Molecules/Matter & Energy

Handcrafted nanoart
Beams of light used to “draw” three-dimensional nanostructures could give scientists more flexibility in creating tiny sensors and electronic components. The new technique, called Optically Directed Assembly, uses a low-power laser to form long filaments from dissolved gold and carbon particles only millionths of a millimeter in size. The energy of the laser fuses these pieces into structures that remain intact after the fluid is drained away, scientists at Argonne National Laboratory report in an upcoming Physical Review Letters. As a first demonstration, the researchers handcrafted a microscopic glyph — the Chinese symbol for “king.” —Devin Powell

Quantum vibes
Pairs of vibrating atoms can be taught to beam energy back and forth like tiny antennas, according to two studies published in the Feb. 24 Nature. This connection, a way to transmit information in quantum computers, caused charged beryllium particles separated by a distance of 40 micrometers to take turns wiggling in a device created by scientists from the National Institute of Standards and Technology in Boulder, Colorado. An independent team from the University of Innsbruck in Austria, working with calcium atoms, found that adding additional atoms to the pair could boost the strength of the signal. —Devin Powell

Twisting in the wind
A blade shaped like a twisted stalk of grass gives a boost to small vertical wind turbines that could generate energy in cities. The unusual but inexpensive design, developed by scientists at McMaster University in Canada, helps to combat forces that tend to destabilize small turbines. Wind tunnel tests of a turbine with three blades spinning around a vertical pole proved the new blade produces as much energy as simpler straight blades, the researchers report in a paper published online February 22 in the Journal of Renewable and Sustainable Energy. —Devin Powell

Invisibility potion
A newly proposed invisibility potion made of tiny metal rods floating in a nonconducting liquid could be a new kind of metamaterial, an artificial substance that interacts with light in unusual ways. In an upcoming issue of Materials, scientists at Kent State University in Ohio use electric fields to line up dissolved gold particles and modestly change the refraction of light — though the researchers report that this refraction would need to be improved by a factor of 10 to make it useful for creating new kinds of optical devices. —Devin Powell

Transmuting medical isotopes
Medical isotopes used in nuclear medicine can be made with powerful laser beams, a team of scientists in Japan reports. This new approach, detailed in a paper posted online February 22 to arXiv.org, could help to head off shortages of these critical materials, many of which can be made only at a handful of sites around the world. As a proof of principle, the scientists transmuted iodine into a pure quantity of the medical isotope iodine-126, and describe how to create other isotopes that are used as tracers in PET scans. Whether this technique could be used to generate some of the most critical medical isotopes — such as molybdenum-99, now made from uranium — remains to be seen.  —Devin Powell