Materials Science
A cooler way to protect silicon surfaces
February 13, 2013 7:49 am | by David L. Chandler, MIT News Office | News | CommentsSilicon requires a surface coating before use in its given applications. The coating "passivates" the material, tying up loose atomic bonds to prevent oxidation that would ruin its electrical properties. But this passivation process consumes a lot of heat and energy, making it costly and limiting the kinds of materials that can be added to the devices. Now a team of researchers has found a way to passivate silicon at room temperature, which could be a significant boon to solar cell production and other silicon-based technologies.
A new cheap, strong lithium-ion battery
February 12, 2013 11:18 am | News | CommentsResearchers at the University of Southern California have developed a new lithium-ion battery design that uses porous silicon nanoparticles in place of the traditional graphite anodes to provide superior performance. The new batteries hold three times as much energy as comparable graphite-based designs and recharge within 10 minutes.
Carbon sponge could soak up coal emissions
February 12, 2013 8:09 am | News | CommentsEmissions from coal power stations could be drastically reduced by a new, energy-efficient material that adsorbs large amounts of carbon dioxide, then release it when exposed to sunlight. Monash University and CSIRO scientists, for the first time, discovered a photosensitive metal organic framework, which has lead to a powerful and cost-effective tool to capture and store, or potentially recycle, carbon dioxide.
Photo-growth of pores in a polymer gel network
February 7, 2013 9:08 am | News | CommentsResearchers at the Massachusetts Institute of Technology have pioneered a new method for producing polymer gels with tailored mechanical properties. The approach, which depends on the use of ultraviolet to break chemical bonds and prime them for new connections, could be used to make new materials that physically grow towards a light source in order to optimize their properties.
Improved “peacock" technology could lock in color for high-res displays
February 5, 2013 12:17 pm | News | CommentsIridescence, or sheen that shifts color depending on your viewing angle, is pretty in peacock feathers. But it's been a nuisance for engineers trying to mimic the birds' unique color mechanism to make high-resolution, reflective, color display screens. Researchers at the University of Michigan have found a way to lock in so-called structural color, which is made with texture rather than chemicals. The finding could lead to advanced color e-books, electronic paper, and screens that don't need their own light to be readable.
Scientists build harness for powerful radiation cancer therapy
February 5, 2013 8:24 am | News | CommentsLow-energy radiation particles, known as beta particles, are often used in radiation treatments for cancer patients. For years, scientists have been studying how to use alpha particles, which are far higher in energy, for the same treatments. The challenge has been finding ways to focus these powerful particles on target cancers without hurting other tissues. A collaboration of scientists have recently created a gold nanoparticle that can transport powerful alpha particles directly to tumors for treatment.
Stronger than Kevlar, light as a tee-shirt
February 4, 2013 8:52 am | by Angela Herring, Northeastern University | News | CommentsTraditionally, carbon fibers are made by “carbonizing” a polymer called poly-acrylonitrile, or PAN, by spinning it into a fiber and heating to form a homogenous carbons structure. Since its invention, improvement have been incremental, and version made with 100% carbon nanotubes are extremely expensive. A researcher at Northeastern University is working on a much cheaper, and stronger, alternative.
Study finds routes toward defect-free graphene
February 1, 2013 12:35 pm | News | CommentsA team led by Oxford University scientists in the U.K., has overcome a key problem of growing graphene—a one atom-thick layer of carbon—when using chemical vapor deposition. The tiny flakes of graphene typically form with random orientations, leaving defects or 'seams' between flakes that grow together. A combination of pressure a simple copper foil can remove these defects.
Physicists find new order in quantum electronic material
February 1, 2013 8:36 am | News | CommentsTwo Rutgers physics professors have proposed an explanation for a new type of order, or symmetry, in an exotic material made with uranium. When cooled to near absolute zero, the material’s electrons essentially act like electronic versions of polarized sunglasses. The new theory that explains this strange behavior may one day lead to enhanced computer displays and data storage systems and more powerful superconducting magnets for medical imaging and levitating high-speed trains.
Novel materials shake ship scum
January 31, 2013 9:46 am | News | CommentsJust as horses shake off pesky flies by twitching their skin, ships may soon be able to shed the unwanted accumulation of bacteria and other marine growth with the flick of a switch. Duke University engineers have developed a material that can be applied like paint to the hull of a ship and will literally be able to dislodge bacteria, keeping it from accumulating on the ship's surface.
New options for transparent contact electrodes
January 29, 2013 10:29 am | News | CommentsFound in flat screens, solar modules, or in new organic light-emitting diode (LED) displays, transparent electrodes have become ubiquitous. But since raw materials like indium are becoming more and more costly, researchers have begun to look elsewhere for alternatives. A new review article sheds some light on the different advantages and disadvantages of established and new materials for use in these kinds of contact electrodes.
Physicists achieve high-energy acceleration of neutral atoms
January 28, 2013 5:43 pm | News | CommentsParticle accelerators normally operate on the principle that charged particles like electrons and protons require high voltages and long acceleration paths. Researchers in India have developed a method that uses lasers to charge a lump of cooled argon particles to high energy and revert them to a neutral, uncharged, state without losing any of the high energy possessed by the particle. The finding could yield a valuable new source of particles for study.
