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Friday, 02 November 2007 |
And you thought the iPod was a breakthrough in terms of size and decibels. Well, just up the road from Apple, physicists at the University of California, Berkeley have built the smallest radio yet--a single carbon nanotube dubbed the Nanotuberadio that's one ten-thousandth the diameter of a human hair.
So what did these scientists want to hear the radio play? Derek & The Dominos ' rendition of "Layla" and the Beach Boys' "Good Vibrations." Which goes to show that the good scientists know more about good science than good music. Not exactly Alexander Graham Bell's "Mr. Watson, come here I want you" but close enough.
The nanoradio, which is currently configured as a receiver but could work as a transmitter, is 100 billion times smaller than the first commercial radio, and could be used in applications such as cell phones and microscopic sensors, according to team leader and physics professor Alex Zettl .
Zettl, Kenneth Jensen, Jeff Weldon, and Henry Garcia came up with a way of building a single carbon nanotube that works as an all-in-one antenna, tuner, amplifier, and demodulator for both AM and FM. The nanoradio detects radio signals by vibrating thousands to millions of times per second in tune with the radio wave. In normal radios, ambient radio waves from different transmitting stations generate small currents at different frequencies in the antenna, while a tuner selects one of these frequencies to amplify. In the nanoradio, the nanotube, as the antenna, detects radio waves mechanically by vibrating at radio frequencies. The nanotube is placed in a vacuum and hooked to a battery, which covers its tip with negatively charged electrons, and the electric field of the radio wave pushes and pulls the tip thousands to millions of times per second.
-- Jonathan Erickson
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Monday, 10 October 2005 |
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ISIS Nanoparticles – billionths of metre in dimensions - produced by nanotechnology have unusual properties not found in the bulk material, which can be exploited in numerous applications such as biosensing, electronics, photovoltaics, diagnostics and drug delivery. However, research within the past few years has turned up a range of potential health hazards, which has given birth to the new discipline of nanotoxicity. - Researchers in the University of Texas in the United States found that carbon nanotubes squirted into the trachea of mice caused serious inflammation of the lungs and granulomas (tumour-like nodules of bloated white blood cells in the lining of the lungs), and five of the nine mice treated with the higher dose died (“Nanotubes highly toxic”, SiS 21) [1, 2].
- In a similar experiment carried out at the National Institute of Occupational Safety and Health in Morgantown, West Virginia, in the Unites States, researchers not only found granulomas in the lungs, but also damage to mitochondrial DNA in the heart and the aortic artery, and substantial oxidative damage, both foreshadowing atherosclerosis (hardening of the arteries) [3].
- In yet another similar experiment in Tottori University, Japan, researchers showed that within a minute of contacting the mice’s tiniest airways, carbon nanotubes began to burrow through gaps between the surface lining cells and into the blood capillaries, where the negatively charged nanoparticles latched onto the normally positively charged red blood cells surface, thereby potentially causing the red blood cells to clump and the blood to clot [3].
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