Ars Technica: Do supercooled molecules exhibit interesting properties such as superfluidity or form Bose–Einstein condensates the way supercooled atoms do? To find out, Martin Zeppenfeld of the Max Planck Institute of Quantum Optics in Germany and his colleagues have developed a method to reduce molecules—which are more polarized than atoms—to temperatures near absolute zero (−273.15 °C). They sent a stream of fluoromethane (CH3F) molecules into a trap of standing microwaves crossed with an IR laser. The combination of excitation by the laser and the jostling from the radio waves caused the molecules to rapidly lose energy. By continually adjusting the frequency of the radio waves and repeating the process over and over—a technique called Sisyphean cooling—the researchers were able to lower the temperature of the molecules to near absolute zero for at least 27 seconds.
Daily Archives: November 19, 2012
Printing polymer circuits with lasers
Technology Review: Polymer circuits are desirable because they have the potential to be cheap, light, and flexible. However, their manufacture usually involves polymers in their liquid form and corrosive solvents, each of which can cause problems. A new technique avoids both problems by using a laser to transfer a solid polymer onto a substrate. Maria Kandyla of the National Technical University of Athens, Greece, and her colleagues spread a layer of solid, conducting polymer on a thin sheet of glass, through which a laser is fired. When the laser passes through the glass, it knocks the polymer off the surface and forces it onto a substrate placed a few micrometers away. By moving the glass sheet and the substrate, Kandyla’s team can trace a circuit made of the conducting polymer onto the surface of the substrate. So far the researchers have tested the technique with two different polymers, but they still have to determine whether the ablation process alters the chemical properties of the polymers and the quality of the resulting circuits.
Nanoparticles used to fight autoimmune disease
Independent: Researchers at Northwestern University in Chicago have been developing a nanoparticle to treat multiple sclerosis (MS) and other immune-related diseases. Unlike drugs that suppress the entire immune system and leave patients more susceptible to infections, nanoparticles target only the part of the immune system responsible for the particular disease being treated. In the trial, mice suffering from MS were injected with nanoparticles attached to myelin antigens, which stopped their immune systems from attacking the myelin sheath surrounding their nerve cells. “The beauty of this new technology is it can be used in many immune-related diseases,” said Stephen Miller, coauthor of the study published in Nature Biotechnology.
Superthin lens can function as both zoom and wide angle
Telegraph: Unlike conventional lenses, which consist of curved glass surfaces that alter the direction of light as it passes through, a new lens is being developed that is made of an ultrathin, flat piece of glass with a layer of gold rods laid on top. A prototype has been built that has an aperture of 80 μm—about the width of a human hair—and a focal length of 60 μm. The researchers are able to switch the tiny lens from wide-angle mode to zoom mode by placing a filter in front of it, which changes the polarization of the light. Shuang Zhang at the University of Birmingham and colleagues are now working to make larger lenses that could be used in electronic devices such as cellphones. Their findings have been published in Nature Communications.