These are a few of the Laboratory's achievements during 2014 in ST&E.
A paper featured on the cover of Advanced Materials Interfaces describes work by Livermore’s Tiziana Bond and collaborators at ETH Zurich in developing a nanomanufacturing technique that creates ultradense arrays of nanopores on metal thin films, over a macroscale area and with high fidelity. The method can create hexagonal arrays of pores below 30 nm in diameter, achieving uniform coverage over an entire wafer 10 cm in diameter. Although other methods exist for creating random nanoporous metal over a large area, creating ordered nanopore arrays is far more challenging, particularly because of problems during the lift-off process. This new technique eliminates the need for a lift-off stage by using nanoscale spheres of poly(methyl methacrylate) that self-align in a polystyrene matrix. When the spheres are removed, the polystyrene acts as an etch mask as nanoscale pores are created in the metal underlayer using argon ion-beam milling. The technique has enormous potential in a wide variety of applications in optics, electronics, energy, and biotechnology, such as improved electrode performance in batteries and sensor materials with improved analyte adsorption.
The achievements by a team of LLNL researchers and colleagues from UC Berkeley and Princeton University who used the National Ignition Facility (NIF) to compress diamond to the density of lead (approximately 12 grams/cm3) were featured on the cover of Nature. As indicated by the accompanying headline—"Inside Jupiter: The Giant Planet's Interior Replicated at the U.S. National Ignition Facility"— the team's results will help validate not only first-principles density functional theory but also theories that have long been used—but not yet experimentally validated—to describe matter in the interiors of giant planets, stars, and inertial-confinement fusion experiments. At NIF, a sample of diamond was ramp compressed to a peak pressure of 5 terapascals (equal to 50 million atmospheres, or 14 times the pressure at Earth’s center), with the sample’s stress, density, and sound speed determined over the entire compression path. Such pressures have been reached before in diamond, but only in shock experiments, which are not relevant to planetary interiors because of the very high temperature to which the sample is heated. The unprecedented conditions attained in these NIF experiments provide new constraints on the equation of state of carbon at pressures more than 30 times that of previous static-compression measurements.
In August, the National Institutes of Health (NIH) awarded a 5-year, $7.8 million grant for Lawrence Livermore to conduct biomedical research using the LLNL-pioneered technique of biological accelerator mass spectrometry (AMS). The work will be conducted by the Laboratory’s Biosciences and Biotechnology Division and the Center for Accelerator Mass Spectrometry (CAMS) operating as the National Resource for Biomedical Accelerator Mass Spectrometry, which currently collaborates with more than 60 medical centers, universities, and other entities around the world. The grant marks the fourth 5-year grant awarded over the past 15 years (the three others were in 1999, 2004, and 2009). This latest grant represents national recognition of Lawrence Livermore’s leadership in biological AMS, including the recent development of a new system that is easier to operate and that can process liquid samples, bypassing the graphitization process. This new system now enables scientists to prepare and analyze samples in minutes instead of days. With the new grant, researchers will use the new system to address important questions in nutrition, toxicology, pharmacology, cancer research, drug development, and comparative medicine. They also hope to validate the new instrument for deployment to general clinical laboratories in about 5 years. In the photo, Ted Ognibene (center), a chemist who co-developed the technique enabling liquid samples, discusses operation of the instrument with biomedical scientist Mike Malfatti. Read More »
An article appearing on the inside-cover of the November 14 issue of Journal of Materials Chemistry A describes LLNL’s research using graphene aerogel for enhanced electrical energy storage that eventually could help smooth out power fluctuations in the nation’s energy grid. An LLNL team found that graphene aerogel-based supercapacitor electrodes could also be useful for electric vehicles because they feature high surface areas, good electrical conductivity, chemical inertness, and long-term cycling stability. Energy storage systems for electric vehicles are especially demanding because they require high power and energy density, cyclability, safety, and low cost. Supercapacitors are seen as a good solution because of their high power density and excellent cycling stability. “Our materials,” says LLNL’s Patrick Campbell, lead author of the paper, “can potentially improve on the performance of these commercial supercapacitors by more than 100 percent.” He adds: “Graphene aerogels are a relatively new type of aerogel that are ideal for energy storage applications because of their extremely high surface area, excellent mechanical properties, and very high electrical conductivity.” Aerogels derived from carbon as well as inorganic materials were developed at LLNL and have found a number of applications—from capturing space dust to lining the inside of targets used in fusion research at the National Ignition Facility. Livermore’s Directed Research and Development (LDRD) Program supported this work under project 12-ERD-035.
