Tag Archives: US National Institute of Standards and Technology

Formation of a time (temporal) crystal

It’s a crystal arranged in time according to a March 8, 2017 University of Texas at Austin news release (also on EurekAlert), Note: Links have been removed,

Salt, snowflakes and diamonds are all crystals, meaning their atoms are arranged in 3-D patterns that repeat. Today scientists are reporting in the journal Nature on the creation of a phase of matter, dubbed a time crystal, in which atoms move in a pattern that repeats in time rather than in space.

The atoms in a time crystal never settle down into what’s known as thermal equilibrium, a state in which they all have the same amount of heat. It’s one of the first examples of a broad new class of matter, called nonequilibrium phases, that have been predicted but until now have remained out of reach. Like explorers stepping onto an uncharted continent, physicists are eager to explore this exotic new realm.

“This opens the door to a whole new world of nonequilibrium phases,” says Andrew Potter, an assistant professor of physics at The University of Texas at Austin. “We’ve taken these theoretical ideas that we’ve been poking around for the last couple of years and actually built it in the laboratory. Hopefully, this is just the first example of these, with many more to come.”

Some of these nonequilibrium phases of matter may prove useful for storing or transferring information in quantum computers.

Potter is part of the team led by researchers at the University of Maryland who successfully created the first time crystal from ions, or electrically charged atoms, of the element ytterbium. By applying just the right electrical field, the researchers levitated 10 of these ions above a surface like a magician’s assistant. Next, they whacked the atoms with a laser pulse, causing them to flip head over heels. Then they hit them again and again in a regular rhythm. That set up a pattern of flips that repeated in time.

Crucially, Potter noted, the pattern of atom flips repeated only half as fast as the laser pulses. This would be like pounding on a bunch of piano keys twice a second and notes coming out only once a second. This weird quantum behavior was a signature that he and his colleagues predicted, and helped confirm that the result was indeed a time crystal.

The team also consists of researchers at the National Institute of Standards and Technology, the University of California, Berkeley and Harvard University, in addition to the University of Maryland and UT Austin.

Frank Wilczek, a Nobel Prize-winning physicist at the Massachusetts Institute of Technology, was teaching a class about crystals in 2012 when he wondered whether a phase of matter could be created such that its atoms move in a pattern that repeats in time, rather than just in space.

Potter and his colleague Norman Yao at UC Berkeley created a recipe for building such a time crystal and developed ways to confirm that, once you had built such a crystal, it was in fact the real deal. That theoretical work was announced publically last August and then published in January in the journal Physical Review Letters.

A team led by Chris Monroe of the University of Maryland in College Park built a time crystal, and Potter and Yao helped confirm that it indeed had the properties they predicted. The team announced that breakthrough—constructing a working time crystal—last September and is publishing the full, peer-reviewed description today in Nature.

A team led by Mikhail Lukin at Harvard University created a second time crystal a month after the first team, in that case, from a diamond.

Here’s a link to and a citation for the paper,

Observation of a discrete time crystal by J. Zhang, P. W. Hess, A. Kyprianidis, P. Becker, A. Lee, J. Smith, G. Pagano, I.-D. Potirniche, A. C. Potter, A. Vishwanath, N. Y. Yao, & C. Monroe. Nature 543, 217–220 (09 March 2017) doi:10.1038/nature21413 Published online 08 March 2017

This paper is behind a paywall.

Using sugar for a better way to clean nanoparticles from organisms

Researchers at the US National Institute of Standards and Technology (NIST) have found that a laboratory technique used for over 60 years is the best way to date to clean nanoparticles from organisms. From a Jan. 26, 2017 news item on ScienceDaily,

Sometimes old-school methods provide the best ways of studying cutting-edge tech and its effects on the modern world.

Giving a 65-year-old laboratory technique a new role, researchers at the National Institute of Standards and Technology (NIST) have performed the cleanest separation to date of synthetic nanoparticles from a living organism. The new NIST method is expected to significantly improve experiments looking at the potential environmental and health impacts of these manufactured entities. It will allow scientists to more accurately count how many nanoparticles have actually been ingested by organisms exposed to them.

A Jan. 26, 2017 NIST news release (also on EurekAlert), which originated the news item, offers more detail,

The common roundworm Caenorhabditis elegans has been used in recent years as a living model for laboratory studies of how biological and chemical compounds may affect multicellular organisms. These compounds include engineered nanoparticles (ENPs), bits of material between 1 and 100 nanometers (billionths of a meter, or about 1/10,000 the diameter of a red blood cell). Previous research has often focused on quantifying the amount and size of engineered nanoparticles ingested by C. elegans. Measuring the nanoparticles that actually make it into an organism is considered a more relevant indicator of potential toxicity than just the amount of ENPs to which the worms are exposed.

Traditional methods for counting ingested ENPs have produced questionable results. Currently, researchers expose C. elegans to metal ENPs such as silver or gold in solution, then rinse the excess particles away with water followed by centrifugation and freeze-drying. A portion of the “cleaned” sample produced is then typically examined by a technique that determines the amount of metal present, known as inductively coupled plasma mass spectrometry (ICP-MS). It often yields ENP counts in the tens of thousands per worm; however, those numbers always seem too high to NIST researchers working with C. elegans.

“Since ICP-MS will detect all of the nanoparticles associated with the worms, both those ingested and those that remain attached externally, we suspect that the latter is what makes the ‘ENPs’ per-worm counts so high,” said NIST analytical chemist Monique Johnson (link sends e-mail), the lead author on the ACS Nano paper. “Since we only wanted to quantify the ingested ENPs, a more robust and reliable separation method was needed.”

