Nano News: May 2015

New 'designer carbon' boosts battery performance

Stanford University scientists have created a new carbon material that significantly boosts the performance of energy-storage technologies. Their results are featured on the cover of the journal ("Ultrahigh Surface Area Three-Dimensional Porous Graphitic Carbon from Conjugated Polymeric Molecular Framework").

A new 'designer carbon' invented by Stanford scientists significantly improved the power delivery rate of this supercapacitor. "We have developed a 'designer carbon' that is both versatile and controllable," said Zhenan Bao, the senior author of the study and a professor of chemical engineering at Stanford. "Our study shows that this material has exceptional energy-storage capacity, enabling unprecedented performance in lithium-sulfur batteries and supercapacitors." According to Bao, the new designer carbon represents a dramatic improvement over conventional activated carbon, an inexpensive material widely used in products ranging from water filters and air deodorizers to energy-storage devices. "A lot of cheap activated carbon is made from coconut shells," Bao said. "To activate the carbon, manufacturers burn the coconut at high temperatures and then chemically treat it." The activation process creates nanosized holes, or pores, that increase the surface area of the carbon, allowing it to catalyze more chemical reactions and store more electrical charges. But activated carbon has serious drawbacks, Bao said. For example, there is little interconnectivity between the pores, which limits their ability to transport electricity. "With activated carbon, there's no way to control pore connectivity," Bao said. "Also, lots of impurities from the coconut shells and other raw starting materials get carried into the carbon. As a refrigerator deodorant, conventional activated carbon is fine, but it doesn't provide high enough performance for electronic devices and energy-storage applications." 3-D networks Instead of using coconut shells, Bao and her colleagues developed a new way to synthesize high-quality carbon using inexpensive - and uncontaminated - chemicals and polymers. The process begins with conducting hydrogel, a water-based polymer with a spongy texture similar to soft contact lenses. "Hydrogel polymers form an interconnected, three-dimensional framework that's ideal for conducting electricity," Bao said. "This framework also contains organic molecules and functional atoms, such as nitrogen, which allow us to tune the electronic properties of the carbon." For the study, the Stanford team used a mild carbonization and activation process to convert the polymer organic frameworks into nanometer-thick sheets of carbon. "The carbon sheets form a 3-D network that has good pore connectivity and high electronic conductivity," said graduate student John To, a co-lead author of the study. "We also added potassium hydroxide to chemically activate the carbon sheets and increase their surface area." The result: designer carbon that can be fine-tuned for a variety of applications. "We call it designer carbon because we can control its chemical composition, pore size and surface area simply by changing the type of polymers and organic linkers we use, or by adjusting the amount of heat we apply during the fabrication process," To said. For example, raising the processing temperature from 750 degrees Fahrenheit (400 degrees Celsius) to 1,650 F (900 C) resulted in a 10-fold increase in pore volume. Subsequent processing produced carbon material with a record-high surface area of 4,073 square meters per gram - the equivalent of three American football fields packed into an ounce of carbon. The maximum surface area achieved with conventional activated carbon is about 3,000 square meters per gram. "High surface area is essential for many applications, including electrocatalysis, storing energy and capturing carbon dioxide emissions from factories and power plants," Bao said. Supercapacitors To see how the new material performed in real-world conditions, the Stanford team fabricated carbon-coated electrodes and installed them in lithium-sulfur batteries and supercapacitors. "Supercapacitors are energy-storage devices widely used in transportation and electronics because of their ultra-fast charging and discharging capability," said postdoctoral scholar Zheng Chen, a co-lead author. "For supercapacitors, the ideal carbon material has a high surface area for storing electrical charges, high conductivity for transporting electrons and a suitable pore architecture that allows for the rapid movement of ions from the electrolyte solution to the carbon surface." In the experiment, a current was applied to supercapacitors equipped with designer-carbon electrodes. The results were dramatic. Electrical conductivity improved threefold compared to supercapacitor electrodes made of conventional activated carbon. "We also found that our designer carbon improved the rate of power delivery and the stability of the electrodes," Bao added. Batteries Tests were also conducted on lithium-sulfur batteries, a promising technology with a serious flaw: When lithium and sulfur react, they produce molecules of lithium polysulfide, which can leak from the electrode into the electrolyte and cause the battery to fail. The Stanford team discovered that electrodes made with designer carbon can trap those pesky polysulfides and improve the battery's performance. "We can easily design electrodes with very small pores that allow lithium ions to diffuse through the carbon but prevent the polysulfides from leaching out," Bao said. "Our designer carbon is simple to make, relatively cheap and meets all of the critical requirements for high-performance electrodes."

Beyond crystallography: Diffractive imaging using coherent x-ray light sources

In 1999, UCLA professor John Miao pioneered a technique called coherent diffractive imaging, or CDI, which allows scientists to re-create the 3D structure of noncrystalline samples or nanocrystals. The achievement was extremely significant because although X-ray crystallography had long allowed scientists to determine the atomic structure of a wide variety of molecules, including DNA, it does not work for noncrystalline materials used in a variety of disciplines, including physics, chemistry, materials science, nanoscience, geology and biology. An article by Miao and his colleagues in the latest issue of ("Beyond crystallography: Diffractive imaging using coherent x-ray light sources") reviews and analyzes the rapid development of brilliant X-ray sources that scientists worldwide have used for a broad range of applications of his invention in physical and biological sciences. CDI now is being used in a wider array of applications than Miao had imagined it would be — and the technique has become ever more important to scientists exploring the borders of observable nanoscience. Miao, a professor of physics and astronomy, found that by illuminating a noncrystalline sample with a brilliant laserlike, or coherent, X-ray, he could use a lensless detector to record the pattern, or diffraction, of the scattering X-rays. He then recreated the 3D structure of the sample by developing advanced phase retrieval algorithms applied to the diffraction pattern, which is why his technique is sometimes referred to as lensless imaging. CDI transformed the conventional view of microscopy by replacing the physical lens with a computational algorithm. By avoiding the use of lenses, CDI can obtain images of nanoscale objects with high resolution and high contrast. It also has advantages over other imaging techniques such as electron microscopy because it can be used to image thick samples in three dimensions. This powerful imaging technique is now expected to profoundly expand our understanding of a wide range of dynamic phenomena in physics, chemistry and microelectronics; for example, phase transitions, when substances change quickly from one state to another. CDI is ideal for quantitative 3D characterization of nanoscale materials for several reasons. X-rays have a larger penetration depth than electrons, so samples in an electron microscope are destroyed by the powerful electron beam of the microscope as they are imaged, but CDI’s X-rays can often avoid sample destruction. CDI also enables nanoscale chemical, elemental, and magnetic 3D mapping of complex matter. In materials science, CDI was used to determine the first 3D deformation field and full strain tensor inside individual nanocrystals with nanoscale resolution, a key to understanding and managing strain, which is fundamental to designing and implementing nanomaterials such as those used in high-speed electronics. CDI also made possible the first 3D imaging of mineral crystals inside bones at the nanometer scale, giving a much greater understanding of the molecular structure of bone. In lithium ion batteries, when the electrode material stores electrical charge, the material undergoes phase transition that reduces the battery’s life. With CDI, scientists can better understand how lithium ion batteries can be made to store more energy and last longer without cracking.

Even steps to quantum computation

Electrons are normally free to move through a solid in all three dimensions. Restricting their motion to a two-dimensional surface can, however, radically alter the properties of the material. A RIKEN-led team has now created a two-dimensional system that displays an exotic physical effect that could be useful for quantum computing (, "Even-denominator fractional quantum Hall physics in ZnO").

Magnetoresistance measurements indicate the presence of electron pairs at the interface between zinc oxide and magnesium zinc oxide. (Image: Joseph Falson, University of Tokyo) Applying an electric potential between the two sides of a two-dimensional sheet of a semiconducting material under a magnetic field can cause charge carriers to flow sideways along the sheet. This is known as the Hall effect, and such materials display electrical resistance both in the direction of the applied voltage and perpendicular to it. The quantum Hall effect, a signature of two-dimensional systems, becomes evident when the magnetic field is increased and the perpendicular Hall resistance increases in discrete steps. Each of these steps corresponds to an electrical conductance equal to a fundamental constant multiplied by a fraction in which both the numerator and denominator are integers. A team of researchers from the RIKEN Center for Emergent Matter Science, University of Tokyo, the Max Planck Institute for Solid State Research in Germany and other Japanese institutions has now observed the fractional quantum Hall effect in a two-dimensional system formed at the interface between zinc oxide and magnesium zinc oxide. Fundamental to the team’s success in observing such an exotic quantum effect was the fabrication of high-quality material systems. The researchers created their ZnO-based structure using a method called molecular beam epitaxy, which is known for its ability to produce materials with high crystalline quality. They then attached eight electrical contacts to their sample and performed magnetoresistance measurements at ultralow temperatures. The researchers observed a series of levels corresponding to fractional states, or filling factors, between 4/3 and 9/2. Most notably, even-denominator states were observed at 3/2 and 7/2, with some evidence for 9/2. Such a series has not been observed in any other material system. These states are believed to arise because of the existence of quasiparticles made of pairs of electrons (Fig. 1). Such particle pairs are expected to be useful in quantum computers. “These quasiparticles are said to be topologically protected and are robust against weak perturbations,” says the study’s lead author Joseph Falson. “This is in contrast to quantum bits in say, silicon, which are very sensitive to slight changes in temperature or electric field. We now plan to probe the details of the states this work has unveiled.”

Physicists conduct most precise measurement yet of interaction between atoms and carbon surfaces

Physicists at the University of Washington have conducted the most precise and controlled measurements yet of the interaction between the atoms and molecules that comprise air and the type of carbon surface used in battery electrodes and air filters — key information for improving those technologies. A team led by David Cobden, UW professor of physics, used a carbon nanotube — a seamless, hollow graphite structure a million times thinner than a drinking straw — acting as a transistor to study what happens when gas atoms come into contact with the nanotube’s surface. Their findings were published in May in the journal ("Surface electron perturbations and the collective behaviour of atoms adsorbed on a cylinder").

