May 27, 2008, 9:37 PM CT

Robots go Where Scientists Fear to Tread

Researchers are diligently working to understand how and why the world's ice shelves are melting. While most of the data they need (temperatures, wind speed, humidity, radiation) can be obtained by satellite, it isn't as accurate as good old-fashioned, on-site measurement and static ground-based weather stations don't allow researchers to collect info from as a number of locations as they'd like.

Unfortunately, the locations in question are volatile ice sheets, possibly cracking, shifting and filling with water - not exactly a safe environment for scientists.

To help researchers collect the more detailed data they need without risking scientists' safety, scientists at the Georgia Institute of Technology, working with Pennsylvania State University, have created specially designed robots called SnoMotes to traverse these potentially dangerous ice environments. The SnoMotes work as a team, autonomously collaborating among themselves to cover all the necessary ground to gather assigned scientific measurements. Data gathered by the Snomotes could give researchers a better understanding of the important dynamics that influence the stability of ice sheets.

"In order to say with certainty how climate change affects the world's ice, researchers need accurate data points to validate their climate models," said Ayanna Howard, lead on the project and an associate professor in the School of Electrical and Computer Engineering at Georgia Tech. "Our goal was to create rovers that could gather more accurate data to help researchers create better climate models. It's definitely science-driven robotics."........ Posted by: Kevin      Read more         Source

Sat, 24 May 2008 22:29:15 GMT

Nanotechnology for Dummies

Don't you just love the "for dummies" series? I hope the title doesn't personally offend anyone. I'm not calling anyone a dummy. I just like the book series.

So, have you read Nanotechnology for Dummies? This book is great because it breaks down the science into a simple, yet meaningful explanation. Many people have misconceptions about what nanotechnology is about. Some think that nanotechnology is just about microscopic robots. Others think that nanotechnology only applies to microchips and computer technology.

It's easy reading and also serves as a nice gift if you're ever in need of one. Visit Dummies.com to see all the other "for dummies" books. Posted by: Joseph Kim, MD      Read more     Source

May 19, 2008, 8:43 PM CT

Researchers Create Superior Polymer

Scientists at Northwestern University and Princeton University have created a new kind of polymer that, because of its extraordinary thermal and mechanical properties, could be used in everything from airplanes to solar cells.

The polymer, a nanocomposite that incorporates functionalized, exfoliated graphene sheets, even conducts electricity, and scientists hope to use that property to eventually create thermally stable, optically transparent conducting polymers.

The results of their research were published May 11 in the online version of Nature Nanotechnology.

Researcher at the McCormick School of Engineering originally teamed up with scientists at Princeton several years ago. McCormick scientists had experience working with polymer nanocomposites, and Princeton scientists had developed a way to exfoliate, or split apart, graphite sheets into very thin single layer, surface-functionalized graphene sheets.

Prior use of graphite in polymers did not garner significantly improved properties since scientists could never get the graphite exfoliated. That meant the graphite was rigid with a low surface area and could only minimally impact properties of the polymer.

But when scientists put even a small amount the newly exfoliated graphene sheets - enough to equal only.05 percent of the material - into the polymer, they found the graphene changed the polymer's thermal stability temperature by 30 degrees. Even adding graphene sheets equal to.01 percent of the material increased stiffness by 33 percent - far beyond what scientists had predicted. The drastic changes in both the thermal stability and the stiffness after adding just a tiny percentage of functionalized graphene indicated that the graphene changes large regions of the polymer radiating out from the nanoparticle surfaces in a percolating network structure......... Posted by: Kevin      Read more         Source

May 19, 2008, 6:34 PM CT

Mid-Infrared Lasers Show Doubled Efficiency

Scientists at the Center for Quantum Devices at the McCormick School of Engineering at Northwestern University have recently doubled the efficiency of infrared lasers under the U.S. Defense Advanced Research Projects Agency's Efficient Mid-wave Infrared Lasers (EMIL) program.

As these types of lasers become more efficient, they could be used in next-generation laser-based defense systems to fool incoming missile attacks or detect explosives or toxins in the atmosphere. Such lasers could also be used in commercial applications like trace chemical analysis, pollution monitoring, and free space communication.

