[Reader-list] Fwd: [cr-india] World's smallest radio fits in the palm of the hand...of an ant

[Monica Narula]

dear all

sometimes the things that are invented!! :-)

best
M

Monica Narula
Raqs
Sarai-CSDS
29 Rajpur Road
Delhi 110 054
www.raqsmediacollective.net
www.sarai.net


Begin forwarded message:

> From: "N.Ramakrishnan" <nram at ideosyncmedia.org>
> Date: 3 November 2007 3:33:08 PM GMT+05:30
> To: "cr-india at sarai.net" <cr-india at sarai.net>
> Subject: [cr-india] World's smallest radio fits in the palm of the  
> hand...of an ant
>
> *World's smallest radio fits in the palm of the hand...of an ant*
>
> *Single carbon nanotube is fully functional radio, receiving music  
> over
> standard radio bandwidth*
>
> Harnessing the electrical and mechanical properties of the carbon
> nanotube, a team of researchers has crafted a working radio from a
> single fiber of that material, according to Eurekalert, the news  
> service
> of the American Association for the Advancement of Science.
>
> Fixed between two electrodes, the vibrating tube successfully  
> performed
> the four critical roles of a radio--antenna, tunable filter, amplifier
> and demodulator--to tune in a radio signal generated in the room and
> play it back through an attached speaker.
>
> Functional across a bandwidth widely used for commercial radio, the  
> tiny
> device could have applications far beyond novelty, from radio- 
> controlled
> devices that could flow in the human bloodstream to highly efficient,
> miniscule, cell phone devices.
>
> Developed at the National Science Foundation's (NSF) Center of
> Integrated Nanomechanical Systems, a research team led by Alex  
> Zettl of
> the University of California at Berkeley announced the findings online
> on Oct. 31, 2007 (http://pubs.acs.org/journals/nalefd/index.html). The
> findings are scheduled to be printed in Nano Letters in November.
>
> "This breakthrough is a perfect example of how the unique behavior of
> matter in the nanoworld enables startling new technologies," says  
> Bruce
> Kramer, a senior advisor for engineering at NSF and the officer
> overseeing the center's work. "The key functions of a radio, the
> quintessential device that heralded the electronic age, have now been
> radically miniaturized using the mechanical vibration of a single  
> carbon
> nanotube."
>
> The source content for the first laboratory test of the radio was
> "Layla," by Derek and the Dominos, followed soon after by "Good
> Vibrations" by the Beach Boys.
>
> One of the primary goals for the center is to develop minuscule  
> sensors
> that can communicate wirelessly, says Settle. "A key issue is how to
> integrate individual molecular-scale components together into a system
> that maintains the nanometer scale. The nanoradio achieves this by
> having one molecular structure, the nanotube, simultaneously  
> perform all
> critical functions," he adds.
>
> The new device works in a manner more similar to the vacuum tubes from
> the 1930s than the transistors found in modern radios. In the new  
> radio,
> a single carbon fiber a few hundred nanometers (billionths of a meter)
> long, and only a few molecules thick, stands glued to a negatively
> charged base of tungsten that acts as a cathode. Roughly one millionth
> of a meter directly across from the base lies a positively charged  
> piece
> of copper that acts as an anode.
>
> Power in the form of streaming electrons travels from an attached
> battery through the cathode, into the nanotube, and across a vacuum to
> the anode via a field-emission tunneling process.
>
> "The field emission process could be likened to a runner jumping  
> across
> a ditch; you only make it across if you have enough speed, i.e.  
> energy,
> to begin with," says Zettl. "So electrons jump the physical gap from
> cathode to anode when you supply enough energy to the device from the
> battery."
>
> The stream of electrons along the nanotube changes when a radio wave
> encoded with information--simply a wave of photons that travels in a
> controlled manner--washes across the tube and causes it to resonate.
> This mechanical action is what amplifies and demodulates, or decodes,
> the radio signal.
>
> Returning to Zettl's runner analogy, the vibrating nanotube is akin  
> to a
> ditch with a constantly changing width. Just as the runner's  
> chances of
> making the leap depend on how far the gap is, the chances of electrons
> making the leap depend on the distance of the nanotube tip from the  
> anode.
>
> "This coupling of the mechanical waving motion of the nanotube to the
> success rate of electrons jumping the gap is key to the functioning of
> the radio," says Zettl. "What emerges from the anode is then the
> information signal, which can be transferred to additional amplifiers
> and a speaker to reveal the originally encoded music or any other  
> data."
>
> By permanently lengthening or shortening the nanotube, a modification
> resulting from sending a short-lived larger-than-normal electrical
> current through the device, the researchers were able to control the
> frequency of the radio signal that the device could receive.
>
> The researchers believe it would be easy to produce such nanotube  
> radios
> for receiving signals in the 40-400 megahertz range, a range within
> which most FM radio broadcasts fall.
>
> The researchers fine tune the nanoradio to a frequency, akin to a
> channel, by using the electrostatic field between the cathode and  
> anode
> to tighten or loosen the nanotube, a process the researchers relate to
> the tightening or loosening of a string on a guitar. According to  
> Zettl,
> the sensitivity of the nanotube radio can be enhanced by attaching an
> external antenna or by using an array of nanotubes that maintain the
> extremely small size.
>
> While the concept of a miniaturized receiver for picking up broadcast
> music signals has appeal, the technology has the potential to  
> assist in
> a range of interesting uses.
>
> Adds Bruce Kramer, "The application of a fully functioning radio
> receiver less than 50 millionths of an inch in length and one  
> millionth
> of an inch in diameter potentially allows the radio control of almost
> anything, from a single receiver in a living cell to a vast array
> embedded in an airplane wing."
>
> -- 
> N.Ramakrishnan
>
> Director of Projects
> Ideosync Media Combine
> 177, Ashoka Enclave III
> Sector 35, Faridabad - 121003
> Haryana - India
> Tel: +91-0129-4131883/6510156/2254395/2254396 (Prefix 95129- from  
> Delhi)
> Telfax: +91-0129-2254395 (Prefix 95129- from Delhi)
> Mobile: +91-9810273883
> Email: nram at ideosyncmedia.org
>
>
> YOU CAN SUPPORT THE COMMUNITY RADIO FORUM (India) BY JOINING AND  
> TAKING AN ACTIVE PART IN ONE OF THESE NETWORKS
>
> http://groups.yahoo.com/group/crforum-awareness  (Awareness building)
> http://groups.yahoo.com/group/crforum-helpdesk (Offering help)
> http://groups.yahoo.com/group/crforum-policy-advocacy (Policy  
> advocacy)
> http://groups.yahoo.com/group/crforum-techoptions (Technical options)
>
> _______________________________________________
> cr-india mailing list
> cr-india at sarai.net
> https://mail.sarai.net/mailman/listinfo/cr-india