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  • 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

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  • 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”.

     
  • richardmitnick 3:48 pm on June 8, 2016 Permalink | Reply
    Tags: , Nanotechnology, Tiny Diamonds Could Enable Huge Advances in Nanotechnology,   

    From Maryland: “Tiny Diamonds Could Enable Huge Advances in Nanotechnology” 

    U Maryland bloc

    University of Maryland

    June 8, 2016
    Matthew Wright
    301-405-9267
    mewright@umd.edu

    1
    This electron microscope image shows two hybrid nanoparticles, each consisting of a nanodiamond (roughly 50 nanometers wide) covered in smaller silver nanoparticles that enhance the diamond’s optical properties. Credit: Min Ouyang

    Nanomaterials have the potential to improve many next-generation technologies. They promise to speed up computer chips, increase the resolution of medical imaging devices and make electronics more energy efficient. But imbuing nanomaterials with the right properties can be time consuming and costly. A new, quick and inexpensive method for constructing diamond-based hybrid nanomaterials could soon launch the field forward.

    University of Maryland researchers developed a method to build diamond-based hybrid nanoparticles in large quantities from the ground up, thereby circumventing many of the problems with current methods. The technique is described in the June 8 issue of the journal Nature Communications.

    The process begins with tiny, nanoscale diamonds that contain a specific type of impurity: a single nitrogen atom where a carbon atom should be, with an empty space right next to it, resulting from a second missing carbon atom. This “nitrogen vacancy” impurity gives each diamond special optical and electromagnetic properties.

    By attaching other materials to the diamond grains, such as metal particles or semiconducting materials known as “quantum dots,” the researchers can create a variety of customizable hybrid nanoparticles, including nanoscale semiconductors and magnets with precisely tailored properties.

    “If you pair one of these diamonds with silver or gold nanoparticles, the metal can enhance the nanodiamond’s optical properties. If you couple the nanodiamond to a semiconducting quantum dot, the hybrid particle can transfer energy more efficiently,” said Min Ouyang, an associate professor of physics at UMD and senior author on the study.

    Evidence also suggests that a single nitrogen vacancy exhibits quantum physical properties and could behave as a quantum bit, or qubit, at room temperature, according to Ouyang. Qubits are the functional units of as-yet-elusive quantum computing technology, which may one day revolutionize the way humans store and process information. Nearly all qubits studied to date require ultra-cold temperatures to function properly.

    A qubit that works at room temperature would represent a significant step forward, facilitating the integration of quantum circuits into industrial, commercial and consumer-level electronics. The new diamond-hybrid nanomaterials described in Nature Communications hold significant promise for enhancing the performance of nitrogen vacancies when used as qubits, Ouyang noted.

    While such applications hold promise for the future, Ouyang and colleagues’ main breakthrough is their method for constructing the hybrid nanoparticles. Although other researchers have paired nanodiamonds with complementary nanoparticles, such efforts relied on relatively imprecise methods, such as manually installing the diamonds and particles next to each other onto a larger surface one by one. These methods are costly, time consuming and introduce a host of complications, the researchers say.

    “Our key innovation is that we can now reliably and efficiently produce these freestanding hybrid particles in large numbers,” explained Ouyang, who also has appointments in the UMD Center for Nanophysics and Advanced Materials and the Maryland NanoCenter, with an affiliate professorship in the UMD Department of Materials Science and Engineering.

    The method developed by Ouyang and his colleagues, UMD physics research associate Jianxiao Gong and physics graduate student Nathaniel Steinsultz, also enables precise control of the particles’ properties, such as the composition and total number of non-diamond particles. The hybrid nanoparticles could speed the design of room-temperature qubits for quantum computers, brighter dyes for biomedical imaging, and highly sensitive magnetic and temperature sensors, to name a few examples.

    “Hybrid materials often have unique properties that arise from interactions between the different components of the hybrid. This is particularly true in nanostructured materials where strong quantum mechanical interactions can occur,” said Matthew Doty, an associate professor of materials science and engineering at the University of Delaware who was not involved with the study. “The UMD team’s new method creates a unique opportunity for bulk production of tailored hybrid materials. I expect that this advance will enable a number of new approaches for sensing and diagnostic technologies.”