An illustration of atoms sticking to a carbon nanotube, affecting the electrons in its surface. (Image: David Cobden and students) Cobden said he and co-authors found that when an atom or molecule sticks to the nanotube a tiny fraction of the charge of one electron is transferred to its surface, resulting in a measurable change in electrical resistance. “This aspect of atoms interacting with surfaces has never been detected unambiguously before,” Cobden said. “When many atoms are stuck to the miniscule tube at the same time, the measurements reveal their collective dances, including big fluctuations that occur on warming analogous to the boiling of water.” Lithium batteries involve lithium atoms sticking and transferring charges to carbon electrodes, and in activated charcoal filters, molecules stick to the carbon surface to be removed, Cobden explained. “Various forms of carbon, including nanotubes, are considered for hydrogen or other fuel storage because they have a huge internal surface area for the fuel molecules to stick to. However, these technological situations are extremely complex and difficult to do precise, clear-cut measurements on.” This work, he said, resulted in the most precise and controlled measurements of these interactions ever made, “and will allow scientists to learn new things about the interplay of atoms and molecules with a carbon surface,” important for improving technologies including batteries, electrodes and air filters.

Breakthrough heralds super-efficient light-based computers

Stanford electrical engineer Jelena Vuckovic wants to make computers faster and more efficient by reinventing how they send data back and forth between chips, where the work is done. In computers today, data is pushed through wires as a stream of electrons. That takes a lot of power, which helps explain why laptops get so warm. "Several years ago, my colleague David Miller carefully analyzed power consumption in computers, and the results were striking," said Vuckovic, referring to electrical engineering Professor David Miller. "Up to 80 percent of the microprocessor power is consumed by sending data over the wires - so called interconnects." In a article ("Inverse design and demonstration of a compact and broadband on-chip wavelength demultiplexer") whose lead author is Stanford graduate student Alexander Piggott, Vuckovic, a professor of electrical engineering, and her team explain a process that could revolutionize computing by making it practical to use light instead of electricity to carry data inside computers. Spec of Silicon Splits Infrared Light Like a Prism

Spec of Silicon Splits Infrared Light Like a Prism

Infrared light enters this silicon structure from the left. The cut-out patterns, determined by an algorithm, route two different frequencies of this light into the pathways on the right. This is a greatly magnified image of a working device that is about the size of a speck of dust. (Image: Alexander Piggott) Proven technology In essence, the Stanford engineers want to miniaturize the proven technology of the Internet, which moves data by beaming photons of light through fiber optic threads. "Optical transport uses far less energy than sending electrons through wires," Piggott said. "For chip-scale links, light can carry more than 20 times as much data." Theoretically, this is doable because silicon is transparent to infrared light - the way glass is transparent to visible light. So wires could be replaced by optical interconnects: silicon structures designed to carry infrared light. But so far, engineers have had to design optical interconnects one at a time. Given that thousands of such linkages are needed for each electronic system, optical data transport has remained impractical. Now the Stanford engineers believe they've broken that bottleneck by inventing what they call an inverse design algorithm. It works as the name suggests: the engineers specify what they want the optical circuit to do, and the software provides the details of how to fabricate a silicon structure to perform the task. "We used the algorithm to design a working optical circuit and made several copies in our lab," Vuckovic said. In addition to Piggott, the research team included former graduate student Jesse Lu (now at Google,) graduate student Jan Petykiewicz and postdoctoral scholars Thomas Babinec and Konstantinos Lagoudakis. As they reported in Nature Photonics, the devices functioned flawlessly despite tiny imperfections. "Our manufacturing processes are not nearly as precise as those at commercial fabrication plants," Piggott said. "The fact that we could build devices this robust on our equipment tells us that this technology will be easy to mass-produce at state-of-the-art facilities." The researchers envision many other potential applications for their inverse design algorithm, including high bandwidth optical communications, compact microscopy systems and ultra-secure quantum communications. Light and silicon The Stanford work relies on the well-known fact that infrared light will pass through silicon the way sunlight shines through glass. And just as a prism bends visible light to reveal the rainbow, different silicon structures can bend infrared light in useful ways. The Stanford algorithm designs silicon structures so slender that more than 20 of them could sit side-by-side inside the diameter of a human hair. These silicon interconnects can direct a specific frequency of infrared light to a specific location to replace a wire. By loading data onto these frequencies, the Stanford algorithm can create switches or conduits or whatever else is required for the task. The inverse design algorithm is what makes optical interconnects practical by describing how to create what amount to silicon prisms to bend infrared light. Once the algorithm has calculated the proper shape for the task, engineers can use standard industrial processes to transfer that pattern onto a slice of silicon. "Our structures look like Swiss cheese but they work better than anything we've seen before," Vuckovic said. She and Piggott have made several different types of optical interconnects and they see no limits on what their inverse design algorithm can do. In their Nature photonics paper, the Stanford authors note that the automation of large-scale circuit design enabled engineers to create today's sophisticated electronics. By automating the process of designing optical interconnects, they feel that they have set the stage for the next generation of even faster and far more energy-efficient computers that use light rather than electricity for internal data transport.

Chemists discover key reaction mechanism behind the highly touted sodium-oxygen battery

Chemists at the University of Waterloo have discovered the key reaction that takes place in sodium-air batteries that could pave the way for development of the so-called holy grail of electrochemical energy storage. Researchers from the Waterloo Institute for Nanotechnology, led by Professor Linda Nazar who holds the Canada Research Chair in Solid State Energy Materials, have described a key mediation pathway that explains why sodium-oxygen batteries are more energy efficient compared with their lithium-oxygen counterparts. Understanding how sodium-oxygen batteries work has implications for developing the more powerful lithium-oxygen battery, which is has been seen as the holy grail of electrochemical energy storage. Their results appear in the journal ("The critical role of phase-transfer catalysis in aprotic sodium oxygen batteries").

Chemists at the University of Waterloo have discovered the key reaction that takes place in sodium-air batteries that could pave the way for development of the so-called holy grail of electrochemical energy storage. The key lies in Nazar's group discovery of the so-called proton phase transfer catalyst. By isolating its role in the battery's discharge and recharge reactions, Nazar and colleagues were not only able to boost the battery's capacity, they achieved a near-perfect recharge of the cell. When the researchers eliminated the catalyst from the system, they found the battery no longer worked. Unlike the traditional solid-state battery design, a metal-oxygen battery uses a gas cathode that takes oxygen and combines it with a metal such as sodium or lithium to form a metal oxide, storing electrons in the process. Applying an electric current reverses the reaction and reverts the metal to its original form. (Image: University of Waterloo) "Our new understanding brings together a lot of different, disconnected bits of a puzzle that have allowed us to assemble the full picture," says Nazar, a Chemistry professor in the Faculty of Science. "These findings will change the way we think about non-aqueous metal-oxygen batteries." Sodium-oxygen batteries are considered by many to be a particularly promising metal-oxygen battery combination. Although less energy dense than lithium-oxygen cells, they can be recharged with more than 93 per cent efficiency and are cheap enough for large-scale electrical grid storage. The key lies in Nazar's group discovery of the so-called proton phase transfer catalyst. By isolating its role in the battery's discharge and recharge reactions, Nazar and colleagues were not only able to boost the battery's capacity, they achieved a near-perfect recharge of the cell. When the researchers eliminated the catalyst from the system, they found the battery no longer worked. Unlike the traditional solid-state battery design, a metal-oxygen battery uses a gas cathode that takes oxygen and combines it with a metal such as sodium or lithium to form a metal oxide, storing electrons in the process. Applying an electric current reverses the reaction and reverts the metal to its original form. In the case of the sodium-oxygen cell, the proton phase catalyst transfers the newly formed sodium superoxide (NaO2) entities to solution where they nucleate into well-defined nanocrystals to grow the discharge product as micron-sized cubes. The dimensions of the initially formed NaO2 are critical; theoretical calculations from a group at MIT has separately shown that NaO2 is energetically preferred over sodium peroxide, Na2O2 at the nanoscale. When the battery is recharged, these NaO2 cubes readily dissociate, with the reverse reaction facilitated once again by the proton phase catalyst. Chemistry says that the proton phase catalyst could work similarly with lithium-oxygen. However, the lithium superoxide (LiO2) entities are too unstable and convert immediately to lithium peroxide (Li2O2). Once Li2O2 forms, the catalyst cannot facilitate the reverse reaction, as the forward and reverse reactions are no longer the same. So, in order to achieve progress on lithium-oxygen systems, researchers need to find an additional redox mediator to charge the cell efficiently. "We are investigating redox mediators as well as exploring new opportunities for sodium-oxygen batteries that this research has inspired," said Nazar."Lithium-oxygen and sodium-oxygen batteries have a very promising future, but their development must take into account the role of how high capacity - and reversibility - can be scientifically achieved."

