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  • richardmitnick 5:02 pm on May 19, 2017 Permalink | Reply
    Tags: 3D-printed Soft Four Legged Robot Can Walk on Sand and Stone, , Nanotechnology, , UCSD   

    From UCSD: “3D-printed Soft Four Legged Robot Can Walk on Sand and Stone” 

    UC San Diego bloc

    UC San Diego

    May 17, 2017
    Ioana Patringenaru

    UC San Diego Jacobs School of Engineering mechanical engineering graduate student Dylan Trotman from the Tolley Lab with the 3D-printed, four-legged robot being pressented at the 2017 IEEE International Conference on Robotics and Automation (ICRA). The entire photo set is on Flickr. Photo credit: UC San Diego Jacobs School of Engineering / David Baillot

    Engineers at the University of California San Diego have developed the first soft robot that is capable of walking on rough surfaces, such as sand and pebbles. The 3D-printed, four-legged robot can climb over obstacles and walk on different terrains.

    Researchers led by Michael Tolley, a mechanical engineering professor at the University of California San Diego, will present the robot at the IEEE International Conference on Robotics and Automation from May 29 to June 3 in Singapore. The robot could be used to capture sensor readings in dangerous environments or for search and rescue.

    The breakthrough was possible thanks to a high-end printer that allowed researchers to print soft and rigid materials together within the same components. This made it possible for researchers to design more complex shapes for the robot’s legs.

    Bringing together soft and rigid materials will help create a new generation of fast, agile robots that are more adaptable than their predecessors and can safely work side by side with humans, said Tolley. The idea of blending soft and hard materials into the robot’s body came from nature, he added. “In nature, complexity has a very low cost,” Tolley said. “Using new manufacturing techniques like 3D printing, we’re trying to translate this to robotics.”

    3-D printing soft and rigid robots rather than relying on molds to manufacture them is much cheaper and faster, Tolley pointed out. So far, soft robots have only been able to shuffle or crawl on the ground without being able to lift their legs. This robot is actually able to walk.

    Researchers successfully tested the tethered robot on large rocks, inclined surfaces and sand (see video). The robot also was able to transition from walking to crawling into an increasingly confined space, much like a cat wiggling into a crawl space.

    Dylan Drotman, a Ph.D. student at the Jacobs School of Engineering at UC San Diego, led the effort to design the legs and the robot’s control systems. He also developed models to predict how the robot would move, which he then compared to how the robot actually behaved in a real-life environment.

    How it’s made

    The legs are made up of three parallel, connected sealed inflatable chambers, or actuators, 3D-printed from a rubber-like material. The chambers are hollow on the inside, so they can be inflated. On the outside, the chambers are bellowed, which allows engineers to better control the legs’ movements. For example, when one chamber is inflated and the other two aren’t, the leg bends. The legs are laid out in the shape of an X and connected to a rigid body.

    The robot’s gait depends on the order of the timing, the amount of pressure and the order in which the pistons in its four legs are inflated. The robot’s walking behavior in real life also closely matched the researcher’s predictions. This will allow engineers to make better educated decisions when designing soft robots.

    The current quadruped robot prototype is tethered to an open source board and an air pump. Researchers are now working on miniaturizing both the board and the pump so that the robot can walk independently. The challenge here is to find the right design for the board and the right components, such as power sources and batteries, Tolley said.

    3D Printed Soft Actuators for a Legged Robot Capable of Navigating Unstructured Terrain

    Authors: Dylan Drotman, Saurabh Jadhav, Mahmood Karimi, Philip deZonia, Michael T. Tolley

    This work is supported by the UC San Diego Frontiers of Innovation Scholarship Program and the Office of Naval Research grant number N000141712062.

    See the full article here .

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    UC San Diego Campus

    The University of California, San Diego (also referred to as UC San Diego or UCSD), is a public research university located in the La Jolla area of San Diego, California, in the United States.[12] The university occupies 2,141 acres (866 ha) near the coast of the Pacific Ocean with the main campus resting on approximately 1,152 acres (466 ha).[13] Established in 1960 near the pre-existing Scripps Institution of Oceanography, UC San Diego is the seventh oldest of the 10 University of California campuses and offers over 200 undergraduate and graduate degree programs, enrolling about 22,700 undergraduate and 6,300 graduate students. UC San Diego is one of America’s Public Ivy universities, which recognizes top public research universities in the United States. UC San Diego was ranked 8th among public universities and 37th among all universities in the United States, and rated the 18th Top World University by U.S. News & World Report ‘s 2015 rankings.

  • richardmitnick 1:54 pm on May 19, 2017 Permalink | Reply
    Tags: A new atom beam machine being installed at SUNY Poly in Albany for use in computer chip manufacturing., , Nanotechnology, , , TimesUnion   

    From SUNY Poly via TimesUnion: “Chip equipment startup at SUNY Poly gains traction” 


    SUNY Polytechnic Institute



    May 19, 2017
    Larry Rulison

    Photo: Neutral Physics Corp.

    A new atom beam machine being installed at SUNY Poly in Albany for use in computer chip manufacturing.

    A semiconductor manufacturing startup based at SUNY Polytechnic Institute in Albany is thriving despite all of the upheaval lately at the school.

    Neutral Physics Corp., a joint venture between Exogenesis Corp. and Sematech, the computer chip manufacturing consortium based at SUNY Poly, had its new atom beam “tool” delivered to one of SUNY Poly’s chip manufacturing clean rooms just this week to begin “alpha” testing.