Luckily, the solution to the problem was already in the lab.

Cross section of the roundworm C. elegans

Scanning electron micrograph showing a cross section of the roundworm C. elegans with two ingested engineered nanoparticles (red dots just right of center). Images such as this provided NIST researchers with visual confirmation that nanoparticle consumption actually occurred. Credit: K. Scott/NIST

In the course of culturing C. elegans for ENP-exposure experiments, Johnson and her colleagues had used sucrose density gradient centrifugation, a decades-old and established system for cleanly separating cellular components, to isolate the worms from debris and bacteria. “We wondered if the same process would allow us to perform an organism-from-ENP separation as well, so I designed a study to find out,” Johnson said.

In their experiment, the NIST researchers first exposed separate samples of C. elegans to low and high concentrations of two sizes of gold nanospheres, 30 and 60 nanometers in diameter. The researchers put each of the samples into a centrifuge and removed the supernatant (liquid portion), leaving the worms and ENPs in the remaining pellets. These were centrifuged twice in a salt solution (rather than just water as in previous separation methods), and then centrifuged again, but this time, through a uniquely designed sucrose density gradient.

“From top to bottom, our gradient consisted of a salt solution layer to trap excess ENPs and three increasingly dense layers of sucrose [20, 40 and 50 percent] to isolate the C. elegans,” Johnson explained. “We followed up the gradient with three water rinses and with centrifugations to ensure that only worms with ingested ENPs, and not the sucrose separation medium with any excess ENPs, would make it into the final pellet.”

Analyzing the range of masses in the ultrapurified samples indicated gold levels more in line with what the researchers expected would be found as ingested ENPs. Experimental validation of the NIST separation method’s success came when the worms were examined in detail under a scanning electron microscope (SEM).

“For me, the eureka moment was when I first saw gold ENPs in the cross section images taken from the C. elegans samples that had been processed through the sucrose density gradient,” Johnson said. “I had been dreaming about finding ENPs in the worm’s digestive tract and now they were really there!”

The high-resolution SEM images also provided visual evidence that only ingested ENPs were counted. “No ENPs were attached to the cuticle, the exoskeleton of C. elegans, in any of the sucrose density gradient samples,” Johnson said. “When we examined worms from our control experiments [processed using the traditional no-gradient, water-rinse-only separation method], there were a number of nanospheres found attached to the cuticle.

Now that it has been successfully demonstrated, the NIST researchers plan to refine and further validate their system for evaluating the uptake of ENPs by C. elegans. “Hopefully, our method will become a useful and valuable tool for reducing the measurement variability and sampling bias that can plague environmental nanotoxicology studies,” Johnson said.

They’ve tested this technique on gold nanoparticles, which begs the question, What kinds of nanoparticles can this technique be used for? Metal nanoparticles only or all nanoparticles?

I’m sure the researchers have already asked these questions and started researching the answers. While the rest of us wait, here’s a link to and a citation for the paper about this promising new technique,

Separation, Sizing, and Quantitation of Engineered Nanoparticles in an Organism Model Using Inductively Coupled Plasma Mass Spectrometry and Image Analysis by Monique E. Johnson, Shannon K. Hanna, Antonio R. Montoro Bustos, Christopher M. Sims, Lindsay C. C. Elliott, Akshay Lingayat, Adrian C. Johnston, Babak Nikoobakht, John T. Elliott, R. David Holbrook, Keana C. K. Scott, Karen E. Murphy, Elijah J. Petersen, Lee L. Yu, and Bryant C. Nelson. ACS Nano, 2017, 11 (1), pp 526–540 DOI: 10.1021/acsnano.6b06582 Publication Date (Web): December 16, 2016

Copyright This article not subject to U.S. Copyright. Published 2016 by the American Chemical Society

This paper is behind a paywall.

Investigating nanoparticles and their environmental impact for industry?

It seems the Center for the Environmental Implications of Nanotechnology (CEINT) at Duke University (North Carolina, US) is making an adjustment to its focus and opening the door to industry, as well as, government research. It has for some years (my first post about the CEINT at Duke University is an Aug. 15, 2011 post about its mesocosms) been focused on examining the impact of nanoparticles (also called nanomaterials) on plant life and aquatic systems. This Jan. 9, 2017 US National Science Foundation (NSF) news release (h/t Jan. 9, 2017 Nanotechnology Now news item) provides a general description of the work,

We can’t see them, but nanomaterials, both natural and manmade, are literally everywhere, from our personal care products to our building materials–we’re even eating and drinking them.

At the NSF-funded Center for Environmental Implications of Nanotechnology (CEINT), headquartered at Duke University, scientists and engineers are researching how some of these nanoscale materials affect living things. One of CEINT’s main goals is to develop tools that can help assess possible risks to human health and the environment. A key aspect of this research happens in mesocosms, which are outdoor experiments that simulate the natural environment – in this case, wetlands. These simulated wetlands in Duke Forest serve as a testbed for exploring how nanomaterials move through an ecosystem and impact living things.

CEINT is a collaborative effort bringing together researchers from Duke, Carnegie Mellon University, Howard University, Virginia Tech, University of Kentucky, Stanford University, and Baylor University. CEINT academic collaborations include on-going activities coordinated with faculty at Clemson, North Carolina State and North Carolina Central universities, with researchers at the National Institute of Standards and Technology and the Environmental Protection Agency labs, and with key international partners.

