Oskar Painter Developes a Nanoscale Device
07-02-09
Oskar Painter, Associate Professor of Applied Physics, has developed a nanoscale device that can be used for force detection, optical communication, and more. The nanoscale device is called a zipper cavity because of the way its dual cantilevers-or nanobeams, as Painter calls them-move together and apart when the device is in use. "If you look at it, it actually looks like a zipper," Painter notes. The device exploits the mechanical properties of light to create an optomechanical cavity in which interactions between light and motion are greatly strengthened and enhanced. These interactions are the largest demonstrated to date. [Caltech Press Release]
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APhMS
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Oskar Painter
Dickinson Reveales that the Twirling Seeds of Maple Trees Spin Like Miniature Helicopters As They Fall to the Ground
07-02-09
Research by Michael H. Dickinson, the Zarem Professor of Bioengineering and David Lentink of Wageningen, reveals that, by swirling, maple seeds generate a tornado-like vortex that sits atop the front leading edge of the seeds as they spin slowly to the ground. This leading-edge vortex lowers the air pressure over the upper surface of the maple seed, effectively sucking the wing upward to oppose gravity, giving it a boost. The vortex doubles the lift generated by the seeds compared to nonswirling seeds. "There is enormous interest in the development of micro air vehicles, which, because of their size, must function using the same physical principles employed by small, natural flying devices such as insects and maple seeds," says Dickinson. [Caltech Press Release]
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Michael Dickinson
Michael Winterrose and Brent Fultz Use High-Pressure "Alchemy" to Create Nonexpanding Metals
07-01-09
Graduate student Michael Winterrose, and Brent Fultz, professor of materials science and applied physics, and colleagues, describe the exotic behavior of materials existing at high pressures in a paper in the June 12th issue of Physical Review Letters. By squeezing a typical metal alloy at pressures hundreds of thousands of times greater than normal atmospheric pressure, the material does not expand when heated, as does nearly every normal metal, and acts like a metal with an entirely different chemical composition. This insight into the behavior of materials existing at high pressures becomes doubly interesting when you consider that some 90 percent of the matter in our solar system exists at these high pressures. [Caltech Press Release]
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Brent Fultz
Sheila Shull Has Won One of the Two 2009 Schmitt Staff Prizes
06-08-09
The Schmitt Prize recognizes a staff member of the Caltech community whose contributions embody the values and spirit that enable the Institute to achieve excellence in research and education. Sheila has been with Applied and Computational Mathematics (ACM) for almost 30 years and takes care of almost every aspect of the day-to-day activities in ACM, including proposal submission and grant management; management of staff members, visitors, and students; organization of international conferences; recruitment of students and instructors; utilization of space; and, most importantly, "care and feeding" of the ACM faculty, which is not without its challenges. As one of her nominators wrote: "It is people like her, in direct daily contact with faculty and students, that truly define the atmosphere in our Institute." Kudos Sheila!
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CMS
John Doyle Discovers the Importance of Fire in Global Climate Change
05-11-09
Scientists Discover Importance of Fire in Global Climate Change. Researchers including John Doyle, Caltech's Braun Professor of Control and Dynamical Systems, Electrical Engineering, and Bioengineering, Emeritus, have determined that fire must be accounted for as an integral part of climate change. Their research shows that intentional deforestation fires alone contribute up to one-fifth of the human-caused increase in emissions of carbon dioxide. According to the article, increasing numbers of natural wildfires are influencing climate as well. [Science Magazine article]
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EE
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CMS
John Doyle
![Scanning electron microscope image of an array of "zipper" optomechanical cavities. The scale and sensitivity of the device is set by its physical mass (40 picograms/40 trillionths of a gram) and the nanoscale gap between the two nanobeams (100 nanometers/100 billionths of a meter). [Credit: Caltech/Matt Eichenfield and Jasper Chan]](https://d39s7jey1vv9fu.cloudfront.net/eas_news/images/251/thumb/oskar-painter-zipper.jpg?1293063653)