    Exogenesis, which is based outside Boston, announced the novel technology development venture with Sematech back in 2015, although it has received little attention since.

    Both Exogenesis and Sematech are shareholders in the company, which is making an atomic particle accelerator that produces atomic-scale etchings onto the silicon wafers used to make computer chips.

    Although Sematech recently dismissed its CEO and has scaled back its operations in recent years, Exogenesis CEO Richard Svrluga told the Times Union that his company’s partnership with Sematech and SUNY Poly has been extremely beneficial.

    The startup just named a new CEO this month – former IBM executive R. “Jaga” Jagannathan – and recent had a “successful” round of Series A financing from outside investors, Svrluga said.

    “Jaga has extensive experience in the semiconductor industry with much of that experience from his years at IBM,” Svrluga said.

    The startup is also being aided by Sematech and Exogenesis executives who have been appointed to leadership roles.

    Sematech has operated as a technology development consortium for the chip industry for most of its history dating back to the 1980s.

    It hasn’t actually started new companies in the past, although the creation of tech startups is part of the mission of SUNY Poly, which moved Sematech to Albany from Austin, Texas about 10 years ago.

    “Our goal is to build a successful business that will in turn generate good jobs for the region,” Svrluga said. “In general, we are feeling extremely positive about where (Neutral Physics Corp.) is at this point of its development. We also very much appreciate the support that we have always received from the staff at Sematech.”

    See the full article here .

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    The State University of New York Polytechnic Institute, commonly referred to as SUNY Polytechnic Institute or SUNY Poly, is a public research university with campuses in the town of Marcy in the Utica-Rome metropolitan area and Albany, New York. Founded in 1966 using classrooms at a primary school, SUNY Poly is New York’s public polytechnic college. The Marcy campus, formerly the SUNY Institute of Technology, has a Utica, New York mailing address and was established in 1987. The Albany campus was formerly a component of the University at Albany, established in January 2003.

    SUNY Poly is accredited by the Middle States Association of Colleges and Schools. The university offers over 30 bachelor’s degrees, 15 master’s degrees, and three doctoral degrees within five different colleges. SUNY Poly students come from across the state of New York, throughout the United States, and more than twenty other nations. More than 25,000 alumni enjoy successful careers in a wide range of fields.

  • richardmitnick 9:45 am on May 18, 2017 Permalink | Reply
    Tags: , Nanotechnology,   

    From SUNY Poly: “SUNY Poly gets $2.25 million toward education program” 


    SUNY Polytechnic Institute


    Times Telegram

    May 17, 2017
    By GateHouse New York

    SUNY Polytechnic Institute has been tapped by the National Science Foundation to receive $2.25 million in federal funding for continued development of the Northeast Advanced Technology Education Center, with the goal of fostering opportunities for semiconductor-related education fields.

    Based at SUNY Poly’s Albany and Marcy campuses, the center will launch credit-bearing high-tech education and training programs over the next three years in support of the region’s advanced semiconductor manufacturing ecosystem, according to a news release.

    “I am honored that the National Science Foundation awarded this grant to SUNY Poly and our partners to continue and dramatically expand NEATEC,” SUNY Poly Professor of Nanoscale Science Robert Geer said in the release. “By supporting the development of exciting new technological education and training modules in nanotechnology and advanced semiconductor manufacturing, SUNY Poly and our key partners at Mohawk Valley Community College, Onondaga Community College and Fulton Montgomery Community College will be able to deploy exciting new programs for addressing the workforce needs of leading innovation- based companies across New York state and the northeast U.S. so that our dramatic expansion of high-tech manufacturing remains robust, with opportunities for all.”

    The center will offer academic certificate programs geared toward advanced technological education programs to help meet the workforce needs of the region’s industries related to semiconductors including power electronics, integrated photonics, silicon photovoltaics and advanced LED lighting technology.

    “MVCC is thrilled to continue our dynamic partnership with SUNY Poly in such a critical area of economic development for Upstate New York,” said MVCC President Randall Van Wagoner in the release.

    See the full article here .

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    The State University of New York Polytechnic Institute, commonly referred to as SUNY Polytechnic Institute or SUNY Poly, is a public research university with campuses in the town of Marcy in the Utica-Rome metropolitan area and Albany, New York. Founded in 1966 using classrooms at a primary school, SUNY Poly is New York’s public polytechnic college. The Marcy campus, formerly the SUNY Institute of Technology, has a Utica, New York mailing address and was established in 1987. The Albany campus was formerly a component of the University at Albany, established in January 2003.

    SUNY Poly is accredited by the Middle States Association of Colleges and Schools. The university offers over 30 bachelor’s degrees, 15 master’s degrees, and three doctoral degrees within five different colleges. SUNY Poly students come from across the state of New York, throughout the United States, and more than twenty other nations. More than 25,000 alumni enjoy successful careers in a wide range of fields.

  • richardmitnick 12:37 pm on May 17, 2017 Permalink | Reply
    Tags: , Capasso Lab, Immersion microscopes, , Lithography, Metalenses, , Nanotechnology, New lens   

    From Paulson: “Building a better microscope​” 

    Harvard School of Engineering and Applied Sciences
    Harvard John A. Paulson School of Engineering and Applied Sciences

    May 9, 2017
    Leah Burrows

    Harvard researchers integrated an immersion meta-lens into a commercial scanning confocal microscope, achieving an imaging spatial resolution of approximately 200 nm. (Image courtesy of the Capasso Lab/Harvard SEAS)

    Metasurface could provide alternative to centuries-old technique.