The research in this episode was supported by NSF award #1266252, Center for the Environmental Implications of NanoTechnology.

The mention of industry is in this video by O’Brien and Kellan, which describes CEINT’s latest work ,

Somewhat similar in approach although without a direction reference to industry, Canada’s Experimental Lakes Area (ELA) is being used as a test site for silver nanoparticles. Here’s more from the Distilling Science at the Experimental Lakes Area: Nanosilver project page,

Water researchers are interested in nanotechnology, and one of its most commonplace applications: nanosilver. Today these tiny particles with anti-microbial properties are being used in a wide range of consumer products. The problem with nanoparticles is that we don’t fully understand what happens when they are released into the environment.

The research at the IISD-ELA [International Institute for Sustainable Development Experimental Lakes Area] will look at the impacts of nanosilver on ecosystems. What happens when it gets into the food chain? And how does it affect plants and animals?

Here’s a video describing the Nanosilver project at the ELA,

You may have noticed a certain tone to the video and it is due to some political shenanigans, which are described in this Aug. 8, 2016 article by Bartley Kives for the Canadian Broadcasting Corporation’s (CBC) online news.

Hopes for nanocellulose in the fields of medicine and green manufacturing

Initially this seemed like an essay extolling the possibilities for nanocellulose but it is also a research announcement. From a Nov. 7, 2016 news item on Nanowerk,

What if you could take one of the most abundant natural materials on earth and harness its strength to lighten the heaviest of objects, to replace synthetic materials, or use it in scaffolding to grow bone, in a fast-growing area of science in oral health care?

This all might be possible with cellulose nanocrystals, the molecular matter of all plant life. As industrial filler material, they can be blended with plastics and other synthetics. They are as strong as steel, tough as glass, lightweight, and green.

“Plastics are currently reinforced with fillers made of steel, carbon, Kevlar, or glass. There is an increasing demand in manufacturing for sustainable materials that are lightweight and strong to replace these fillers,” said Douglas M. Fox, associate professor of chemistry at American University.
“Cellulose nanocrystals are an environmentally friendly filler. If there comes a time that they’re used widely in manufacturing, cellulose nanocrystals will lessen the weight of materials, which will reduce energy.”

A Nov. 7, 2016 American University news release on EurekAlert, which originated the news item, continues into the research,

Fox has submitted a patent for his work with cellulose nanocrystals, which involves a simple, scalable method to improve their performance. Published results of his method can be found in the chemistry journal ACS Applied Materials and Interfaces. Fox’s method could be used as a biomaterial and for applications in transportation, infrastructure and wind turbines.

The power of cellulose

Cellulose gives stems, leaves and other organic material in the natural world their strength. That strength already has been harnessed for use in many commercial materials. At the nano-level, cellulose fibers can be broken down into tiny crystals, particles smaller than ten millionths of a meter. Deriving cellulose from natural sources such as wood, tunicate (ocean-dwelling sea cucumbers) and certain kinds of bacteria, researchers prepare crystals of different sizes and strengths.

For all of the industry potential, hurdles abound. As nanocellulose disperses within plastic, scientists must find the sweet spot: the right amount of nanoparticle-matrix interaction that yields the strongest, lightest property. Fox overcame four main barriers by altering the surface chemistry of nanocrystals with a simple process of ion exchange. Ion exchange reduces water absorption (cellulose composites lose their strength if they absorb water); increases the temperature at which the nanocrystals decompose (needed to blend with plastics); reduces clumping; and improves re-dispersal after the crystals dry.

Cell growth

Cellulose nanocrystals as a biomaterial is yet another commercial prospect. In dental regenerative medicine, restoring sufficient bone volume is needed to support a patient’s teeth or dental implants. Researchers at the National Institute of Standards and Technology [NIST], through an agreement with the National Institute of Dental and Craniofacial Research of the National Institutes of Health, are looking for an improved clinical approach that would regrow a patient’s bone. When researchers experimented with Fox’s modified nanocrystals, they were able to disperse the nanocrystals in scaffolds for dental regenerative medicine purposes.

“When we cultivated cells on the cellulose nanocrystal-based scaffolds, preliminary results showed remarkable potential of the scaffolds for both their mechanical properties and the biological response. This suggests that scaffolds with appropriate cellulose nanocrystal concentrations are a promising approach for bone regeneration,” said Martin Chiang, team leader for NIST’s Biomaterials for Oral Health Project.

Another collaboration Fox has is with Georgia Institute of Technology and Owens Corning, a company specializing in fiberglass insulation and composites, to research the benefits to replace glass-reinforced plastic used in airplanes, cars and wind turbines. He also is working with Vireo Advisors and NIST to characterize the health and safety of cellulose nanocrystals and nanofibers.

“As we continue to show these nanomaterials are safe, and make it easier to disperse them into a variety of materials, we get closer to utilizing nature’s chemically resistant, strong, and most abundant polymer in everyday products,” Fox said.

Here’s a link to and a citation for the paper,

Simultaneously Tailoring Surface Energies and Thermal Stabilities of Cellulose Nanocrystals Using Ion Exchange: Effects on Polymer Composite Properties for Transportation, Infrastructure, and Renewable Energy Applications by Douglas M. Fox, Rebeca S. Rodriguez, Mackenzie N. Devilbiss, Jeremiah Woodcock, Chelsea S. Davis, Robert Sinko, Sinan Keten, and Jeffrey W. Gilman. ACS Appl. Mater. Interfaces, 2016, 8 (40), pp 27270–27281 DOI: 10.1021/acsami.6b06083 Publication Date (Web): September 14, 2016

Copyright © 2016 American Chemical Society

This paper is behind a paywall.