    The special properties of the nanodiamonds are determined by their nitrogen vacancies, which cause defects in the diamond’s crystal structure. Pure diamonds consist of an orderly lattice of carbon atoms and are completely transparent. However, pure diamonds are quite rare in natural diamond deposits; most have defects resulting from non-carbon impurities such as nitrogen, boron and phosphorus. Such defects create the subtle and desirable color variations seen in gemstone diamonds.

    The nanoscale diamonds used in the study were created artificially, and have at least one nitrogen vacancy. This impurity results in an altered bond structure in the otherwise orderly carbon lattice. The altered bond is the source of the optical, electromagnetic and quantum physical properties that make the diamonds useful when paired with other nanomaterials.

    Although the current study describes diamonds with nitrogen substitutions, Ouyang points out that the technique can be extended to other diamond impurities as well, each of which could open up new possibilities.

    “A major strength of our technique is that it is broadly useful and can be applied to a variety of diamond types and paired with a variety of other nanomaterials,” Ouyang explained. “It can also be scaled up fairly easily. We are interested in studying the basic physics further, but also moving toward specific applications. The potential for room-temperature quantum entanglement is particularly exciting and important.”

    This work was supported by the United States Department of Energy (Award No. DESC0010833), the Office of Naval Research (Award No. N000141410328) and the National Science Foundation (Award No. DMR1307800). The content of this article does not necessarily reflect the views of these organizations.

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    U Maryland Campus

    Driven by the pursuit of excellence, the University of Maryland has enjoyed a remarkable rise in accomplishment and reputation over the past two decades. By any measure, Maryland is now one of the nation’s preeminent public research universities and on a path to become one of the world’s best. To fulfill this promise, we must capitalize on our momentum, fully exploit our competitive advantages, and pursue ambitious goals with great discipline and entrepreneurial spirit. This promise is within reach. This strategic plan is our working agenda.

    The plan is comprehensive, bold, and action oriented. It sets forth a vision of the University as an institution unmatched in its capacity to attract talent, address the most important issues of our time, and produce the leaders of tomorrow. The plan will guide the investment of our human and material resources as we strengthen our undergraduate and graduate programs and expand research, outreach and partnerships, become a truly international center, and enhance our surrounding community.

    Our success will benefit Maryland in the near and long term, strengthen the State’s competitive capacity in a challenging and changing environment and enrich the economic, social and cultural life of the region. We will be a catalyst for progress, the State’s most valuable asset, and an indispensable contributor to the nation’s well-being. Achieving the goals of Transforming Maryland requires broad-based and sustained support from our extended community. We ask our stakeholders to join with us to make the University an institution of world-class quality with world-wide reach and unparalleled impact as it serves the people and the state of Maryland.

     
  • richardmitnick 4:01 pm on May 22, 2016 Permalink | Reply
    Tags: , Nanotechnology,   

    From SA: “Nanosized Materials Help Electronics Compute Like Real Brains” 

    Scientific American

    Scientific American

    May 20, 2016
    Michael Torrice, Chemical & Engineering News

    1
    Credit: Eyewire/Getty Images (MARS)

    Although processors have gotten smaller and faster over time, few computers can compete with the speed and computing power of the human brain. And none comes close to the organ’s energy efficiency. So some engineers want to develop electronics that mimic how the brain computes to build more powerful and efficient devices.

    A team at IBM Research, Zurich, now reports that nanosized devices made from phase-change materials can mimic how neurons fire to perform certain calculations (Nat. Nanotechnol. 2016, DOI:10.1038/nnano.2016.70).

    This report “shows quite concretely that we can make simple but effective hardware mimics of neurons, which could be made really small and therefore have low operating powers,” says C. David Wright, an electrical engineer at the University of Exeter who wrote a commentary accompanying the new article.

    The IBM team’s device imitates how an individual neuron integrates incoming signals from other neurons to determine when it should fire. These input signals change the electrical potential across the neuron’s membrane—some increase it, others decrease it. Once that potential passes a certain threshold, the neuron fires.