    A team of researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) has developed the first flat lens for immersion microscopy. This lens, which can be designed for any liquid, may provide a cost-effective and easy-to-manufacture alternative to the expensive, centuries-old technique of hand polishing lenses for immersion objectives.

    The research is described in Nano Letters.

    “This new lens has the potential to overcome the drawbacks and challenges of lens-polishing techniques that have been used for centuries,” said Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at SEAS, and senior author of the paper.

    When light hits an object, it scatters. Optical microscopes work by collecting that scattered light through a series of lenses and reconstructing it into an image. However, the fine detailed geometrical information of an object is carried by the portion of scattered light propagating with angles too large to be collected. Immersing the object in a liquid reduces the angles and allows for the capturing of light that was previously impossible, improving the resolving power of the microscope.

    Based on this principle, immersion microscopes use a layer of liquid — usually water or oil — between the specimen slide and the objective lens. These liquids have higher refractive indices compared to free space so the spatial resolution is increased by a factor equal to the refractive index of the liquid used.

    Immersion microscopes, like all microscopes, are comprised of a series of cascading lenses. The first, known as the front lens, is the smallest and most important component. Only a few millimeters in size, these semicircular lenses look like perfectly preserved rain drops.

    Because of their distinctive shape, most front lenses of high-end microscopes produced today are hand polished. This process, not surprisingly, is expensive and time-consuming and produces lenses that only work within a few specific refractive indices of immersion liquids. So, if one specimen is under blood and another underwater, you would need to hand-craft two different lenses.

    To simplify and speed-up this process, SEAS researchers used nanotechnology to design a front planar lens that can be easily tailored and manufactured for different liquids with different refractive indices. The lens is made up of an array of titanium dioxide nanofins and fabricated using a single-step lithographic process.

    The array of titanium dioxide nanofins can be tailored for any immersion liquid (Image courtesy of Capasso Lab)

    “These lenses are made using a single layer of lithography, a technique widely used in industry,” said Wei Ting Chen, first author of the paper and postdoctoral fellow at SEAS. “They can be mass-produced with existing foundry technology or nanoimprinting for cost-effective high-end immersion optics.”

    Using this process, the team designed metalenses that can not only be tailored for any immersion liquid but also for multiple layers of different refractive indices. This is especially important for imaging biological material, such as skin.

    “Our immersion meta-lens can take into account the refractive indices of epidermis and dermis to focus light on the tissue under human skin without any additional design or fabrication complexity,” said Alexander Zhu, coauthor of the paper and graduate student at SEAS.

    “We foresee that immersion metalenses will find many uses not only in biological imaging but will enable entirely new applications and eventually outperform conventional lenses in existing markets,” said Capasso.

    See the full article here .

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    Through research and scholarship, the Harvard School of Engineering and Applied Sciences (SEAS) will create collaborative bridges across Harvard and educate the next generation of global leaders. By harnessing the power of engineering and applied sciences we will address the greatest challenges facing our society.

    Specifically, that means that SEAS will provide to all Harvard College students an introduction to and familiarity with engineering and technology as this is essential knowledge in the 21st century.

    Moreover, our concentrators will be immersed in the liberal arts environment and be able to understand the societal context for their problem solving, capable of working seamlessly withothers, including those in the arts, the sciences, and the professional schools. They will focus on the fundamental engineering and applied science disciplines for the 21st century; as we will not teach legacy 20th century engineering disciplines.

    Instead, our curriculum will be rigorous but inviting to students, and be infused with active learning, interdisciplinary research, entrepreneurship and engineering design experiences. For our concentrators and graduate students, we will educate “T-shaped” individuals – with depth in one discipline but capable of working seamlessly with others, including arts, humanities, natural science and social science.

    To address current and future societal challenges, knowledge from fundamental science, art, and the humanities must all be linked through the application of engineering principles with the professions of law, medicine, public policy, design and business practice.

    In other words, solving important issues requires a multidisciplinary approach.

    With the combined strengths of SEAS, the Faculty of Arts and Sciences, and the professional schools, Harvard is ideally positioned to both broadly educate the next generation of leaders who understand the complexities of technology and society and to use its intellectual resources and innovative thinking to meet the challenges of the 21st century.

    Ultimately, we will provide to our graduates a rigorous quantitative liberal arts education that is an excellent launching point for any career and profession.

  • richardmitnick 6:32 am on May 15, 2017 Permalink | Reply
    Tags: , , , Nanotechnology,   

    From COSMOS: “Physicists sketch plans for a matter-wave tractor beam” 

    Cosmos Magazine bloc


    15 May 2017
    Robyn Arianrhod

    UFO-style tractor beams may not be in the cards, but matter waves could provide an unprecedented ability to manipulate particles at microscopic scales.
    Aaron Foster / Getty

    A team of physicists have outlined a means of making tractor beams to push and pull objects at a distance using “matter waves”, those strange analogues of light waves that underlie quantum mechanics.

    Tractor beams, staple tools of science fiction for remotely pulling in space shuttles and yanking away incoming space debris, have been edging into reality in recent years.

    The first real-life tractor beams were made of photons. It is easy to imagine a stream of photons carrying a particle of matter along like a river picking up a leaf and carrying it downstream. What is astounding about tractor beams is that by skilfully manipulating the transfer of momentum from the beam, physicists do not have to rely only on pushing particles, but can make light pull particles of matter, like a tractor. Beams made of sound waves have also been demonstrated in the lab.

