New Technique Could Harvest More of the Sun's Energy
Harry A. Atwater, Jr., Howard Hughes Professor of Applied Physics and Materials Science as well as Director of the Resnick Sustainability Institute, and colleagues have created a new technique to harness the lost energy from solar panels. “Silicon absorbs only a certain fraction of the spectrum, and it's transparent to the rest. If I put a photovoltaic module on my roof, the silicon absorbs that portion of the spectrum, and some of that light gets converted into power. But the rest of it ends up just heating up my roof," explains Professor Atwater. Now they have found a way to absorb and make use of these infrared waves with a structure composed not of silicon, but entirely of metal. [Caltech story]
Heat Transfer Sets the Noise Floor for Ultrasensitive Electronics
Austin Minnich, Assistant Professor of Mechanical Engineering and Applied Physics, and colleagues have identified a source of electronic noise that could affect the functioning of instruments operating at very low temperatures, such as devices used in radio telescopes and advanced physics experiments. The team's findings also suggest that it may be possible to develop engineering strategies to make phonon heat transfer more efficient at low temperatures. For example, one possibility might be to change the design of transistors so that phonon generation takes place over a broader volume. "If you can make the phonon generation more spread out, then in principle you could reduce the temperature rise that occurs," Professor Minnich says. "We don't know what the precise strategy will be yet, but now we know the direction we should be going. That's an improvement." [Caltech release]
Professor Rosakis Elected to Academia Europaea
Ares J. Rosakis, Theodore von Karman Professor of Aeronautics and Mechanical Engineering as well as the Otis Booth Leadership Chair of the Division of Engineering and Applied Science, has been elected to the Academy of Europe (Academia Europaea) in the section of Physics and Engineering Sciences. The Academia Europaea was founded in 1988 and is an organization of eminent, individual scholars from across the continent of Europe. The 3000 members cover a wide range of academic disciplines including the humanities, social, physical and life sciences as well as mathematics, engineering and medicine. In addition to Professor Ares Rosakis, Caltech's Provost Edward Stolper, the Institute's past president David Baltimore, and Professor Alexander Varshavsky are members of the Academy.