    Previously, engineers have mimicked this process using combinations of capacitors and silicon transistors, which can be complex and difficult to scale down, Wright explains in his commentary.

    In the new work, IBM’s Evangelos Eleftheriou and colleagues demonstrate a potentially simpler system that uses a phase-change material to play the part of a neuron’s membrane potential. The doped chalcogenide Ge2Sb2Te5, which has been tested in conventional memory devices, can exist in two phases: a glassy amorphous state and a crystalline one. Electrical pulses slowly convert the material from amorphous to crystalline, which, in turn, changes its conductance. At a certain level of phase change, the material’s conductance suddenly jumps, and the device fires like a neuron.

    The IBM team tested a mushroom-shaped device consisting of a 100-nm-thick layer of the chalcogenide sandwiched between two electrodes. In one demonstration, they used the neuronlike device to detect correlations in 1,000 streams of binary data. Such a calculation could spot trends in social media chatter or even in stock market transactions, Wright says.

    He also points out that the devices fire faster than actual neurons, on a nanosecond timescale compared with a millisecond one. The neuron mimics, Wright says, are another step toward hardware that can process information as the brain does but at speeds orders of magnitudes faster than the organ. “That could do some remarkable things.”

    See the full article here .

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    Scientific American, the oldest continuously published magazine in the U.S., has been bringing its readers unique insights about developments in science and technology for more than 160 years.

     
  • richardmitnick 6:13 pm on May 16, 2016 Permalink | Reply
    Tags: , , MIT.nano rising, Nanotechnology   

    From MIT: “MIT.nano rising” 

    MIT News
    MIT News
    MIT Widget

    1
    MIT.nano steel structure, looking northwest. Photo: Lillie Paquette/School of Engineering

    2
    MIT.nano steelworkers. Photo: Lillie Paquette/School of Engineering

    April 20, 2016 [Just appeared in social media.]

    MIT’s future home for cutting-edge nanoscience and nanotechnology research gets fitted with 23 tons of steel per day.

    A spectacular show has been going on outside the windows of central-campus buildings all spring. An enormous steel structure has been growing — piece by piece, and bolt by bolt — out of a giant hole in the ground formerly occupied by Building 12. At a March 24 “tool talk” information session for the MIT community on the construction of MIT.nano, representatives from MIT Facilities and the contractors who are building the new 200,000 square foot nanoscale characterization and fabrication facility gave an overview not only of where things stand with the project, but how they got stood up.

    “In our structural-steel erection progress log, we’ve been averaging around 23 tons per day,” said Peter Johnson of Turner Construction. “We’re putting up 2,101 tons total, and we’re 22 percent complete.”

    On day 469 of the 1,000 days of construction for the project, about 75 percent of the first level was complete, and a quarter of the level 3 cleanroom was installed down to the floor decking. The framing for the entire structure, which will reach a final height of 90 feet above grade, is scheduled to be complete by late May. To get there, Johnson and others have spent years organizing and refining a minutely detailed project plan that links engineering design and fabrication, and the installation process. They have had to map out construction logistics on an hour-to-hour, and foot-by-foot basis. It all must be calibrated to unfold within specific timelines and within the tight confines of MIT.nano’s central campus location. “There’s not a lot of space when it comes to material handling and the movement of workers,” Johnson noted.

    Decisions about cranes, Johnson said, were particularly critical. “While we could have used a single crane to reach the entire footprint, it was too slow. We have a several thousand line item project schedule with hundreds of steel-related tasks,” Johnson explained. “So having two cranes for a shorter period of time made the job more efficient.”

    The first crane was erected during the excavation phase, so workers could use it to lower concrete and rebar into the excavated hole for elements of the foundation. The next crane arrived just prior to steel installation. Positioned strategically in locations that do not block truck routes, the cranes hoist pre-fabricated, specially packaged bundles of steel into the specific locations where they will be needed for construction. Within these packages, each piece has a number that corresponds to its function and placement, and each one has been specifically manufactured for its location, with features like pre-drilled holes to accommodate plumbing and electrical connections. (“So someone knows where the number goes, and that side A connects to side B?” asked Vladimir Bulovic, the faculty lead on the design and construction of MIT.nano. “Just like my Ikea furniture, but bigger.” The construction experts did not dismiss the comparison.)