Mimicking rain and sun to test plastic for nanoparticle release

One of Canada’s nanotechnology experts once informed a House of Commons Committee on Health that nanoparticles encased in plastic (he was talking about cell phones) weren’t likely to harm you except in two circumstances (when workers were using them in the manufacturing process and when the product was being disposed of). Apparently, under some circumstances, that isn’t true any more. From a Sept. 30, 2016 news item on Nanowerk,

If the 1967 film “The Graduate” were remade today, Mr. McGuire’s famous advice to young Benjamin Braddock would probably be updated to “Plastics … with nanoparticles.” These days, the mechanical, electrical and durability properties of polymers—the class of materials that includes plastics—are often enhanced by adding miniature particles (smaller than 100 nanometers or billionths of a meter) made of elements such as silicon or silver. But could those nanoparticles be released into the environment after the polymers are exposed to years of sun and water—and if so, what might be the health and ecological consequences?

A Sept. 30, 2016 US National Institute of Standards and Technology (NIST) news release, which originated the news item, describes how the research was conducted and its results (Note: Links have been removed),

In a recently published paper (link is external), researchers from the National Institute of Standards and Technology (NIST) describe how they subjected a commercial nanoparticle-infused coating to NIST-developed methods for accelerating the effects of weathering from ultraviolet (UV) radiation and simulated washings of rainwater. Their results indicate that humidity and exposure time are contributing factors for nanoparticle release, findings that may be useful in designing future studies to determine potential impacts.

In their recent experiment, the researchers exposed multiple samples of a commercially available polyurethane coating containing silicon dioxide nanoparticles to intense UV radiation for 100 days inside the NIST SPHERE (Simulated Photodegradation via High-Energy Radiant Exposure), a hollow, 2-meter (7-foot) diameter black aluminum chamber lined with highly UV reflective material that bears a casual resemblance to the Death Star in the film “Star Wars.” For this study, one day in the SPHERE was equivalent to 10 to 15 days outdoors. All samples were weathered at a constant temperature of 50 degrees Celsius (122 degrees Fahrenheit) with one group done in extremely dry conditions (approximately 0 percent humidity) and the other in humid conditions (75 percent humidity).

To determine if any nanoparticles were released from the polymer coating during UV exposure, the researchers used a technique they created and dubbed “NIST simulated rain.” Filtered water was converted into tiny droplets, sprayed under pressure onto the individual samples, and then the runoff—with any loose nanoparticles—was collected in a bottle. This procedure was conducted at the beginning of the UV exposure, at every two weeks during the weathering run and at the end. All of the runoff fluids were then analyzed by NIST chemists for the presence of silicon and in what amounts. Additionally, the weathered coatings were examined with atomic force microscopy (AFM) and scanning electron microscopy (SEM) to reveal surface changes resulting from UV exposure.

Both sets of coating samples—those weathered in very low humidity and the others in very humid conditions—degraded but released only small amounts of nanoparticles. The researchers found that more silicon was recovered from the samples weathered in humid conditions and that nanoparticle release increased as the UV exposure time increased. Microscopic examination showed that deformations in the coating surface became more numerous with longer exposure time, and that nanoparticles left behind after the coating degraded often bound together in clusters.

“These data, and the data from future experiments of this type, are valuable for developing computer models to predict the long-term release of nanoparticles from commercial coatings used outdoors, and in turn, help manufacturers, regulatory officials and others assess any health and environmental impacts from them,” said NIST research chemist Deborah Jacobs, lead author on the study published in the Journal of Coatings Technology and Research (link is external).

Here’s a link to and a citation for the paper,

Surface degradation and nanoparticle release of a commercial nanosilica/polyurethane coating under UV exposure by Deborah S. Jacobs, Sin-Ru Huang, Yu-Lun Cheng, Savelas A. Rabb, Justin M. Gorham, Peter J. Krommenhoek, Lee L. Yu, Tinh Nguyen, Lipiin Sung. J Coat Technol Res (2016) 13: 735. doi:10.1007/s11998-016-9796-2 First published online 13 July 2016

This paper is behind a paywall.

For anyone interested in the details about the House of Commons nano story I told at the start of this post, here’s the June 23, 2010 posting where I summarized the hearing on nanotechnology. If you scroll down about 50% of the way, you’ll find Dr. Nils Petersen’s (then director of Canada’s National Institute of Nanotechnology) comments about nanoparticles being encased. The topic had been nanosunscreens and he was describing the conditions under which he believed nanoparticles could be dangerous.

Creating multiferroic material at room temperature

A Sept. 23, 2016 news item on ScienceDaily describes some research from Cornell University (US),

Multiferroics — materials that exhibit both magnetic and electric order — are of interest for next-generation computing but difficult to create because the conditions conducive to each of those states are usually mutually exclusive. And in most multiferroics found to date, their respective properties emerge only at extremely low temperatures.

Two years ago, researchers in the labs of Darrell Schlom, the Herbert Fisk Johnson Professor of Industrial Chemistry in the Department of Materials Science and Engineering, and Dan Ralph, the F.R. Newman Professor in the College of Arts and Sciences, in collaboration with professor Ramamoorthy Ramesh at UC Berkeley, published a paper announcing a breakthrough in multiferroics involving the only known material in which magnetism can be controlled by applying an electric field at room temperature: the multiferroic bismuth ferrite.