Linking superconductivity and structure

Superconductivity is a rare physical state in which matter is able to conduct electricity--maintain a flow of electrons--without any resistance. It can only be found in certain materials, and even then it can only be achieved under controlled conditions of low temperatures and high pressures. New research from a team including Carnegie's Elissaios Stavrou, Xiao-Jia Chen, and Alexander Goncharov hones in on the structural changes underlying superconductivity in iron arsenide compounds--those containing iron and arsenic. It is published by . Tetragonal Structure

This is the tetragonal crystal structure of NaFe2As2. Sodium (Na) is represented by the black balls, iron (Fe) by the red balls, and arsenic (As) by the yellow balls. (Image: Alexander Goncharov) Although superconductivity has many practical applications for electronics (including scientific research instruments), medical engineering (MRI and NMR machines), and potential future applications including high-performance power transmission and storage, and very fast train travel, the difficulty of creating superconducting materials prevents it from being used to its full potential. As such, any newly discovered superconducting ability is of great interest to scientists and engineers. Iron arsenides are relatively recently discovered superconductors. The nature of superconductivity in these particular materials remains a challenge for modern solid state physics. If the complex links between superconductivity, structure, and magnetism in these materials are unlocked, then iron arsenides could potentially be used to reveal superconductivity at much higher temperatures than previously seen, which would vastly increase the ease of practical applications for superconductivity. When iron arsenide is combined with a metal--such as in the sodium-containing NaFe2As2 compound studied here--it was known that the ensuing compound is crystallized in a tetrahedral structure. But until now, a detailed structure of the atomic positions involved and how they change under pressure had not been determined. The layering of arsenic and iron (As-Fe-As) in this structure is believed to be key to the compound's superconductivity. However, under pressure, this structure is thought to be partially misshapen into a so-called collapsed tetragonal lattice, which is no longer capable of superconducting, or has diminished superconducting ability. The team used experimental evidence and modeling under pressure to actually demonstrate these previously theorized structural changes--tetragonal to collapsed tetragonal--on the atomic level. This is just the first step toward definitively determining the link between structure and superconductivity, which could potentially make higher-temperature superconductivity a real possibility. They showed that at about 40,000 times normal atmospheric pressure (4 gigapascals), NaFe2As2 takes on the collapsed tetragonal structure. This changes the angles in the arsenic-iron-arsenic layers and is coincident with the loss in superconductivity. Moreover, they found that this transition is accompanied by a major change in bonding coordination in the formation of the interlayer arsenic-arsenic bonds. A direct consequence of this new coordination is that the system loses its two-dimensionality, and with it, superconductivity. "Our findings are an important step in identifying the hypothesized connection between structure and superconductivity in iron-containing compounds," Goncharov said. "Understanding the loss of superconductivity on an atomic level could enhance our ease of manufacturing such compounds for practical applications, as well as improving our understanding of condensed matter physics."

Experiments in the realm of the impossible

Physicists of Jena University (Germany) simulate for the first time charged Majorana particles – elementary particles, which are not supposed to exist. In the new edition of the science magazine ("Optical simulation of charge conservation violation and Majorana dynamics") they explain their approach: Professor Dr. Alexander Szameit and his team developed a photonic set-up that consists of complex waveguide circuits engraved in a glass chip, which enables them to simulate charged Majorana particles and, thus, allows to conduct physical experiments.

Alexander Szameit and his team of the University Jena developed a photonic set-up that can simulate non-physical processes in a laboratory. March 1938: The Italian elementary particle physicist Ettore Majorana boarded a post ship in Naples, heading for Palermo. But he either never arrives there - or he leaves the city straight away – ever since that day there has been no trace of the exceptional scientist and until today his mysterious disappearance remains unresolved. Since then, Majorana, a pupil of the Nobel Prize winner Enrico Fermi, has more or less been forgotten. What the scientific world does remember though is a theory about nuclear forces, which he developed, and a very particular elementary particle. “This particle named after Majorana, the so-called Majoranon, has some amazing characteristics“, the physicist Professor Dr. Alexander Szameit of the Friedrich Schiller University Jena says. “Characteristics which are not supposed to be existent in our real world.“ Majorana particles are, for instance, their own antiparticles: Internally they combine completely opposing characteristics – like opposing charges and spins. If they were to exist, they would extinguish themselves immediately. “Therefore, Majoranons are of an entirely theoretical nature and cannot be measured in experiments.“ Together with colleagues from Austria, India, and Singapore, Alexander Szameit and his team succeeded in realizing the impossible. In the new edition of the science magazine they explain their approach: Szameit and his team developed a photonic set-up that consists of complex waveguide circuits engraved in a glass chip, which enables them to simulate charged Majorana particles and, thus, allows to conduct physical experiments. “At the same time we send two rays of light through parallel running waveguide lattices, which show the opposing characteristics separately,“ explains Dr. Robert Keil, the first author of the study. After evolution through the lattices, the two waves interfere and form an optical Majoranon, which can be measured as a light distribution. Thus, the scientists create an image that catches this effect like a photograph – in this case the state of a Majoranon at a defined moment in time. “With the help of many of such single images the particles can be observed like in a film and their behaviour can be analyzed,“ says Keil. This model allows the Jena scientists to enter completely unknown scientific territory, as Alexander Szameit stresses. “Now, it is possible for us to gain access to phenomena that so far only have been described in exotic theories.“ With the help of this system, one can conduct experiments in which conservation of charge – one of the pillars of modern physics – can easily be suspended. “Our results show that one can simulate non-physical processes in a laboratory and, thus, can make practical use of exotic characteristics of particles that are impossible to observe in nature.“ Szameit foresees one particular promising application of simulated Majoranons in a new generation of quantum computers. “With this approach, much higher computing capacities than are possible at the moment can be achieved.“

Seeing the action involved in cell membrane hemifusion

Cells are biological wonders. Throughout billions of years of existence on Earth, these tiny units of life have evolved to collaborate at the smallest levels in promoting, preserving and protecting the organism they comprise. Among these functions is the transport of lipids and other biomacromolecules between cells via membrane adhesion and fusion -- processes that occur in many biological functions, including waste transport, egg fertilization and digestion. At the University of California, Santa Barbara, chemical engineers have developed a way to directly observe both the forces present and the behavior that occurs during cell hemifusion, a process by which only the outer layers of the lipid bilayer of cell membranes merge. While many different techniques have been used to observe membrane hemifusion, simultaneous measurements of membrane thickness and interaction forces present a greater challenge, according to Dong Woog Lee, lead author of a paper that appears in the journal ("Real-time intermembrane force measurements and imaging of lipid domain morphology during hemifusion").

An artist's concept of cell hemifusion. (Illustration by Peter Allen) 'It is hard to simultaneously image hemifusion and measure membrane thickness and interaction forces due to the technical limitations,' he said. However, by combining the capabilities of the Surface Forces Apparatus (SFA) -- a device that can measure the tiny forces generated by the interaction of two surfaces at the sub-nano scale -- and simultaneous imaging using a fluorescence microscope, the researchers were able to see in real time how the cell membranes rearrange in order to connect and open a fusion conduit between them. The SFA was developed in Professor Jacob Israelachvili's Interfacial Sciences Lab at UCSB. Israelachvili is a faculty member in the Department of Chemical Engineering at UCSB. To capture real time data on the behavior of cell membranes during hemifusion, the researchers pressed together two supported lipid bilayers on the opposing surfaces of the SFA. These bilayers consisted of lipid domains -- collections of lipids that in non-fusion circumstances are organized in more or less regularly occurring or mixed arrangements within the cell membrane. 'We monitored these lipid domains to see how they reorganize and relocate during hemifusion,' said Lee. The SFA measured the forces and distances between the two membrane surfaces as they were pushed together, visualized at the Ångstrom (one-tenth of a nanometer) level. Meanwhile, fluorescent imaging made it possible to see the action as the more ordered-phase (more solid) domains reorganized and allowed the more disordered-phase (more fluid) domains to concentrate at the point of contact. 'This is the first time observing fluorescent images during a hemifusion process simultaneously with how the combined thickness of the two bilayers evolve to form a single layer,' said Lee. This rearrangement of the domains, he added, lowers the amount of energy needed during the many processes that require membrane fusion. At higher pressures, according to the study, the extra energy activates faster hemifusion of the lipid layers. Lipid domains have been seen in many biological cell membranes, and have been linked to various diseases such as multiple sclerosis, Alzheimer's disease and lung diseases. According to the researchers, this novel device could be used to diagnose, provide a marker for, or study dynamic transformations in situations involving lipid domains in pathological membranes. The fundamental insights provided by this device could also prove useful for other materials in which dynamic changes occur between membranes, including surfactant monolayers and bilayers, biomolecules, colloidal particles, surfactant-coated nanoparticles and smart materials.

Nanotechnology identifies brain tumor types through MRI 'virtual biopsy'

Biomedical researchers at Cedars-Sinai have invented a tiny drug-delivery system that can identify cancer cell types in the brain through “virtual biopsies” and then attack the molecular structure of the disease. If laboratory research with mice is borne out in human studies, the results could be used to deliver nano-scale drugs that can distinguish and fight tumor cells in the brain without resorting to surgery. “Our nanodrug can be engineered to carry a variety of drugs, proteins and genetic materials to attack tumors on several fronts from within the brain,” said Julia Ljubimova, MD, PhD, professor of neurosurgery and biomedical sciences at Cedars-Sinai and a lead author of an article published online in ("MRI Virtual Biopsy and Treatment of Brain Metastatic Tumors with Targeted Nanobioconjugates: Nanoclinic in the Brain").

