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NANOTECHNOLOGY

A D V A N C E D M A T E R I A L S & P R O C E S S E S | J A N U A R Y 2 0 1 6

used for labs and industries that use ammonia or need to detect nitrogen oxides. psu.edu.

USING ELECTRON MICROSCOPES TO BUILD 3D STRUCTURES

Researchers at the Department of Energy’s Oak Ridge National Laborato- ry, Tenn., have developed a unique way to build 3D structures with finely con- trolled shapes as small as one to two billionths of a meter. The study demon- strates how scanning transmission electron microscopes, normally used as imaging tools, are also capable of pre- cision sculpting of nanometer-sized 3D features in complex oxide materials. By offering single atomic plane precision, the technique could find use in fabricat- ing structures for functional nanoscale devices such as microchips. The struc- tures grow in perfect crystalline align- ment, which ensures that the same electrical and mechanical properties extend throughout the whole material. ornl.gov.

Drawing of boron-doped graphene. Courtesy of Terrones, Penn State.

requiring frequent replacement. By comparison, graphene is resistant to the damaging effects of chlorine. For more information: Jeffrey Grossman, 617.324.3566, jcg@mit.edu , mit.edu. BORON-DOPED GRAPHENE ENABLES SUPER SENSITIVE SENSORS Graphene is known for its remark- able strength and ability to transport electrons at high speed, but it is also a highly sensitive gas sensor. In a study conducted by an international research team, graphene sensors with the addi- tion of boron atoms detected noxious gas molecules at extremely low concen- trations, parts per billion in the case of nitrogen oxides and parts per million for ammonia. This translates to 27 × great- er sensitivity to nitrogen oxides and 10,000 × greater sensitivity to ammonia compared to pristine graphene. Re- searchers from Pennsylvania State Uni- versity, State College, and colleagues believe these results will enable devel- opment of high-performance sensors that can detect trace amounts of many other molecules. These sensors can be

GRAPHENE BOOSTS DESALINATION EFFICIENCY The laboratory of Jeffrey Gross- man, a professor at Massachusetts In- stitute of Technology, Cambridge, has demonstrated strong results showing that new filters made from graphene could greatly improve the energy effi- ciency of desalination plants while po- tentially reducing other costs as well. At only an atom thick, there is far less friction loss when you push seawater through a perforated graphene filter compared with the polyamide plastic filters that have been used for the last 50 years, says Grossman. “The process of pumping seawater through filters represents about half the operating costs of a desalination plant. With graphene, we could use 15% less energy for seawater and up to 50% less energy for brackish water,” he explains. Another advantage is that graphene filters do not become fouled with bio- growth at nearly the rate that occurs with polyamide filters. In addition, the chlorine used to clean the filters reduc- es the polyamide’s structural integrity,

Researchers use a new SEM technique to sculpt 3D nanoscale features in a com- plex oxide material. Courtesy of ORNL.

BRIEF A 4000-sq-ft nanomaterials r s arch laboratory is opening at Cornell University, Ithaca, N.Y. The C nter for Nanom terials Engineering and Technology (CNET) includes equipment for mate ials synthesis, phys- ical characterization, and sc le-up. The tools can be used to develop and analyze materials for applications including carbon capture and conversion, electrochemical energy storage in batteries, and hydrogels for biomedicine and drug delivery. cnet.research.engineering.cornell.edu.

BRIEFS Aleris, Cleveland, offers a new 7017 aluminum alloy in North America for commercial plate and defense uses. After extensive review and testing, the U.S. Army Research Lab issued MIL-DTL-32505 for use in armor applications. 7017 offers high strength, good weldability, and corrosion resistance. It is currently used in Europe and Asia on combat vehicles to achieve superior ballistic protection. aleris.com.