Schlom’s group has partnered with David Muller and Craig Fennie, professors of applied and engineering physics, to take that research a step further: The researchers have combined two non-multiferroic materials, using the best attributes of both to create a new room-temperature multiferroic.

Their paper, “Atomically engineered ferroic layers yield a room-temperature magnetoelectric multiferroic,” was published — along with a companion News & Views piece — Sept. 22 [2016] in Nature. …

A Sept. 22, 2016 Cornell University news release by Tom Fleischman, which originated the news item, details more about the work (Note: A link has been removed),

The group engineered thin films of hexagonal lutetium iron oxide (LuFeO3), a material known to be a robust ferroelectric but not strongly magnetic. The LuFeO3 consists of alternating single monolayers of lutetium oxide and iron oxide, and differs from a strong ferrimagnetic oxide (LuFe2O4), which consists of alternating monolayers of lutetium oxide with double monolayers of iron oxide.

The researchers found, however, that they could combine these two materials at the atomic-scale to create a new compound that was not only multiferroic but had better properties that either of the individual constituents. In particular, they found they need to add just one extra monolayer of iron oxide to every 10 atomic repeats of the LuFeO3 to dramatically change the properties of the system.

That precision engineering was done via molecular-beam epitaxy (MBE), a specialty of the Schlom lab. A technique Schlom likens to “atomic spray painting,” MBE let the researchers design and assemble the two different materials in layers, a single atom at a time.

The combination of the two materials produced a strongly ferrimagnetic layer near room temperature. They then tested the new material at the Lawrence Berkeley National Laboratory (LBNL) Advanced Light Source in collaboration with co-author Ramesh to show that the ferrimagnetic atoms followed the alignment of their ferroelectric neighbors when switched by an electric field.

“It was when our collaborators at LBNL demonstrated electrical control of magnetism in the material that we made that things got super exciting,” Schlom said. “Room-temperature multiferroics are exceedingly rare and only multiferroics that enable electrical control of magnetism are relevant to applications.”

In electronics devices, the advantages of multiferroics include their reversible polarization in response to low-power electric fields – as opposed to heat-generating and power-sapping electrical currents – and their ability to hold their polarized state without the need for continuous power. High-performance memory chips make use of ferroelectric or ferromagnetic materials.

“Our work shows that an entirely different mechanism is active in this new material,” Schlom said, “giving us hope for even better – higher-temperature and stronger – multiferroics for the future.”

Collaborators hailed from the University of Illinois at Urbana-Champaign, the National Institute of Standards and Technology, the University of Michigan and Penn State University.

Here is a link and a citation to the paper and to a companion piece,

Atomically engineered ferroic layers yield a room-temperature magnetoelectric multiferroic by Julia A. Mundy, Charles M. Brooks, Megan E. Holtz, Jarrett A. Moyer, Hena Das, Alejandro F. Rébola, John T. Heron, James D. Clarkson, Steven M. Disseler, Zhiqi Liu, Alan Farhan, Rainer Held, Robert Hovden, Elliot Padgett, Qingyun Mao, Hanjong Paik, Rajiv Misra, Lena F. Kourkoutis, Elke Arenholz, Andreas Scholl, Julie A. Borchers, William D. Ratcliff, Ramamoorthy Ramesh, Craig J. Fennie, Peter Schiffer et al. Nature 537, 523–527 (22 September 2016) doi:10.1038/nature19343 Published online 21 September 2016

Condensed-matter physics: Multitasking materials from atomic templates by Manfred Fiebig. Nature 537, 499–500  (22 September 2016) doi:10.1038/537499a Published online 21 September 2016

Both the paper and its companion piece are behind a paywall.

US white paper on neuromorphic computing (or the nanotechnology-inspired Grand Challenge for future computing)

The US has embarked on a number of what is called “Grand Challenges.” I first came across the concept when reading about the Bill and Melinda Gates (of Microsoft fame) Foundation. I gather these challenges are intended to provide funding for research that advances bold visions.

There is the US National Strategic Computing Initiative established on July 29, 2015 and its first anniversary results were announced one year to the day later. Within that initiative a nanotechnology-inspired Grand Challenge for Future Computing was issued and, according to a July 29, 2016 news item on Nanowerk, a white paper on the topic has been issued (Note: A link has been removed),

Today [July 29, 2016), Federal agencies participating in the National Nanotechnology Initiative (NNI) released a white paper (pdf) describing the collective Federal vision for the emerging and innovative solutions needed to realize the Nanotechnology-Inspired Grand Challenge for Future Computing.

The grand challenge, announced on October 20, 2015, is to “create a new type of computer that can proactively interpret and learn from data, solve unfamiliar problems using what it has learned, and operate with the energy efficiency of the human brain.” The white paper describes the technical priorities shared by the agencies, highlights the challenges and opportunities associated with these priorities, and presents a guiding vision for the research and development (R&D) needed to achieve key technical goals. By coordinating and collaborating across multiple levels of government, industry, academia, and nonprofit organizations, the nanotechnology and computer science communities can look beyond the decades-old approach to computing based on the von Neumann architecture and chart a new path that will continue the rapid pace of innovation beyond the next decade.