    In a paper published last week in Physical Review Letters, Alexey Gorlach from Belarusian State University and colleagues from St Petersburg’s ITMO University and the Technical University of Denmark make the case for using a more exotic, less tangible kind of wave.

    The new research is purely theoretical, but the result is still surprising: “The completely different (probabilistic) interpretation of quantum mechanics does not harm the pulling force phenomenon,” the authors write.

    It’s surprising because matter waves are essentially waves of probability – they point the way to predicting where a particle is most likely to be at any point in time. Yet Gorlach’s team’s calculations suggest that these waves of chance can still be harnessed to pull physical nanoparticles as if they were magnets drawing tiny iron filings.

    “It is the wave nature that is the uniting principle,” the researchers point out: light, sound, and matter waves all behave in similar ways. All have different wavelengths, however, and wavelength determines the size of the particles that can be towed by the tractor beam. (The particle must be smaller than the wavelength of the beam.)

    The wavelength of visible light ranges from about 1000 nanometres to 10 nanometres. In 2014, a team from ANU set the optical record [Nature Photonics] by towing microscopic glass beads for a distance of 20 centimetres. The wavelength of sound is longer than that of light, and in 2015, a team from Bristol [Nature Communications]used these longer waves to pull larger objects (up to a millimetre in diameter).

    At the nanoscale is where matter waves could have an edge. Their wavelengths are much smaller than those of light, and Gorlach’s team are looking at wavelengths of one hundredth of a nanometre.

    Optical and acoustic beams are still in the testing phase, and matter-wave tractor beams are yet to make it into the lab, but the possibilities are huge. Gorlach’s team member Andrey Novitsky outlines one such application: “Matter-wave tractor beams could be used in an electron microscope that enables us not only to see atomic-scale objects with unprecedented precision, but also to manipulate them.”

    See the full article here .

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  • richardmitnick 5:12 pm on May 4, 2017 Permalink | Reply
    Tags: Nanoscopy-super-resolution microscopy, Nanotechnology, Optics, , ,   

    From physicsworld.com: “Optical chip gives microscopes nanoscale resolution” 


    May 3, 2017
    Michael Allen

    Super resolution: image taken using the new chip. No image credit.

    A photonic chip that allows a conventional microscope to work at nanoscale resolution has been developed by a team of physicists in Germany and Norway. The researchers claim that as well as opening up nanoscopy to many more people, the mass-producible optical chip also offers a much larger field of view than current nanoscopy techniques, which rely on complex microscopes.

    Nanoscopy, which is also known as super-resolution microscopy, allows scientists to see features smaller than the diffraction limit – about half the wavelength of visible light. It can be used to produce images with resolutions as high as 20–30 nm – approximately 10 times better than a normal microscope. Such techniques have important implications for biological and medical research, with the potential to provide new insights into disease and improve medical diagnostics.

    “The resolution of the standard optical microscope is basically limited by the diffraction barrier of light, which restricts the resolution to 200–300 nm for visible light,” explains Mark Schüttpelz, a physicist at Bielefeld University in Germany. “But many structures, especially biological structures like compartments of cells, are well below the diffraction limit. Here, super-resolution will open up new insights into cells, visualizing proteins ‘at work’ in the cell in order to understand structures and dynamics of cells.”

    Expensive and complex

    There are a number of different nanoscopy techniques that rely on fluorescent dyes to label molecules within the specimen being imaged. A special microscope illuminates and determines the position of individual fluorescent molecules with nanometre precision to build up an image. The problem with these techniques, however, is that they use expensive and complex equipment. “It is not very straightforward to acquire super-resolved images,” says Schüttpelz. “Although there are some rather expensive nanoscopes on the market, trained and experienced operators are required to obtain high-quality images with nanometer resolution.”

    To tackle this, Schüttpelz and his colleagues turned current techniques on their head. Instead of using a complex microscope with a simple glass slide to hold the sample, their method uses a simple microscope for imaging combined with a complex, but mass-producible, optical chip to hold and illuminate the sample.

    “Our photonic chip technology can be retrofitted to any standard microscope to convert it into an optical nanoscope,” explains Balpreet Ahluwalia, a physicist at The Arctic University of Norway, who was also involved in the research.

    Etched channels

    The chip is essentially a waveguide that completely removes the need for the microscope to contain a light source that excites the fluorescent molecules. It consists of five 25–500 μm-wide channels etched into a combination of materials that causes total internal reflection of light.

    The chip is illuminated by two solid-state lasers that are coupled to the chip by a lens or lensed fibres. Light with two different wavelengths is tightly confined within the channels and illuminates the sample, which sits on top of the chip. A lens and camera on the microscope record the resulting fluorescent signal, and the data obtained are used to construct a high-resolution image of the sample.

    To test the effectiveness of the chip, the researchers imaged liver cells. They demonstrated that a field of view of 0.5 × 0.5 mm2 can be achieved at a resolution of around 340 nm in less than half a minute. In principle, this is fast enough to capture live events in cells. For imaging times of up to 30 min, a similar field of view at a resolution better than 140 nm is possible. Resolutions of less than 50 nm are also achievable with the chip, but require higher magnification lenses, which limit the field of view to around 150 μm.

    Many cells

    Ahluwalia told Physics World that the advantage of using the photonic chip for nanoscopy is that it “decouples illumination and detection light paths” and the “waveguide generates illumination over large fields of view”. He adds that this has enabled the team to acquire super-resolved images over an area 100 times larger than with other techniques. This makes single images of as many as 50 living cells possible.

