Materials Science
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.
Bisphenol A substitute could spell trouble
January 23, 2013 8:35 am | News | CommentsIn the same week that a team of researchers in France announced the harmful effects of bisphenol A (BPA) on hormone levels in human tissue, researchers in Texas have demonstrated through experiments that the BPA substitute bisphenol S also disrupts hormone activity at an extremely low level of exposure, and in an even more problematic way.
Researchers create self-healing, stretchable wires using liquid metal
January 23, 2013 8:20 am | News | CommentsResearchers from North Carolina State University have developed elastic, self-healing wires in which both the liquid-metal core and the polymer sheath reconnect at the molecular level after being severed.
Nanosponge filters out herbicide poisons
January 21, 2013 8:19 am | News | CommentsNew research has demonstrated the potential of a new kind of nanomaterial to filter out environmental toxins in water. A team of researchers has developed a highly porous metal organic framework (MOF) that, almost uniquely, is stable and able to filter substances in water. This study is one of the first to demonstrate MOFs separation applications in an aqueous environment.
Rare earth metals make water-repellent surfaces that last
January 21, 2013 8:01 am | by David L. Chandler, MIT News Office | News | CommentsWater-shedding surfaces that are robust in harsh environments could have broad applications in many industries. Hydrophobic materials can greatly enhance the efficiency of this process. But these materials have one major problem: Most employ thin polymer coatings that degrade when heated, and can easily be destroyed by wear. Massachusetts Institute of Technology researchers have now come up with a new class of hydrophobic ceramics that can overcome these problems.
Quantitative magneto-mechanical made possible by the Barkhausen Effect
January 17, 2013 9:45 pm | News | CommentsThe Barkhausen Effect is the noise in the magnetic output of a ferromagnet when the magnetizing force applied to it is changed. Almost 100 years after its initial discovery, a team of scientists in Alberta have harnessed this effect as a new kind of high-resolution microscopy for the insides of magnetic materials.
Self-assembled “soft Legos” create complex crystal shapes
January 17, 2013 12:24 pm | News | CommentsA team of researchers in Austria has shown that so-called block copolymer stars—polymers that consist of two different blocks and are chemically anchored on a common point—have a robust and flexible architecture and they possess the ability to self-assemble at different levels. The team has called their invention, which can form complex crystal diamonds or cubes, the “soft Lego”.
RABiTS technology enables record-setting performance
January 17, 2013 7:57 am | News | CommentsA technology invented at Oak Ridge National Laboratory for manufacturing copper-oxide-based high-temperature superconducting materials has been used to make an iron-based superconducting wire capable of carrying very high electrical currents under exceptionally high magnetic fields.
New surfaces repel most known liquids
January 16, 2013 1:18 pm | News | CommentsIn an advance toward stain-proof, spill-proof clothing, protective garments and other products that shrug off virtually every liquid—from blood and ketchup to concentrated acids—scientists are reporting development of new "superomniphobic" surfaces. These new surfaces display extreme repellency to two families of liquids: Newtonian and non-Newtonian.
Researchers develop integrated dual-mode active and passive infrared camera
January 16, 2013 1:14 pm | News | CommentsHigh-performance infrared cameras are usual for night-vision goggles and are usually either active, which use invisible infrared sources, or passive, which detect thermal radiation without the need for illumination. Integrating both modes has proven challenging, but researchers at Northwestern University have done by using advanced type-II superlattice materials.
New research gives insight into graphene grain boundaries
January 15, 2013 11:45 am | by Steve McGaughey, Beckman Institute | News | CommentsMaking the one-atom thick sheets of carbon known as graphene in a way that could be easily integrated into mass production methods has proven difficult. Now, research from the Beckman Institute at the University of Illinois is giving new insight into the electronics behavior of graphene. They have obtained information about electron scattering at graphene’s boundaries that shows it significantly limits the electronic performance compared to grain boundary free graphene.
New effort to create green electronics, workforce
January 15, 2013 10:18 am | by Emil Venere, Purdue University | News | CommentsThe world's love affair with gadgets—many of which contain hazardous materials—is generating millions of tons of electronic waste annually. Now, Purdue and Tuskegee universities are leading an international effort to replace conventional electronics with more sustainable technologies and train a workforce of specialists to make the transition possible.
NRL designs multijunction solar cell to break efficiency barrier
January 14, 2013 10:42 am | News | CommentsU.S. Naval Research Laboratory scientists, in collaboration with the Imperial College London and MicroLink Devices Inc., have proposed a novel triple-junction solar cell with the potential to break the 50% conversion efficiency barrier, which is the current goal in multijunction photovoltaic development.
DOE launches rare earth metals research hub
January 11, 2013 10:37 am | News | CommentsThe U.S. Department of Energy (DOE) has launched a research hub that focuses on solutions to the domestic shortages of rare earth metals and other materials critical for U.S. energy security.
New material harvests energy from water vapor
January 10, 2013 2:50 pm | by Anne Trafton, MIT News Office | News | CommentsMassachusetts Institute of Technology engineers have created a new polymer film that can generate electricity by drawing on a ubiquitous source: water vapor. The new material changes its shape after absorbing tiny amounts of evaporated water, allowing it to repeatedly curl up and down. Harnessing this continuous motion could drive robotic limbs or generate enough electricity to power micro- and nanoelectronic devices, such as environmental sensors.
Stopping leaks the way blood does
January 8, 2013 2:00 pm | by David L. Chandler, MIT News Office | News | CommentsA team of Massachusetts Institute of Technology researchers has analyzed the blood clotting process and found, for the first time, exactly how the different molecular components work together to block the flow of blood from a cut. Now, they are working on applying that knowledge to the development of synthetic materials that could be used to control different kinds of liquid flows, and could lead to a variety of new self-assembling materials.
A temperature below absolute zero
January 7, 2013 1:46 pm | News | CommentsAccording to the physical meaning of temperature, the temperature of a gas is determined by the chaotic movement of its particles. At zero kelvin (-273 C) the particles stop moving and all disorder disappears. Thus, nothing can be colder than absolute zero on the Kelvin scale. Nevertheless, researchers in Germany have now created an atomic gas in the laboratory that has negative Kelvin values.
Better than diamond
January 7, 2013 1:39 pm | by Gunnar Bartsch | News | CommentsSilicon carbide crystals consist of a regular lattice formed by silicon and carbon atoms. At present, these semiconductors are extensively used in micro and opto-electronics. Physicists have recently modified silicon carbide crystals in a way that these exhibit new and surprising properties. This makes them interesting with regard to the design of high-performance computers or data transmission.
New path to more efficient organic solar cells
January 7, 2013 1:11 pm | News | CommentsWorking at Lawrence Berkeley National Laboratory's Advanced Light Source (ALS), an international team of scientists found that for highly efficient polymer/organic solar cells, size matters. Impure domains if made sufficiently small can lead to improved performances in polymer-based organic photovoltaics.
Jumping droplets help heat transfer
January 4, 2013 7:30 am | by David L. Chandler, MIT News Office | News | CommentsMany industrial plants depend on water vapor condensing on metal plates. The efficiency of such plants depends crucially on how easily droplets of water can form on these metal plates, or condensers, and how easily they fall away, leaving room for more droplets to form. The key to improving the efficiency of such plants is to increase the condensers’ heat-transfer coefficient. A team from Massachusetts Institute of Technology has done just that.