MRI Virtual Biopsy and Treatment of Brain Metastatic Tumors with Targeted Nanobioconjugates

Polymeric nanoimaging agents carrying attached MRI tracer are able to pass through the blood–brain barrier (BBB) and specifically target cancer cells for efficient imaging. A qualitative/quantitative “MRI virtual biopsy” method is based on a nanoconjugate carrying MRI contrast agent gadolinium-DOTA and antibodies recognizing tumor-specific markers and extravasating through the BBB. In newly developed double tumor xenogeneic mouse models of brain metastasis this noninvasive method allowed differential diagnosis of HER2- and EGFR-expressing brain tumors. (© ACS) Ljubimova, director of the Nanomedicine Research Center in the Department of Neurosurgery and director of the Nanomedicine Program at the Samuel Oschin Comprehensive Cancer Institute, has received a $2.5 million grant from the National Institutes of Health to continue the research. The drug delivery system and its component parts, together called a nanobioconjugate or nanodrug, is in an emerging class of molecular drugs designed to slow or stop cancers by blocking them in multiple ways within the brain. The drug is about 20 to 30 nanometers in size – a fraction of a human hair, which is 80,000 to 100,000 nanometers wide. Cedars-Sinai scientists began developing the “platform” of the drug delivery system about a decade ago. The nanodrug can have a variety of chemical and biological “modules” attached. “Each component serves a specialized function, such as seeking out cancer cells and binding to them, permeating the walls of blood vessels and tumor cells, or dismantling molecular mechanisms that promote tumor growth,” said Eggehard Holler, PhD, professor of neurosurgery and director of nanodrug synthesis at Cedars-Sinai. The new delivery system plays two roles: diagnosing brain tumors by identifying cells that have spread to the brain from other organs, and then fighting the cancer with precise, individualized tumor treatment. Researchers can determine tumor type by attaching a tracer visible on an MRI. If the tracer accumulates in the tumor, it will be visible on MRI. With the cancer’s molecular makeup identified through this virtual biopsy, researches can load the “delivery system” with cancer-targeting components that specifically attack the molecular structure. To show that the virtual biopsies could distinguish one cancer cell type from another, the researchers devised what is believed to be a unique method, implanting different kinds of breast and lung cancers into laboratory mice to represent metastatic disease – with one type of cancer implanted on each side of the brain. Lung and breast cancers are those that most often spread to the brain. The researchers used the nano delivery system to identify and attack the cancers. In each instance, animals that received treatment lived significantly longer than those in control groups. “Several drugs are quite effective in treating different types of breast cancers, lung cancer, lymphoma and other cancers at their original sites, but they are ineffective against cancers that spread to the brain because they are not able to cross the blood-brain barrier that protects the brain from toxins in the blood,” said Keith Black, MD, chair of the Department of Neurosurgery, director of the Maxine Dunitz Neurosurgical Institute, director of the Johnnie L. Cochran, Jr., Brain Tumor Center and the Ruth and Lawrence Harvey Chair in Neuroscience. “The nanodrug is engineered to cross this barrier with its payload intact, so drugs that are effective outside the brain may be effective inside as well,” Black added. Ljubimova, Black and Holler led the study and contributed equally to the article. Rameshwar Patil, PhD, a project scientist in Ljubimova’s laboratory, is first author. Researchers from Cedars-Sinai’s Department of Neurosurgery, Department of Biomedical Sciences, Department of Imaging, and the Samuel Oschin Comprehensive Cancer Institute contributed to the study with colleagues from the University of Southern California and Arrogene Inc., a biotech company associated with Cedars-Sinai.

Computational physicists advance understanding of electrical vortices in certain materials

Computational physicists have developed a novel method that accurately reveals how electrical vortices affect electronic properties of materials that are used in a wide range of applications, including cell phones and military sonar. Zhigang Gui, a doctoral student in physics at the University of Arkansas, and Laurent Bellaiche, Distinguished Professor of physics at the U of A, along with Lin-Wang Wang at Lawrence Berkeley National Laboratory, published their findings in ("Electronic Properties of Electrical Vortices in Ferroelectric Nanocomposites from Large-Scale Ab Initio Computations").

Zhigang Gui (left), Laurent Bellaiche Gui used supercomputers at Oak Ridge National Laboratory to perform large-scale computations to determine the electrical properties of electrical vortices in ferroelectric materials, which generate an electric field when their shape is changed. An electrical vortex occurs when the electric dipoles arrange themselves in an unusual swirling movement, Bellaiche said. In this ferroelectric system, electrical vortices are created and determined by the temperature of the material, Bellaiche said. The simulations also revealed that the existence of an electrical vortex increases the band gap – the major factor determining a material’s conductivity – in this material, which offers insight to the controversial issue about the origin of the conductivity of electrical vortices. “By changing temperature we are changing the band alignment,” Gui said. “Imagine having the same system having two different band alignments, which can lead to different applications. When decreasing temperature, our systems can transform from a Type-I band alignment, which favors light-emitting devices, to a Type-II band alignment, which favors sensors in semiconductor industries.”

A new formulation of quantum mechanics

Quantum mechanics remains one of the most tested theory in the history of physics and yet it represents one of the most challenging theory human kind has come up with. While the Schrödinger formulation is the de-facto standard, describing systems in terms of wave-functions, it is certainly not the only approach possible. Other formalisms are possible too. For example the path integral method, suggested by R. Feynman, is one possibility to describe systems in terms of classical particles. Another method is the one suggested by E. Wigner where systems are described in terms of (quasi-)distribution functions, therefore allowing quantum mechanics in the phase-space. Recently, a new formulation of quantum mechanics has been developed, called the "Signed particle formulation". This novel theory has been suggested by Dr. J.M. Sellier, an Associate Professor at the Bulgarian Academy of Sciences. This new approach to quantum systems is based on classical particles which interact with external potentials by means of creation and annihilation of signed particles only. This novel theory is based on rewriting the time-dependent Wigner equation and on giving a physical interpretation to the various mathematical terms obtained. In particular the sign of a particle, perhaps the most puzzling new introduced feature, has a physical interpretation based on observations in the context of quantum tomography. This new theory provides several advantages:

Simple picture of the quantum world: Quantum systems are described by ensembles of classical particles which provides a whole range of statistical information close to the language of experimentalists.
Simplicity of implementation: The description of systems is based on evolving particles which are trivial to implement in a computer program. Moreover a working implementation in C is available onwww.nano-archimedes.com
Parallelization: Signed particles are independent from each other, therefore providing a way for incredible levels of parallelization.
Classical limit: The transition from quantum to classical systems becomes practically trivial in this new formulation.

A preprint of the paper, which was accepted a few days ago on the is available online: "A Signed Particle Formulation of Non-Relativistic Quantum Mechanics" (pdf).

DNA double helix does double duty in assembling arrays of nanoparticles

In a new twist on the use of DNA in nanoscale construction, scientists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory and collaborators put synthetic strands of the biological material to work in two ways: They used ropelike configurations of the DNA double helix to form a rigid geometrical framework, and added dangling pieces of single-stranded DNA to glue nanoparticles in place. The method, described in the journal ("Prescribed nanoparticle cluster architectures and low-dimensional arrays built using octahedral DNA origami frames"), produced predictable clusters and arrays of nanoparticles--an important step toward the design of materials with tailored structures and functions for applications in energy, optics, and medicine.

Scientists built octahedrons using ropelike structures made of bundles of DNA double-helix molecules to form the frames (a). Single strands of DNA attached at the vertices (numbered in red) can be used to attach nanoparticles coated with complementary strands. This approach can yield a variety of structures, including ones with the same type of particle at each vertex (b), arrangements with particles placed only on certain vertices (c), and structures with different particles placed strategically on different vertices (d). "These arrays of nanoparticles with predictable geometric configurations are somewhat analogous to molecules made of atoms," said Brookhaven physicist Oleg Gang, who led the project at the Lab's Center for Functional Nanomaterials (CFN, http://www.bnl.gov/cfn/), a DOE Office of Science User Facility. "While atoms form molecules based on the nature of their chemical bonds, there has been no easy way to impose such a specific spatial binding scheme on nanoparticles. This is exactly the problem that our method addresses." Using the new method, the scientists say they can potentially orchestrate the arrangements of different types of nanoparticles to take advantage of collective or synergistic effects. Examples could include materials that regulate energy flow, rotate light, or deliver biomolecules. "We may be able to design materials that mimic nature's machinery to harvest solar energy, or manipulate light for telecommunications applications, or design novel catalysts for speeding up a variety of chemical reactions," Gang said. The scientists demonstrated the technique to engineer nanoparticle architectures using an octahedral scaffold with particles positioned in precise locations on the scaffold according to the specificity of DNA coding. The designs included two different arrangements of the same set of particles, where each configuration had different optical characteristics. They also used the geometrical clusters as building blocks for larger arrays, including linear chains and two-dimensional planar sheets. "Our work demonstrates the versatility of this approach and opens up numerous exciting opportunities for high-yield precision assembly of tailored 3D building blocks in which multiple nanoparticles of different structures and functions can be integrated," said CFN scientist Ye Tian, one of the lead authors on the paper.

A combination cryo-electron microscopy image of an octahedral frame with one gold nanoparticle bound to each of the six vertices, shown from three different angles. Details of assembly This nanoscale construction approach takes advantage of two key characteristics of the DNA molecule: the twisted-ladder double helix shape, and the natural tendency of strands with complementary bases (the A, T, G, and C letters of the genetic code) to pair up in a precise way. First, the scientists created bundles of six double-helix molecules, then put four of these bundles together to make a stable, somewhat rigid building material--similar to the way individual fibrous strands are woven together to make a very strong rope. The scientists then used these ropelike girders to form the frame of three-dimensional octahedrons, "stapling" the linear DNA chains together with hundreds of short complementary DNA strands. "We refer to these as DNA origami octahedrons," Gang said. To make it possible to "glue" nanoparticles to the 3D frames, the scientists engineered each of the original six-helix bundles to have one helix with an extra single-stranded piece of DNA sticking out from both ends. When assembled into the 3D octahedrons, each vertex of the frame had a few of these "sticky end" tethers available for binding with objects coated with complementary DNA strands. "When nanoparticles coated with single strand tethers are mixed with the DNA origami octahedrons, the 'free' pieces of DNA find one another so the bases can pair up according to the rules of the DNA complementarity code. Thus the specifically DNA-encoded particles can find their correspondingly designed place on the octahedron vertices" Gang said. The scientists can change what binds to each vertex by changing the DNA sequences encoded on the tethers. In one experiment, they encoded the same sequence on all the octahedron's tethers, and attached strands with a complementary sequence to gold nanoparticles. The result: One gold nanoparticle attached to each of octahedron's six vertices. In additional experiments the scientists changed the sequence of some vertices and used complementary strands on different kinds of particles, illustrating that they could direct the assembly and arrangement of the particles in a very precise way. In one case they made two different arrangements of the same three pairs of particles of different sizes, producing products with different optical properties. They were even able to use DNA tethers on selected vertices to link octahedrons end to end, forming chains, and in 2D arrays, forming sheets. using octahedrons to link nanoparticles into one-dimensional chainlike arrays (left) and two-dimensional square sheets

using octahedrons to link nanoparticles into one-dimensional chainlike arrays (left) and two-dimensional square sheets

By strategically placing tethers on particular vertices, the scientists used the octahedrons to link nanoparticles into one-dimensional chainlike arrays (left) and two-dimensional square sheets (right). Visualization of arrays Confirming the particle arrangements and structures was a major challenge because the nanoparticles and the DNA molecules making up the frames have very different densities. Certain microscopy techniques would reveal only the particles, while others would distort the 3D structures. To see both the particles and origami frames, the scientists used cryo-electron microscopy (cryo-EM), led by Brookhaven Lab and Stony Brook University biologist Huilin Li, an expert in this technique, and Tong Wang, the paper's other lead co-author, who works in Brookhaven's Biosciences department with Li. They had to subtract information from the images to "see" the different density components separately, then combine the information using single particle 3D reconstruction and tomography to produce the final images. "Cryo-EM preserves samples in their near-native states and provides close to nanometer resolution," Wang said. "We show that cryo-EM can be successfully applied to probe the 3D structure of DNA-nanoparticle clusters." These images confirm that this approach to direct the placement of nanoparticles on DNA-encoded vertices of molecular frames could be a successful strategy for fabricating novel nanomaterials.