A July 29, 2016 US National Nanotechnology Coordination Office news release, which originated the news item, further and succinctly describes the contents of the paper,

“Materials and devices for computing have been and will continue to be a key application domain in the field of nanotechnology. As evident by the R&D topics highlighted in the white paper, this challenge will require the convergence of nanotechnology, neuroscience, and computer science to create a whole new paradigm for low-power computing with revolutionary, brain-like capabilities,” said Dr. Michael Meador, Director of the National Nanotechnology Coordination Office. …

The white paper was produced as a collaboration by technical staff at the Department of Energy, the National Science Foundation, the Department of Defense, the National Institute of Standards and Technology, and the Intelligence Community. …

The white paper titled “A Federal Vision for Future Computing: A Nanotechnology-Inspired Grand Challenge” is 15 pp. and it offers tidbits such as this (Note: Footnotes not included),

A new materials base may be needed for future electronic hardware. While most of today’s electronics use silicon, this approach is unsustainable if billions of disposable and short-lived sensor nodes are needed for the coming Internet-of-Things (IoT). To what extent can the materials base for the implementation of future information technology (IT) components and systems support sustainability through recycling and bio-degradability? More sustainable materials, such as compostable or biodegradable systems (polymers, paper, etc.) that can be recycled or reused,  may play an important role. The potential role for such alternative materials in the fabrication of integrated systems needs to be explored as well. [p. 5]

The basic architecture of computers today is essentially the same as those built in the 1940s—the von Neumann architecture—with separate compute, high-speed memory, and high-density storage components that are electronically interconnected. However, it is well known that continued performance increases using this architecture are not feasible in the long term, with power density constraints being one of the fundamental roadblocks.7 Further advances in the current approach using multiple cores, chip multiprocessors, and associated architectures are plagued by challenges in software and programming models. Thus,  research and development is required in radically new and different computing architectures involving processors, memory, input-output devices, and how they behave and are interconnected. [p. 7]

Neuroscience research suggests that the brain is a complex, high-performance computing system with low energy consumption and incredible parallelism. A highly plastic and flexible organ, the human brain is able to grow new neurons, synapses, and connections to cope with an ever-changing environment. Energy efficiency, growth, and flexibility occur at all scales, from molecular to cellular, and allow the brain, from early to late stage, to never stop learning and to act with proactive intelligence in both familiar and novel situations. Understanding how these mechanisms work and cooperate within and across scales has the potential to offer tremendous technical insights and novel engineering frameworks for materials, devices, and systems seeking to perform efficient and autonomous computing. This research focus area is the most synergistic with the national BRAIN Initiative. However, unlike the BRAIN Initiative, where the goal is to map the network connectivity of the brain, the objective here is to understand the nature, methods, and mechanisms for computation,  and how the brain performs some of its tasks. Even within this broad paradigm,  one can loosely distinguish between neuromorphic computing and artificial neural network (ANN) approaches. The goal of neuromorphic computing is oriented towards a hardware approach to reverse engineering the computational architecture of the brain. On the other hand, ANNs include algorithmic approaches arising from machinelearning,  which in turn could leverage advancements and understanding in neuroscience as well as novel cognitive, mathematical, and statistical techniques. Indeed, the ultimate intelligent systems may as well be the result of merging existing ANN (e.g., deep learning) and bio-inspired techniques. [p. 8]

As government documents go, this is quite readable.

For anyone interested in learning more about the future federal plans for computing in the US, there is a July 29, 2016 posting on the White House blog celebrating the first year of the US National Strategic Computing Initiative Strategic Plan (29 pp. PDF; awkward but that is the title).

Carbon nanotubes: faster, cheaper, easier, and more consistent

One of the big problems with nanomaterials has to do with production issues such as: consistent size and shape. It seems that scientists at the US National Institute of Standards and Technology (NIST) have developed a technique for producing carbon nanotubes (CNTs) which addresses these issues. From a July 19, 2016 news item on Nanotechnology Now,

Just as many of us might be resigned to clogged salt shakers or rush-hour traffic, those working to exploit the special properties of carbon nanotubes have typically shrugged their shoulders when these tiniest of cylinders fill with water during processing. But for nanotube practitioners who have reached their Popeye threshold and “can’t stands no more,” the National Institute of Standards and Technology (NIST) has devised a cheap, quick and effective strategy that reliably enhances the quality and consistency of the materials–important for using them effectively in applications such as new computing technologies.

To prevent filling of the cores of single-wall carbon nanotubes with water or other detrimental substances, the NIST researchers advise intentionally prefilling them with a desired chemical of known properties. Taking this step before separating and dispersing the materials, usually done in water, yields a consistently uniform collection of nanotubes. In quantity and quality, the results are superior to water-filled nanotubes, especially for optical applications such as sensors and photodetectors.

A July 15, 2016 NIST news release, which originated the news item, expands on the theme,

The approach opens a straightforward route for engineering the properties of single-wall carbon nanotubes—rolled up sheets of carbon atoms arranged like chicken wire or honey combs—with improved or new properties.

“This approach is so easy, inexpensive and broadly useful that I can’t think of a reason not to use it,” said NIST chemical engineer Jeffrey Fagan.

In their proof-of-concept experiments, the NIST team inserted more than 20 different compounds into an assortment of single-wall carbon nanotubes with an interior diameter that ranged from more than 2 down to about 0.5 nanometers. Led by visiting researcher Jochen Campo, the scientists tested their strategy by using hydrocarbons called alkanes as fillers.

The alkanes, which include such familiar compounds as propane and butane, served to render the nanotube interiors unreactive. In other words, the alkane-filled nanotubes behaved almost as if they were empty—precisely the goal of Campo, Fagan and colleagues.

Compared with nanotubes filled with water and possibly ions, acids and other unwanted chemicals encountered during processing, empty nanotubes possess far superior properties. For example, when stimulated by light, empty carbon nanotubes fluoresce far brighter and with sharper signals.