The National Institutes of Health (NIH) has awarded LLNL a grant to develop an electrode array system that will be used to help understand how the brain works. Lawrence Livermore’s neural measurement and manipulation system—an advanced electronics system to monitor and modulate neurons—will be packed with more than 1,000 tiny electrodes embedded in different areas of the brain to record and stimulate neural circuitry. The goal is a system that will allow scientists to simultaneously study how thousands of neuronal cells in various brain regions work together during complex tasks such as decision making and learning. The project is a collaboration between Livermore’s Neural Technology Group, the University of California–San Francisco, Intan Technology, and SpikeGadgets and is part of NIH efforts to support the White House’s Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative, a new research effort to revolutionize our understanding of the human mind and uncover ways to treat, prevent, and cure brain disorders. (This grant follows an earlier award this year from the Defense Advanced Research Projects Agency to develop an implantable neural interface to study post-traumatic stress disorder and other ailments.) Early investments at LLNL to develop these electrode arrays were made by the Laboratory Directed Research and Development Program. In the photo, Lawrence Livermore’s Kye Lee, Angela Tooker, Sarah Felix, and Vanessa Tolosa (left to right) hold a silicon wafer containing micromachined implantable neural devices.
Lawrence Livermore received four awards in this year’s R&D 100 competition, bringing to 152 the total number of awards LLNL has won since 1978 in what is widely referred to as the “Oscars of invention.” This year’s award-winners also account for four out of 32 won by DOE laboratories this time around. “These awards recognize the tremendous value of our national labs,” said Secretary of Energy Ernest Moniz. “Research and development at the national labs continues to help our nation address its energy challenges and pursue the scientific and technological innovations necessary to remain globally competitive.” Remarked LLNL Director Bill Goldstein, “It is a great tribute to our scientists and engineers that we continue to be among the nation’s leaders in being recognized for outstanding industrial innovation through the R&D 100 Awards competition.” The four winning technologies—two of which had important early support from the Laboratory Directed Research and Development (LDRD) Program—are as follows:
Portable kit for detecting explosives and drugs. A team of LLNL chemists from the Laboratory’s Energetic Materials Center and the Forensic Science Center developed a miniaturized, portable, thin-layer chromatography kit commercialized as the product microTLC, which can detect and identify explosives, illicit drugs, insecticides, pesticides, and other targets in samples. MicroTLC also won a 2014 award for technology transfer under the Federal Laboratory Consortium’s Far West Regional Awards.
High-precision spectrometer for identifying trace elements. The superconducting tunnel junction x-ray spectrometer can measure x-ray energies 10 times more precisely than current spectrometers based on silicon or germanium semiconductors. Built in conjunction with STAR Cryoelectronics, the new spectrometer is a powerful tool for identifying unknown substances, such as traces of evidence from crime-scenes samples, impurities in computer-chip materials, and toxic metals in biomedical components. This advanced science and technology was developed over a long period, with early support from LDRD.
Faster, cheaper system for polishing laser optics. Optics for imaging systems, lithography, and fusion research at the National Ignition Facility can now be polished and finished more quickly and economically thanks to the convergent polishing system. The new system can finish flat and spherical glass optics in a single iteration, regardless of the workpiece’s initial shape and without operator intervention. This reduced-step technique achieves the precision optics industry’s “Holy Grail” of convergence, comments an executive at a California precision optics company. This work was supported by the LDRD Program under project 11-ERD-036. The photo above shows an LLNL optics polisher that incorporates the breakthrough method.
Beam-combining optical element. An optical technology named EXUDE (for “extreme-power, ultralow-loss dispersive element”) enables the beams from many small lasers to be combined into a single high-power beam. Developed in partnership with Lockheed Martin Laser and Sensor Systems and Advanced Thin Films, EXUDE does this by superimposing the component beams into an electrically efficient, single-output system. A recent demonstration combined multiple fiber lasers into a single 30-kilowatt beam while maintaining excellent efficiency and beam quality, thus paving the way for advanced defense applications. Other possible applications include material processing, such as marking, cutting, welding, and drilling.
A team of engineers and scientists at Lawrence Livermore has developed an additive-manufacturing technique to design and fabricate, at the microscale, new cushioning materials with a broad range of programmable properties. The resulting material combines the advantages of gel and foam with an engineered architecture that actually overcomes the limitations of the component material—an example of the power of additive manufacturing, also known as 3-D printing. This research, led by Eric Duoss and Tom Wilson, is described in a paper published in Advanced Functional Materials. Supported by the Laboratory Directed Research and Development Program as a strategic initiative (11-SI-005), the work focused on creating a micro-architected cushioning with a silicone-based ink that cures to form a rubberlike material. During printing, a first layer of ink is deposited as a series of horizontally aligned filaments, which can be as fine as a human hair. The second layer of filaments is then deposited vertically and so on, until the desired height and pore structure is reached. These novel energy-absorbing materials have many applications, including protective materials for sensitive instrumentation and in aerospace applications to combat the effects of temperature fluctuations and vibration.