Engineering phase changes in nanoparticle arrays

Scientists at the U.S. Department of Energy's Brookhaven National Laboratory have just taken a big step toward the goal of engineering dynamic nanomaterials whose structure and associated properties can be switched on demand. In a paper appearing in ("Selective transformations between nanoparticle superlattices via the reprogramming of DNA-mediated interactions"), they describe a way to selectively rearrange the nanoparticles in three-dimensional arrays to produce different configurations, or phases, from the same nano-components. Engineering Phase Changes in Nanoparticle Arrays

Introducing "reprogramming" DNA strands into an already assembled nanoparticle array triggers a transition from a "mother phase," where particles occupy the corners and center of a cube (left), to a more compact "daughter phase" (right). The change represented in the schematic diagrams is revealed by the associated small-angle x-ray scattering patterns. Such phase-changes could potentially be used to switch a material's properties on demand. "One of the goals in nanoparticle self-assembly has been to create structures by design," said Oleg Gang, who led the work at Brookhaven's Center for Functional Nanomaterials, a DOE Office of Science User Facility. "Until now, most of the structures we've built have been static. Now we are trying to achieve an even more ambitious goal: making materials that can transform so we can take advantage of properties that emerge with the particles' rearrangements." The ability to direct particle rearrangements, or phase changes, will allow the scientists to choose the desired properties-say, the material's response to light or a magnetic field-and switch them as needed. Such phase-changing materials could lead to new applications, such as dynamic energy-harvesting or responsive optical materials. DNA-directed rearrangement This latest advance in nanoscale engineering builds on the team's previous work developing ways to get nanoparticles to self-assemble into complex composite arrays, including linking them together with tethers constructed of complementary strands of synthetic DNA. In this case, they started with an assembly of nanoparticles already linked in a regular array by the complementary binding of the A, T, G, and C bases on single stranded DNA tethers, then added "reprogramming" DNA strands to alter the interparticle interactions. "We know that properties of materials built from nanoparticles are strongly dependent on their arrangements," said Gang. "Previously, we've even been able to manipulate optical properties by shortening or lengthening the DNA tethers. But that approach does not permit us to achieve a global reorganization of the entire structure once it's already built." In the new approach, the reprogramming DNA strands adhere to open binding sites on the already assembled nanoparticles. These strands exert additional forces on the linked-up nanoparticles.

Injecting different kinds of reprogramming DNA strands can change the interparticle interactions in different ways depending on whether the new strands increase attraction, repulsion, or a combination of these forces between particles. "By introducing different types of reprogramming DNA strands, we modify the DNA shells surrounding the nanoparticles," explained CFN postdoctoral fellow Yugang Zhang, the lead author on the paper. "Altering these shells can selectively shift the particle-particle interactions, either by increasing both attraction and repulsion, or by separately increasing only attraction or only repulsion. These reprogrammed interactions impose new constraints on the particles, forcing them to achieve a new structural organization to satisfy those constraints." Using their method, the team demonstrated that they could switch their original nanoparticle array, the "mother" phase, into multiple different daughter phases with precision control. This is quite different from phase changes driven by external physical conditions such as pressure or temperature, Gang said, which typically result in single phase shifts, or sometimes sequential ones. "In those cases, to go from phase A to phase C, you first have to shift from A to B and then B to C," said Gang. "Our method allows us to pick which daughter phase we want and go right to that one because the daughter phase is completely determined by the type of DNA reprogramming strands we use." reprogrammin strands

Various types of reprogramming strands can be used to selectively trigger the transformation to different phases, or configurations, of the same particle combinations. The scientists were able to observe the structural transformations to various daughter phases using a technique called in situ small-angle x-ray scattering at the National Synchrotron Light Source (http://www.bnl.gov/ps/), another DOE Office of Science User Facility that operated at Brookhaven Lab from 1982 until last September (now replaced by NSLS-II, which produces x-ray beams 10,000 times brighter). The team also used computational modeling to calculate how different kinds of reprogramming strands would alter the interparticle interactions, and found their calculations agreed well with their experimental observations. "The ability to dynamically switch the phase of an entire superlattice array will allow the creation of reprogrammable and switchable materials wherein multiple, different functions can be activated on demand," said Gang. "Our experimental work and accompanying theoretical analysis confirm that reprogramming DNA-mediated interactions among nanoparticles is a viable way to achieve this goal."

Table-top extreme UV laser system heralds imaging at the nanoscale

Researchers at Swinburne University of Technology have discovered a new way to generate bright beams of coherent extreme UV radiation using a table-top setup that could be used to produce high resolution images of tiny structures at the nanoscale. “The ability to image nano-scale features with a conventional optical microscope is limited by the wavelength of the light used to illuminate the sample, Professor Lap van Dao, who led the research, said. “One way to achieve higher spatial resolution is to use radiation with shorter wavelengths such as extreme UV radiation or ‘soft’ x-rays.” The new table-top system may offer a cost-effective and convenient alternative to large-scale, multi-million-dollar facilities such as synchrotrons or free-electron lasers, which, until now, were the only way to generate bright coherent beams of extreme UV radiation. Table-top extreme UV laser system

The researchers from the Centre for Quantum and Optical Science used their table-top laser setup to illuminate a gas cell of argon with two intense beams of ultrashort laser pulses at different wavelengths. One beam generates ‘high-order harmonics’ in the extreme UV, while the effect of the second overlapping beam is to amplify the extreme UV radiation by a process known as optical parametric amplification. These bright coherent beams of extreme UV radiation will be used for high resolution imaging based on a ‘lensless’ imaging technique called coherent diffractive imaging, in which images are reconstructed by a computer. “This research paves the way for the generation of intense radiation at still shorter wavelengths and ultimately to apply coherent diffractive imaging techniques to nano-scale structures and to biological samples in the water window region (2-4 nanometres),” Emeritus Professor Peter Hannaford said. The new research has been published in the prestigious journal ("Perturbative optical parametric amplification in the extreme ultraviolet").

Nanostructures increase corrosion resistance in metallic body implants

Researchers studied the corrosion and immunity behavior of a new type of nanostructures and used them in the production of metallic body implants (, "Effect of Equal Channel Angular Pressing Process on the Corrosion Behavior of Type 316L Stainless Steel in Ringer's Solution"). Corrosion behavior of metallic biomaterials has a strong effect on the biodegradability of medical metallic implants. Therefore, it is very important to study this characteristic. Stainless Steel 316L has an important role in the production of metallic implants. However, it may cause biological problems for people due to the corrosion process inside the body in a long period. The corrosion of the metal releases toxic ions, including nickel and chrome, which cause allergy and infection in the body. In this research, the structure of stainless steel 316L is modified by a nanostructure. Therefore, the corrosion resistance of the steel increases significantly in the liquid atmosphere of the body that contains chlorine corrosive ion. Increasing the corrosion resistance of the implant inside the body increases its biocompatibility and immunity in the body atmosphere. In addition, the probability of the creation of allergy by releasing metallic ions from the implant surface due to the corrosion of the metallic implant inside the body minimizes. The modified steel in this research has an average size of 78 nm. Based on the results, corrosion resistance of the nanostructure stainless steel 316L is about 4 times higher than its microstructure form.

Nonfriction literature

$500 billion. That's a low estimate of how much friction and wear costs the U.S. every year. In fact, studies suggest that so-called "normal wear and tear" costs industrialized countries some 2 to 6 percent of their annual gross domestic product. How so? Nearly every machine ever created has at least one performance-critical sliding interface. Joints, bushings and bearings must operate reliably with low friction and low wear or the machine to perform as desired. When parts wear out, materials are wasted, quality suffers, and downtime and replacement expenses accrue on a massive scale, across all industry and consumer sectors. Apologies to William Shakespeare, but...ay, there's the rub. Dr. Brandon Krick is a tribologist - an expert in the study of the effects of friction on moving machine parts, and methods of easing those effects. "Tribology is absolutely integrated with everything we do daily, yet it is very poorly understood," he says. "The fact is that nothing - nothing -- would work without friction."

