exercising an influence on behalf of humanity and civilization.” Stanford opened its doors in 1891, and more than a century later, it remains dedicated to finding solutions to the great challenges of the day and to preparing our students for leadership in today’s complex world. Stanford, is an American private research university located in Stanford, California on an 8,180-acre (3,310 ha) campus near Palo Alto. Since 1952, more than 54 Stanford faculty, staff, and alumni have won the Nobel Prize, including 19 current faculty members

    Stanford University Seal

     
  • richardmitnick 12:19 pm on June 24, 2016 Permalink | Reply
    Tags: , Nanotechnology,   

    From Northwestern: “Nanoscientists Develop the ‘Ultimate Discovery Tool’ “ 

    Northwestern U bloc
    Northwestern University

    Jun 23, 2016
    Megan Fellman

    The discovery power of the gene chip is coming to nanotechnology. A Northwestern University research team is developing a tool to rapidly test millions and perhaps even billions or more different nanoparticles at one time to zero in on the best particle for a specific use.

    When materials are miniaturized, their properties — optical, structural, electrical, mechanical and chemical — change, offering new possibilities. But determining what nanoparticle size and composition are best for a given application, such as catalysts, biodiagnostic labels, pharmaceuticals and electronic devices, is a daunting task.

    “As scientists, we’ve only just begun to investigate what materials can be made on the nanoscale,” said Northwestern’s Chad A. Mirkin, a world leader in nanotechnology research and its application, who led the study. “Screening a million potentially useful nanoparticles, for example, could take several lifetimes. Once optimized, our tool will enable researchers to pick the winner much faster than conventional methods. We have the ultimate discovery tool.”

    Using a Northwestern technique that deposits materials on a surface, Mirkin and his team figured out how to make combinatorial libraries of nanoparticles in a very controlled way. (A combinatorial library is a collection of systematically varied structures encoded at specific sites on a surface.) Their study will be published June 24 by the journal Science.

    The nanoparticle libraries are much like a gene chip, Mirkin says, where thousands of different spots of DNA are used to identify the presence of a disease or toxin. Thousands of reactions can be done simultaneously, providing results in just a few hours. Similarly, Mirkin and his team’s libraries will enable scientists to rapidly make and screen millions to billions of nanoparticles of different compositions and sizes for desirable physical and chemical properties.

    “The ability to make libraries of nanoparticles will open a new field of nanocombinatorics, where size — on a scale that matters — and composition become tunable parameters,” Mirkin said. “This is a powerful approach to discovery science.”

    Mirkin is the George B. Rathmann Professor of Chemistry in the Weinberg College of Arts and Sciences and founding director of Northwestern’s International Institute for Nanotechnology.

    “I liken our combinatorial nanopatterning approach to providing a broad palette of bold colors to an artist who previously had been working with a handful of dull and pale black, white and grey pastels,” said co-author Vinayak P. Dravid, the Abraham Harris Professor of Materials Science and Engineering in the McCormick School of Engineering.

    Using five metallic elements — gold, silver, cobalt, copper and nickel — Mirkin and his team developed an array of unique structures by varying every elemental combination. In previous work, the researchers had shown that particle diameter also can be varied deliberately on the 1- to 100-nanometer length scale.

    Some of the compositions can be found in nature, but more than half of them have never existed before on Earth. And when pictured using high-powered imaging techniques, the nanoparticles appear like an array of colorful Easter eggs, each compositional element contributing to the palette.

    To build the combinatorial libraries, Mirkin and his team used Dip-Pen Nanolithography, a technique developed at Northwestern in 1999, to deposit onto a surface individual polymer “dots,” each loaded with different metal salts of interest. The researchers then heated the polymer dots, reducing the salts to metal atoms and forming a single nanoparticle. The size of the polymer dot can be varied to change the size of the final nanoparticle.

    This control of both size and composition of nanoparticles is very important, Mirkin stressed. Having demonstrated control, the researchers used the tool to systematically generate a library of 31 nanostructures using the five different metals.

    To help analyze the complex elemental compositions and size/shape of the nanoparticles down to the sub-nanometer scale, the team turned to Dravid, Mirkin’s longtime friend and collaborator. Dravid, founding director of Northwestern’s NUANCE Center, contributed his expertise and the advanced electron microscopes of NUANCE to spatially map the compositional trajectories of the combinatorial nanoparticles.

    Now, scientists can begin to study these nanoparticles as well as build other useful combinatorial libraries consisting of billions of structures that subtly differ in size and composition. These structures may become the next materials that power fuel cells, efficiently harvest solar energy and convert it into useful fuels, and catalyze reactions that take low-value feedstocks from the petroleum industry and turn them into high-value products useful in the chemical and pharmaceutical industries.

    Mirkin is a member of the Robert H. Lurie Comprehensive Cancer Center of Northwestern University as well as co-director of the Northwestern University Center for Cancer Nanotechnology Excellence. He also is a professor of medicine, chemical and biological engineering, biomedical engineering and materials science at Northwestern.

    The research was supported by GlaxoSmithKline, the Air Force Office of Scientific Research (award FA9550-12-1-0141) and the Asian Office of Aerospace R&D (award FA2386-13-1-4124).

    The paper is titled Polyelemental nanoparticle libraries. In addition to Mirkin and Dravid, authors of the paper are Peng-Cheng Chen (first author), Xiaolong Liu, James L. Hedrick, Zhuang Xie, Shunzhi Wang, Qing-Yuan Lin, and Mark C. Hersam, all of Northwestern University.

    1
    A combinatorial library of polyelemental nanoparticles was developed using Dip-Pen Nanolithography. This novel nanoparticle library opens up a new field of nanocombinatorics for rapid screening of nanomaterials for a multitude of properties. Credit: Peng-Cheng Chen/James Hedrick

    See the full article here .