Yet, “spontaneous ingestion” of water or other solvents by the nanotubes during processing is an “endemic but often neglected phenomenon with strong implications for the development of nanotube applications,” the NIST team wrote in a recent article in Nanoscale Horizons.

Perhaps because of the additional cost and effort required to filter out and gather nanotubes, researchers tend to tolerate mixed batches of unfilled (empty) and mostly filled single-wall carbon nanotubes. Separating unfilled nanotubes from these mixtures requires expensive ultracentrifuge equipment and, even then, the yield is only about 10 percent, Campo estimates.

“If your goal is to use nanotubes for electronic circuits, for example, or for fluorescent anti-cancer image contrast agents, then you require much greater quantities of materials of consistent composition and quality,” Campo explained, who was exploring these applications while doing postdoctoral research at the University of Antwerp. “This particular need inspired development of the new prefilling method by asking the question, can we put some passive chemical into the nanotube instead to keep the water out.”

From the very first simple experiments, the answer was yes. And the benefits can be significant. In fluorescence experiments, alkane-filled nanotubes emitted signals two to three times stronger than those emitted by water-filled nanotubes. Performance approached that of empty nanotubes—the gold standard for these comparisons.

As important, the NIST-developed prefilling strategy is controllable, versatile and easily incorporated into existing methods for processing single-wall carbon nanotubes, according to the researchers.

Here’s a link to and citation for the paper,

Enhancing single-wall carbon nanotube properties through controlled endohedral filling by J. Campo, Y. Piao, S. Lam, C. M. Stafford, J. K. Streit, J. R. Simpson, A. R. Hight Walker, and J. A. Fagan. Nanoscale Horiz., 2016,1, 317-324 DOI: 10.1039/C6NH00062B First published online 10 May 2016

This paper is open access but you do need to register on the site (it is a free registration).

US Nanotechnology Initiative for water sustainability

Wednesday, March 23, 2016 was World Water Day and to coincide with that event the US National Nanotechnology Initiative (NNI) in collaboration with several other agencies announced a new ‘signature initiative’. From a March 24, 2016 news item on Nanowerk (Note: A link has been removed),

As a part of the White House Water Summit held yesterday on World Water Day, the Federal agencies participating in the National Nanotechnology Initiative (NNI) announced the launch of a Nanotechnology Signature Initiative (NSI), Water Sustainability through Nanotechnology: Nanoscale Solutions for a Global-Scale Challenge.

A March 23, 2016 NNI news release provides more information about why this initiative is important,

Access to clean water remains one of the world’s most pressing needs. As today’s White House Office of Science and Technology blog post explains, “the small size and exceptional properties of engineered nanomaterials are particularly promising for addressing the key technical challenges related to water quality and quantity.”

“One cannot find an issue more critical to human life and global security than clean, plentiful, and reliable water sources,” said Dr. Michael Meador, Director of the National Nanotechnology Coordination Office (NNCO). “Through the NSI mechanism, NNI member agencies will have an even greater ability to make meaningful strides toward this initiative’s thrust areas: increasing water availability, improving the efficiency of water delivery and use, and enabling next-generation water monitoring systems.”

A March 23, 2016 US White House blog posting by Lloyd Whitman and Lisa Friedersdorf describes the efforts in more detail (Note: A link has been removed),

The small size and exceptional properties of engineered nanomaterials are particularly promising for addressing the pressing technical challenges related to water quality and quantity. For example, the increased surface area—a cubic centimeter of nanoparticles has a surface area larger than a football field—and reactivity of nanometer-scale particles can be exploited to create catalysts for water purification that do not require rare or precious metals. And composites incorporating nanomaterials such as carbon nanotubes might one day enable stronger, lighter, and more durable piping systems and components. Under this NSI, Federal agencies will coordinate and collaborate to more rapidly develop nanotechnology-enabled solutions in three main thrusts: [thrust 1] increasing water availability; [thrust 2] improving the efficiency of water delivery and use; and [thrust 3] enabling next-generation water monitoring systems.

A technical “white paper” released by the agencies this week highlights key technical challenges for each thrust, identifies key objectives to overcome those challenges, and notes areas of research and development where nanotechnology promises to provide the needed solutions. By shining a spotlight on these areas, the new NSI will increase Federal coordination and collaboration, including with public and private stakeholders, which is vital to making progress in these areas. The additional focus and associated collective efforts will advance stewardship of water resources to support the essential food, energy, security, and environment needs of all stakeholders.

We applaud the commitment of the Federal agencies who will participate in this effort—the Department of Commerce/National Institute of Standards and Technology, Department of Energy, Environmental Protection Agency, National Aeronautics and Space Administration, National Science Foundation, and U.S. Department of Agriculture/National Institute of Food and Agriculture. As made clear at this week’s White House Water Summit, the world’s water systems are under tremendous stress, and new and emerging technologies will play a critical role in ensuring a sustainable water future.

The white paper (12 pp.) is titled: Water Sustainability through Nanotechnology: Nanoscale Solutions for a Global-Scale Challenge and describes the thrusts in more detail.