    Working with Ontario-based steel fabricator, Canatal, Johnson and his colleagues at Turner developed a four-dimensional plan for steel engineering, delivery, and installation. “We went through a painstaking process to maximize efficiency of this sequence,” says Johnson. “This allows us to avoid times when a crane is down because it’s waiting” for a delivery of steel.

    As the structure grows, engineers continuously monitor the basement walls and foundation of the structure with inclinometers, a seismograph, and a three-dimensional laser scanner to gauge how they are responding to the additional weight of the steel. The corner braces in the building’s 50-foot-deep excavation that counteract pressure coming from outside the walls will be removed after the steel is finished and concrete is poured on the building’s first floor. “The building is performing the way we expected it to,” said Richard Amster, director of campus construction.

    See the full article here .

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    The mission of MIT is to advance knowledge and educate students in science, technology, and other areas of scholarship that will best serve the nation and the world in the twenty-first century. We seek to develop in each member of the MIT community the ability and passion to work wisely, creatively, and effectively for the betterment of humankind.

    MIT Campus

     
  • richardmitnick 9:40 pm on May 9, 2016 Permalink | Reply
    Tags: , Nanotechnology,   

    From Ohio University: “Scientists develop synchronized molecular motors” 

    Ohio U bloc

    Ohio University

    May 9, 2016
    Saw-Wai Hla
    (740) 593-1718
    hla@ohio.edu

    Andrea Gibson,
    (740) 597-2166
    gibsona@ohio.edu

    Jennifer Hughes,
    (740) 597-1939
    hughesj2@ohio.edu

    1
    (Top) This illustration shows parallel motors with dipolar rotator arms indicated by arrows. The green and red units represent negative and positive charges. (Bottom) Scanning tunneling microscope image showing a parallel arrangement of dipolar motor assembly. Image credit: Saw-Wai Hla

    An international team of scientists has created molecular motors that can communicate and synchronize their movements.

    The team, led by physicist Saw-Wai Hla of Ohio University, published* an Advanced Online Publication today in the journal Nature Nanotechnology demonstrating that scientists can control the coordinated motions of tiny machines at the nanoscale. The research has implications for the future development of technologies that can be used in computers, photonics and electronics as well as novel nanoscale devices.

    “Our goal is to mimic natural biological machines by creating synthetic machines we can control,” said Hla, a professor of physics and astronomy.

    Hla’s team observed up to 500 molecular motors move simultaneously in the same direction when the scientists applied 1 volt of energy through the tip of a scanning tunneling microscope. At lower levels of energy, the motors also rotated, but in different directions. However, this motion was not random, but showed patterns of coordination, Hla said.

    In the experiment, scientists observed the synchronized movements at minus 316 degrees Fahrenheit.

    The motors have two decks: The upper deck is the rotor and the lower deck is the stator, which has eight sulfur atoms that act as atomic glue to stick to surfaces of gold or copper. The rotating and stationary decks are connected with an atom of europium that serves as an atomic ball bearing.

    Scientists at CEMES/CNRS in France synthesized the molecular motors, which include a dipole in the rotor arms, which means that they have a positive and negative side. This unique feature allows the individual motors to communicate and coordinate their motions, Hla’s team found.

    In addition, the scientists learned that a hexagon arrangement of the motors is key for the synchronization, as it allows the motors to effectively communicate.

    The molecular motors create a ferroelectric system, which is a prized property of materials used in various electronic devices, Hla added.

    The nanomotors are so small that scientists can fit 44,000 billion of them in a 1 centimeter square area.

    “One of the goals of nanotechnology is to assemble billions of nanomachines packed into a tiny area that can be operated in a synchronized manner to transport information or to coherently transfer energy to multiple destinations within nanometer range,” Hla explained.

    The Ohio team received funding from the U.S. Department of Energy and the French team is supported by the French National Research Agency.