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    Northwestern South Campus
    South Campus

    On May 31, 1850, nine men gathered to begin planning a university that would serve the Northwest Territory.

    Given that they had little money, no land and limited higher education experience, their vision was ambitious. But through a combination of creative financing, shrewd politicking, religious inspiration and an abundance of hard work, the founders of Northwestern University were able to make that dream a reality.

    In 1853, the founders purchased a 379-acre tract of land on the shore of Lake Michigan 12 miles north of Chicago. They established a campus and developed the land near it, naming the surrounding town Evanston in honor of one of the University’s founders, John Evans. After completing its first building in 1855, Northwestern began classes that fall with two faculty members and 10 students.
    Twenty-one presidents have presided over Northwestern in the years since. The University has grown to include 12 schools and colleges, with additional campuses in Chicago and Doha, Qatar.

    Northwestern is recognized nationally and internationally for its educational programs.

     
  • richardmitnick 12:00 pm on June 13, 2016 Permalink | Reply
    Tags: , Nano ‘hall of mirrors’ causes molecules to mix with light, Nanotechnology, ,   

    From Cambridge: “Nano ‘hall of mirrors’ causes molecules to mix with light” 

    U Cambridge bloc

    Cambridge University

    13 Jun 2016
    Sarah Collins
    sarah.collins@admin.cam.ac.uk

    1

    Researchers have successfully used quantum states to mix a molecule with light at room temperature, which will aid in the exploration of quantum technologies and provide new ways to manipulate the physical and chemical properties of matter.

    When a molecule emits a blink of light, it doesn’t expect it to ever come back. However researchers have now managed to place single molecules in such a tiny optical cavity that emitted photons, or particles of light, return to the molecule before they have properly left. The energy oscillates back and forth between light and molecule, resulting in a complete mixing of the two.

    Previous attempts to mix molecules with light have been complex to produce and only achievable at very low temperatures, but the researchers, led by the University of Cambridge, have developed a method to produce these ‘half-light’ molecules at room temperature.

    These unusual interactions of molecules with light provide new ways to manipulate the physical and chemical properties of matter, and could be used to process quantum information, aid in the understanding of complex processes at work in photosynthesis, or even manipulate the chemical bonds between atoms. The results are reported in the journal Nature.

    To use single molecules in this way, the researchers had to reliably construct cavities only a billionth of a metre (one nanometre) across in order to trap light. They used the tiny gap between a gold nanoparticle and a mirror, and placed a coloured dye molecule inside.

    “It’s like a hall of mirrors for a molecule, only spaced a hundred thousand times thinner than a human hair,” said Professor Jeremy Baumberg of the NanoPhotonics Centre at Cambridge’s Cavendish Laboratory, who led the research.

    In order to achieve the molecule-light mixing, the dye molecules needed to be correctly positioned in the tiny gap. “Our molecules like to lie down flat on the gold, and it was really hard to persuade them to stand up straight,” said Rohit Chikkaraddy, lead author of the study.

    To solve this, the team joined with a team of chemists at Cambridge led by Professor Oren Scherman to encapsulate the dyes in hollow barrel-shaped molecular cages called cucurbiturils, which are able to hold the dye molecules in the desired upright position.

    When assembled together correctly, the molecule scattering spectrum splits into two separated quantum states which is the signature of this ‘mixing’. This spacing in colour corresponds to photons taking less than a trillionth of a second to come back to the molecule.

    A key advance was to show strong mixing of light and matter was possible for single molecules even with large absorption of light in the metal and at room temperature. “Finding single-molecule signatures took months of data collection,” said Chikkaraddy.

    The researchers were also able to observe steps in the colour spacing of the states corresponding to whether one, two, or three molecules were in the gap.

    The Cambridge team collaborated with theorists Professor Ortwin Hess at the Blackett Laboratory, Imperial College London and Dr Edina Rosta at Kings College London to understand the confinement and interaction of light in such tiny gaps, matching experiments amazingly well.

    The research is funded as part of a UK Engineering and Physical Sciences Research Council (EPSRC) investment in the Cambridge NanoPhotonics Centre, as well as the European Research Council (ERC), the Winton Programme for the Physics of Sustainability and St John’s College.

    Reference:
    Rohit Chikkaraddy et al. ‘Single-molecule strong coupling at room temperature in plasmonic nanocavities.’ Nature (2016). DOI: 10.1038/nature17974

    See the full article here .

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    U Cambridge Campus

    The University of Cambridge[note 1] (abbreviated as Cantab in post-nominal letters[note 2]) is a collegiate public research university in Cambridge, England. Founded in 1209, Cambridge is the second-oldest university in the English-speaking world and the world’s fourth-oldest surviving university.[6] It grew out of an association of scholars who left the University of Oxford after a dispute with townsfolk.[7] The two ancient universities share many common features and are often jointly referred to as “Oxbridge”.

    Cambridge is formed from a variety of institutions which include 31 constituent colleges and over 100 academic departments organised into six schools.[8] The university occupies buildings throughout the town, many of which are of historical importance. The colleges are self-governing institutions founded as integral parts of the university. In the year ended 31 July 2014, the university had a total income of £1.51 billion, of which £371 million was from research grants and contracts. The central university and colleges have a combined endowment of around £4.9 billion, the largest of any university outside the United States.[9] Cambridge is a member of many associations and forms part of the “golden triangle” of leading English universities and Cambridge University Health Partners, an academic health science centre. The university is closely linked with the development of the high-tech business cluster known as “Silicon Fen”.

     
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