    According to Schüttpelz, the technique represents “a paradigm shift in optical nanoscopy”. “Not only highly specialized laboratories will have access to super-resolution imaging, but many scientists all over the world can convert their standard microscope into a super-resolution microscope just by retrofitting the microscope in order to use waveguide chips,” he says. “Nanoscopy will then be available to everyone at low costs in the near future.”

    The chip is described in Nature Photonics.

    See the full article here .

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    PhysicsWorld is a publication of the Institute of Physics. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application.

    We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications.
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  • richardmitnick 2:56 pm on April 24, 2017 Permalink | Reply
    Tags: Change the color of assembled nanoparticles with an electrical stimulant, Color is dynamically tunable, , Nanotechnology,   

    From LLNL: “Research comes through with flying colors” 

    Lawrence Livermore National Laboratory

    April 24, 2017
    Anne M Stark

    Dynamic color tunability of amorphous photonic structures in response to external electrical stimuli using electrophoretic deposition process. Image by Ryan Chen/LLNL

    Like a chameleon changing colors to blend into the environment, Lawrence Livermore researchers have created a technique to change the color of assembled nanoparticles with an electrical stimulant.

    The team used core/shell nanoparticles to improve color contrast and expand color schemes by using a combination of pigmentary color (from inherent properties) and structural color (from particle assemblies).

    “We were motivated by various examples in living organisms, such as birds, insects and plants,” said Jinkyu Han, lead author of a paper appearing on the cover of the April 3 edition of the journal Advanced Optics Materials . “The assemblies of core/shell nanoparticles can not only imitate interesting colors observed in living organisms, but can be applied in electronic paper displays and colored-reflective photonic displays.”

    Applications of electronic visual displays include electronic pricing labels in retail shops and digital signage, time tables at bus stations, electronic billboards, mobile phone displays and e-readers able to display digital versions of books and magazines.

    The resulting non-iridescent brilliant colors can be manipulated by shell thickness, particle concentration and external electrical stimuli using an electrophoretic deposition process.

    The technique is fully reversible with instantaneous color changes as well as noticeable differences between transmitted and reflected colors.

    The photographs of nanostructures in an electrophoretic deposition (EPD) cell in the absence (OFF state) and presence (ON state) of applied voltage under diffusive illumination. Black carbon tape (LLNL logo) with a white paper was put on the backside of the cell to distinguish the reflected and transmitted color more clearly.

    The particle arrangement in the system is not perfectly ordered nor crystalline, referred to as “amorphous photonic crystal,” which creates the resulting color from light reflection that does not change with viewing angles.

    “The angle independence of the observed colors from the assemblies is quite a unique and interesting property of our system and is ideal for display applications,” Han said.

    The resulting color is dynamically tunable in response to electric stimuli since the nanoparticle arrangement (i.e., inter-particle distance, particle structures) is highly affected by the electric field.

    Contributing authors are Elaine Lee, Jessica Dudoff, Michael Bagge-Hansen, Jonathan Lee, Andrew Pascall, Joshua Kuntz, Trevor Willey, Marcus Worsley and T. Yong-Jin Han.

    See the full article here .

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    Operated by Lawrence Livermore National Security, LLC, for the Department of Energy’s National Nuclear Security
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  • richardmitnick 4:26 pm on April 20, 2017 Permalink | Reply
    Tags: , , , Nanotechnology   

    From BNL: “Q&A with CFN User Davood Shahrjerdi” 

    Brookhaven Lab

    April 18, 2017
    Ariana Tantillo

    Combining the unique properties of emerging nanomaterials with advanced silicon-based electronics, NYU’s Shahrjerdi engineers nano-bioelectronics

    Davood Shahrjerdi in the scanning electron microscope facility at Brookhaven Lab’s Center for Functional Nanomaterials (CFN). The image on the screen is a Hall bar structure for measuring carrier transport in a semiconductor wire.

    Davood Shahrjerdi is an assistant professor of electrical and computer engineering at New York University (NYU) and a principal investigator at the NYU Laboratory for Nano-Engineered Hybrid Integrated Systems. Shahrjerdi, who holds a doctorate in solid-state electronics from The University of Texas at Austin, engineers nanodevices for sensing and life science applications through integrating the unique properties of emerging nanomaterials with advanced silicon-based electronics. For the past two years, he has been using facilities at the Center for Functional Nanomaterials (CFN)—a U.S. Department of Energy (DOE) Office of Science User Facility at Brookhaven National Laboratory—to fabricate and characterize these nanodevices.

    What is the mission of the NYU Laboratory for Nano-Engineered Hybrid Integrated Systems?

    My lab’s mission is to create new electronic devices for sensing and life science applications. To achieve this goal, we combine the benefits of emerging nanomaterials—such as two-dimensional (2D) materials like graphene—and advanced silicon integrated circuits. These nano-engineered bioelectronic systems offer new functionalities that exist in neither nanomaterials nor silicon electronics alone. At the moment, we are leveraging our expertise to engineer new tools for neuroscience applications.

    We are also doing research for realizing high-performance flexible electronics for bioelectronics applications. Our approach is two pronged: (1) flexible electronics using technologically mature materials, such as silicon, that are conventionally mechanically rigid, and (2) flexible electronics using atomically thin 2D nanomaterials that are inherently flexible.

    Given the resources of NYU and the plethora of nanotechnology research centers in the surrounding New York City area, why bring your research to CFN?