Lawrence Livermore recently established a strategic partnership with Kansas State University (KSU) to deliver its next-generation agricultural pathogen-fighting tools to protect U.S. agriculture and bolster our national security. The two technologies—the Lawrence Livermore Microbial Detection Array (LLMDA) and a new multiplex polymerase chain reaction assay that detects ten important swine respiratory pathogens—are being evaluated under a Laboratory Director Research and Development Program (LDRD) project and will be transitioned to KSU for diagnostics and surveillance of emerging and foreign animal disease pathogens. The technologies will advance the current diagnostic approach from “one pathogen/one assay” to a system that can screen up to thousands of pathogens in a single test. The LLNL team includes biologists Crystal Jaing (who helped develop LLMDA under LDRD project 08-SI-002), Pejman Naraghi-Arani, and Pam Hullinger, while the KSU team is being led by Dr. Bob Rowland, who said, “The idea [with the partnership] is to take some of this ‘Star Trek technology’ and bring it to diagnostic laboratories and the clinical practice level.” The photo shows KSU’s Rebecca Ober (left) and Jamie Thompson, two members of Dr. Rowland’s team who will be working with LLNL researchers. (Photo courtesy of KSU.)
In an article in Review of Scientific Instruments, a team led by LLNL scientists describe a technique for computationally processing high-speed velocity interferometry images of laser-shocked materials, bringing previously fuzzy features into focus. This achievement has potential applications in revealing a material’s three-dimensional behavior. Velocity interferometer is conventionally used to measure a target along a line (i.e., in one dimension), but the team, led by David Erskine, used short laser pulses and the Velocity Interferometer System for Any Reflector (VISAR) in two dimensions to capture snapshot-like images. Then, numerical postprocessing based on Fourier transform yielded 3-D, holographic images from the data. The team is planning to use this technique to explore how materials such as diamond fracture and disintegrate when decompressing from high pressure. Most of the experiments in this research were performed at LLNL’s Jupiter Laser facility. The figure shows images of laser-shocked silicon before numerical focusing (a and c) and after (b and d).
In three articles in two consecutive issues of the Journal of Environmental Radioactivity, LLNL researchers working in environmental radiochemistry and isotopic signatures published results obtained with their deep expertise in using mass spectrometry and isotope ratios in a broad range of applications. The first paper, which originated as a summer intern project, investigated contamination from an abandoned uranium mine in the Sierra Nevada mountains of California. Measurements of the isotopic composition in water and sediment samples, combined with isotopic mixing models, show that the source of uranium contamination is weathering of uranium mine tailings. The second article describes how a new high-sensitivity inductively coupled plasma mass spectrometry method can be used to measure ultralow levels of neptunium-237—a major contributor to radioactivity in spent nuclear fuel—in groundwater samples. The LLNL technique was shown to provide the best direct measurement of transport rates of neptunium-237 in groundwater and concludes that the isotope does not appear to pose significant environmental risks. The third article demonstrates how fissiogenic xenon isotopes in radioactive fallout from a nuclear explosion are uniquely able to constrain the timescale of fallout formation, the chemical fractionation that occurs when fission products and nuclear fuel are incorporated into fallout, and the speciation of fission products in the fireball. In short, xenon isotopes provide a window into the chemical composition of the fireball in the seconds following a nuclear explosion, improving our understanding of the physical and thermo-chemical conditions under which fallout forms. The figures are optical microscope images of fallout particles analyzed in the third study.
Livermore computational scientist Amanda Randles has received a Director’s Early Independence Award from the National Institutes of Health (NIH) to pursue research to develop tools for predicting sites in the human body to which cancer is likely to metastasize. The method will combine personalized massively parallel computational models and experimental approaches. Amanda, an LLNL Lawrence Fellow, credits the fellowship and her colleagues for the “amazing opportunity” that the NIH award represents. “Everyone at Livermore has been very supportive of my research goals,” she said. The NIH award provides funding to encourage exceptional young scientists to pursue “high-risk, high-reward” independent research in biomedical and behavioral science. Amanda will receive about $2.5 million over five years. The funding will allow her to develop a method to simulate realistic numbers of cells flowing through the circulatory system, and to study the impact of cell characteristics on the movement of circulating tumor cells. This work will improve understanding of the mechanisms driving cancer metastasis, inform clinical decisions, and “have a direct impact on patient care,” says Amanda, who will be collaborating with the Dana-Farber Cancer Institute and Brigham and Women’s Hospital.
