use of bacteria as small "motors" ...

One of the main challenges in developing microscale robots lies in miniaturising their power and propulsion. Now, researchers in the US may have found a solution to this problem, by exploiting the natural movement of bacteria to propel micro-objects through water.

Many bacteria propel themselves along in a fluid by rotating their corkscrew-like tails, called flagella, at relatively high speeds. These flagella are only around 20 nanometres in diameter and are about 10,000 nm long.

Motors made from bacterial flagella have been used as novel "nano-actuators" before (see Bacteria harnessed as miniature pumps), but Metin Sitti and Bahareh Behkam of Carnegie Mellon University in Pennsylvania, US, have taken another approach. They use the entire microorganism as the motor and control its on/off motion with chemicals.

Bacteria harnessed as micro propeller motors - tech - 26 January 2007 - New Scientist Tech

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Nature article on new very high density molecular electronic memory circuit

The primary metric for gauging progress in the various semiconductor integrated circuit technologies is the spacing, or pitch, between the most closely spaced wires within a dynamic random access memory (DRAM) circuit¹. Modern DRAM circuits have 140 nm pitch wires and a memory cell size of 0.0408 m². Improving integrated circuit technology will require that these dimensions decrease over time. However, at present a large fraction of the patterning and materials requirements that we expect to need for the construction of new integrated circuit technologies in 2013 have 'no known solution'¹. Promising ingredients for advances in integrated circuit technology are nanowires², molecular electronics³ and defect-tolerant architectures⁴, as demonstrated by reports of single devices^{5, 6, 7} and small circuits^{8, 9}. Methods of extending these approaches to large-scale, high-density circuitry are largely undeveloped. Here we describe a 160,000-bit molecular electronic memory circuit, fabricated at a density of 10¹¹ bits cm^-2 (pitch 33 nm; memory cell size 0.0011 m²), that is, roughly analogous to the dimensions of a DRAM circuit¹ projected to be available by 2020. A monolayer of bistable, [2]rotaxane molecules¹⁰ served as the data storage elements. Although the circuit has large numbers of defects, those defects could be readily identified through electronic testing and isolated using software coding. The working bits were then configured to form a fully functional random access memory circuit for storing and retrieving information.

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Strange but True: Turning a Wobbly Table Will Make It Steady

For every table—turn, turn, turn... there is a proof

It's a problem as old as civilization: the wobbly table. You may have thought your only recourse against this scourge is a hastily folded cocktail napkin stuffed under the offending leg. If so, take heart, because mathematicians have recently proved a more elegant solution. Just rotate the table.The intuitive argument, which dates back at least to a 1973 Scientific American column by Martin Gardner, is straightforward. Consider a square table with four equally long legs. Any three of the legs must be able to rest on the floor simultaneously, as a tripod does. Assume the floor undulates smoothly and the fourth leg hovers above it.Now imagine turning the table about its center while keeping the first three legs grounded, or balanced. Once the table has rotated by 90 degrees, the wobbly leg must lie below the floor. (If you do not see why, imagine pushing down equally on the wobbly leg and a neighboring leg until the neighbor sinks below the floor and the wobbly leg touches down.) And so, at some point along the wobbly leg's arc, it has to hit a spot on which it can rest. As simple as this argument may sound, however, proof was a long time coming.The first serious mathematical inroad against table wobbling seems to have occurred in the late 1960s with Roger Fenn, a PhD student at the University of London. One day Fenn and his graduate adviser ended up at a coffee shop faced with—you guessed it—an unsteady table. "The table wouldn't stop wobbling and we fiddled it around until we got it to stop," recalls Fenn, who is now at the University of Sussex.At his adviser's suggestion, Fenn wrote out a proof that for any smoothly curving floor that bulges upward like a hill, there is at least one way to position the table so that it is balanced and horizontal. But he did not reveal how exactly to find that sweet spot, and he quickly tabled the subject. "I didn't think people were going to take this very seriously," he admits. "You say to somebody you've met, 'Well I'm trying to put a table on the floor so it doesn't wobble'; they'll say, 'Oh yeah?'"The season for proving the table turning hypothesis would not arrive for another 35 years. By then, the idea had become such a part of mathematical lore that two years ago mathematician Burkard Polster of Monash University in Australia included it in an article on neat math tricks for teachers. He promptly received a letter pointing out that the idea would not work if a floor was too uneven or possessed sheer cliffs, such as between tiles.Polster rose to the challenge. "It's never been really pinpointed exactly what the ground should be like," he says. So he and some of his colleagues ran through the appropriate trigonometry and satisfied themselves that if a floor has no spots that slope by more than 35 degrees, then turning will indeed balance a square or rectangular table. They detail the proof in a paper accepted for publication by the Mathematical Intelligencer. (In one of those odd cases of co-discovery, a retired CERN physicist named André Martin published a similar result a few months before the Australians did.)Polster's group even spells out a procedure for balancing the table [see video above]. First lift up the leg of the table diagonal from the wobbly leg. Make sure both legs are roughly equal distances off the ground and then begin rotating. "In practice," the researchers write, "it does not seem to matter how exactly you turn your table on the spot, as long as you turn roughly around the center of the table."So, next time you feel a table start to tilt, put that napkin down and don't be shy about turning the tables on a wobbly dining experience. Rest assured, mathematics is on your side.

Scientific American: Strange but True: Turning a Wobbly Table Will Make It Steady

Photon Compression??

Researchers condense entire image into single photon - Engadget

A team of researchers has managed to find a way to store a large amount of data in a single photon of light. Although the first stored item -- an image of the characters "UR" -- implies that the inventor was a 13 year old girl dealing with an extremely low text messaging limit, the image was in fact intended to signify the institution which developed the technology, the University of Rochester (either that or it's the shortest example of the "UR IN MY ... " meme that we've seen in the while.) Apparently the system works because "instead of storing ones and zeros" (a la binary code), the team has figured out how to store an entire image in a single photon, which sounds sort of impossible to us. Funny, because that's exactly what John Howell, the leader of the team said about the system. One of the key components of the process is the particle-wave duality nature of light: by firing a single photon of light through a stencil -- we presume one heckuva small one -- the wave carries a shadow of the image along with it at a very high signal-to-noise ratio, even with low light levels. The light is then slowed down in a cell of cesium gas, where it is compressed to 1 percent of its original length. This is where the storage aspect of the device comes in, as the researchers hope to be able to delay a single photon almost permanently, resulting in a device that can store "incredible amounts of information in just a few photons": an enticing thought for a world currently satisfied with a maximum of 1TB hard drives based on physical platters. A pity then that the world is completely distracted by the potential for "Photon on photons" jokes that this throws into the ring.

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Can't Touch This - Jeff Han - Touch Screen

Jefferson Han, a pale, bespectacled engineer dressed in Manhattan black, faced the thousand or so attendees on the first day of TED 2006, the annual technology, entertainment, and design conference in Monterey, California. The 30-year-old was little more than a curiosity at the confab, where, as its ad copy goes, "the world's leading thinkers and doers gather to find inspiration." And on that day, the thinkers and doers included Google (NASDAQ:GOOG) gazillionaires Sergey Brin and Larry Page, e-tail amazon Jeff Bezos, and Bill Joy, who helped code Sun Microsystems (NASDAQ:SUNW) from scratch. Titans of technology. It was enough to make anyone feel a bit small.

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