A March 22, 2016 US White House fact sheet lays out more details including funding,

Click here to learn more about all of the commitments and announcements being made today. They include:

  • Nearly $4 billion in private capital committed to investment in a broad range of water-infrastructure projects nationwide. This includes $1.5 billion from Ultra Capital to finance decentralized and scalable water-management solutions, and $500 million from Sustainable Water to develop water reclamation and reuse systems.
  • More than $1 billion from the private sector over the next decade to conduct research and development into new technologies. This includes $500 million from GE to fuel innovation, expertise, and global capabilities in advanced water, wastewater, and reuse technologies.
  • A Presidential Memorandum and supporting Action Plan on building national capabilities for long-term drought resilience in the United States, including by setting drought resilience policy goals, directing specific drought resilience activities to be completed by the end of the year, and permanently establishing the National Drought Resilience Partnership as an interagency task force responsible for coordinating drought-resilience, response, and recovery efforts.
  • Nearly $35 million this year in Federal grants from the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, the National Science Foundation, and the U.S. Department of Agriculture to support cutting-edge water science;
  • The release of a new National Water Model that will dramatically enhance the Nation’s river-forecasting capabilities by delivering forecasts for approximately 2.7 million locations, up from 4,000 locations today (a 700-fold increase in forecast density).

This seems promising and hopefully other countries will follow suit.

Monsieur Kilogram; an SI (international system of units) Superhero

I wouldn’t have thought that measurement was such a crucial issue that it would require a superhero team but I have to admit the folks at the US National Institute of Standards and Technology (NIST) make a compelling case in a Feb. 2, 2016 NIST news release (also on EurekAlert but dated Feb. 4, 2016),

The nefarious Major Uncertainty has kidnapped Monsieur Kilogram, putting the world’s measurements of mass in jeopardy. As the world spirals into “Mass Hysteria,” the remaining SI Superheroes, champions of the metric system, leap into action to save the day, and hopefully Monsieur Kilogram as well.

This crisis kicks off the third and latest adventure from the League of SI Superheroes, the animated online series from the National Institute of Standards and Technology (NIST). “Mass Hysteria” touches upon a topic—how to redefine the basic unit of mass known as the kilogram—that represents a cutting-edge undertaking for researchers working to modernize the worldwide metric measurement system known as the International System of Units (SI).

From the very big to the very small, accurately measuring mass is important in the world around us. For example, many of the products you buy at the grocery store and other places are sold by mass or the related quantity of weight. Roughly speaking, mass is the amount and type of “stuff” there is in something, and weight is the force pulling on the mass by gravity. The masses of every ingredient in medications from aspirin tablets to cancer drugs are carefully measured to ensure that they are both safe and effective. In many cases, medical doctors consider the mass of the patient to determine the dosage of the medications they prescribe as well. And both the fuel and the amount of thrust produced by the huge engines that power airplanes and rockets depend on mass.

Small errors of even a few milligrams per kilogram may not sound like much, but they can be costly when measuring huge quantities of something like a tanker ship full of grain or oil. With medicines, slightly too little of a chemical could make it ineffective and slightly too much could be toxic.

Here’s a peek at Monsieur Kilogram who seems like a pretty tough customer,

Monsieur Kilogram, a character in NIST’s League of SI Superheroes animated online series, is able to determine the mass of any object simply by holding it. ©NIST

Monsieur Kilogram, a character in NIST’s League of SI Superheroes animated online series, is able to determine the mass of any object simply by holding it. ©NIST

Getting back to the news release and the importance of accurate measurement,

Being the last standard unit of measure still based on an actual physical object, in this case a golf-ball-sized cylinder of platinum and iridium, the kilogram is vulnerable to damage, as well as being lost or even stolen. While the international prototype kilogram itself cannot change because it is the kilogram by definition, copies of the international prototype that many countries use as their standard of mass have been gaining or losing mass relative to it.

The SI Superheroes’ latest episode briefly explores one of the efforts to redefine the kilogram in terms of natural forces called the watt balance, a complex machine that uses electric and magnetic forces to balance a 1-kilogram mass against the Earth’s gravity. Precise measurements related to these forces can then be used to provide a consistent definition of the amount of mass in the kilogram.

While the superheroes’ antics are not exactly representative of the efforts of actual researchers, super scientists at NIST and elsewhere have been working for years to reduce the errors in their measurement of this quantity to the point where the watt balance can take over for the international prototype kilogram.

They are closing in on their goal, and it is widely anticipated that the kilogram will be redefined in 2018.

Once this process is complete, the kilogram will have been freed from its dependence on a physical object, and anyone with the right technical expertise and equipment will be able to determine the mass of a kilogram for themselves.

Will the SI Superheroes finish the watt balance in time? Watch the next episode and find out! Modeled on the seven base units of the International System of Units, or SI, the League of SI Superheroes are:

Meter Man: With his laser interferometer eyes, graduated arms and extendable body, no dimension is too big or too small for Meter Man to measure.

The Mole: Able to sniff out and count the atoms of every element, the Mole is a master of chemistry.

Professor Second: By reading the vibrations of her laser-cooled cesium atoms, Professor Second can measure any frequency and calibrate any clock.

Monsieur Kilogram: Monsieur Kilogram loves lifting weights, and it shows. He is able to determine the mass of any object simply by holding it.

Ms. Ampere: Ms. Ampere rules the flow of electrons—electrical current—and makes sure that the right amount gets where it needs to go.

Dr. Kelvin: Dr. Kelvin heats up or cools down objects by speeding up or slowing down particles inside them. He can also measure the temperature of anything in the universe with his trusty thermometer.

Candela: Don’t let her small size fool you. Candela’s power over light helps to brighten the whole world.

Catch up on their adventures at The League of SI Superheroes kids’ page. Teachers can also request a classroom set of SI educational materials by submitting their contact information and grade level to TheSI@nist.gov.

Here’s the latest adventure,

Enjoy!