    Before I joined academia, I was a research staff member at the IBM Thomas J. Watson Research Center, where I had easy access to advanced fabrication and characterization facilities. When I joined NYU in September 2014, I began to look for research facilities to pursue my research projects. In my search, I discovered CFN and reached out to its scientists, who were very helpful in explaining the research proposal process and the available facilities for my research. In the past two years, my research projects have evolved tremendously, and access to CFN laboratories has been instrumental to this evolution. Because research-active scientists maintain CFN labs, I can conduct my research without major hiccups—a rare occurrence in academia, where equipment downtime and process changes could set back experiments.

    It is not only the state-of-the-art facilities but also the interactions with scientists that have made CFN invaluable to my research. I could use other fabrication facilities in Manhattan, but I prefer to come to CFN. At IBM, I could walk out of my office and knock on any door, gaining access to the expertise of chemists, physicists, and device engineers. This multidisciplinary environment similarly exists at CFN, and it is conducive to driving science forward. Bringing my research to the CFN also means that my doctoral students and postdocs have the opportunity to use state-of-the-art facilities and interact with world-class scientists.

    What tools do you use at CFN to conduct your research, and what are some of the projects you are currently working on?

    We synthesize the 2D nanomaterials at my NYU lab, with subsequent device fabrication and some advanced material characterization at CFN. After device fabrication, we perform electrical characterization at my NYU lab.

    In addition to using the materials processing capabilities in CFN’s clean room, we use advanced material characterization capabilities to glean information about the properties of our materials and devices at the nanoscale. These capabilities include transmission electron microscopy (TEM) to study the structure of the materials, X-ray photoelectron spectroscopy to examine their chemical state, and nano-Auger electron spectroscopy to probe their elemental composition.

    The 5,000-square-foot clean room at CFN is dedicated to state-of-the-art processing of thin-film materials and devices. Capabilities include high-resolution patterning by electron-beam and nanoimprint lithography methods, plasma-based dry etch processes, and material deposition.

    One of our projects is the large-area synthesis of 2D transition metal dichalcogenide semiconductors, which are materials that have a transition metal atom (such as molybdenum or tungsten) sandwiched between two chalcogen atoms (sulfur, selenium, or tellurium). Using a modified version of chemical vapor deposition (referring to the deposition of gaseous reactants onto a substrate to form a solid), my team synthesized a monolayer of tungsten disulfide that has the highest carrier mobility reported for this material. I am now working with CFN scientists to understand the origin of this high electrical performance through low-energy electron microscopy (LEEM). Our understanding could lead to the development of next-generation flexible biomedical devices.

    The single-atom-thick tungsten disulfide (illustration, left) can absorb and emit light, making it attractive for applications in optoelectronics, sensing, and flexible electronics. The photoemission image of the NYU logo (right) shows the monolayer material emitting light.

    Recently, our team together with CFN scientists published a paper on studying the defects in another 2D transition metal dichalcogenide, monolayer molybdenum disulfide. We treated the material with a superacid and used the nano-Auger technique to determine which structural defects were “healed” by the superacid. Our electrical measurements revealed the superacid treatment improves the material’s performance.

    Shahrjerdi and his team fabricated top-gated field-effect transistors (FETs)—devices that utilize a small voltage to control current—on as-grown and superacid-treated molybdenum disulfide films. A schematic of the device is shown in (a). As seen in the graph (b), the chemical treatment (TFSI, red line) improves the electronic properties of the device. From Applied Physics Letters 110, 033503 (2017).

    Another ongoing project in my NYU lab involves a collaborative effort with the NYU Center for Neural Science to develop next-generation neuroprobes for understanding not only the electrical signaling in the brain but also the chemical signaling. This problem is challenging to solve, and we are excited about the prospects of nanotechnology for realizing an innovative solution to it.

    In fabricating nanoelectronic materials and components, what are some of the challenges you face?

    Nanomaterials are usually difficult to handle—they are often very thin and are highly sensitive to defects or misprocessing. As a result, reproducibility could be a challenge. To understand what is causing a particular observed behavior, we have to fabricate many samples and try to reproduce the same result to understand the physical origin of an observed behavior.

    Also, it often happens that you expect to observe a certain behavior but you might end up observing an anomalous behavior that could lead to new discoveries. For example, I accidentally stumbled on the epitaxial growth of silicon on silicon at 120-degrees Celsius while playing around with hydrogen dilution during the deposition of amorphous silicon. This temperature is much lower than the usual temperature required by the traditional approach. My IBM collaborators and I published the work, and it actually led to a best paper award from the Journal of Electronic Materials!

    What is the most exciting thing on the horizon for nanoelectronics? What do you personally hope to achieve?

    Over the next 5 to 10 years, the field of nanoelectronics has great potential to transform our lives—especially in the areas of bioelectronics and bio-inspired electronics, with the marriage between nanomaterials and conventional electronics leading to new discoveries in the life sciences.

    Biosensing is the area that I am most passionate about. The research community still has a limited understanding of how the brain functions, hindering the progress for developing treatments and drugs for neurological disorders such as Parkinson’s. Developing next-generation sensors that advance our understanding of the brain will have tremendous economic and societal impact. I am very excited about our neuroprobe project.

    Also, better understanding of the brain could lead to new discoveries for realizing next-generation computing systems that are inspired by the brain. For example, nanoscale memory devices that could mimic the synapses of the brain would open new horizons for brain-inspired computing. I am engaged in a collaborative effort with The University of Texas at Austin to explore the prospects of nanoscale memristors (short for memory resistor, a new class of electrical circuits with memories that retain information even after the power is shut off) for such an application.