    Ohio University team members on the study were S.-W. Hla, Y. Zhang, H. Kersell, V. Iancu, U.G.E. Perera, Y. Li, A. Deshpande and K.-F. Braun of the Department of Physics and Astronomy and Nanoscale and Quantum Phenomena Institute. Hla also is the head of the Quantum and Energy Materials research group at the Center for Nanoscale Materials in Argonne National Laboratory. C. Joachim, R. Stefak and J. Echeverria of CEMES/CNRS in France and G. Rapenne of CEMES/CNRS and the University of Toulouse in France collaborated on the study.

    *Science paper:
    Simultaneous and coordinated rotational switching of all molecular rotors in a network

    See the full article here .

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    Ohio U campus

    n 1786, 11 men gathered at the Bunch of Grapes Tavern in Boston to propose development of the area north of the Ohio River and west of the Allegheny Mountains known then as the Ohio Country. Led by Manasseh Cutler and Rufus Putnam, the Ohio Company petitioned Congress to take action on the proposed settlement. The eventual outcome was the enactment of the Northwest Ordinance of 1787, which provided for settlement and government of the territory and stated that “…schools and the means of education shall forever be encouraged.”

    In 1803, Ohio became a state and on February 18, 1804, the Ohio General Assembly passed an act establishing “The Ohio University.” The University opened in 1808 with one building, three students, and one professor, Jacob Lindley. One of the first two graduates of the University, Thomas Ewing, later became a United States senator and distinguished himself as cabinet member or advisor to four presidents.

    Twenty-four years after its founding, in 1828, Ohio University conferred an A.B. degree on John Newton Templeton, its first black graduate and only the third black man to graduate from a college in the United States. In 1873, Margaret Boyd received her B.A. degree and became the first woman to graduate from the University. Soon after, the institution graduated its first international alumnus, Saki Taro Murayama of Japan, in 1895.

     
  • richardmitnick 8:00 am on March 31, 2016 Permalink | Reply
    Tags: , , , , Nanotechnology   

    From LBL: “Revealing the Fluctuations of Flexible DNA in 3-D” 

    Berkeley Logo

    Berkeley Lab

    March 30, 2016
    Glenn Roberts Jr.
    510-486-5582
    geroberts@lbl.gov

    `
    In a Berkeley Lab-led study, flexible double-helix DNA segments connected to gold nanoparticles are revealed from the 3-D density maps (purple and yellow) reconstructed from individual samples using a Berkeley Lab-developed technique called individual-particle electron tomography or IPET. Projections of the structures are shown in the background grid. (Credit: Berkeley Lab)

    An international team working at the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) has captured the first high-resolution 3-D images from individual double-helix DNA segments attached at either end to gold nanoparticles. The images detail the flexible structure of the DNA segments, which appear as nanoscale jump ropes.

    This unique imaging capability, pioneered by Berkeley Lab scientists, could aid in the use of DNA segments as building blocks for molecular devices that function as nanoscale drug-delivery systems, markers for biological research, and components for computer memory and electronic devices. It could also lead to images of important disease-relevant proteins that have proven elusive for other imaging techniques, and of the assembly process that forms DNA from separate, individual strands.

    The shapes of the coiled DNA strands, which were sandwiched between polygon-shaped gold nanoparticles, were reconstructed in 3-D using a cutting-edge electron microscope technique coupled with a protein-staining process and sophisticated software that provided structural details to the scale of about 2 nanometers, or two billionths of a meter.

    “We had no idea about what the double-strand DNA would look like between the nanogold particles,” said Gang “Gary” Ren, a Berkeley Lab scientist who led the research. “This is the first time for directly visualizing an individual double-strand DNA segment in 3-D,” he said. The results were published in the March 30 edition of Nature Communications.

    The method developed by this team, called individual-particle electron tomography (IPET), had earlier captured the 3-D structure of a single protein that plays a key role in human cholesterol metabolism. By grabbing 2-D images of the same object from different angles, the technique allows researchers to assemble a 3-D image of that object. The team has also used the technique to uncover the fluctuation of another well-known flexible protein, human immunoglobulin 1, which plays a role in our immune system.


