11-03-2011, 03:06 PM
Presented BY
Anand Mohan Patel
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FIBRE THAT CAN HEAR AND SING
A tie that records your conversations? Pajamas that sing you to sleep?
Innovation
On July 12, 2010
By : Yoel Fink
At: MIT's Research Lab of Electronics.
“What we have done is start thinking how fibers go beyond that and change their properties.”
Yoel Fink principal investigator at MIT’s Research Lab of electonics
introduction
MIT researchers pass a milestone on the path to fibers that interact with their surroundings in new ways.
The Fink lab has demonstrated that it can manufacture acoustic fibers with:-
A. flat surfaces.
B. Circular cross sections.
Fibers, whether they are for clothing or telecommunications, have always been static.
Incapable of doing more than one thing: Hold fabric together, or transmit optical signals, for instance.
The key to electronic textiles is fiber that can change its properties over a wide range of frequencies, says Fink.
Construction of optical fiber
Optical fiber consists of three sections: 1) the core, 2) the cladding, and 3) the buffer coating.
Core a made of by large cylindrical single material .
Core is constructed in three step:-
A. Heating
B. Drawing out
C. Cooled
Construction of acoustic fibers
Acoustic fibers developed in Fink's lab, by contrast, derive their functionality from the elaborate geometrical arrangement of several different materials.
Heating
Drawing process
Working
The heart of the new acoustic fibers is a plastic which is used in microphones.
By playing with the plastic's fluorine content, its molecules remain lopsided .
With fluorine atoms lined up on one side and hydrogen atoms on the other — even during heating and drawing.
The asymmetry of the molecules is what makes the plastic "piezoelectric.
Piezoelectricity is the key property in plastic.
Giving them the ability to function as both a microphone and a speaker.
Piezoelectric effect
In a conventional piezoelectric microphone, the electric field is generated by metal electrodes.
But in a fiber microphone, the drawing process would cause metal electrodes to lose their shape.
So the researchers instead used a conducting plastic that contains graphite.
When heated, the conducting plastic maintains a higher viscosity — it yields a thicker fluid — than a metal would.
This prevent the mixing of materials.
After the fiber has been drawn, the researchers need to align all the piezoelectric molecules in the same direction.
That requires the application of a powerful electric field.
Sound result
Future scope
To reduce the dimensions of the fiber so it may some day be woven into clothing.
Fashioned into clothes capable of capturing speech.
Nets that can act as sound sensors.
Sonar:
Loose nets that monitor the flow of water in the ocean.
Monitor your health by listening to your heart.
Monitoring marine activities.
Difficulty
Strong vibrations, for instance, could vary the optical properties of a reflecting fiber.
It's a very scalable technique. But for applications that require relatively short strands of fiber.
Right now the width of the fiber is around 2.5 mm, while in clothing today, the fibers are at around 50 microns.
conclusion
Smart world is near
The fiber can vibrate when we supply current to it. So if we use this fiber to build a little thing, maybe it will move as snake or flea. May be the iphone G8 will be made of this kind of fiber. So I can imagine that I call my iphone G8 which was put in the floor: "come to me, dear phone". It will answer:"Ok, i'm coming", and creeps to me.
Hope this fiber will be apply extensively, so the smart world is near.
But we need to reduce its dimension.