Tribologist Brandon A. Krick and graduate student Mark Sidebottom will lead experimental efforts. (Image: Lehigh University) Professor Krick is partnering with colleagues from DuPont on a project that's recently won a "GOALI" grant from the National Science Foundation (NSF). The intent is to expand the Lehigh Tribology Lab's fight against friction, its war on wear. A 2013 addition to the mechanical engineering faculty at Lehigh University, Krick studies the fundamental origins of friction, wear, materials deformation, and adhesion on complex surfaces ranging from cells to nanocomposites, in environments ranging from space to thousands of feet under water. Netting a GOALI The NSF's Grant Opportunities for Academic Liaison with Industry (GOALI) program promotes university-industry partnerships by making project funds or fellowships/traineeships available to support an eclectic mix of industry-university linkages. According to the NSF Web site, special consideration is provided to interdisciplinary projects that create opportunities for faculty, postdoctoral researchers, and students to conduct research and gain experience in an industrial setting, while enabling industrial scientists and engineers to bring their perspective and skills to academia. Professor Krick says that the Lehigh-DuPont team will develop and study ultralow-wear composite materials suitable for manufacturability and usage in commercial and industrial settings. Krick will serve as principal investigator on the project, with DuPont scientists Christopher Junk and Gregory Blackman serving as co-principal investigators and Lehigh graduate student Mark Sidebottom leading the experimental efforts. "We'll be exploring how various material structures, composition, processing and operating conditions impact tribological performance," Krick reports. "We'll also gain a much more complete understanding of the mechanical and chemical processes involved in wearing down materials we're developing." "Working on this NSF GOALI proposal has been a truly collaborative, multidisciplinary process that could not have been completed without the help of our talented team members," say DuPont collaborators Junk and Blackman. "This project will focus on very fundamental questions, but with real applications in mind. Being on this team with Professor Krick has made us all better scientists and engineers, and we are eager to continue to build our partnership and help train new researchers along the way." According to the grant materials, "the research will use student-built instruments to directly validate the hypothesized mechanism that in situ tribochemical reaction products alter the properties of otherwise inert fluoropolymers. A multi-faceted characterization approach will systematically test the hypotheses and discover new mechanisms of these materials that could, ultimately, enable science-based design of new materials that are incredibly resistant to wear." The grant also calls for the development of outreach programs and educational opportunities in the field of tribology. Krick and his colleagues at DuPont have been partners fighting wear for several years. DuPont supported much of Krick's work as a student and researcher at the University of Florida, and the relationship has carried over into his activities at Lehigh. "DuPont is one of the world's premier industrial scientific communities," says Krick. "Working with the DuPont team has been one of the most productive and rewarding collaborations of my life." Krick was attracted to Lehigh due to its intense focus on interdisciplinary education and research and the power of its material characterization facility - the Center for Advanced Materials and Nanotechnology. "I'm in this field that relies heavily on collaboration, and I saw a lot of talented students and faculty here, and research capabilities that are right in my wheelhouse - the right place to build a research program," he says. Krick feels that the study of tribology gets far less credit than it deserves. "Lately there has been a large push for green manufacturing, new sources of energy, ways to make things more efficient. With tribology, we can make machines work more efficiently, significantly improving energy and material usage. If we can reduce the energy demands of machines and devices, we make use of alternative energy sources much more feasible."

Atomic-level flyovers show how radiation bombardment boosts superconductivity

Sometimes a little damage can do a lot of good -- at least in the case of iron-based high-temperature superconductors. Bombarding these materials with high-energy heavy ions introduces nanometer-scale damage tracks that can enhance the materials' ability to carry high current with no energy loss -- and without lowering the critical operating temperature. Such high-current, high-temperature superconductors could one day find application in zero-energy-loss power transmission lines or energy-generating turbines. But before that can happen, scientists would like to understand quantitatively and in detail how the damage helps--and use that knowledge to strategically engineer superconductors with the best characteristics for a given application. In a paper published May 22, 2015, in ("Imaging atomic-scale effects of high-energy ion irradiation on superconductivity and vortex pinning in Fe(Se,Te)"), researchers from the U.S. Department of Energy's (DOE) Brookhaven and Argonne national laboratories describe atomic-level "flyovers" of the pockmarked landscape of an iron-based superconductor after bombardment with heavy ion radiation. The surface-scanning images show how certain types of damage can pin potentially disruptive magnetic vortices in place, preventing them from interfering with superconductivity. Atomic Level Flyover of Superconductor

High-energy gold ions impact the crystal surface from above at the sites indicated schematically by dashed circles. Measurement of the strength of superconductivity in this same field of view, as shown on the lower panel, reveals how the impact sites are the regions where the superconductivity is also annihilated. In additional studies, the scientists discovered that it is in these same regions that the strongest pinning of quantized vortices occurs, followed at higher magnetic fields by pinning at the single atom crystal damage sites. Pinning the vortices allows high current superconductivity to flow unimpeded through the rest of the sample. (Image: Brookhaven National Laboratory) The work is a product of the Center for Emergent Superconductivity, a DOE Energy Frontier Research Center established at Brookhaven in partnership with Argonne and the University of Illinois to foster collaboration and maximize the impact of this research. "This study opens a new way forward for designing and understanding high-current, high-performing superconductors," said study co-author J.C. Séamus Davis, a physicist at Brookhaven Lab and Cornell University. "We demonstrated a procedure whereby you can irradiate a sample with heavy ions, visualize what the ions do to the crystal at the atomic scale, and simultaneously see what happens to the superconductivity in precisely the same field of view." Argonne physicist Wai-Kwong Kwok led the effort on heavy ion bombardment. "Heavy ions such as gold can create nearly continuous or discontinuous column shaped damage tracks penetrating through the crystal. As the very high-energy ions traverse the material, they melt the crystal at the atomic scale and destroy the crystal structure over a diameter of a few nanometers. It's important to understand the details of how these atomic-scale defects affect local electronic properties and the macroscopic current carrying capacity of the bulk material," he said. The scientists were particularly interested in how the nanoscale defects interact with microscopic magnetic vortices that form when iron-based superconductors are placed in a strong magnetic field -- the type that would be present in turbines and other energy applications. "These quantum vortices are like eddies in a river moving across or counter to the direction of flow," Davis said. "They are the enemy of superconductivity. You can't prevent them from forming, but scientists as long ago as the 1970s found you can sometimes prevent them from moving around by shooting some high-energy ions into the material to form atomic-scale damage tracks that trap the vortices." But random bombardment is, literally, hit-or-miss. Scientists developing materials for energy applications would like to take a more strategic approach by developing a quantitative and predictive theory for how to engineer these materials. "If a company comes to us and says we are developing these superconductors and we want them to have this current at a certain temperature in this type of magnetic field, we'd like to be able to tell them exactly what type of defects to introduce," Kwok said. To do that they needed a way to map out the defects, map out the superconductivity, and map out the locations of the vortices -- and a quantitative theoretical model that describes how those variables relate to one another and the material's bulk superconductivity. A precision spectroscopic-imaging scanning tunneling microscope (SI-STM) developed by Davis is the first tool that can map out those three characteristics on the same material. Under Davis' guidance, Brookhaven Lab postdoctoral fellow Freek Massee (now at University Paris-Sud in France) and Cornell University graduate student Peter Sprau -- the two lead co-authors on the paper -- used the instrument's fine electron-tunneling tip to scan over the material's surface, imaging the atomic structure of the landscape below and the properties of its electrons, atom by atom. The precision allows the scientists to scan the same atoms repeatedly under different external conditions -- such as changes in temperature and ramped up magnetic fields -- to study the formation, movement, and effects of quantum vortices. Their atomic-scale imaging studies reveal that vortex pinning -- the ability to keep those disruptive eddies in place -- depends on the shape of the high-energy ion damage tracks (specifically whether they are point-like or elongated), and also on a form of "collateral damage" discovered by the researchers far from the primary route traversed by each ion. Collaborating theorists at the University of Illinois are now using the experimental results to develop a descriptive framework the scientists can use to predict and test new approaches for materials design. "These studies will really help us solve at which temperature which type of defects will be best for carrying a particular current," Kwok said. "The ability to achieve critical current by design is one of the ultimate goals of the Center for Emergent Superconductivity."

UCF's new nanotechnology Master's degree is first in Florida

The University of Central Florida (UCF) is now the first and only university in Florida to offer a research-focused master’s degree in nanoscience. The Master of Science in Nanotechnology program further elevates the prominence of UCF’s nanotechnology research, said Sudipta Seal, director of the university’s NanoScience Technology Center, Advanced Materials Processing and Analysis Center (AMPAC) and interim chair of Materials Science and Engineering. The new program is expected to draw students from who have earned a bachelor’s degree in physics, chemistry, biology or engineering and who are interested in nanoscience, where research is opening up new technologies at a rapid pace. The two-year nanoscience master’s program, which will launch in the upcoming fall 2015 semester, is geared toward students interested in a career in research, as well as those who want to ultimately earn a doctoral degree. Participants will write and defend a thesis while earning their master’s degree. Last year, UCF launched a similar degree track aimed at students who want to take their nanotech knowledge into the business world. The Professional Science Master’s in Nanotechnology pares core courses in nanoscience with professional development courses in business and entrepreneurship. It does not require a thesis, but culminates in an internship within the industry. “We will prepare students for research and careers in industry or academia,” Seal said. “UCF is still leading the state and the nation with this dual degree program.” The U.S. National Science Foundation estimates the global market for nanotechnology-related goods and services at $1 trillion, making it one of the fastest-growing industries in history. There is an increasing demand for skilled workers and academic researchers in nanoscience. The NanoScience Technology Center is an interdisciplinary facility with a diverse faculty, all of whom have joint appointments to the both the center and other academic departments. “Among the faculty we have chemists, physicists, engineers, and biomedical scientists,” said professor Qun “Treen” Huo. “The center offers a central hub for education, training and research. We have a wide range of instruments and equipment for biomedical, energy and engineering-related interdisciplinary research, so we’ll be able to provide lab facilities and a direct research training experience for the students.” Huo said the center hopes to enroll 10-15 students in the program at its start. Visit here for more information.