Bioinspired fibers change color when stretched
January 28, 2013 4:31 pm | News | CommentsA team of materials scientists at Harvard University and the University of Exeter have invented a new fiber that changes color when stretched. Inspired by nature, the researchers identified and replicated the unique structural elements that create the bright iridescent blue color of a tropical plant's fruit.
Magnetic nanovehicles control, target drug release in the body
January 28, 2013 10:57 am | News | CommentsResearchers in Switzerland have designed tiny vessels that are capable of releasing active agents in the body. These “nanovehicles” are made from a liposome just 100 to 200 nm in diameter. By attaching magnetic iron oxide nanoparticles to the surface, scientists are able to target the vessel, heating it up to release the drug.
Scientists unravel the mysteries of spider silk
January 28, 2013 8:22 am | News | CommentsScientists at Arizona State University are celebrating their recent success on the path to understanding what makes the fiber that spiders spin—weight for weight—at least five times as strong as piano wire. They have found a way to obtain a wide variety of elastic properties of the silk of several intact spiders' webs using a sophisticated but non–invasive laser light scattering technique.
EU science projects win up to billion euros each
January 28, 2013 8:16 am | News | CommentsTwo science projects—one to map the human brain, the other to explore the extraordinary properties of the carbon-based material graphene—were declared the winners Monday of an EU technologies contest and will receive up to €1 billion ($1.35 billion) each over the next 10 years.
A safer way to vaccinate
January 28, 2013 7:43 am | by Anne Trafton, MIT News Office | News | CommentsMassachusetts Institute of Technology researchers describe a new type of vaccine-delivery film that holds promise for improving the effectiveness of DNA vaccines. If such vaccines could be successfully delivered to humans, they could overcome not only the safety risks of using viruses to vaccinate against diseases such as HIV, but they would also be more stable, making it possible to ship and store them at room temperature.
Scientists confirm surprisingly small proton radius
January 25, 2013 11:17 am | by Olivia Meyer-Streng, Max Planck Institute of Quantum Optics | News | CommentsUsing laser spectroscopy to examine an exotic form of hydrogen, which has a negatively charged muon instead of an electron, physicists at the Paul Scherrer Institute in Switzerland have for the first time determined the magnetic radius of the proton. The result significantly different than the one from previous investigations of regular hydrogen.
Liquid metal makes silicon crystals at record low temperatures
January 25, 2013 7:35 am | News | CommentsA new way of making crystalline silicon, developed by University of Michigan researchers, could make this crucial ingredient of computers and solar cells much cheaper and greener. The researchers discovered a way to make silicon crystals, directly at just 180 F, the internal temperature of a cooked turkey, by taking advantage of a phenomenon seen in your kitchen.
Liquid crystal’s chaotic inner dynamics
January 24, 2013 4:08 pm | News | CommentsPhysicists have recently demonstrated that the application of a very strong alternating electric field to thin liquid crystal cells leads to a new distinct nonlinear dynamic effect in the response of the cells. Researchers were able to explain this result through spatio-temporal chaos theory. The finding has implications for the operation of liquid crystal devices because their operation depends on electro-optic switch phenomena.
Organic ferroelectric molecule shows promise for memory chips
January 24, 2013 2:31 pm | News | CommentsAt the heart of computing are tiny crystals that transmit and store digital information's ones and zeroes. Today these are hard and brittle materials. But cheap, flexible, nontoxic organic molecules may play a role in the future of hardware. A team led by the University of Washington and the Southeast University discovered a molecule that shows promise as an organic alternative to today's silicon-based semiconductors.
Exotic chemical compound could be useful in batteries
January 24, 2013 2:08 pm | News | CommentsNorthwestern University graduate student Jonathan Barnes had a hunch for creating an exotic new chemical compound, and his idea that the force of love is stronger than hate proved correct. He and his colleagues are the first to permanently interlock two identical tetracationic rings that normally are repelled by each other. Many experts had said it couldn't be done.
Research paves way for larger, safer lithium-ion batteries
January 24, 2013 7:45 am | News | CommentsLooking toward improved batteries for charging electric cars and storing energy from renewable but intermittent solar and wind, scientists at Oak Ridge National Laboratory have developed the first high-performance, nanostructured solid electrolyte for more energy-dense lithium-ion batteries.
Sensors from a spray can: Organic materials increase camera sensitivity
January 23, 2013 5:41 pm | News | CommentsResearchers in Germany have developed a new generation of image sensors that are more sensitive to light than the conventional silicon versions. Simple and cheap to produce, they consist of electrically conductive plastics which are sprayed onto the sensor surface in an ultra-thin layer. The chemical composition of the polymer spray coating can be altered so that even the invisible range of the light spectrum can be captured.
Self-assembling silica microwires may enable integrated optical devices
January 23, 2013 10:23 am | News | CommentsSilica microwires are the tiny and as-yet underutilized cousins of optical fibers. If precisely manufactured, however, these hair-like slivers of silica could enable applications and technology not currently possible with comparatively bulky optical fiber. By carefully controlling the shape of water droplets with an ultraviolet laser, a team of researchers from Australia and France has found a way to coax silica nanoparticles to self-assemble into much more highly uniform silica wires.