    NYU is home to the second-highest number of international students in the United States, representing more than 130 different countries, and CFN employs staff and hosts users from around the world. How has being in these multicultural environments impacted your research?

    I believe science has no boundaries because it is shared by people who are driven by their curiosity to discover unknowns and have the desire to better humanity. These sentiments are at the core of scientific communities. Though we may have different backgrounds, our common ground is working on problems that have not yet been solved or discovering the undiscovered.

    How did you become interested in science in general and specifically neuroscience?

    As a kid, I was fascinated with science, particularly physics, and building things. By high school, I had also developed an interest in biology and particularly the brain. When I completed high school in Iran, I had to make the decision of whether I wanted to pursue an undergraduate degree or attend medical school. In Iran, there are no pre-med programs—you start medical school directly after high school, and you cannot enroll in medical school after you have taken the undergraduate route.

    My passion at the time was electrical engineering, so I went for the undergraduate degree. This passion evolved into device physics, my PhD field. After a few years at IBM as a device physicist, my love of bioelectronics was rekindled. I started studying neuroscience and even contemplated attending medical school in the United States. Finally, I decided to join academia and apply my knowledge of physics and electronics to the area of bioelectronics. I feel fortunate to have found a career in which I can combine my expertise and interests.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    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.

  • richardmitnick 4:05 pm on April 20, 2017 Permalink | Reply
    Tags: , Focused Ion Beam Milling, Nanotechnology,   

    From Oxford: “Widely used engineering technique has unintended consequences new research reveals” 

    U Oxford bloc

    Oxford University


    20 Apr 2017

    A technique that revolutionised scientists’ ability to manipulate and study materials at the nano-scale may have dramatic unintended consequences, new Oxford University research reveals.

    Focused Ion Beam Milling (FIB) uses a tiny beam of highly energetic particles to cut and analyse materials smaller than one thousandth of a stand of human hair.

    This remarkable capability transformed scientific fields ranging from materials science and engineering to biology and earth sciences. FIB is now an essential tool for a number of applications including; researching high performance alloys for aerospace engineering, nuclear and automotive applications and for prototyping in micro-electronics and micro-fluidics.

    FIB was previously understood to cause structural damage within a thin surface layer (tens of atoms thick) of the material being cut. Until now it was assumed that the effects of FIB would not extend beyond this thin damaged layer. Ground-breaking new results from the University of Oxford demonstrate that this is not the case, and that FIB can in fact dramatically alter the material’s structural identity. This work was carried out in collaboration with colleagues from Argonne National Laboratory, USA, LaTrobe University, Australia, and the Culham Centre for Fusion Energy, UK.

    In research newly published in the journal Scientific Reports, the team studied the damage caused by FIB using a technique called coherent synchrotron X-ray diffraction. This relies on ultra-bright high energy X-rays, available only at central facilities such as the Advanced Photon Source at Argonne National Lab, USA. These X-rays can probe the 3D structure of materials at the nano-scale. The results show that even very low FIB doses, previously thought negligible, have a dramatic effect.

    Felix Hofmann, Associate Professor in Oxford’s Department of Engineering Science and lead author on the study, said, ‘Our research shows that FIB beams have much further-reaching consequences than first thought, and that the structural damage caused is considerable. It affects the entire sample, fundamentally changing the material. Given the role FIB has come to play in science and technology, there is an urgent need to develop new strategies to properly understand the effects of FIB damage and how it might be controlled.’

    Prior to the development of FIB, sample preparation techniques were limited, only allowing sections to be prepared from the material bulk, but not from specific features. FIB transformed this field by making it possible to cut out tiny coupons from specific sites in a material. This progression enabled scientists to examine specific material features using high-resolution electron microscopes. Furthermore it has made mechanical testing of tiny material specimens possible, a necessity for the study of dangerous or extremely precious materials.

    Although keen for his peers to heed the serious consequence of FIB, Professor Hofmann said, ‘The scientific community has been aware of this issue for a while now, but no one (myself included) realised the scale of the problem. There is no way we could have known that FIB had such invasive side effects. The technique is integral to our work and has transformed our approach to prototyping and microscopy, completely changing the way we do science. It has become a central part of modern life.’

    Moving forward, the team is keen to develop awareness of FIB damage. Furthermore, they will build on their current work to gain a better understanding of the damage formed and how it might be removed. Professor Hofmann said, ‘We’re learning how to get better. We have gone from using the technique blindly, to working out how we can actually see the distortions caused by FIB. Next we can consider approaches to mitigate FIB damage. Importantly the new X-ray techniques that we have developed will allow us to assess how effective these approaches are. From this information we can then start to formulate strategies for actively managing FIB damage.’

    See the full article here.

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition

    U Oxford campus

    Oxford is a collegiate university, consisting of the central University and colleges. The central University is composed of academic departments and research centres, administrative departments, libraries and museums. The 38 colleges are self-governing and financially independent institutions, which are related to the central University in a federal system. There are also six permanent private halls, which were founded by different Christian denominations and which still retain their Christian character.

    The different roles of the colleges and the University have evolved over time.

  • richardmitnick 11:15 am on March 31, 2017 Permalink | Reply
    Tags: , , Methanol, Nanotechnology, NSLS-II   

    From BNL: “Chemists ID Catalytic ‘Key’ for Converting CO2 to Methanol” 

    Brookhaven Lab

    March 23, 2017
    Karen McNulty Walsh,
    (631) 344-8350

    Peter Genzer
    (631) 344-3174

    Results will guide design of improved catalysts for transforming pollutant to useful chemicals.