In a paper appearing in Nature Climate Change, LLNL scientists Paul Durack, Peter Gleckler, and Karl Taylor use satellite observations and climate models to demonstrate that long-term ocean warming in the upper 700 meters of Southern Hemisphere oceans has likely been underestimated. The team found inconsistencies between simulations and observations of sea level rise—a leading indicator of climate change—and changes in ocean heat content for the Northern and Southern Hemispheres. They suggest that until recent improvements in observations in the early 21st century, changes in Southern Hemisphere ocean heat content were likely underestimated, resulting in estimates of global global ocean warming that were too low by 24 to 58 percent—the first quantization of a systematic error that had been suspected for years. Because most of the excess heat associated with global warming exists in the oceans, this study has important implications for how scientists view the Earth’s overall energy budget, said Paul. The study was conducted under Lawrence Livermore’s Climate Research Program, which is funded by the Department of Energy’s Regional and Global Climate Modeling Program, and with some support from the Laboratory Directed Research and Development (LDRD) Program. The figure shows the oceanic deployment of an Argo float, a global flotilla of which gather crucial data such as that used in this study.
Publishing in the journal Nature, a team led by Lawrence Livermore scientists has announced a new kind of carbon nanotube that behaves like the pores in a living cell’s membrane, presenting significant potential in health care, bioengineering, and other applications. The researchers have demonstrated that the nanotubes can be tailored to insert themselves into natural or synthetic membranes to form tiny pores—porins—that only allow specific molecules through, such as water, pharmaceuticals, or even DNA (see image). In short, the porins behave much like the natural ion channels that regulate molecular traffic into a cell—even opening or closing according to local channel and membrane charges. The nanopores could therefore serve as a platform for delivering drugs into the body, as the foundation of novel biosensors and DNA-sequencing tools, or as components of synthetic cells. “Taken together,” says lead author and LLNL postdoc Jia Geng, “our findings establish [carbon nanotube] porins as a promising prototype of a synthetic membrane channel.” Senior author and project leader Aleksandr Noy stated, “We found that these nanopores are a promising biomimetic platform for developing cell interfaces, studying transport in biological channels, and creating biosensors.” Much pioneering work in carbon nanotubes has been done at LLNL, where the Laboratory Directed Research and Development Program currently supports this effort (under project 12-ERD-073) and has been an early investor in this aspect of carbon nanotube technology (see projects 05-LW-040 and 07-LW-056, for instance).
Lawrence Livermore National Laboratory researchers have developed a computational technique that uses software running on LLNL supercomputers to determine whether a potential new drug could have adverse side effects in humans. When undiscovered prior to a drug’s release, such side effects can be a significant public health issue and a source of major economic liability that inhibits future drug development. The LLNL team developed an algorithm that predicts whether a drug candidate could interact with important proteins in the human body related to adverse side effects. The team recently published its findings in the journal PLOS ONE. “We need to do something to identify these side effects earlier in the drug development cycle to save lives and reduce costs,” said Computation Directorate researcher Monte LaBute, the paper’s lead author. The paper describes how the team used the Livermore-developed program VinaLC, a parallelized version of AutoDock Vina, to dock 906 small-molecule drugs to a virtual panel of 409 protein targets. By comparing their results with those of FDA-approved drugs with known side effects, the team showed that in two categories of disorders their computational model delivers more-accurate predictions than are possible with the current statistical methods. This achievement thus provides the drug industry with a cost-effective and reliable method to screen for side effects. Their goal is to expand their computational pharmaceutical research to include more off-target proteins for testing and eventually screen every protein in the body. “If we can do that, the drugs of tomorrow will have less side effects that can potentially lead to fatalities,” says Monte. The photo shows Monte (center) examining a docking simulation with team member Felice Lightstone.
In a paper featured on the cover of Advanced Materials, lead author Monika Biener and her Livermore colleagues report their success in synthesizing new ultralow-density, ultrahigh-surface-area bulk materials (Al2O3 and TiO2) with an interconnected, nanotubular structure. This structure makes possible a high strength-to-weight ratio that overcomes a longstanding disadvantage of such ultralow-density materials, unlocking their potential for broad-ranging applications. The paper’s authors—who also include Jianchao Ye, Ted Baumann, Morris Wang, Swanee Shin, Juergen Biener, and Alex Hamza—developed an atomic layer deposition method using a tunable substrate of nanoporous gold. Their approach allows control over the material’s density (from 5 to 400 mg/cm3), pore size (30 nm to 4 μm), and composition. With their narrow, tightly constrained pore-size distributions and thin-walled design, the resulting materials are 10 times stronger and stiffer than traditional aerogels of the same density, and are also thermally stable. The new technique can easily be extended to other atomic layer deposition processes and to other substrates. One possible use is enabling mass transport through two independent pore systems separated by a nanometer-thick three-dimensional membrane, which would have applications in fields such as energy harvesting, catalysis, sensing, and filtration. This work was supported by Livermore’s LDRD Program under project 13-LW-031, which was also led by Monika.