Artificial muscles get graphene boost

Ionic polymer metal composites (IPMCs), often referred to as artificial muscles, are electro-active polymer actuators that change in size or shape when stimulated by an electric field. IPMCs have been extensively investigated for their potential use in robotics inspired by nature, such as underwater vehicles propelled by fish-like fins, and in rehabilitation devices for people with disabilities. An IPMC “motor”, or actuator, is formed from a molecular membrane stretched between two metal electrodes. When an electric field is applied to the actuator, the resulting migration and redistribution of ions in the membrane causes the structure to bend. IPMC actuators are known for their low power consumption, as well as their ability to bend under low voltage and to mimic movements that occur naturally in the environment. They have a major disadvantage, however. Cracks can form on the metal electrodes after a period of exposure to air and electric currents. This can lead to the leakage of ions through the electrodes, resulting in reduced performance. Improving the durability of IPMC actuators is a major challenge in the field of artificial muscles. Researchers are investigating ways to develop a flexible, cost-effective, highly conductive and crack-free electrode that can be used to construct a durable polymer actuator. Schematic of an ionic polymer-graphene composite (IPGC) actuator

Schematic of an ionic polymer-graphene composite (IPGC) actuator

Schematic of the ionic polymer-graphene composite (IPGC) actuator or “motor”. When an electric field is applied, the redistribution of ions causes the structure to bend. (Image: Korea Advanced Institute of Science and Technology) In a paper published in ("Durable and Water-Floatable Ionic Polymer Actuator with Hydrophobic and Asymmetrically Laser-Scribed Reduced Graphene Oxide Paper Electrodes"), researchers from the Korea Advanced Institute of Science and Technology report the development of a thin-film electrode based on a novel ionic polymer-graphene composite (IPGC). Graphene is a single-atom-thick layer of carbon with exceptional mechanical, electrical and thermal properties. The new electrodes have a smooth outer surface that repels water and doesn’t have apparent cracks, which makes them nearly impermeable to liquids. They also have a rough inner surface, which facilitates the migration of ions within the membrane to stimulate bending. The new IPGC actuator demonstrates exceptional durability without apparent degradation, even under very high input voltage. It shows promise for use in biomedical devices, “biomimetic” robots that mimic movements occurring in nature, and flexible soft electronics. The researchers acknowledge that there are still many challenges and more research is needed to realise the full potential of the graphene-based electrodes and their subsequent commercialisation. In 2015, they plan to further enhance the bending performance of the actuators, their ability to store energy and their power. They also plan to develop a biomimetic robot that can walk and jump on water like a water strider. They will do this by constructing floatable IPGC actuators with a reliable bending performance that can continue for a period of six hours without any apparent change in durability.

Mission possible: This device will self-destruct when heated

Where do electronics go when they die? Most devices are laid to eternal rest in landfills. But what if they just dissolved away, or broke down to their molecular components so that the material could be recycled? University of Illinois researchers have developed heat-triggered self-destructing electronic devices, a step toward greatly reducing electronic waste and boosting sustainability in device manufacturing. They also developed a radio-controlled trigger that could remotely activate self-destruction on demand. The researchers, led by aerospace engineering professor Scott R. White, published their work in the journal ("Thermally Triggered Degradation of Transient Electronic Devices"). Heat-Triggered Electronic Device Destruction

Heat-Triggered Electronic Device Destruction

A device is remotely triggered to self-destruct. A radio-frequency signal turns on a heating element at the center of the device. The circuits dissolve completely. (Image: Scott White, University of Illinois) "We have demonstrated electronics that are there when you need them and gone when you don't need them anymore," White said. "This is a way of creating sustainability in the materials that are used in modern-day electronics. This was our first attempt to use an environmental stimulus to trigger destruction." White's group teamed up with John A. Rogers, a Swanlund chair in materials science and engineering and director of the Frederick Seitz Materials Laboratory at Illinois. Rogers' group pioneered transient devices that dissolve in water, with applications for biomedical implants. Together, the two multi-disciplinary research groups have tackled the problem of using other triggers to break down devices, including ultraviolet light, heat and mechanical stress. The goal is to find ways to disintegrate the devices so that manufacturers can recycle costly materials from used or obsolete devices or so that the devices could break down in a landfill. The heat-triggered devices use magnesium circuits printed on very thin, flexible materials. The researchers trap microscopic droplets of a weak acid in wax, and coat the devices with the wax. When the devices are heated, the wax melts, releasing the acid. The acid dissolves the device quickly and completely. To remotely trigger the reaction, researchers embedded a radio-frequency receiver and an inductive heating coil in the device. The user can send a signal to cause the coil to heat up, which melts the wax and dissolves the device. Watch a video of the researchers demonstrating and explaining the devices:

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"This work demonstrates the extent to which clever chemistries can qualitatively expand the breadth of mechanisms in transience, and therefore the range of potential applications," Rogers said. The researchers can control how fast the device degrades by tuning the thickness of the wax, the concentration of the acid, and the temperature. They can design a device to self-destruct within 20 seconds to a couple of minutes after heat is applied. The devices also can degrade in steps by encasing different parts in waxes with different melting temperatures. This gives more precise control over which parts of a device are operative, creating possibilities for sophisticated devices that can sense something in the environment and respond to it. White's group has long been concerned with device sustainability and has pioneered methods of self-healing to extend the life of materials. "We took our ideas in terms of materials regeneration and flipped it 180 degrees," White said. "If you can't keep using something, whether it's obsolete or just doesn't work anymore, we'd like to be able to bring it back to the building blocks of the material so you can recycle them when you're done, or if you can't recycle it, have it dissolve away and not sit around in landfills."

New software allows simulation of molecular dynamics in large systems

Image: T. Mori (Theoretical Molecular Science Laboratory) This software promises to open a new era in computational biophysics and biochemistry by allowing scientists to make connections between molecular and cellular-level understanding and to integrate experimental knowledge with theoretical and computational insights.

Although other programs are now available that can perform MD simulations of biomolecules such as proteins, DNA, membranes, and oligosaccharides, a key advantage of GENESIS is its superior computational efficiency on massively parallel supercomputers like the K computer. Using GENESIS, more than ten thousand CPUs can be used in parallel without any reduction in the computational efficiency. This has been achieved thanks to the developments of several new algorithms, including the inverse lookup table, a new domain decomposition scheme, and the use of hybrid (OpenMP + MPI) parallelization.

In the first molecular dynamics simulation, performed by researchers at Harvard University in 1977, protein dynamics were simulated in vacuum conditions. Beginning in the 1990s, simulations of molecules in water or a lipid bilayer have been possible due to advances in MD algorithms and improvements in computer performance. To investigate biomolecular dynamics and function within more realistic cellular environments, much larger biological systems need to be simulated in milli- or microsecond time scales. GENESIS has the potential to be a good computational platform in this context, as it will help to break down the current limitations facing biological MD simulations in terms of size and time.

Nanowerk Nanotechnology Research News

http://bit.ly/1K2oLEc Nanotechnology Nanotechnology research news headlines from Nanowerk Copyright Nanowerk LLC http://bit.ly/1K2oLEc http://bit.ly/1HafTcb en-us Mon, 11 May 2015 14:56:39 -0400 http://bit.ly/1HafRkt Scientists have successfully visualized anisotropic carrier motion by using time-resolved microscopic optical second-harmonic generation (TRM-SHG) imaging.

]]> http://bit.ly/1HafRkt Mon, 11 May 2015 03:34:42 -0400 http://bit.ly/1HafRku An international team of scientists have pioneered a new technique to embed transparent, flexible graphene electrodes into fibres commonly associated with the textile industry. ]]> http://bit.ly/1HafRku Mon, 11 May 2015 09:53:04 -0400 http://bit.ly/1HafTcd Physicists were able to show for the first time that the nuclear spins of single molecules can be detected with the help of magnetic particles at room temperature. ]]> http://bit.ly/1HafTcd Mon, 11 May 2015 10:07:44 -0400 http://bit.ly/1K2oLEi Tuning up Rydberg atoms for quantum information applications.

]]> http://bit.ly/1K2oLEi Mon, 11 May 2015 12:37:11 -0400 http://bit.ly/1K2oLEj Researchers produced biocompatible and biodegradable non-ionic polymeric nanocarriers that can be used in the targeted anticancer drug delivery. ]]> http://bit.ly/1K2oLEj Sat, 09 May 2015 04:24:55 -0400 http://bit.ly/1K2oNfw Precise control of interactions between light and vibrating mirrors at the level of single light particles could open a new field of complex quantum physical states.

]]> http://bit.ly/1K2oNfw Fri, 08 May 2015 04:09:31 -0400 http://bit.ly/1K2oLEn By speeding up a real atomic force microscope and slowing down a simulation of one, researchers have conducted the first atomic-scale experiments on friction at overlapping speeds.

]]> http://bit.ly/1K2oLEn Fri, 08 May 2015 04:16:39 -0400 http://bit.ly/1K2oNvR Scientists have not only uncovered the quantitative secret to understanding friction in materials, like graphite, they even invented a way to measure it.

]]> http://bit.ly/1K2oNvR Fri, 08 May 2015 04:25:22 -0400 http://bit.ly/1HafTsy A convenient procedure to visualize defects on graphene layers by mapping the surface of carbon materials with an appropriate contrast agent.

]]> http://bit.ly/1HafTsy Fri, 08 May 2015 09:07:07 -0400 http://bit.ly/1K2oNvS Plant-based cellulose nanofibres do not pose a short-term health risk, especially short fibres, shows a new study. ]]> http://bit.ly/1K2oNvS Thu, 07 May 2015 14:32:51 -0400 http://bit.ly/1K2oNvT Researchers have discovered a novel way of combining plasmonic and magneto-optical effects. They experimentally demonstrated that patterning of magnetic materials into arrays of nanoscale dots can lead to a very strong and highly controllable modification of the polarization of light when the beam reflects from the array.

]]> http://bit.ly/1K2oNvT Thu, 07 May 2015 07:48:59 -0400 http://bit.ly/1HafTsD In a study that could open doors for new applications of photonics from molecular sensing to wireless communications, scientists have discovered a new method to tune the light-induced vibrations of nanoparticles through slight alterations to the surface to which the particles are attached.