    Jingguang Chen and Jose Rodriguez (standing) discuss the catalytic mechanism with Ping Liu and Shyam Kattel (seated).

    Capturing carbon dioxide (CO2) and converting it to useful chemicals such as methanol could reduce both pollution and our dependence on petroleum products. So scientists are intensely interested in the catalysts that facilitate such chemical conversions. Like molecular dealmakers, catalysts bring the reacting chemicals together in a way that makes it easier for them to break and rearrange their chemical bonds. Understanding details of these molecular interactions could point to strategies to improve the catalysts for more energy-efficient reactions.

    With that goal in mind, chemists from the U.S. Department of Energy’s Brookhaven National Laboratory and their collaborators just released results from experiments and computational modeling studies that definitively identify the “active site” of a catalyst commonly used for making methanol from CO2. The results, published in the journal Science, resolve a longstanding debate about exactly which catalytic components take part in the chemical reactions—and should be the focus of efforts to boost performance.

    “This catalyst—made of copper, zinc oxide, and aluminum oxide—is used in industry, but it’s not very efficient or selective,” said Brookhaven chemist Ping Liu, the study’s lead author, who also holds an adjunct position at nearby Stony Brook University (SBU). “We want to improve it, and get it to operate at lower temperatures and lower pressures, which would save energy,” she said.

    But prior to this study, different groups of scientists had proposed two different active sites for the catalyst—a portion of the system with just copper and zinc atoms, or a portion with copper zinc oxide.

    “We wanted to know which part of the molecular structure binds and breaks and makes bonds to convert reactants to product—and how it does that,” said co-author Jose Rodriguez, another Brookhaven chemist associated with SBU.

    To find out, Rodriguez performed a series of laboratory experiments using well-defined model catalysts, including one made of zinc nanoparticles supported on a copper surface, and another with zinc oxide nanoparticles on copper. To tell the two apart, he used an energetic x-ray beam to zap the samples, and measured the properties of electrons emitted. These electronic “signatures” contain information about the oxidation state of the atoms the electrons came from—whether zinc or zinc oxide.

    Brookhaven chemist Ping Liu

    Meanwhile Liu, Jingguang Chen of Brookhaven Lab and Columbia University, and Shyam Kattel, the first author of the paper and a postdoctoral fellow co-advised by Liu and Chen, used computational resources at Brookhaven’s Center for Functional Nanomaterials (CFN) and the National Energy Research Scientific Computing Center (NERSC)—two DOE Office of Science User Facilities—to model how these two types of catalysts would engage in the CO2-to-methanol transformations. These theoretical studies use calculations that take into account the basic principles of breaking and making chemical bonds, including the energy required, the electronic states of the atoms, and the reaction conditions, allowing scientists to derive the reaction rates and determine which catalyst will give the best rate of conversion.

    “We found that copper zinc oxide should give the best results, and that copper zinc is not even stable under reaction conditions,” said Liu. “In fact, it reacts with oxygen and transforms to copper zinc oxide.”

    Those predictions matched what Rodriguez observed in the laboratory. “We found that all the sites participating in these reactions were copper zinc oxide,” he said.

    But don’t forget the copper.

    “In our simulations, all the reaction intermediates—the chemicals that form on the pathway from CO2 to methanol—bind at both the copper and zinc oxide,” Kattel said. “So there’s a synergy between the copper and zinc oxide that accelerates the chemical transformation. You need both the copper and the zinc oxide.”

    Ping Liu and Shyam Kattel with the x-ray source used in this study.

    Optimizing the copper/zinc oxide interface will become the driving principal for designing a new catalyst, the scientists say.

    “This work clearly demonstrates the synergy from combining theoretical and experimental efforts for studying catalytic systems of industrial importance,” said Chen. “We will continue to utilize the same combined approaches in future studies.”

    For example, said Rodriguez, “We’ll try different configurations of the atoms at the copper/zinc oxide interface to see how that affects the reaction rate. Also, we’ll be going from studying the model system to systems that would be more practical for use by industry.”

    An essential tool for this next step will be Brookhaven’s National Synchrotron Light Source II (NSLS-II), another Office of Science User Facility. NSLS-II produces extremely bright beams of x-rays—about 10,000 times brighter than the broad-beam laboratory x-ray source used in this study. Those intense x-ray beams will allow the scientists to take high-resolution snapshots that reveal both structural and chemical information about the catalyst, the reactants, and the chemical intermediates that form as the reaction occurs.

    Brookhaven scientists identified how a zinc/copper (Zn/Cu) catalyst transforms carbon dioxide (two red and one grey balls) and hydrogen (two white balls) to methanol (one grey, one red, and four white balls), a potential fuel. Under reaction conditions, Zn/Cu transforms to ZnO/Cu, where the interface between the ZnO and Cu provides the active sites that allow the formation of methanol.

    “And we’ll continue to expand the theory,” said Liu. “The theory points to the mechanistic details. We want to modify interactions at the copper/zinc oxide interface to see how that affects the activity and efficiency of the catalyst, and we’ll need the theory to move forward with that as well.”

    An additional co-author, Pedro Ramírez of Universidad Central de Venezuela, made important contributions to this study by helping to test the activity of the copper zinc and copper zinc oxide catalysts.

    This research was supported by the DOE Office of Science.

    See the full article here .

    Please help promote STEM in your local schools.

    STEM Icon

    Stem Education Coalition
    BNL Campus

    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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