A new DOE-funded project will use high-performance computing to develop and apply the most complete climate and Earth system model to date to bolster research on climate change. Eight national laboratories, including Lawrence Livermore, are combining forces with the National Center for Atmospheric Research, four academic institutions, and one private-sector company in the new effort. The project, Accelerated Climate Modeling for Energy (ACME), is being led by Livermore’s own Dave Bader and is designed to accelerate the development and application of fully coupled, state-of-the-science Earth system models that can also support a broad range of scientific and energy applications. The initial focus will be on three climate change science drivers: water cycle (e.g., how the hydrological cycle and water resources interact with the climate system on local to global scales), biogeochemistry (such as how carbon, nitrogen, and phosphorus cycles regulate climate system feedback), and cryosphere systems (including whether a dynamical instability in the Antarctic Ice Sheet could be triggered within the next 40 years). Over a planned 10-year span, the project aims to conduct simulations and modeling on the most sophisticated supercomputers as they come online. Initial funding for the effort has been provided by DOE’s Office of Science. The image is from the cover of the project’s strategy and implementation plan.
Livermore researchers at the National Ignition Facility (NIF) recently achieved a key step along the path to fusion ignition—fuel gain, in which the energy generated through fusion reactions exceeds the amount of energy deposited by the drive lasers into the deuterium–tritium (DT) fuel. Reached for the first time on any facility anywhere in the world, this milestone achievement is detailed in a paper published in the journal Nature.
In the paper, LLNL’s Omar Hurricane and colleagues report that fusion fuel gains exceeding unity were achieved in experiments using the “high-foot” implosion process developed at Livermore. The experiments also showed an order-of-magnitude improvement in yield performance over previous NIF shots as well as a significant contribution to the yield from alpha particle self-heating, in which the alpha particles (helium nuclei) produced in DT fusion deposit their energy into the fuel. This further heats the fuel and increases the rate of fusion reaction, producing more alpha particles in a “bootstrapping” process that accelerates the fusion rate to eventual self-sustaining fusion burn and ignition. The figure shows a metallic case called a hohlraum that holds the DT fuel capsule, which is visible through a tiny window in the hohlraum. Read More »
The existence of element 117—first discovered by LLNL scientists and their international collaborators in 2010—has been confirmed by a second international team, bringing the element one step closer to being named and officially inducted into the Periodic Table of Elements. A team led by scientists at Germany’s GSI Helmholtz Centre for Heavy Ion Research confirmed element 117 (and its decay chain into elements 115 and 113) and published its findings in a paper in Physical Review Letters. The next step is for the International Union of Pure and Applied Chemistry (IUPAC) to review the new findings and the original research and decide whether further experiments are needed before officially acknowledging the element’s discovery. Upon acceptance, IUPAC would then determine which institution may propose names. Among those participating in the German experiments were Livermore researchers Narek Gharibyan and Dawn Shaughnessy and former postdoc Evgeny Tereshatov. Dawn was also part of the original U.S.–Russian team that first synthesized element 117—work that was supported at Livermore by the LDRD Program. Read More »
A team of LLNL researchers and international collaborators have tracked the orbit of the exoplanet Beta Pictoris b—located 63 light years from Earth—using the next-generation, high-contrast adaptive optics system on the Gemini Planet Imager (GPI), which came online only recently. In this achievement, announced in a paper published in Proceedings of the National Academy of Sciences, the team refined their estimate of the planet’s orbit by analyzing the two disks around the parent star, Beta Pictoris, finding that the planet is aligned not with the main debris disk but rather with a warped secondary disk.
“If Beta Pictoris b is warping the disk,” explains Livermore’s Lisa Poyneer, a coauthor of the paper, “that helps us see how the planet-forming disk in our own solar system might have evolved long ago.” The adaptive optics technique that captured this first-ever light image of Beta Pictoris b was developed at LLNL with early support from the Laboratory Directed Research and Development Program. The figure shows (left) a GPI first-light image of young star HR4796A, highlighting the disk of dust that orbits it, and (right) a single image of Beta Pictoris that visually captured the orbiting planet (at the 5:00 position). Read More »