But first, scientists must find the right laser sources at the right wavelengths. The mid-infrared wavelength range (3 to 5 microns) is particularly useful for defense-based applications, and laser technology in this range has been targeted by the U.S. Defense Advanced Research Projects Agency (DARPA) as a strategic technology. The agency created the EMIL program to develop high efficiency, compact semiconductor laser sources with the hopes of demonstrating both high power (~1 W) and high power efficiency (50 percent) from an individual laser at room temperature. Besides demonstrating a significant energy savings over currently available sources, this technology (the quantum cascade laser) will also be more compact than any other laser technology for this wavelength range and operating temperature, with an active volume that is smaller than a human hair......... Posted by: Kevin      Read more         Source

May 18, 2008, 10:05 PM CT

Nanosoccer Robots in Action in Pittsburgh

Nanosoccer returns to the field later this month, when the National Institute of Standards and Technology (NIST) hosts for the second time the world's most Lilliputian sport. Three student teams will participate in a public exhibition at the 2008 U.S. "RoboCup Open" in Pittsburgh, Pa., May 25 to 27, where miniature "soccer players"-computer-driven robots six times smaller than an amoeba operating on a field the size of a grain of rice-will show off their skills.

The teams from Carnegie-Mellon University (Pittsburgh, Pa.), the U.S. Naval Academy (Annapolis, Md.) and the University of Waterloo (Waterloo, Ontario, Canada) will meet at the Carnegie Science Center in Pittsburgh, Pa., to put their nanobots (nanoscale robots) through their paces. The nanobots will be demonstrating agility, maneuverability, response to computer control and ability to move objects-all tools that future miniaturized mechanized workers will need for tasks such as microsurgery within the human body or the manufacturing of atom-sized components for microscopic electronic devices.

RoboCup is an annual international competition designed to foster innovations and advances in artificial intelligence and intelligent robotics by using the game of soccer as a testing ground. NIST's goal in coordinating competitions between the world's smallest robots is to show the feasibility and accessibility of technologies for fabricating MicroElectroMechanical Systems (MEMS), tiny mechanical devices built onto semiconductor chips and measured in micrometers (millionth of a meter)......... Posted by: Kevin      Read more         Source

May 15, 2008, 7:31 PM CT

Gravity-defying bird beak mystery

As Charles Darwin showed nearly 150 years ago, bird beaks are exquisitely adapted to the birds' feeding strategy. A team of MIT mathematicians and engineers has now explained exactly how some shorebirds use their long, thin beaks to defy gravity and transport food into their mouths.

The phalarope, commonly found in western North America, takes advantage of surface interactions between its beak and water droplets to propel bits of food from the tip of its long beak to its mouth, the research team reports in the May 16 issue of Science.

These surface interactions depend on the chemical properties of the liquid involved, so phalaropes and about 20 other birds species that use this mechanism are extremely sensitive to anything that contaminates the water surface, especially detergents or oil.

"Some species rely exclusively on this feeding mechanism, and so are extremely vulnerable to oil spills," said John Bush, MIT associate professor of applied mathematics and senior author of the paper.

Wildlife biologists have long noted the unusual feeding behavior of phalaropes, which spin in circles on the water, creating a vortex that sweeps small crustaceans up to the surface, just like tea leaves in a swirling tea cup.

The birds peck at the surface, picking up millimetric droplets of water with their prey trapped inside. Since the birds point their beaks downward during the feeding process, gravity must be overcome to get those droplets from the tip of the bird's long beak to its mouth. Until now, scientists have been puzzled as to how that happens......... Posted by: Ashley      Read more         Source

May 11, 2008, 10:22 AM CT

Evolution of "gas giants"

By shooting the high-energy Omega laser onto precompressed samples of planetary fluids, researchers are gaining a better understanding of the evolution and internal structure of Jupiter, Saturn and extrasolar giant planets.

The properties of dense helium (He) - which happens to be a principal constituent of giant gas planets like Jupiter - at thermodynamic conditions between those of condensed matter and high-temperature plasmas are theoretically challenging and unexplored experimentally.