]]> http://bit.ly/1HafTsD Thu, 07 May 2015 10:01:40 -0400 http://bit.ly/1HafTsI Scientists have found a way to control heat propagation in photonic nano-sized devices, which will be used for high speed communications and quantum information technologies.

]]> http://bit.ly/1HafTsI Thu, 07 May 2015 10:26:46 -0400 http://bit.ly/1K2oOA3 Engineers have devised a process to repair leaksin graphene, filling cracks and plugging holes using a combination of chemical deposition and polymerization techniques. The team then used a process it developed previously to create tiny, uniform pores in the material, small enough to allow only water to pass through. ]]> http://bit.ly/1K2oOA3 Thu, 07 May 2015 14:32:37 -0400 http://bit.ly/1K2oOA4 Researchers have succeeded in creating a new 'whispering gallery' effect for electrons in a sheet of graphene - making it possible to precisely control a region that reflects electrons within the material. They say the accomplishment could provide a basic building block for new kinds of electronic lenses, as well as quantum-based devices that combine electronics and optics.

]]> http://bit.ly/1K2oOA4 Thu, 07 May 2015 14:31:44 -0400 http://bit.ly/1K2oNvY The National Nanotechnology Coordination Office (NNCO) will hold the second in a series of free webinars focusing on the experiences, successes, and challenges for small- and medium-sized nanotechnology businesses and on issues of interest to the nanotechnology business community on Wednesday May 20, 2015 from 2-3pm EDT. ]]> http://bit.ly/1K2oNvY Thu, 07 May 2015 15:00:17 -0400 http://bit.ly/1HafRB5 The National Nanotechnology Coordination Office (NNCO) has announced the winner of the first EnvisioNano nanotechnology image contest for students.

]]> http://bit.ly/1HafRB5 Wed, 06 May 2015 02:18:49 -0400 http://bit.ly/1K2oNMh Scientists are inching closer to developing a nano-scale drug delivery system with the aim of specifically targeting cancer cells.

]]> http://bit.ly/1K2oNMh Wed, 06 May 2015 08:45:44 -0400 http://bit.ly/1K2oOQl Scientists are reporting progress toward that goal with the development of a novel DNA-based GPS.

]]> http://bit.ly/1K2oOQl Wed, 06 May 2015 09:51:05 -0400 http://bit.ly/1HafTIZ Scientists have developed a simple, thermometer-like device that could help doctors diagnose heart attacks with minimal materials and cost.

]]> http://bit.ly/1HafTIZ Wed, 06 May 2015 09:56:34 -0400 http://bit.ly/1K2oNMi Researchers devise new technique to produce long, custom-designed DNA strands. ]]> http://bit.ly/1K2oNMi Wed, 06 May 2015 11:33:28 -0400 http://bit.ly/1HafRB8 Researchers developed an inkjet printing technology to produce kesterite thin film absorbers (CZTSSe). Based on the inkjet-printed absorbers, solar cells with total area conversion efficiency of up to 6.4 % have been achieved.

]]> http://bit.ly/1HafRB8 Wed, 06 May 2015 13:02:48 -0400 http://bit.ly/1HafRB9 Technology in common household humidifiers could enable the next wave of high-tech medical imaging and targeted medicine, thanks to a new method for making tiny silicone microspheres.

]]> http://bit.ly/1HafRB9 Wed, 06 May 2015 13:15:55 -0400 http://bit.ly/1K2oOQs Some substances, when they undergo a process called rapid-freezing or supercooling, remain in liquid form - even at below-freezing temperatures. A new study is the first to break down the rules governing the complex process of crystallization through rapid-cooling. Its findings may revolutionize the delivery of drugs in the human body, providing a way to 'freeze' the drugs at an optimal time and location in the body. ]]> http://bit.ly/1K2oOQs Wed, 06 May 2015 13:30:05 -0400 http://bit.ly/1HafUwA Electronics is based on the manipulation of electrons and other charge carriers, but in addition to charge, electrons possess a property known as spin. When spin is manipulated with magnetic and electric fields, the result is a spin-polarised current that carries more information than is possible with charge alone. Spin-transport electronics, or spintronics, is a subject of active investigation within Europe's Graphene Flagship.

]]> http://bit.ly/1HafUwA Tue, 05 May 2015 05:50:24 -0400 http://bit.ly/1HafUwB Researchers have found that covering an implantable neural electrode with nanoporous gold could eliminate the risk of scar tissue forming over the electrode?s surface.

]]> http://bit.ly/1HafUwB Tue, 05 May 2015 06:06:12 -0400 http://bit.ly/1HafTJ6 Researchers have developed an inexpensive technique called 'microcombing' to align carbon nanotubes (CNTs), which can be used to create large, pure CNT films that are stronger than any previous such films. The technique also improves the electrical conductivity that makes these films attractive for use in electronic and aerospace applications.

]]> http://bit.ly/1HafTJ6 Tue, 05 May 2015 06:13:20 -0400 http://bit.ly/1HafTJ7 Researchers have discovered topologically protected one-dimensional electron conducting channels at the domain walls of bilayer graphene. These conducting channels are 'valley polarized', which means they can serve as filters for electron valley polarization in future devices such as quantum computers.

]]> http://bit.ly/1HafTJ7 Tue, 05 May 2015 06:19:22 -0400 http://bit.ly/1HafUwD Researchers have found that silver nanoparticles produced with an extract of wormwood, an herb with strong antioxidant properties, can stop several strains of the deadly fungus phytophthora. ]]> http://bit.ly/1HafUwD Tue, 05 May 2015 06:22:27 -0400 http://bit.ly/1K2oOQt Researchers successfully fabricated halide organic-inorganic hybrid perovskite field-effect transistors and measure their electrical characteristics at room temperature. ]]> http://bit.ly/1K2oOQt Tue, 05 May 2015 08:57:12 -0400

First theoretical proof: Measurement of a single nuclear spin in biological samples

Physicists of the University of Basel and the Swiss Nanoscience Institute were able to show for the first time that the nuclear spins of single molecules can be detected with the help of magnetic particles at room temperature. In ("High-efficiency resonant amplification of weak magnetic fields for single spin magnetometry at room temperature"), the researchers describe a novel experimental setup with which the tiny magnetic fields of the nuclear spins of single biomolecules – undetectable so far – could be registered for the first time. The proposed concept would improve medical diagnostics as well as analyses of biological and chemical samples in a decisive step forward. The measurement of nuclear spins is routine by now in medical diagnostics (MRI). However, the currently existing devices need billions of atoms for the analysis and thus are not useful for many small-scale applications. Over many decades, scientists worldwide have thus engaged in an intense search for alternative methods, which would improve the sensitivity of the measurement techniques. With the help of various types of sensors (SQUID- and Hall-sensors) and with magnetic resonance force microscopes, it has become possible to detect spins of single electrons and achieve structural resolution at the nanoscale. However, the detection of single nuclear spins of complex biological samples – the holy grail in the field – has not been possible so far. Diamond crystals with tiny defects The researchers from Basel now investigate the application of sensors made out of diamonds that host tiny defects in their crystal structure. In the crystal lattice of the diamond a Carbon atom is replaced by a Nitrogen atom, with a vacant site next to it. These so-called Nitrogen-Vacancy (NV) centers generate spins, which are ideally suited for detection of magnetic fields. At room temperature, researchers have shown experimentally in many labs before that with such NV centers resolution of single molecules is possible. However, this requires atomistically close distances between sensor and sample, which is not possible for biological material. A tiny ferromagnetic particle, placed between sample and NV center, can solve this problem. Indeed, if the nuclear spin of the sample is driven at a specific resonance frequency, the resonance of the ferromagnetic particle changes. With the help of an NV center that is in close proximity of the magnetic particle, the scientists can then detect this modified resonance. Measuring technology breakthrough? The theoretical analysis and experimental techniques of the researchers in the teams of Prof. Daniel Loss and Prof. Patrick Maletinsky have shown that the use of such ferromagnetic particles can lead to a ten-thousand-fold amplification of the magnetic field of nuclear spins. „I am confident that our concept will soon be implemented in real systems and will lead to a breakthrough in metrology“, comments Daniel Loss the recent publication, where the first author Dr. Luka Trifunovic, postdoc in the Loss team, made essential contributions and which was performed in collaboration with colleagues from the JARA Institute for Quantum Information (Aachen, Deutschland) and the Harvard University (Cambridge, USA).

Curcumin nanodrug breaks cancers' resistance to treatment

Researchers from Cancer Research Center of Tehran University of Medical Sciences produced biocompatible and biodegradable non-ionic polymeric nanocarriers that can be used in the targeted anticancer drug delivery (, "Encapsulation of Curcumin in Diblock Copolymer Micelles for Cancer Therapy"). The nanocarrier has been produced without using toxic catalysts and it has successfully passed clinical tests on a number of patients who suffered from cancer. Studies show that curcumin – the active pharmaceutical ingredient in turmeric – has anticancer properties as well as having anti-oxidant and anti-inflammation characteristics, and it can prevent the cancer. However, when curcumin is consumed orally, very tiny amount of it is found in blood plasma or in target tissue. This fact can be caused because of the low amount of sorption, quick metabolism or quick elimination of curcumin from the body. Therefore, numerous methods have been developed to increase the amount of curcumin in plasma or in the target tissue. According to the results of the research, encapsulation of curcumin in nano-emulsions (nano-curcumin) can increase therapeutic properties of the drug. Comprehensive studies carried out by the research team showed that nano-curcumin has much stronger effects on cancerous cells in cultivation media and in animal samples. This nanodrug is tolerable without any toxicity in the first phase of clinical tests (investigation of its toxicity and the tolerable dosage) even in high dosages. At the moment, this nanodrug is in the end of the second phase of clinical test to treat digestion and breast cancers that resist treatment.