    Access mp4 video here .

    For this latest study of DNA nanostructures, Ren used an electron-beam study technique called cryo-electron microscopy (cryo-EM) to examine frozen DNA-nanogold samples, and used IPET to reconstruct 3-D images from samples stained with heavy metal salts. The team also used molecular simulation tools to test the natural shape variations, called “conformations,” in the samples, and compared these simulated shapes with observations.

    Ren explained that the naturally flexible dynamics of samples, like a man waving his arms, cannot be fully detailed by any method that uses an average of many observations.

    A popular way to view the nanoscale structural details of delicate biological samples is to form them into crystals and zap them with X-rays, though this does not preserve their natural shape and the DNA-nanogold samples in this study are incredibly challenging to crystallize. Other common research techniques may require a collection of thousands near-identical objects, viewed with an electron microscope, to compile a single, averaged 3-D structure. But this 3-D image may not adequately show the natural shape fluctuations of a given object.

    The samples in the latest experiment were formed from individual polygon gold nanostructures, measuring about 5 nanometers across, connected to single DNA-segment strands with 84 base pairs. Base pairs are basic chemical building blocks that give DNA its structure. Each individual DNA segment and gold nanoparticle naturally zipped together with a partner to form the double-stranded DNA segment with a gold particle at either end.


    Access mp4 video here .
    These views compare the various shape fluctuations obtained from different samples of the same type of double-helix DNA segment (DNA renderings in green, 3-D reconstructions in purple) connected to gold nanoparticles (yellow). (Credit: Berkeley Lab)

    The samples were flash-frozen to preserve their structure for study with cryo-EM imaging, and the distance between the two gold particles in individual samples varied from 20-30 nanometers based on different shapes observed in the DNA segments. Researchers used a cryo-electron microscope at Berkeley Lab’s Molecular Foundry for this study.

    They collected a series of tilted images of the stained objects, and reconstructed 14 electron-density maps that detailed the structure of individual samples using the IPET technique. They gathered a dozen conformations for the samples and found the DNA shape variations were consistent with those measured in the flash-frozen cryo-EM samples. The shapes were also consistent with samples studied using other electron-based imaging and X-ray scattering methods, and with computer simulations.

    While the 3-D reconstructions show the basic nanoscale structure of the samples, Ren said that the next step will be to work to improve the resolution to the sub-nanometer scale.

    3
    Gang Ren (standing) and Lei Zhang participated in a study at Berkeley Lab’s Molecular Foundry that produced 3-D reproductions of individual samples of double-helix DNA segments attached to gold nanoparticles. (Photo by Roy Kaltschmidt/Berkeley Lab)

    “Even in this current state we begin to see 3-D structures at 1- to 2-nanometer resolution,” he said. “Through better instrumentation and improved computational algorithms, it would be promising to push the resolution to that visualizing a single DNA helix within an individual protein.”

    The technique, he said, has already excited interest among some prominent pharmaceutical companies and nanotechnology researchers, and his science team already has dozens of related research projects in the pipeline.

    In future studies, researchers could attempt to improve the imaging resolution for complex structures that incorporate more DNA segments as a sort of “DNA origami,” Ren said. Researchers hope to build and better characterize nanoscale molecular devices using DNA segments that can, for example, store and deliver drugs to targeted areas in the body.

    “DNA is easy to program, synthesize and replicate, so it can be used as a special material to quickly self-assemble into nanostructures and to guide the operation of molecular-scale devices,” he said. “Our current study is just a proof of concept for imaging these kinds of molecular devices’ structures.”

    The Molecular Foundry is a DOE Office of Science User Facility.

    In addition to Berkeley Lab scientists, other researchers contributing to this study were from UC Berkeley, the Kavli Energy NanoSciences Institute at Berkeley Lab and UC Berkeley, and Xi’an Jiaotong University in China.

    This work was supported by the National Science Foundation, DOE Office of Basic Energy Sciences, National Institutes of Health, the National Natural Science Foundation of China, Xi’an Jiaotong University in China, and the Ministry of Science and Technology in China.

    View more about Gary Ren’s research group here.

    See the full article here .

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