Laboratory researchers collaborating with scientists at the Laboratory for Laser Energetics, CEA France and UC Berkeley were able to determine the equation of state (EOS) for fluid He at pressures above 100 GPa (one million times more pressure than the Earth's atmosphere - one GPa (gigapascal) equals 10,000 atmospheres).

The only prior high temperature and pressure He EOS data available for constraining planetary models waccording toformed at LLNL by Bill Nellis and his team using a two-stage gas gun. However, those earlier experiments used cryogenic techniques at ambient pressure so their densities were significantly lower than those achieved with the precompressed samples. Also, the final pressures, 16 GPa for a single shock, were significantly lower than the new laser shock data......... Posted by: Kevin      Read more         Source

May 11, 2008, 10:18 AM CT

Pressure Effects On Nanomaterials

Transistors, lasers and solar-energy conversion devices may be easier to manipulate because of recent research by Lawrence Livermore National Laboratory scientists.

The scientists defined the role high pressure plays in precisely tuning the fundamental properties of nanomaterials and, in particular, nanoparticle assemblies that are important for device applications.

The team, made up of LLNL researchers Christian Grant, Jonathan Crowhurst, Sebastien Hamel, Natalia Zaitseva and former LLNL researcher Andrew Williamson (now at Physic Ventures), subjected quantum dot solids (in this case assemblies of cadmium selenide, or CdSe, nanocrystals) to very high static pressures on the order of 70,000 atmospheres and studied in-situ their response using a laser-based luminescence technique. A quantum dot is a semiconductor whose electrons are confined in all three spatial dimensions.

"We closely compared our results with theoretical calculations," Grant said. "These results were completely consistent with our experimental observations".

But when they applied nonuniform pressure, the results were quite different.

It led to large shifts in the energy linked to the very strong fluorescence of CdSe. CdSe, it was found, is extremely sensitive to the local stress state......... Posted by: Kevin      Read more         Source

May 11, 2008, 9:14 AM CT

Designer Isotopes Push the Frontier of Science

Designer labels have a lot of cachet, a principle that's equally true in fashion and physics.

The future of nuclear physics is in designer isotopes--the relatively new power researchers have to make specific rare isotopes to solve scientific problems and open doors to new technologies, as per Bradley Sherrill, a University distinguished professor of physics and associate director for research at the National Superconducting Cyclotron Laboratory (NSCL) at Michigan State University (MSU).

"We have developed a remarkable capability over the last 10 or so years that allows us to build a specific isotope to use in research," Sherrill said. "It is a new tool that promises to allow whole new directions in research to move forward. There are tremendous advances that are possible".

Sherrill outlined some of the possibilities and what it will take to get there in a perspective piece in the May 9 edition of Science magazine.

In that article, he writes nanotechnology is getting a lot of attention for the astonishing possibilities of constructing objects with individual atoms and molecules. Sherrill, however, said that nanotechnology hardly is the last word in small.

The chemical changes that brought about the formation of the elements in the bellies of stars are being recreated in laboratories such as MSU's NSCL. Advances in basic nuclear science already have given way to technologies such as PET (short for positron emission tomography) scans, which are medical procedures that use special isotopes to target specific types of tumors......... Posted by: Sarah      Read more         Source

April 30, 2008, 5:20 PM CT

Heat transfer between materials

Managing heat is a major challenge for engineers who work on devices from jet engines to personal electronics to nano-scale transistors.

A team led by a University of Michigan mechanical engineer has received a five-year, $6.8-million grant from the Air Force to examine this problem, which is a barrier to more powerful, efficient devices.

Led by Kevin Pipe, an assistant professor in the Department of Mechanical Engineering, the team has received a Multidisciplinary University Research Initiative (MURI) award from the Air Force Office of Scientific Research. The research group includes nine researchers and engineers from three universities, including Brown University and the University of California at Santa Cruz.

"The processes by which heat is transferred at interfaces between different materials are poorly understood," Pipe said. "But in a number of systems, the ability to either efficiently transfer or block heat flow from one material to another is critically important to performance and reliability".

Inefficient heat flow is a main roadblock in the development of lasers and transistors that can attain higher powers. Conversely, blocking heat exchange can dramatically improve the efficiency of thermoelectric energy conversion for compact power sources......... Posted by: Kevin      Read more         Source