Other materials stories that may be of interestPublished on December 11th, 2012 | By: Peter Wray
Pretty interesting stuff:
(Yale News) Engineers at Yale University have developed a new breed of micro fuel cell that could serve as a long-lasting, low-cost, and eco-friendly power source for portable electronic devices, such as tablet computers, smart phones, and remote sensors. The researchers describe the novel device in a paper published online in the journal Small. Major components of the new device are made of bulk metallic glasses – extremely pliable metal alloys that nonetheless are more durable than the metals typically used in micro fuel cells. BMGs can be finely shaped and molded using a comparatively efficient and inexpensive fabrication process akin to processes used in shaping plastics. The BMG components of the Yale team’s micro fuel cell (the entirety of which measures three cubic centimeters) are based on zirconium and platinum compounds. The team demonstrated that its fuel cell generates power and is now working to increase it. “These amorphous metal alloys are amazing materials that can be easily shaped into both large and small nanostructures, yet retain suitable properties for a wide range of electrochemical applications,” said André D. Taylor, an assistant professor of chemical and environmental engineering at Yale School of Engineering & Applied Science and a principal investigator of the research.
(Nature) Here we report an optical method that allows non-invasive imaging of a fluorescent object that is completely hidden behind an opaque scattering layer. We illuminate the object with laser light that has passed through the scattering layer. We scan the angle of incidence of the laser beam and detect the total fluorescence of the object from the front. From the detected signal, we obtain the image of the hidden object using an iterative algorithm14, 15. As a proof of concept, we retrieve a detailed image of a fluorescent object, comparable in size (50 micrometres) to a typical human cell, hidden 6 millimetres behind an opaque optical diffuser, and an image of a complex biological sample enclosed between two opaque screens. This approach to non-invasive imaging through strongly scattering media can be generalized to other contrast mechanisms and geometries.
(Nature Materials/RPI) A team of interdisciplinary researchers at Rensselaer Polytechnic Institute has developed a new method for significantly increasing the heat transfer rate across two different materials. Results of the team’s study, published in the journal Nature Materials, could enable new advances in cooling computer chips and lighting-emitting diode devices, collecting solar power, harvesting waste heat, and other applications. By sandwiching a layer of ultrathin “nanoglue” between copper and silica, the research team demonstrated a four-fold increase in thermal conductance at the interface between the two materials. Less than a nanometer-or one billionth of a meter-thick, the nanoglue is a layer of molecules that form strong links with the copper (a metal) and the silica (a ceramic), which otherwise would not stick together well. This kind of nanomolecular locking improves adhesion, and also helps to sync up the vibrations of atoms that make up the two materials which, in turn, facilitates more efficient transport of heat particles called phonons. Beyond copper and silica, the research team has demonstrated their approach works with other metal-ceramic interfaces.
(Energy.gov Blog) During Hurricane Sandy, fuel cells were instrumental in providing backup power for cell towers and keeping cell phone communications open for many in New York, New Jersey and Connecticut. Altergy, a manufacturer of fuel cell power systems, had more than 60 fuel cells in the immediate Sandy disaster area acting as backup power for cell phone towers. While many of the diesel, propane and battery cell phone tower backup generators were affected by the storm, all of the cell towers powered by fuel cells ran without any issues—allowing many disaster victims to continue accessing their cell phone network. UTC Power, another fuel cell manufacturer, had more than 20 fuel cells systems installed in the New England and New York area affected by Sandy. Its 400 kW systems provided continuous power to buildings such as grocery stores, with only one fuel cell shut down temporarily due to an issue related to the fuel cell’s balance of plant. The unit restarted after it was quickly and safely repaired. Why are fuel cells a good energy supply during natural disasters? Fuel cells can run as long as the fuel supply (usually hydrogen or methanol) is available. Fuel cells using hydrogen tanks can run for several days before a replacement tank is needed, depending on the size or number of the tanks.
The electronic properties of graphene films are directly affected by the characteristics of the substrates on which they are grown or to which they are transferred. Researchers are taking advantage of this to create graphene p-n junctions by transferring films of the promising electronic material to substrates that have been patterned by compounds that are either strong electron donors or electron acceptors. A low temperature, controllable and stable method has been developed to dope graphene films using self-assembled monolayers that modify the interface of graphene and its support substrate. Using this concept, a team of researchers at the Georgia Institute of Technology has created graphene p-n junctions—which are essential to fabricating devices—without damaging the material’s lattice structure or significantly reducing electron/hole mobility. The graphene was grown on a copper film using chemical vapor deposition. The graphene films were transferred to silicon dioxide substrates that were functionalized with the self-assembled monolayers.
Buildings and statues constructed of limestone can be protected from pollution by applying a thin, single layer of a water-resistant coating according to a University of Iowa researcher and her colleagues from Cardiff University in a paper published in the journal Scientific Reports. In the study, the researchers report a new way to minimize chemical reactions that cause buildings to deteriorate, according to Vicki Grassian, F. Wendell Miller professor in the UI departments of chemistry and chemical and biochemical engineering. The coating includes a mixture of fatty acids derived from olive oil and fluorinated substances that increase limestone’s resistance to pollution. Other attempts have been made to protect existing stonework in cultural heritage sites; however, those coatings block the stone microstructure and prevent the edifice from “breathing,” thus creating mold and salt buildup.
A coalition of the world’s five largest patent offices—the IP5—announced the upcoming release of the IP5 Statistics Report 2011 Edition, which has been designed to facilitate an understanding of operations and patent procedures among the Offices, while providing a means for gauging inventive activity, technology flow, and comparing procedures. The IP5 is comprised of the US Department of Commerce’s United States Patent and Trademark Office, the European Patent Office, the Japan Patent Office, the Korean Intellectual Property Office, and the State Intellectual Property Office of the People’s Republic of China. The IP5 Offices, which together handle about 80% of the world’s patent applications, began meeting in 2007 and have since worked together to explore ways to further optimize their joint efforts to improve quality and efficiency of the examination process and to explore and optimize work sharing opportunities between the Offices.
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